Despite knowledge concerning the prevalence and adverse consequences of pediatric stroke, there is limited awareness of the immediate and long-term effects on social-emotional functioning and psychological adjustment. Evidence from the broader childhood literature suggests that young individuals living with disabilities or neurological conditions are at considerably greater risk for emotional and behavioral concerns and lower quality of life. Qualitative research methodology can elucidate personal and subjective aspects of experience that cannot be entirely represented through quantitative measures. Although the parent experience of pediatric stroke has been qualitatively investigated, we endeavored to fill a gap in the pediatric stroke literature by focusing on the youth voice. The current project aimed to qualitatively explore emotional, behavioral, and social outcomes in pediatric stroke and identify personal and environmental factors that can influence psychological risk and resilience.

Individual interviews were conducted with 14 children, aged 8 to 18 years, with a history of ischemic stroke. The semi-structured interview protocol aimed to capture the lived experience of survivors and encompassed open-ended questions about daily life, memories, perceptions, and psychosocial experiences. Interviews spanned 40-60 minutes in length, were audio recorded, transcribed verbatim, and qualitatively analyzed using reflexive Thematic Analysis methodology. Coding, theme generation, and data visualization were completed using NVivo12 software.

Participants discussed their views and understanding of their stroke, the perceived impact of stroke on their daily life, and the meaning-making process surrounding this experience. Children shared their perceptions regarding their abilities, challenges, life circumstances, aspirations, and relations to peers. Prominent themes encompassed shyness and social anxiety, cognitive and learning troubles, test anxiety, concealing feelings of sadness, the stigma of physical disability and its impact on social participation, bullying, and loneliness/isolation. Insight into adaptive coping mechanisms was present, as was emphasis on family closeness and the importance of supportive peers. Participants described feeling unique and were proud of their values and personal identity. Gratitude was expressed regarding stroke medical care and rehabilitative services, with an emergent theme surrounding the desire to give back to society.

Taken together, our qualitative study findings illustrate the profound impact that pediatric stroke can have on children’s emotional experiences, personal identity, self-efficacy, learning, behavior, and psychosocial functioning. Despite these challenges, an enormous degree of resiliency was also demonstrated in youth’s insights into coping and adaptation to challenge. Our findings speak to the importance of psychological assessment and treatment planning surrounding internalizing symptoms in children with stroke. Given the potential for pervasive changes in various aspects of daily life, a comprehensive understanding of the personal psychological experiences and perceptions of pediatric stroke patients is essential, as it will facilitate opportunity for timely interventions that can improve coping and adaptive outcome. Implications will be discussed with regard to empowering pediatric stroke survivors, enhancing public education efforts about childhood acquired brain injury, and reducing stigma associated with disability and use of required supports.

Childhood ischemic and hemorrhagic stroke is often associated with neuropsychological and cognitive deficits. Stroke induces an inflammatory response in the central and peripheral nervous systems. High levels of inflammatory markers in the plasma have been associated with poorer cognitive outcomes. The role of inflammation in neurological prognosis of stroke has been studied previously; however, there is a limited understanding of the association between inflammatory markers and neuropsychological outcome post-stroke. The present review examined the existing literature on the association between inflammatory markers and post-stroke functioning.

Data bases (PsycINFO, PubMed, Web of Science, and Ovid) were reviewed in October 2020. Articles were restricted to English-language literature. Articles were included regardless of recruitment setting, number of strokes, mechanism of stroke, timing of blood collection and outcome assessment. The articles focused on patients with stroke (between the ages of 0 to 95), measured post-stroke outcome by neurological and cognitive outcome measures (i.e., it included findings on any aspect of cognition such as memory, information processing, or attention), and on pro-inflammatory cytokines and c-reactive proteins as measures of inflammation. The systematic literature search retrieved 954 articles to review against inclusion criteria. Descriptive statistics were performed using IBM SPSS 27.0 Statistics Software.

A total of 18 articles were included in this review. The population age ranged from 21 to 95, and, when reported (n=17), mean participant age was 66.31. Among stroke patient populations, ischemic stroke was most researched (n=15). The most widely investigated biomarkers were CRP (n=9), IL-6 (n=8), TNF- a (n=7), IL-1 b (n=5), and IL-10 (n=5). The time of initial blood collection ranged from on admission to within 3 months poststroke. Equal number of studies used both neurological and cognitive tests (n=7), or only neurological (n=7), 2 studies only used cognitive tests, and one study used all three types of measures. The most commonly used cognitive test was the Mini Mental State Examination, MMSE (n=7). The next commonly used cognitive test was the Montreal Cognitive Assessment (MoCA), (n=4). Only two studies used a comprehensive neuropsychological battery.

There is a lack of research into diverse stroke populations. All the studies examined the association between inflammatory markers and the post-stroke outcomes in adult populations and mostly in patients with ischemic stroke. The lack of research on pediatric and young adult stroke represents a significant gap in understanding predictors of neurological and cognitive outcomes. Further, the review revealed a lack of comprehensive neurocognitive assessment post stroke, with most studies measuring neuropsychological outcome using brief cognitive instruments. Our findings highlight a critical need for addressing the above gaps to help elucidate the role of inflammatory markers in the neuropsychological prognosis of stroke in younger populations.

Epilepsy, and specifically drug-resistant epilepsy (DRE), is associated with an increased risk of psychiatric dysfunction, likely due to a combination of physiological mechanisms, emotional reactions to disease burden, and bi-directional influences. Women with epilepsy warrant special consideration due to many factors, including hormonal influences on seizure susceptibility, reproductive health considerations, and unique psychiatric and clinical profiles. However, there is yet to be large-scale research characterizing women with DRE. The present study characterized psychiatric conditions, treatment, and hospitalization data in a Veterans Health Administration (VHA)-wide sample of women Veterans and then compared results to a male Veteran sample to explore sex differences.

Data from 52,579 Veterans enrolled in VHA care between FY2014 and 2nd Quarter FY2020 were gathered from the VHA Corporate Data Warehouse administrative data. The sample was comprised of 5,983 women (11.4%) and 46,596 men (88.6%). Demographics, psychiatric diagnoses, psychiatric medications, ER visits, and hospitalizations were characterized. Chi-square analyses were used to examine group differences between men and women.

The vast majority of the women Veteran sample had at least one psychiatric diagnosis (86.1%), with over half of the sample diagnosed with depression (68.3%), PTSD (54.1%), and/or anxiety disorders (57.7%). When compared to men, women Veterans were more likely to have a psychiatric diagnosis (86.1% vs. 68.1%), evidenced a higher number of co-morbid psychiatric conditions (2.4 vs. 1.6), and were prescribed more psychiatric medications (3.4 vs. 2.3; all significant at p<0.001). All individual psychiatric diagnoses were more prevalent in women than men and, notably, suicidality was also higher in women (13.5% vs. 10.0%; p < 0.001). Women Veterans also had a higher number of ER visits (6.9 vs. 5.5; p < 0.001) and psychiatric hospitalizations than men (.4 vs. .3, p < 0.001).

