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Evaluating Mild Cognitive Impairment in Essential Tremor: How Many and Which Neuropsychological Tests?

Published online by Cambridge University Press:  10 October 2018

Tess E.K. Cersonsky ,
Sarah Morgan ,
Sarah Kellner ,
Daphne Robakis ,
Xinhua Liu ,
Edward D. Huey ,
Elan D. Louis  and
Stephanie Cosentino
Tess E.K. Cersonsky
Affiliation:
Division of Movement Disorders, Department of Neurology, Yale School of Medicine, Yale University, New Haven, Connecticut
Sarah Morgan
Affiliation:
Division of Movement Disorders, Department of Neurology, Yale School of Medicine, Yale University, New Haven, Connecticut
Sarah Kellner
Affiliation:
Division of Movement Disorders, Department of Neurology, Yale School of Medicine, Yale University, New Haven, Connecticut
Daphne Robakis
Affiliation:
Division of Movement Disorders, Department of Neurology, Yale School of Medicine, Yale University, New Haven, Connecticut
Xinhua Liu
Affiliation:
Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, New York
Edward D. Huey
Affiliation:
Department of Psychiatry, College of Physicians and Surgeons, Columbia University, New York, New York Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, New York
Elan D. Louis
Affiliation:
Division of Movement Disorders, Department of Neurology, Yale School of Medicine, Yale University, New Haven, Connecticut Department of Chronic Disease Epidemiology, Yale School of Public Health, Yale University, New Haven, Connecticut Center for Neuroepidemiology and Clinical Neurological Research, Yale School of Medicine, Yale University, New Haven, Connecticut
Stephanie Cosentino*
Affiliation:
Department of Neurology, College of Physicians and Surgeons, Columbia University, New York, New York Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, College of Physicians and Surgeons, Columbia University, New York, New York
*
Correspondence and reprint requests to: Stephanie Cosentino; Columbia University Medical Center, 630 West 168th Street; P&S Mailbox 16; NY, NY 10032; E-mail: sc2460@cumc.columbia.edu
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Abstract

Objectives: Essential tremor (ET) confers an increased risk for developing both amnestic and non-amnestic mild cognitive impairment (MCI). Yet, the optimal measures for detecting mild cognitive changes in individuals with this movement disorder have not been established. We sought to identify the cognitive domains and specific motor-free neuropsychological tests that are most sensitive to mild deficits in cognition as defined by a Clinical Dementia Rating (CDR) of 0.5, which is generally associated with a clinical diagnosis of MCI. Methods: A total of 196 ET subjects enrolled in a prospective, longitudinal, clinical-pathological study underwent an extensive motor-free neuropsychological test battery and were assigned a CDR score. Logistic regression analyses were performed to identify the neuropsychological tests which best identified individuals with CDR of 0.5 (mild deficits in cognition) versus 0 (normal cognition). Results: In regression models, we identified five tests in the domains of Memory and Executive Function which best discriminated subjects with CDR of 0.5 versus 0 (86.9% model classification accuracy). These tests were the California Verbal Learning Test II Total Recall, Logical Memory II, Verbal-Paired Associates I, Category Switching Fluency, and Color-Word Inhibition. Conclusions: Mild cognitive difficulty among ET subjects is best predicted by combined performance on five measures of memory and executive function. These results inform the nature of cognitive dysfunction in ET and the creation of a brief cognitive battery to assess patients with ET for cognitively driven dysfunction in life that could indicate the presence of MCI. (JINS, 2018, 24, 1084–1098)

Keywords

Movement disordersCognitionMental status and dementia testsMemory and learning testsMemoryExecutive function
Type
Regular Research
Information
Journal of the International Neuropsychological Society , Volume 24 , Issue 10 , November 2018 , pp. 1084 - 1098
Copyright
Copyright © The International Neuropsychological Society 2018 

