During the “DBS Canada Day” symposium held in Toronto July 4-5, 2014, the scientific committee invited experts to discuss three main questions on target selection for deep brain stimulation (DBS) of patients with Parkinson’s disease (PD). First, is the subthalamic nucleus (STN) or the globus pallidus internus (GPi) the ideal target? In summary, both targets are equally effective in improving the motor symptoms of PD. STN allows a greater medications reduction, while GPi exerts a direct antidyskinetic effect. Second, are there further potential targets? Ventral intermediate nucleus DBS has significant long-term benefit for tremor control but insufficiently addresses other motor features of PD. DBS in the posterior subthalamic area also reduces tremor. The pedunculopontine nucleus remains an investigational target. Third, should DBS for PD be performed unilaterally, bilaterally or staged? Unilateral STN DBS can be proposed to asymmetric patients. There is no evidence that a staged bilateral approach reduces the incidence of DBS-related adverse events.

Objective: Prospective memory (PM) is a cognitive function defined as the ability to perform an intention at an appropriate moment in the future. In the aging population, PM is essential for maintaining independent daily living. Introduced as a simple and quick way to assess PM in clinical settings, the envelope task has to date received very limited empirical and practical interest. Methods: The present study investigated the task’s clinical utility in detecting PM impairment in a sample composed of 49 healthy older adults (OA), 41 patients with Alzheimer’s disease, and 64 individuals with amnestic and nonamnestic mild cognitive impairment (MCI) of heterogeneous etiology: 17 of idiopathic nature, 20 presenting an idiopathic rapid-eye movement sleep behaviour disorder, and 27 patients diagnosed with idiopathic Parkinson’s disease. Results: The envelope task was highly sensitive and specific in discriminating Alzheimer’s disease patients from OA. Although it was specific in distinguishing MCI individuals from OA, its sensitivity was modest, especially in patients presenting a nonamnestic MCI subtype. Conclusions: Given its high specificity and simple low-cost administration procedure, the envelope task is a promising instrument for clinicians who seek to rapidly assess PM impairment in their daily practice.

Objective: Hyperfamiliarity is a phenomenon where new stimuli are perceived as familiar. Previous studies have demonstrated familiarity disorder in mild cognitive impairment (MCI), but mostly from the perspective of a neuropsychological approach, and the exact correlation of MCI aetiologies with the phenomenon remains uncertain. Based on current evidence suggesting a frontal-subcortical pathway contributing to familiarity processing, we hypothesize that individuals with a vascular aetiology of MCI will likely suffer more familiarity deficits. This study aims to examine the real-life hyperfamiliarity symptoms in amnestic versus vascular MCI. Methods: Informants of 11 amnestic and 9 vascular cognitive impairment patients were interviewed about the frequency of hyperfamiliarity symptoms in the previous month. MRI brain images of vascular cognitive impairment patients were analysed as well. Results: Patients with vascular cognitive impairment with no dementia (VCIND) showed a significantly higher frequency of hyperfamiliarity for people but not places or objects. Within VCIND patients, overall basal ganglia hyperintensities, particularly in the putamen, were found to significantly correlate to hyperfamiliarity. Conclusions: Patients with VCIND suffer more real-life hyperfamiliarity during people recognition compared to patients with amnestic mild cognitive impairment (aMCI), despite a comparative global decline in cognitive. This is likely due to impaired memory retrieval and matching processes resulting from subcortical ischaemic lesions.