The present study represents the largest known investigation to date of women with DRE and is also the largest study of women Veterans with any form of epilepsy. It highlights a vast psychiatric burden in this subset of women Veterans, with high rates of psychiatric comorbidity, lending to downstream effects on psychiatric medication burden and risk for emergency care usage and psychiatric hospitalization. Comparisons to men emphasize that women are differentially impacted by the psychiatric toll of DRE and warrant special consideration. The markedly higher rates of depressive disorders and suicidality in women Veterans with DRE is especially notable when considering risk of harm and mortality. Overall, the present work adds to the paucity of literature of women Veterans with seizures and gaps in the broader DRE research base, with implications for specialized screening and maximizing treatment interventions in this population.

The women who served in the 19901991 Persian Gulf War (GW) are unique in that they were the first group to have fewer restrictions in terms of military occupations and exposure to combat. Of the nearly 41,000 US troops who were women deployed to the GW, many were serving in frontline positions and were exposed to the same toxicants as their male counterparts. Toxicant exposures such as pesticide sprays and creams, oil well fires, diesel fuels, chemical and biological warfare (CBW) agents and anti-nerve gas (PB) pills have been found to result in cognitive impairments across a range of neuropsychological tests. Our research team has been following cohorts of women who were deployed to the GW and correlated exposures with neuropsychological outcomes. Overall, in small cohorts of women veterans we found that higher levels of exposures to pesticide sprays and creams and CBW are correlated with short-term memory, mood, and motor deficits. These findings were different from those of their male counterparts. In a recently developed data-repository we have compiled larger groups of women veterans to validate our prior findings.

The current study is an analysis of data from a national bio/data-repository (Boston Biorepository Recruitment and Integrative Network for Gulf War Illness; BBRAIN) which includes key data samples from prior GW studies that have been merged and combined into retrospective datasets. Data include general health and chronic symptom questionnaires, demographics, deployment and self-reported exposure histories (separated into no exposure, fewer than 7 days exposure and greater than or equal to 7 days exposure), as well as key neuropsychological test variables. Three separate datasets were combined to include 62 women. Exposures to chemical alarms, oil well fires, pesticide cream or spray, pesticide fogging, and PB pills were self-reported. Linear regression models were produced for each continuous cognitive outcome, modeled on a given exposure, and controlling for age, education level, PTSD, and other exposures.

Of the 62 women, the majority were White (77%). 74% of women surveyed were employed and 55% were married. 63% of women had at least a high school education. Deployed women who had > 7 days of exposure to pesticide sprays, CBW, smoke from oil well fires, and PB pills were more likely to show deficits in the areas of verbal learning and short-term memory (p < .03) and those with exposure to CBW, smoke from oil well fires, pesticides creams and PB pills had more errors on a test of executive functioning (p < .01). These data differ from the findings from cohorts of men.

These data validate the findings of our prior studies and add credence to the need for separate analyses for men and women. The unique outcomes may lead to individualized treatments for women veterans that may also help women with similar exposures from other deployments in addition to women with occupational exposures.

All premenopausal women who survive traumatic brain injury (TBI) will eventually experience menopause. Challenges experienced by women with TBI are superimposed on challenges associated with hormonal changes in midlife. Some women with stressful life contexts such as TBI are more vulnerable to the added burdens of the menopause transition, potentiating its effects. Although it may be argued that TBI research correctly overrepresents the male experience given disparities in injury rates (4:1), there are important differences in how females and males age, their specific health needs, and the psychosocial context of midlife. Development of evidence-based interventions begins with understanding the experience of menopause after TBI, including where and when key problems may emerge.

All participants were women 40-60 years old, not taking hormones (i.e., replacement therapy or other systematic hormones), with intact ovaries. Women with TBI were > 2 years post injury, whose menstrual period returned after injury, and were living in the community. Severity of injury ranged from complicated-mild to severe TBI. Pre/peri and postmenopausal status was determined by presence/absence of menstrual period in previous 6 months, respectively. Eighteen common menopause symptoms (vasomotor, somatic, psychological, and cognitive) were assessed for presence and frequency (rarely-always), along with Quality of Life in Neurological Disorders (Neuro-QOL) Sleep Disturbance and Traumatic Brain Injury Quality of Life (TBIQOL) Anxiety, Depression, and Fatigue scales.

Overall, women with TBI (n = 68) showed greater presence and frequency of symptoms than women without TBI (n = 153), with fewer within-group differences by menopausal status. Among pre/peri-menopausal women, TBI and non-TBI groups did not significantly differ and showed small effect sizes on symptoms associated with changes in estrogen during menopause, including hot flashes, night sweats, bowel and bladder sequelae, and breast tenderness. However, pre/peri-menopausal women with TBI also endorsed body aches and headaches, as well as troubles with memory, focus, fatigue, cognitive concerns, sleep, and anxiety significantly more than their pre/peri-menopausal counterparts (all medium effect sizes). Among postmenopausal women, those with TBI had significantly greater frequency of hot flashes, crying spells, poor memory, worry, moodiness, panic attacks, sleep disturbance, and anxiety than women without TBI. Within TBI, only hot flashes and breast tenderness were greater in postmenopausal versus pre/peri-menopausal women. Within non-TBI, postmenopausal status was associated with significantly greater hot flashes, night sweats, restlessness, poor memory, irritability, sleep disturbance, and anxiety, with greater fatigue but not significantly.

The findings support a model of TBI and menopause in which symptoms most closely associated with estrogen decline in pre/peri-menopause are generally similar between women with and without TBI, and symptoms that overlap with common TBI sequelae were generally more often present and frequently experienced among women with TBI versus non-TBI. We did not observe a synergistic or potentiating effect of TBI on menopause symptoms in post-menopause. These findings offer insight that contextualizes the experience of menopause symptoms among women with TBI. Such insights are essential for the development of treatment approaches that maximize health and wellbeing during the menopause transition for women with TBI.

The vast majority of existing research on outcomes following concussion is androcentric with women notably understudied in all settings where concussion commonly occurs, including sport, military, and civilian domains. Clinical care for concussed women is, by extension, far less evidenced-based as it is largely extrapolated from male-dominated studies. We therefore sought to center concussion outcomes of women in big data sources in this investigation to capitalize on both sample size and breadth of setting in which concussion occurs.

We identified all studies with publicly released data as of 4/7/21 that included both male and female adults, enough information to determine severity of injury consistent with concussion/mild traumatic brain injury (TBI), a measure of postconcussive symptoms (PCS), and objective measures of neurocognitive functioning from the Federal Interagency Traumatic Brain Injury Research (FITBIR) Informatics System. FITBIR is a collaborative effort of the National Institutes of Health (NIH) and the Department of Defense (DoD), developed to share data across the entire TBI research community. This resulted in inclusion of six studies with a total of 9370 participants, 32% female. PCS data was drawn from the Neurobehavioral Symptom Inventory (NSI), the Rivermead Post-Concussion Symptoms Questionnaire (RPSQ), and the Sport Concussion Assessment Tool - 3rd Edition (SCAT 3), specifically the 22-item participant symptom evaluation rated on a 7-point scale. The questionnaires were harmonized and the following symptom domains emerged: Somatic, Cognitive, and Affective. Data were analyzed using linear mixed-effects models.

We found a small to medium sized significant effect of sex, with women reporting higher symptoms overall. Mean symptom endorsement scores were higher overall on the NSI in comparison to the RPSQ and SCAT (ps < .001). Follow-up analyses revealed sex differences were largest for cognitive symptoms, followed by somatic symptoms, then affective symptoms. We also found significant main effects of population (military>sport/civilian, p = .003) and sex (women>males, p < .001) on the overall composite, as well as a significant population-by-sex interaction such that female service members/veterans endorsed the highest rates of symptoms (p < .001). Similar patterns of significance and effect sizes were observed for the somatic and affective composites. Cognitive symptom composites showed a similar pattern, but with smaller effect sizes overall. Racial and ethnic diversity was also limited in the sample.

In one of the largest samples of women to date, we found a small to medium effect of sex on symptom reporting such that women reported higher levels of postconcussive symptoms than males. Notably, however, the women in military/Veteran samples endorsed the highest levels of symptoms. Despite using a large publicly available dataset to maximize the representation of women, the current sample was still predominantly male and racial and ethnic diversity among the sample was not consistent with expected broader population demographics. Dramatically more concerted efforts need to be made to engage women in all spheres of concussion research (military, civilian, and sport). Strategies to be more inclusive in concussion research will be highlighted.

There are critical and perplexing sex/gender differences in Alzheimer’s disease (AD). Women show a more favorable clinical profile in preclinical AD particularly with verbal memory, but a steeper decline post mild cognitive impairment (MCI) diagnosis and, ultimately, higher rates of AD. Longitudinal studies are needed to understand sex differences across the AD trajectory. Using data from the Alzheimer’s Disease Neuroimaging Initiative, we identified profiles of memory trajectories among those with evidence of preclinical AD or MCI at baseline and how these trajectories differ by sex.

In our sample of 659 participants (age range: 55-90, mean age=72.9 [SD=7.4], 95% non-Hispanic White; mean follow-up=41.2 [SD=32.3] months), 233 were labelled “preclinical” AD (51% women) at baseline based on a cognitively normal status but positivity for either the cerebrospinal fluid p-Tau/Aß42, Amyloid PET or Tau PET biomarkers, and 426 participants (44% women) were MCI at baseline based on Jak/Bondi criteria. We applied latent class growth curve modeling to the heterogeneous change in the Rey Auditory Verbal Learning Test (RAVLT) Immediate and Delayed Recall within preclinical and MCI groups separately. Models in MCI group included Non-Linear Spline to account for differential change rates within subgroups. Models were compared on Bayesian Information Criterion, Entropy, and Class distribution to determine a best-fitting model. Effects of sex on trajectories were the primary outcomes. All models included APOE4 carrier status and age.

Women outperformed men on Immediate and Delayed Recall at baseline in the preclinical and MCI groups (ps<.05). Within the preclinical group, 3-class models representing stable, decline, and accelerated decline provided optimal fit for both Immediate and Delayed Recall. Whereas, on average, preclinical women showed more stable Immediate Recall than men (beta=6.24, SE=.82, p<.0001), they were more likely to be in the Immediate Recall accelerated decline class (23.4% vs. 16.25%; female:male; Chi-square=36.29, p<.00001). On average, preclinical women and men did not differ in Delayed Recall trajectories (beta=.31, SE=.30, p=.28); however, preclinical women were more likely to be in the stable Delayed Recall class (11.04% vs. 6.5%; Chi-Square=19.19, p<.0001). Within the MCI group, 2-class models representing a stable decline group and an accelerated decline group provided optimal fit for both outcomes. Whereas, on average, MCI women showed more stable Immediate Recall than men (beta=3.55, SE=.79, p<.0001), they were more likely to be in the Immediate Recall accelerated decline class, although not significantly. Women and men did not differ, on average, in their Delayed Recall trajectories; however, women were significantly more likely to be in the Delayed Recall accelerated decline class (Chi-square=32.24, p<.0001).

Our findings indicate that sex is an important determinant of the variability observed in early-stage AD trajectories; however, sex differences varied by Immediate versus Delayed Recall likely due, in-part, to psychometric test properties. Our results suggest that, when looking at sex differences in AD trajectories on average, women’s superior stability in verbal learning masks their higher likelihood of rapid decline. Our findings have implications for our ability to optimally diagnose and track disease progression in both sexes.

Neuropsychologists have difficulty detecting cognitive decline in high-functioning older adults, in whom substantially greater neurological change may need to occur before performance on cognitive tests are low enough to indicate cognitive impairment. For high-functioning older adults, subjective cognitive concerns (SCC) may indicate decline that is not detected by the presence of low cognitive test scores but may be related to the absence of high scores and the presence of latent neurological changes. We hypothesized that high-functioning older adults with SCC would have fewer high scores than those without concerns, but a comparable number of low scores. These findings would indicate that objective decline has occurred but would not be detected by a traditional focus on low scores. We also hypothesized that SCC would be associated with lower frontoparietal network volume, thickness, and connectivity, indicating latent neurological change underlying subjective cognitive concerns.

Participants from an imaging sub-study of an ongoing longitudinal aging study were selected if they had high estimated premorbid functioning, defined as either (a) estimated intelligence >75th percentile on the North American Adult Reading Test (n=48) or (b) having a college degree (n=62). This resulted in 68 participants subdivided based on SCC, defined as one or more self-reported SCC on the Medical Outcomes Study Cognitive Functioning Scale (MOS-Cog). Participants with SCC (n=35; 73.9 years-old, SD=9.6, range: 60-95; 62.9% female; 94.3% White) and without SCC (n=33; 71.0 years-old, SD=7.2, range: 61-85, 75.8% female; 100% White) completed a neuropsychological test battery of memory and executive functions, including the Rey Auditory Verbal Learning Test, Trail Making Test Parts A and B, Controlled Oral Word Association Test, Digit Span, and Letter-Number Sequencing, and underwent structural MRI. MR images were analyzed for frontoparietal network volume, thickness, and connectivity.