Objectives: To summarize the clinical characteristics and outcomes of pediatric sports-related concussion (SRC) patients who were evaluated and managed at a multidisciplinary pediatric concussion program and examine the healthcare resources and personnel required to meet the needs of this patient population. Methods: We conducted a retrospective review of all pediatric SRC patients referred to the Pan Am Concussion Program from September 1st, 2013 to May 25th, 2015. Initial assessments and diagnoses were carried out by a single neurosurgeon. Return-to-Play decision-making was carried out by the multidisciplinary team. Results: 604 patients, including 423 pediatric SRC patients were evaluated at the Pan Am Concussion Program during the study period. The mean age of study patients was 14.30 years (SD: 2.32, range 7-19 years); 252 (59.57%) were males. Hockey (182; 43.03%) and soccer (60; 14.18%) were the most commonly played sports at the time of injury. Overall, 294 (69.50%) of SRC patients met the clinical criteria for concussion recovery, while 75 (17.73%) were lost to follow-up, and 53 (12.53%) remained in active treatment at the end of the study period. The median duration of symptoms among the 261 acute SRC patients with complete follow-up was 23 days (IQR: 15, 36). Overall, 25.30% of pediatric SRC patients underwent at least one diagnostic imaging test and 32.62% received referral to another member of our multidisciplinary clinical team. Conclusion: Comprehensive care of pediatric SRC patients requires access to appropriate diagnostic resources and the multidisciplinary collaboration of experts with national and provincially-recognized training in TBI.

Background: Tuberous sclerosis complex (TSC) is a neurocutaneous disorder with a wide spectrum of manifestations. Recent consensus recommendations stress the importance of multidisciplinary management of children with TSC. The objective of this study was to examine the manifestations of TSC at a large referral centre to determine the care needs of this population. Methods: A retrospective, systematic chart review was performed of children with TSC managed at British Columbia Children’s Hospital. Patients were identified through epilepsy and clinical neurophysiology databases. Results: The study population comprised 81 patients, born between 1987 and 2014, who were a median of 10 years (range, 0.2-23.2) at most recent follow-up. Epilepsy occurred in 91% of patients, including 32% with a history of infantile spasms. Nineteen patients underwent epilepsy surgery, nine (47%) of whom were seizure-free at most recent follow-up. Overall, 61% of epilepsy patients had been seizure-free for at least 1 year at the time of last follow-up. Neuropsychiatric disorders were diagnosed in 49% of children, with autism (25%), attention deficit hyperactivity order (19%) and anxiety (16%) being the most common. Cardiac rhabdomyomata occurred in 35% of children and renal angiomyolipomas were seen in 43%. A total of 91% had skin manifestations. Conclusion: This study outlines the multisystem manifestations of TSC, observed through a large pediatric referral center. Epilepsy and neuropsychiatric disorders are the major source of morbidity in this age group and provide many challenges to the treating clinician. Because a subset of the study population is still quite young, the prevalence of neuropsychiatric disorders is likely underestimated.

Objective: To explore the relationship between migraine and anxiety disorders, mood disorders and perceived mental health in a population-based sample of adolescents. Methods: The Canadian Community Health Survey (CCHS) is a cross-sectional health survey sampling a nationally representative group of Canadians. In this observational study, data on all 61,375 participants aged 12-19 years from six survey cycles were analyzed. The relationships between self-reported migraine, perceived mental health, and mood/anxiety disorders were modeled using univariate and multivariate logistic regression. The migraine–depression association was also explored in a subset of participants using the Composite International Diagnostic Interview–Short Form (CIDI–SF) depression scale. Results: The odds of migraine were higher among those with mood disorders, with the strongest association in 2011-2 (adjusted odds ratio [aOR]=4.59; 95% confidence interval [CI95%]=3.44-6.12), and the weakest in 2009-10 (aOR=3.06, CI95%=2.06-4.55). The migraine–mood disorders association was also significant throughout all cycles, other than 2011-2, when the CIDI–SF depression scale was employed. The odds of migraine were higher among those with anxiety disorders, with the strongest association in 2011-2 (aOR=4.21, CI95%=3.31-5.35) and the weakest in 2010 (aOR=1.87, CI95%=1.10-3.37). The inverse association between high perceived mental health and the odds of migraine was observed in all CCHS cycles, with the strongest association in 2011-2 (aOR=0.58, CI95%=0.48-0.69) and the weakest in 2003-4 (aOR=0.75, CI95%=0.62-0.91). Conclusions: This study provides evidence, derived from a large population-based sample of adolescents, for a link between migraine and mood/anxiety disorders.