Participants with and without SCC were compared on the number of low test scores (i.e., at or below the 16th percentile) and high test scores (i.e., at or above the 75th percentile), finding a comparable number of low scores, t=1.66, p=.103, d=.40, but a lower number of high scores among participants with SCC, t=2.95, p=.004, d=.71. Participants with SCC had lower bilateral mean frontoparietal network volumes (left: t=2.98, p=.004, d=.74; right: t=2.63, p=.011, d=.66) and cortical thickness (left: t=2.65, p=.010, d=.66; right: t=2.18, p=.033, d=.54), but did not differ from those without SCC in terms of network connectivity.

SCC have been reported as a potential risk factor for dementia in older adults. High-functioning older adults with SCC presented with fewer high scores than those without SCC but had a comparable number of low scores. Among high-functioning older adults, subjective cognitive decline may correspond with objective cognitive change not detected by the traditional emphasis on low scores, but rather the absence of high scores. SCC were also related to underlying changes in the volume and thickness of the frontoparietal network, but not connectivity. In high-functioning older adults, subjective cognitive decline may correspond with a reduction from high average functioning in some domains and underlying neurological changes.

There is increasing recognition of cognitive and pathological heterogeneity in early-stage Alzheimer’s disease and other dementias. Data-driven approaches have demonstrated cognitive heterogeneity in those with mild cognitive impairment (MCI), but few studies have examined this heterogeneity and its association with progression to MCI/dementia in cognitively unimpaired (CU) older adults. We identified cluster-derived subgroups of CU participants based on comprehensive neuropsychological data and compared baseline characteristics and rates of progression to MCI/dementia or a Dementia Rating Scale (DRS) of <129 across subgroups.

A hierarchical cluster analysis was conducted using 11 baseline neuropsychological test scores from 365 CU participants in the UCSD Shiley-Marcos Alzheimer’s Disease Research Center (age M=71.93 years, SD=7.51; 55.9% women; 15.6% Hispanic/Latino/a/x/e). A discriminate function analysis was then conducted to test whether the individual neuropsychological scores predicted cluster-group membership. Cox regressions examined the risk of progression to consensus diagnosis of MCI or dementia, or to DRS score <129, by cluster group.

Cluster analysis identified 5 groups: All-Average (n=139), Low-Visuospatial (n=46), Low-Executive (n=51), Low-Memory/Language (n=83), and Low-All Domains (n=46). The discriminant function analysis using the neuropsychological measures to predict group membership into these 5 clusters correctly classified 85.2% of the participants. Subgroups had unique demographic and clinical characteristics. Relative to the All-Average group, the Low-Visuospatial (hazard ratio [HR] 2.39, 95% CI [1.03, 5.56], p=.044), Low-Memory/Language (HR 4.37, 95% CI [2.24, 8.51], p<.001), and Low-All Domains (HR 7.21, 95% CI [3.59, 14.48], p<.001) groups had greater risk of progression to MCI/dementia. The Low-Executive group was also twice as likely to progress to MCI/dementia compared to the AllAverage group, but did not statistically differ (HR 2.03, 95% CI [0.88,4.70], p=.096). A similar pattern of results was found for progression to DRS score <129, with the Low-Executive (HR 2.82, 95% CI [1.26, 6.29], p=.012), Low-Memory/Language (HR 3.70, 95% CI [1.80, 7.56], p<.001) and Low-All Domains (HR 5.79, 95% CI [2.74, 12.27], p<.001) groups at greater risk of progression to a DRS score <129 than the All-Average group. The Low-Visuospatial group was also twice as likely to progress to DRS <129 compared to the All-Average group, but did not statistically differ (HR 2.02, 95% CI [0.80, 5.06], p=.135).

Our results add to a growing literature documenting heterogeneity in the earliest cognitive and pathological presentations associated with Alzheimer’s disease and related disorders. Participants with subtle memory/language, executive, and visuospatial weaknesses all declined at faster rates than the All-Average group, suggesting that there are multiple pathways and/or unique subtle cognitive decline profiles that ultimately lead to a diagnosis of MCI/dementia. These results have important implications for early identification of individuals at risk for MCI/dementia. Given that the same classification approach may not be optimal for everyone, determining profiles of subtle cognitive difficulties in CU individuals and implementing neuropsychological test batteries that assess multiple cognitive domains may be a key step towards an individualized approach to early detection and fewer missed opportunities for early intervention.

Type 2 diabetes (T2D) is a risk factor for cognitive impairment/dementia and has been shown to modify the impact of Alzheimer’s disease (AD) biomarkers on cognition and everyday functioning. Studies examining amyloid-ß (Aß), one of the hallmark AD pathologies, have shown mixed results regarding associations of Aß biomarkers with cross-sectional cognition as well as T2D, though Aß is generally associated with future cognitive declines. The purpose of the present study is to examine whether T2D impacts the associations between amyloid positron emission tomography (PET) and cognition in older Veterans.

The current study included 202 mostly male Vietnam-Era Veterans from the Department of Defense-Alzheimer’s Disease Neuroimaging Initiative (DOD ADNI) study (age M=69.38 years, SD=4.37; 40% with self-reported T2D) who completed neuropsychological testing and florbetapir PET imaging. The Aß PET standardized uptake variable ratio (SUVR) was measured using a previously-validated summary SUVR calculated by dividing the mean uptake across 4 AD-vulnerable cortical regions by whole cerebellar uptake. General linear models examined whether T2D moderated the relationship of Aß PET with memory, attention/executive functioning, and language composite scores. Models adjusted for age, education, apolipoprotein E e4 carrier status, vascular risk burden, depressive symptoms, post-traumatic stress disorder (PTSD) symptom severity, and history of traumatic brain injury (TBI).

There was no main effect of diabetes on memory, attention/executive functioning, or language performance, and higher Aß PET SUVR was only associated with worse attention/executive functioning performance (ß=-.146, 95% CI [-.261, -.031], p=.013). The Aß PET x T2D interaction was significant for attention/executive functioning such that higher Aß PET SUVR was associated with lower attention/executive functioning scores, but only in those with T2D (ß=-.116, [-.225, -.006], p=.038). This interaction was not significant for language or memory.

The results show that Aß may negatively impact attention/executive functioning, but this effect was only found in Veterans with T2D. Prior work has suggested that T2D may be more associated with tau biomarkers than markers of Aß, so it is possible that the current results are due to a compounding effect of Aß pathology plus microvascular and/or tau pathology. Notably, the sample was relatively young, a relatively large proportion had elevated PTSD symptoms and/or a TBI history (which have both been shown to relate to attention/executive function), and the measures that made up the attention/executive composite (Trail Making Test A and B) have been shown to be particularly sensitive - all of which may have contributed to the domain-specific effects. Future research is needed to investigate the role that tau and vascular pathology may play in cognition among individuals with T2D. Longitudinal studies are also needed to better understand the timing and progression of these relationships.

History of traumatic brain injury (TBI) is associated with increased risk of dementia, but few studies have evaluated whether TBI history alters the course of neurocognitive decline, and existing literature on this topic is limited to short follow-up and smaller samples. The primary aim of this study was to evaluate whether a history of TBI (TBI+) influences neurocognitive decline later-in-life among older adults with or without cognitive impairment [i.e., normally aging, Mild Cognitive Impairment (MCI), or dementia].

Participants included individuals from the National Alzheimer’s Coordinating Center (NACC) who were at least 50 years old and with 3 to 6 visits (M number of visits = 4.43). Participants with any self-reported history of TBI (n = 1,467) were matched 1:1 to individuals with no reported history of TBI (TBI-) from a sample of approximately 45,000 participants using case-control matching based on age (+/- 2 years), sex, education, race, ethnicity, cognitive diagnosis [cognitively normal (CN), MCI, or all-cause dementia], etiology of cognitive impairment, functional decline (Clinical Dementia Rating Scale, CDR), number of Apolipoprotein E4 (APOE ε4) alleles, and number of annual visits (3 to 6). Mixed linear models were used to assess longitudinal neuropsychological test composites (using NACC normative data) of executive functioning/attention/speed (EFAS), language, and memory in TBI+ and TBI- participants. Interactions between TBI and demographics, APOE ε4 status, and cognitive diagnosis were also examined.

Following matching procedures, TBI+ (n=1467) and TBI- (n=1467) groups were nearly identical in age (TBI+ M = 71.59, SD = 8.49; TBI- M = 71.63, SD = 8.44), education (TBI+ M = 16.12, SD = 2.59; TBI- M = 16.10, SD = 2.52), sex (both 55% male), race (both 90% White), ethnicity (both 98% non-Hispanic), APOE ε4 alleles (both 0 = 62%, 1 = 33%, 2 = 5%), baseline cognitive diagnoses (both CN = 60%, MCI = 18%, dementia = 12%), and global CDR (TBI+ M = 0.30, SD = 0.38, TBI- M = 0.30, SD = 0.38). At baseline, groups had similar Z-scores of in EFAS (TBI+ Mefas = -0.02, SD = 1.21; TBI- Mefas = -0.04, SD = 1.27), language (TBI+ MLanguage = -0.48, SD = 0.98; TBI- MLanguage = -0.55, SD = 1.05), and memory (TBI+ MMemory = -0.45, SD = 1.28; TBI- MMemory = -0.45, SD =1.28). The course of change in neuropsychological functioning worsened longitudinally, but did not differ between TBI groups (p’s > .110). There were no significant interactions between TBI history and age, sex, education, race/ethnicity, number of APOE ε4 status, or cognitive diagnosis (all p’s > .027).

In this matched case-control design, our findings suggest that a history of TBI, regardless of demographic factors, APOE ε4 status, and cognitive diagnosis, does not significantly alter the course of neurocognitive functioning later-in-life in older adults with and without cognitive impairment. Future clinicopathological longitudinal studies with well characterized TBI histories and the associated clinical course are needed to help clarify the mechanism by which TBI may increase dementia risk for some individuals, without affecting course of decline.

Tissue inhibitor of metalloproteinases 2 (TIMP2) is produced peripherally, crosses the blood-brain barrier, and improves synaptic plasticity and hippocampal-dependent cognition in aged mice; however, the role of TIMP2 in human cognitive aging is unclear. We examined associations of circulating TIMP2 levels in blood with a known plasticity-inducing behavior, physical activity, and cognitive functioning among older adults along the Alzheimer’s disease continuum.

Participants included 84 community-dwelling older adults (meanage = 78.8; 57% female; 82% cognitively normal; 14% MCI; 4% mild dementia; 35% PET Aß+) enrolled in the UC San Francisco Memory and Aging Center. All participants completed 30 days of observational FitbitTM monitoring to quantify physical activity (average daily steps), as well as a comprehensive in-person visit including blood draw (proteins assayed on SOMAscan platform), [18F]AV-45 positron emission tomography (PET) to quantify brain beta-amyloid (centiloids), and neuropsychological assessment. Composite cognitive z-scores were calculated for memory (California Verbal Learning Test-II [CVLT-II] and Benson Figure Recall), semantic processing (animal fluency and Boston Naming Test), and executive functioning (digits backwards span, Stroop inhibition, modified trail making test, lexical fluency, and design fluency). Multiple linear regression examined TIMP2 as a function of physical activity, covarying for age and PET centiloids. Additional regression models separately examined cognitive z-scores as a function of TIMP2, covarying for age, sex, education, PET centiloids, and body mass index (BMI).

TIMP2 was not significantly correlated with age, sex, education, or PET centiloids (ps > 0.05); however, TIMP2 was negatively correlated with BMI (r = -0.23, p = 0.036). Greater average daily steps related to higher levels of TIMP2 (b = 0.30, 95%CI = 0.04-0.55, p = 0.022). TIMP2 also related to better semantic processing (b = 0.28, 95%CI = 0.04-0.51, p = 0.021) and executive functioning (b = 0.26, 95%CI = 0.03-0.49, p = 0.028). TIMP2 did not significantly relate to memory (p > 0.05).

Greater physical activity was associated with higher concentrations of blood factor TIMP2, which in turn related to better cognitive functioning independent of Alzheimer’s disease pathology burden. These results support previous mouse models by broadly replicating relationships between TIMP2 and cognition in humans, while also uniquely demonstrating an association between TIMP2 and physical activity, a modifiable protective factor in both typical and diseased cognitive aging. Our domain-specific results, however, suggest that benefits of TIMP2 in humans may involve a broader neuroanatomical network than the hippocampal-specific effects previously shown in mice. Although exact mechanisms of TIMP2 need further examination, TIMP2 is known to be enriched in human umbilical cord plasma, has been shown to be involved in cell-growth promoting activities, and may relate to increased neural plasticity in older age. Further examination of TIMP2 and other novel blood-based proteins as potential therapeutic targets for improved cognitive aging, including in the presence of Alzheimer’s disease, is warranted.

Alterations in cerebral blood flow (CBF) are associated with risk of cognitive decline and Alzheimer’s disease (AD). Although apolipoprotein E (APOE) ε4 and greater vascular risk burden have both been linked to reduced CBF in older adults, less is known about how APOE ε4 status and vascular risk may interact to influence CBF. We aimed to determine whether the effect of vascular risk on CBF varies by gene dose of APOE ε4 alleles (i.e., number of e4 alleles) in older adults without dementia.