Background: Despite the critical role played by neurosurgeons in performing radiosurgery, neurosurgery residents in Canada have limited exposure to radiosurgery during their training. A survey of neurosurgery residents and faculty along with radiation oncology faculty was conducted to analyze perspectives regarding incorporating formal radiosurgery training into the neurosurgery residency curriculum Methods: An online survey platform was employed. Descriptive statistics were used to summarize center and respondent characteristics. Categorical variables were compared using odds ratios and corresponding 95% confidence intervals. The chi-squared test was utilized to assess statistical significance. A value of p<0.05 was considered significant Results: The response rate was 31% (119/381); 87% (102/119) of respondents were from the neurosurgical specialty and 13% (17/119) from radiation oncology. Some 46% of residents (18/40) were “very uncomfortable” with radiosurgery techniques, and 57% of faculty (42/73) believed that dedicated radiosurgery training would be beneficial though impractical. No respondents felt that “no training” would be beneficial. A total of 46% of residents (19/41) felt that this training would be beneficial and that time should be taken away from other rotations, if needed, while 58% of faculty (42/73) and 75% (28/41) of residents believed that either 1 or 1-3 months of time dedicated to training in radiosurgery would suffice Conclusions: Canadian neurosurgeons are actively involved in radiosurgery. Despite residents anticipating a greater role for radiosurgery in their future, they are uncomfortable with the practice. With the indications for radiosurgery expanding, this training gap can have serious adverse consequences for patients. Considerations regarding the incorporation and optimal duration of dedicated radiosurgery training into the Canadian neurosurgery residency curriculum are necessary.

Background: Functional magnetic resonance imaging (fMRI) is being increasingly used for the preoperative evaluation of patients with brain tumours. Methods: The study is a retrospective chart review investigating the use of clinical fMRI from 2002 through 2013 in the preoperative evaluation of brain tumour patients. Baseline demographic and clinical data were collected. The specific fMRI protocols used for each patient were recorded. Results: Sixty patients were identified over the 12-year period. The tumour types most commonly investigated were high-grade glioma (World Health Organization grade III or IV), low-grade glioma (World Health Organization grade II), and meningioma. Most common presenting symptoms were seizures (69.6%), language deficits (23.2%), and headache (19.6%). There was a predominance of left hemispheric lesions investigated with fMRI (76.8% vs 23.2% for right). The most commonly involved lobes were frontal (64.3%), temporal (33.9%), parietal (21.4%), and insular (7.1%). The most common fMRI paradigms were language (83.9%), motor (75.0%), sensory (16.1%), and memory (10.7%). The majority of patients ultimately underwent a craniotomy (75.0%), whereas smaller groups underwent stereotactic biopsy (8.9%) and nonsurgical management (16.1%). Time from request for fMRI to actual fMRI acquisition was 3.1±2.3 weeks. Time from fMRI acquisition to intervention was 4.9±5.5 weeks. Conclusions: We have characterized patient demographics in a retrospective single-surgeon cohort undergoing preoperative clinical fMRI at a Canadian centre. Our experience suggests an acceptable wait time from scan request to scan completion/analysis and from scan to intervention.