144 older adults without dementia from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) underwent arterial spin labeling (ASL) and T1-weighted MRI, APOE genotyping, fluorodeoxyglucose positron emission tomography (FDG-PET), lumbar puncture, and blood pressure assessment. Vascular risk was assessed using pulse pressure (systolic blood pressure -diastolic blood pressure), which is thought to be a proxy for arterial stiffening. Participants were classified by number of APOE ε4 alleles (n0 alleles = 87, m allele = 46, n2 alleles = 11). CBF in six FreeSurfer-derived a priori regions of interest (ROIs) vulnerable to AD were examined: entorhinal cortex, hippocampus, inferior temporal cortex, inferior parietal cortex, rostral middle frontal gyrus, and medial orbitofrontal cortex. Linear regression models tested the interaction between categorical APOE ε4 dose (0, 1, or 2 alleles) and continuous pulse pressure on CBF in each ROI, adjusting for age, sex, cognitive diagnosis (cognitively unimpaired vs. mild cognitive impairment), antihypertensive medication use, cerebral metabolism (FDG-PET composite), reference CBF region (precentral gyrus), and AD biomarker positivity defined using the ADNI-optimized phosphorylated tau/ß-amyloid ratio cut-off of > 0.0251 pg/ml.

A significant pulse pressure X APOE ε4 dose interaction was found on CBF in the entorhinal cortex, hippocampus, and inferior parietal cortex (ps < .005). Among participants with two e4 alleles, higher pulse pressure was significantly associated with lower CBF (ps < .001). However, among participants with zero or one ε4 allele, there was no significant association between pulse pressure and CBF (ps > .234). No significant pulse pressure X APOE ε4 dose interaction was found in the inferior temporal cortex, rostral middle frontal gyrus, or medial orbitofrontal cortex (ps > .109). Results remained unchanged when additionally controlling for general vascular risk assessed via the modified Hachinski Ischemic Scale.

These findings demonstrate that the cross-sectional association between pulse pressure and region-specific CBF differs by APOE ε4 dose. In particular, a detrimental effect of elevated pulse pressure on CBF in AD-vulnerable regions was found only among participants with the e4/e4 genotype. Our findings suggest that pulse pressure may play a mechanistic role in neurovascular unit dysregulation for those genetically at greater risk for AD. Given that pulse pressure is just one of many potentially modifiable vascular risk factors for AD, future studies should seek to examine how these other factors (e.g., diabetes, high cholesterol) may interact with APOE genotype to affect cerebrovascular dysfunction.

Cognitive dysfunction is a common non-motor symptom of Parkinson’s disease (PD). Cognitive decline in PD is likely associated with dysfunction in the cholinergic system, which is affected by synuclein pathology early in the disease course. Recent studies have shown an association between reduced integrity of the basal forebrain (BF), which provides cholinergic innervation to most of cortex, and diminished cognitive functioning in PD. Specifically, those with PD and reduced cholinergic innervation also have higher rates of cognitive impairment. However, no study has directly investigated the relationship between basal forebrain integrity and cortical cholinergic levels. In the present study, we examined this relationship through measures of basal forebrain microstructural integrity and cholinergic nerve terminal density in cortical and subcortical gray matter.

Participants included 92 non-demented individuals with idiopathic PD (M:F=64:28; Age=67.0±7.1 yrs) who underwent structural MRI, diffusion MRI, and [18F] fluoroethoxybenzovesamicol (FEOBV) cholinergic PET imaging. We used a basal forebrain and region of interest defined by AssemblyNet, which uses ensembles of pretrained convolutional neural networks to create a full brain segmentation. Bilateral putamen from this atlas was also included as a control region. We measured microstructural integrity using free water fraction (FWF), a diffusion MRI-derived metric of extracellular water that associates with cellular density and neuroinflammation. For PET data, we computed the distribution volume ratio (DVR) by regions as defined by FreeSurfer. A factor analysis of DVR in all 88 FreeSurfer ROIs resulted in seven clusters of ROIs covering 1) widespread bilateral cortical regions (PC1); 2) subcortical and limbic regions (PC2); 3) bilateral cingulate regions (PC3); 4) left frontal regions (PC4); 5) right frontal and temporal regions (PC5); 6) cerebellum (PC6); and 7) bilateral entorhinal cortex and left temporal cortex (PC7). We performed seven separate regression analyses per ROI (controlling for age and disease duration) to evaluate the association between BF FWF and cholinergic levels in these regions. To determine if these ROIs showed unique associations with BF FWF, we then entered ROIs with a significant association with BF FWF as independent variables in a stepwise regression with forward selection with BF FWF as the dependent variable.

BF FWF was significantly and negatively associated with cholinergic levels in PC1 (AR2=.042, ß=-0.208, p=.04), PC3 (AR2=.044, ß=-0.206, p=.03), PC4 (AR2=.056, ß=-0.239, p=.02), and PC7 (ß=-0.215, p=.04). BF FWF trended towards a negative association with cholinergic levels in PC5 (AR2=.045, ß=-0.168, p=.09) and PC6 (ß=-0.188, p=.09). Putamen FWF did not significantly associate with any of the ROIs. In the follow-up stepwise regression, only PC4 contributed significantly to the overall model (AR2=.061, ß=-0.261, p=.02).

Basal forebrain FWF was inversely related to cholinergic levels in regions that are directly innervated by the basal forebrain (e.g., cingulate cortex, left frontal cortex, and bilateral entorhinal cortex). Future research should directly investigate the relationship between basal forebrain integrity, cortical cholinergic levels, and cognition. Separating the basal forebrain into specific nuclei would also be beneficial, as different nuclei may have differing associations with specific hemispheric cholinergic pathways and cognition.

Parkinson’s disease (PD) is associated with metabolic disorders such as insulin resistance. Pharmacological intervention used to treat insulin resistance, like GLP-1 agonists, may have auspicious results in the treatment for PD. The objective of this clinical trial was to assess the therapeutic effect of liraglutide on non-motor symptoms, such as, but not limited to, cognitive function and emotional well-being, and quality of life for individuals with PD.

In a single-center, randomized, double-blind, placebo-controlled trial, PD patients self-administered liraglutide injections once-daily (1.2 or 1.8 mg, as tolerated) or placebo in a 2:1 study design for 52 weeks after titration. Primary outcomes included adjusted difference in the OFF-state Movement Disorders Society Unified PD Rating Scale (MDS-UPDRS) part III, non-motor symptom scale (NMSS) and Mattis Dementia Rating Scale (MDRS-2). Secondary outcomes included quality of life scores (Parkinson Disease Questionnaire, PDQ-39) and other neuropsychological tests, including Delis-Kaplan Executive Function System (DKEFS), Geriatric Depression Scale (GDS), and Parkinson’s Anxiety Scale (PAS) scores.

Sixty-three subjects were enrolled and randomized to liraglutide (n=42) or placebo (n=21). Mean age in years was 63.5 (9.8) and 64.2 (6.4) for liraglutide and placebo cohorts, respectively (p=0.78), and mean age at symptom onset was 58.9 (10.5) and 59.3 (7.5) for liraglutide and placebo cohorts, respectively (p=0.86). At 54 weeks, NMSS scores had improved by 6.6 points in the liraglutide group and worsened by 6.5 points in the placebo group, a 13.1 point adjusted mean difference (p<0.05). Further analysis showed all nine NMSS sub-domain changes favoring the liraglutide group, with one (attention/memory) reaching statistical significance (p<0.05). Secondary outcome analyses revealed a significant improvement of PDQ-39 (p<0.001) and Parkinson’s Anxiety Scale - Avoidance Behavior scores (p<0.05) in the treatment group. MDRS-2 sub-scores did not further differentiate study groups, while DKEFS letter fluency scores favored placebo group (p<0.05).

Treatment with liraglutide improved self-reported non-motor symptoms of PD, activities of daily living, and quality of life. These results validate similar outcomes reported with other GLP-1 agonists implicating consideration for novel treatment opportunities for individuals with PD. Notably, the absence of significant performance-based cognitive changes over the duration of the trial for the participants in this study has several plausible explanations given participant-related baseline demographic and clinical factors. Implications for neuropsychologists will be discussed.

Autonomic dysfunction is an important non-motor symptom of Parkinson’s disease (PD), with point prevalence estimates of approximately 50-70%. Common presentations include cardiovascular dysregulation, gastrointestinal dysfunction, impaired thermoregulation, and sexual dysfunction. In the present study, we sought to examine whether autonomic symptoms would predict trajectories of change in depression and anxiety over a 5-year period in newly diagnosed individuals with PD. Given that alterations in autonomic nervous system functioning (e.g., reduced heart rate variability, lower autonomic arousal) are frequently observed in individuals who have anxiety and depression, as well as the negative influence these symptoms can have on quality of life/functioning, we predicted that greater autonomic symptoms would be related to increased mood symptoms over time.

Participants included 414 individuals from the Parkinson’s Progression Markers Initiative, a prospective study of newly diagnosed and untreated individuals with PD. The PD participants (mean age=61.6+9.7, mean education=15.6+3.0, 92.5% non-Hispanic White) were followed annually for up to five years. Self-reported autonomic symptoms were measured using the Scales for Outcomes in Parkinson’s Disease-Autonomic Dysfunction (SCOPA-AUT), which consists of a total score and 6 subdomain scores (gastrointestinal, urinary, cardiovascular, thermoregulatory, pupillomotor, sexual). Mood measures included the Geriatric Depression Scale (GDS) and State-Trait Anxiety Inventory (STAI). Motor severity was assessed using the Unified Parkinson’s Disease Rating Scale (UPDRS) Part III. Bootstrapped linear regressions were performed to evaluate the relationship between autonomic symptoms (subdomains) and mood using data from the last visit (year 5). For longitudinal analyses, bootstrapped multilevel modeling was used to examine a) changes in SCOPA-AUT total over time (unconditional growth model only) and b) the relationship between mood and SCOPA-AUT total score over time, controlling for age/sex and motor severity.

Autonomic symptoms explained 28.2% of the total variance in trait anxiety, with unique predictors of gastrointestinal (/3=.266, p<.001) and thermoregulatory (ß=.202, p=.004) symptoms. For depression, autonomic symptoms explained 27.9% of the total variance, with unique predictors of gastrointestinal (ß=.225, p=.012), thermoregulatory (ß=.178, p=.013), and cardiovascular (ß=.154, p=.012) symptoms. There was a gradual linear increase in total autonomic symptoms over time (b=0.86, p<.001). Greater total autonomic symptoms were associated with higher average trait anxiety (b=0.54, p<.001), slightly greater increase in trait anxiety over time (b=0.04, p<.05), and occasion-to-occasion fluctuations in trait anxiety (b=0.24, p<.001). Similarly, increased total autonomic symptoms were associated with higher average depressive symptoms (b=0.14, p<.001), minimally greater increase in depressive symptoms over time (b=0.01, p<.05), and occasion-to-occasion fluctuations in depressive symptoms (b=0.08, p<.001). Motor severity did not explain individual differences or trajectories of change in depression or trait anxiety.

Autonomic symptoms, particularly gastrointestinal, cardiovascular, and thermoregulatory dysfunction, were related to increased mood symptoms in PD patients and predicted increases in depression/anxiety over time. Our findings do not distinguish between two theoretical possibilities - whether autonomic symptoms lead to depression/anxiety versus involvement of co-occurring neural systems underlying both. Regardless, our study highlights the importance of treating autonomic dysfunction in early PD, and future work should incorporate additional measures of autonomic dysfunction (e.g., physiological probes).

Apathy is a primary lack of motivation that is frequently reported in Parkinson’s disease (PD) and often misdiagnosed as depression. In PD, apathy worsens over time with motor symptom progression. Evidence over the past 15 years has documented that use of selective serotonin reuptake inhibitors (SSRIs) is associated with increased apathy in patients with depression, including individuals with PD. In PD, this appears to be related to downregulation of dopaminergic systems by serotonin. Despite increasing evidence, SSRIs continue to be heavily prescribed in individuals with PD— potentially worsening apathy and decreasing quality of life for these individuals. This study is an update, re-examining the relationship between apathy and the use of SSRIs and other antidepressants in a large cohort of individuals with PD.

Participants included a convenience sample of 387 nondemented individuals with idiopathic PD who were in their mid-60's (mean age=64.9+8.72 years), well-educated (mean=14.95+2.78 years), predominantly male (72.4%), non-Hispanic white (94.5%), and in mid-stage of disease severity (on medication Unified Parkinson Disease Rating Scale motor score=25.3+10.1). All scored above clinical cutoff for dementia on a cognitive screener (Dementia Rating Scale-2 (DRS) > 125). Medications, cognitive, mood, and clinical data were extracted from chart review. Depression and apathy were measured using the Beck Depression Inventory-II (BDI-Il) and the Apathy Scale (AS). Antidepressant medications were grouped into SSRIs, serotonin and norepinephrine reuptake inhibitors (SNRIs) and other. Analyses included bootstrapped Pearson’s correlations, Pearson’s chi-square, and linear regressions

Among 387 individuals with PD, 41.3% (N=160) were taking antidepressant medications. Of these 160, 61.3% were on SSRIs, 24.4% on SNRIs, and the remainder on other antidepressants. Approximately 36.9% of the 387 PD patients exceeded recommended clinical cutoffs for apathy (AS >14) and 23.5% for depression (BDI-II >14) (Starkstein et al., 1992; Beck et al., 1996). Individuals taking SSRIs (N=98, x2=5.14, p=0.023) or SNRIs (N=39; x2=5.43, p=0.020) were more likely to be clinically apathetic than those taking other depression medications (N=23; x2=1.28, p=0.26). Results of a multiple regression with age, education, disease duration, motor severity, DRS-2, BDI-II, and all psychotropic medications (anti-depressants, anti-anxiety, anti-psychotics) as independent variables explained 42.8% of the variance in total apathy scores (F[17,285]=12.550, p<0.001). SSRIs were the only medication to significantly predict greater AS scores (ß=0.110, p=0.020) in this model. Less education (ß=-0.119, p=0.017) worse cognition (ß=-0.128, p=0.009), and greater depressive symptoms (ß=0.561, p<0.001) were also significant predictors of apathy.