Background: Our study evaluated the perioperative quality of life (QoL) in Cushing’s disease (CD) patients, along with correlations between patient variables and cure rate. Methods: The 36-item Short-Form Health Survey (SF)-36 questionnaire was used to assess perioperative QoL. Patients completed one survey preoperatively and two surveys postoperatively. Retrospective chart review was conducted to collect SF-36 data as well as examine variables including: age, hospital stay, size of tumour, pathological diagnosis, timing of cure, and complication rates. Statistical analysis was conducted on the scores reported by the SF-36, and were compared with the normal Canadian population values, and to a sample of QoL from nonfunctioning pituitary tumour patients. This project was approved by University of British Columbia Research Ethics Board #H15-01572. Results: In general, CD patients have relatively poor QoL that does improve as expected when cured, but not quite to normal levels. Factors associated with cure included presence of macroadenoma, confirmatory pathology, and patient age. Postoperative timing of cure appears to affect the durability of cure, with an immediate cure having a higher durability rate than delayed cure. Most recurrences occurred within 10 months postoperatively. Conclusions: This review of the perioperative QoL in CD helps to illustrate how QoL changes throughout the treatment process, how QoL compares to normal Canadian population levels, and how QoL compares to patients with nonfunctioning pituitary adenomas. As treatment outcome has such a high impact on QoL, the variables identified in this study will help to better inform patients about the treatment course.

Objective: Cervical spine clinical adjacent segment pathology (CASP) has a reported 3% annual incidence and 26% ten-year prevalence. Its pathophysiology remains controversial, whether due to mechanical stress of a fusion segment on adjacent levels or due to patient propensity to develop progressive degenerative change. We investigate this relationship by comparing prevalence of CASP in traumatic and spondylotic patient cohorts. Method: A retrospective review of traumatic cervical spine fusion cases performed by the local group of neurosurgeons from 2004-2008 was completed. Surgery for CASP and presence of radiological adjacent segment pathology (RASP) were identified by telephone and electronic medical record (EMR) review, and compared to those in patients having elective cervical fusion for degenerative disease. Results: There was a higher proportion of males (50/100 vs. 37/46, p<0.001) in the traumatic group. Median age between groups was not significantly different (47 years in the trauma cohort, 50 years in the degenerative cohort; p>0.05). Mean follow-up times were different (6.4 years in the trauma group, 7.1 years in the degenerative group; p<0.01), although this was not thought to be clinically significant. The degenerative group was found to have a significantly higher reoperation rate for CASP (10/100 vs. 0/46, p=0.031, Fisher’s Exact Test), and rate of RASP (20/100 vs. 1/32, p=0.025) Conclusion: This is the only cohort study to our knowledge comparing surgery for CASP in trauma patients to those with degenerative disease. A higher rate of repeat surgery in degenerative disease patients was found. This suggests that CASP is more related to patient factors predisposing to progressive degenerative disease and not increased mechanical stress.

Background: Spinal cord stimulation (SCS) is a well-established treatment for chronic neuropathic pain in the lower limbs. Upper limb pain comprises a significant proportion of neuropathic pain patients, but is often difficult to target specifically and consistently with paresthesias. We hypothesized that the use of dorsal nerve root stimulation (DNRS), as an option along with SCS, would help us better relieve pain in these patients. Methods: All 35 patients trialed with spinal stimulation for upper limb pain between July 1, 2011, and October 31, 2013, were included. We performed permanent implantation in 23/35 patients based on a visual analogue scale pain score decrease of ≥50% during trial stimulation. Results: Both the SCS and DNRS groups had significant improvements in average visual analogue scale pain scores at 12 months compared with baseline, and the majority of patients in both groups obtained ≥50% pain relief. The majority of patients in both groups were able to reduce their opioid use, and on average had improvements in Short Form-36 quality of life scores. Complication rates did not differ significantly between the two groups. Conclusions: Treatment with SCS or DNRS provides meaningful long-term relief of chronic neuropathic pain in the upper limbs.

Background: Pathophysiological mechanisms that contribute to neurodegeneration in Amyotrophic Lateral Sclerosis (ALS) include oxidative stress and inflammation. We conducted a preliminary study to explore these mechanisms, to discuss their link in ALS, and to determine the feasibility of incorporating this combined analysis into current biomarkers research. Methods: We enrolled 10 ALS patients and 10 controls. We measured the activities of glutathione peroxidase, glutathione reductase, superoxyde dismutase (SOD), and the levels of serum total antioxidant status (TAS), malondialdehyde (MDA), 8-hydroxy-2’-deoxyguanosine (8-OHdG), and glutathione status (e.g. glutathione disulfide, GSSG/reduced glutathione, GSH). We analysed the concentrations of homocysteine, several cytokines, vitamins and metals by standard methods used in routine practice. Results: There was a significant decrease in TAS levels (p=0.027) and increase in 8-OHdG (p=0.014) and MDA (p=0.011) levels in ALS patients. We also observed a significantly higher GSSG/GSH ratio (p=0.022), and IL-6 (p=0.0079) and IL-8 (p=0.009) concentrations in ALS patients. Correlations were found between biological and clinical markers (homosysteine vs. clinical status at diagnosis, p=0.02) and between some biological markers such as IL-6 vs. GSSG/GSH (p=0.045) or SOD activity (p=0.017). Conclusion: We confirmed the systemic alteration of both the redox and the inflammation status in ALS patients, and we observed a link with some clinical parameters. These promising results encourage us to pursue this study with collection of combined oxidative stress and inflammatory markers.

Background: Sepsis is a systemic response to infection that can affect brain function by inducing resident cells (including astrocytes and microglia) to generate brain chemokines and cytokines. However, there are few studies on the human brain. Since this information may shed further light on pathogenesis, our study objective was to measure the expression of 36 chemokines and cytokines in autopsied brain from 3 cases of sepsis and 10 controls, and to relate this to astrocyte and microglial activation. Methods: The right frontal pole was removed at autopsy and chemokine and cytokine expression measured by multiplexed enzyme-linked immunosorbent assay and real-time quantitative polymerase chain reaction (qPCR). Immunohistochemistry and image analysis were carried out to determine the expression of glial fibrillary acidic protein (GFAP), a marker of activated astrocytes, and CD68 and CD45, markers of activated microglial cells. Results: Concentrations of the chemokines CXCL8, CXCL10, CXCL12, CCL13 and CCL22 were increased in pooled data from the three cases of sepsis (p<0.05); however, their messenger RNA (mRNA) expression was unaltered. CXCL13, CXCL1, CXCL2, CCL1, CCL2, CCL8, CCL20, (interleukin) IL-16, IL-1β and (tumour necrosis factor) TNF concentrations showed increases in two of three sepsis cases. Additionally, individual sepsis cases showed increases in mRNA expression for HDAC (histone deacetylase) 6 and EIF (eukaryotic translation initiation factor) 4A2. Brain GFAP expression was significantly increased (p<0.05) in pooled data from the three sepsis cases. Individual sepsis cases showed increases in CD68 or CD45 expression. Conclusions: These expression patterns add to our understanding of the pathogenesis of sepsis and its effects on the brain.

Decompressive craniectomy (DC) after devastating brain injury (DBI) may influence the manner in which patients die, having implications for end-of-life care and organ donation. We performed a retrospective review of deaths following a non-traumatic DBI between 2008 and 2012. 160 patients were reviewed; 26 were treated with DC and 134 received standard care. There was no relationship between DC and mechanism of death, (OR 1.18, 95% CI 0.44-3.17). Prospective studies are required to confirm these preliminary finding. DC studies should report the mechanism of death.

Patterns of practice for management of cerebral venous thrombosis in Canada are unknown. We surveyed Canadian neurologists and hematologists regarding anticoagulation in cerebral venous thrombosis. The response rate was 28%, with 27 neurologists and 20 hematologists responding. We found that choice of first-line initial anticoagulation differed significantly between neurologists and hematologists, with 89% of neurologists favouring unfractionated heparin and hematologists’ preference split between unfractionated heparin (50%) and low-molecular-weight heparin (50%). Differences in patterns of practice likely reflect clinical equipoise.

Although the common carotid artery is the second most common site for extracranial carotid artery stenosis, complete symptomatic occlusion in the absence of devastating stroke is rare. We present a case of complete common carotid artery occlusion failing medical management and requiring endovascular intervention. The clinical presentation, diagnostic investigations, and management of complete carotid artery occlusions are discussed.