These findings suggest that use of SSRIs, but not other antidepressants, is associated with greater apathy in PD. Given the interactive relationship between serotonin and dopamine, the current findings highlight the importance of considering apathy as a potential adverse effect when determining which anti-depressants to prescribe to individuals with PD. Similarly, switching a SSRI for an alternative anti-depressant in individuals with PD who are apathetic may be a potential treatment for apathy that needs further study. Longitudinal studies are also needed to elucidate the relationship of apathy and anti-depressant use over time, specifically to determine potential causality of this observed association. Funding: T32-NS082168

While Parkinson’s disease (PD) is traditionally known as a movement disorder, cognitive decline is one of the most debilitating and common non-motor symptoms. Cognitive profiles of individuals with PD are notably heterogeneous (Goldman et al., 2018). While this variability may arise from the disease itself, other factors might play a role. Greater anticholinergic medication use has been linked to worse cognition in those with PD (Fox et al., 2011, Shah et al., 2013). However, past studies on this topic had small sample sizes, limited ranges of disease duration, and only used cognitive screeners. Thus, this study aimed to examine this question within a large, clinical sample, using a more comprehensive neuropsychological battery. We hypothesized that higher anticholinergic medication usage would relate to worse cognitive performance, particularly memory.

Participants included 491 nondemented individuals with PD (m=64.7, SD=9.04 years old; education m=15.01, SD=2.79; 71.9% male; 94.3% non-Hispanics white) who underwent a comprehensive neuropsychological assessment at the UF Fixel Institute’s movement disorders program. Medications at the time of the neuropsychological evaluation were identified from chart review and scored based on anticholinergic properties using the Magellan Anticholinergic Risk Scale (Rudolph J.L., et al, 2008); each medication was scored from 0 (no load) to 3 (high load). The neuropsychological battery included measures across 5 cognitive domains: (1) executive function (Trails B, Stroop Interference, Letter Fluency), (2) verbal delayed memory (WMS-III Logical Memory and Hopkin’s Verbal Learning Test-Revised delayed recalls), (3) language (Boston Naming Test-II, Animal Fluency), (4) visuospatial skills (Judgment of Line Orientation, Face Recognition Test), and (5) attention/working memory (WAIS-III Digit Span Forward and Backward). The published normative scores for each task were converted into z-scores and averaged into a domain composite. Due to non-normality of Magellan scores, Spearman correlations examined the relationship between each cognitive domain composite score and Magellan scores.

As predicted, higher Magellan scores were significantly associated with worse memory (r=-0.11, p=0.016), with a small effect size. There were no significant relationships between Magellan scores and the remaining cognitive domains (EF, language, visuospatial, attention).

We found that greater anticholinergic burden was associated with worse performance on memory, but not other neuropsychological domains, in a large cohort of nondemented individuals with PD who underwent comprehensive assessment. This finding corresponds to previous literature in smaller PD cohorts. Though the effect size was low, this finding highlights the importance of monitoring anticholinergic burden in PD patients in order to minimize detrimental effects of medications on memory function. Future work should examine whether greater anticholinergic burden predicts future progression of memory decline.

Acknowledgement: Supported in part by the NIH, T32-NS082168

Non-motor symptoms, such as mild cognitive impairment and dementia, are an overwhelming cause of disability in Parkinson’s disease (PD). While subthalamic nucleus deep brain stimulation (STN DBS) is safe and effective for motor symptoms, declines in verbal fluency after bilateral DBS surgery have been widely replicated. However, little is known about cognitive outcomes following unilateral surgeries.

We enrolled 31 PD patients who underwent unilateral STN-DBS in a randomized, cross-over, double-blind study (SUNDIAL Trial). Targets were chosen based on treatment of the most symptomatic side (n = 17 left hemisphere and 14 right hemisphere). All participants completed a neuropsychological battery (FAS/CFL, AVLT, DKEFS Color-Word Test) at baseline, then 2, 4, and 6 months post-surgery. Outcomes include raw scores for verbal fluency, immediate and delayed recall, and DKEFS Color-Word Inhibition trial (Trial 3) completion time. At 2, 4, and 6 months, the neurostimulation type (directional versus ring mode) was randomized for each participant. We compared baseline scores for all cognitive outcome measures using Welch’s two-sample t-tests and used linear mixed effects models to examine longitudinal effects of hemisphere and stimulation on cognition. This test battery was converted to a teleneuropsychology administration because of COVID-19 mid-study, and this was included as a covariate in all statistical models, along with years of education, baseline cognitive scores, and levodopa equivalent medication dose at each time point.

At baseline, patients who underwent left hemisphere implants scored lower on verbal fluency than right implants (t(20.66) = -2.49, p = 0.02). There were not significant differences between hemispheres in immediate recall (p = 0.57), delayed recall (p = 0.22), or response inhibition (p = 0.51). Post-operatively, left STN DBS patients experienced significant declines in verbal fluency over the study period (p = 0.02), while patients with right-sided stimulation demonstrated improvements (p < .001). There was no main effect of stimulation parameters (directional versus ring) on verbal fluency, memory, or inhibition, but there was a three-way interaction between time, stimulation parameters, and hemisphere on inhibition, such that left STN DBS patients receiving ring stimulation completed the inhibition trial faster (p = 0.035). After surgery, right STN DBS patients displayed faster inhibition times than patients with left implants (p = 0.015).

Declines in verbal fluency after bilateral stimulation are the most commonly reported cognitive sequalae of DBS for movement disorders. Here we found group level declines in verbal fluency after unilateral left STN implants, but not right STN DBS up to 6 months after surgery. Patients with right hemisphere implants displayed improvements in verbal fluency. Compared to bilateral DBS, unilateral DBS surgery, particularly in the right hemisphere, is likely a modifiable risk factor for verbal fluency declines in patients with Parkinson’s disease.