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References

REFERENCES

Abner, E.L., Kryscio, R.J., Schmitt, F.A., Fardo, D.W., Moga, D.C., Ighodaro, E.T., Nelson, P.T. (2017). Outcomes after diagnosis of mild cognitive impairment in a large autopsy series. Annals of Neurology, 81(4), 549–559.Google Scholar
Aretouli, E., Okonkwo, O.C., Samek, J., & Brandt, J. (2011). The fate of the 0.5s: Predictors of 2-year outcome in mild cognitive impairment. Journal of the International Neuropsychological Society, 17(2), 277–288.Google Scholar
Benito-León, J., & Louis, E.D. (2013). Rate of cognitive decline during the premotor phase of ET: A prospective study. Neurology, 81, 60–66.Google Scholar
Benito-León, J., Louis, E.D., Romero, J., Hernández-Tamames, J., Manzanedo, E., Álvarez-Linera, J., Rocon, E. (2015). Altered functional connectivity in essential tremor: A resting-state fMRI study. Medicine, 94(49), e1936.Google Scholar
Benito-León, J., Louis, E.D., Bermejo-Pareja, F., & NEDICES Study Group. (2006a). Elderly-onset essential tremor is associated with dementia. Neurology, 66(10), 1500–1505.Google Scholar
Benito-León, J., Louis, E.D., Bermejo-Pareja, F., & NEDICES Study Group. (2006b). Population-based case-control study of cognitive function in essential tremor. Neurology, 66(1), 69–74.Google Scholar
Benito-León, J., Louis, E.D., Mitchell, A.J., & Bermejo-Pareja, F. (2011). Elderly-onset essential tremor and mild cognitive impairment: A population-based study (NEDICES). Journal of Alzheimer’s Disease, 23(4), 727–735. doi:10.3233/JAD-2011-101572 Google Scholar
Benton, A., & Van Allen, M. (1968). Impairment in facial recognition in patients with cerebral disease. Cortex, 4, 344–358. doi:10.1016/S0010-9452(68)80018-8 Google Scholar
Benton, A., des Hamsher, K., Rey, G., & Sivan, A. (1994). Multilingual Aphasia Examination (3rd ed.). Iowa City, IA: AJA Associates.Google Scholar
Benton, A., Sivan, A., des Hamsher, K., Varney, N., & Spreen, O. (1994). Contributions to neuropsychological assessment (2nd ed.). New York: Oxford University Press.Google Scholar
Bermejo-Pareja, F., Louis, E.D., Benito-León, J., & NEDICES Study Group. (2007). Risk of incident dementia in essential tremor: A population-based study. Movement Disorders, 22(11), 1573–1580.Google Scholar
Bourke, J., Castleden, C., Stephen, R., & Dennis, M. (1995). A comparison of clock and pentagon drawing in Alzheimer’s disease. Geriatric Psychiatry, 10(8), 703–705.Google Scholar
Chapman, K., Bing-Canar, H., Alosco, M., Steinberg, E., Martin, B., Chaisson, C., Stern, R. (2016). Mini Mental State Examination and Logical Memory scores for entry into Alzheimer’s disease trials. Alzheimer’s Research and Therapy, 8, 9. doi:10.1186/s13195-016-0176-z Google Scholar
Clark, D.G., Kapur, P., Geldmacher, D.S., Brockington, J.C., Harrell, L., DeRamus, T.P., Marson, D.C. (2014). Latent information in fluency lists predicts functional decline in persons at risk for Alzheimer disease. Cortex, 55, 202–218.Google Scholar
Collins, K., Rohl, B., Morgan, S., Huey, E., Louis, E., & Cosentino, S. (2017). Mild cognitive impairment subtypes in a cohort of elderly essential tremor cases. Journal of the International Neuropsychological Society, 23, 1–10. doi:10.1017/S1355617717000170 Google Scholar
Cummings, J.L., Mega, M., Gray, K., Rosenberg-Thompson, S., Carusi, D.A., & Gornbein, J. (1994). The Neuropsychiatric Inventory: Comprehensive assessment of psychopathology in dementia. Neurology, 44, 2308–2314.Google Scholar
Delis, D., Kaplan, E., & Kramer, J. (2001). Delis Kaplan Executive Function System (DKEFS) Examiner’s Manual. San Antonio, TX: Pearson.Google Scholar
Delis, D., Kramer, J., Kaplan, E., & Ober, B. (2000). California Verbal Learning Test - second edition (CVLT-II). San Antonio, TX: Psychological Corporation.Google Scholar
Deuschl, G., Wenzelburger, R., Loffler, K., Raethjen, J., & Stolze, H. (2000). Essential Tremor and cerebellar dysfunction clinical and kinematic analysis of intention tremor. Brain, 123, 1568–1580.Google Scholar
Dogu, O., Sevim, S., Camdeviren, H., Sasmaz, T., Bugdayci, R., Aral, M., Louis, E.D. (2003). Prevalence of essential tremor: Door-to-door neurologic exams in Mersin Province, Turkey. Neurology, 61(12), 1804–1806.Google Scholar
Folstein, M.F., Folstein, S.E., & McHugh, P.R. (1975). “Mini-mental state”. A practical method for grading the cognitive state of patients for the clinician. Journal of Psychiatric Research, 12(3), 189–198.Google Scholar
Frisina, P., Tse, W., Halbig, T., & Libow, L. (2009). The pattern of cognitive-functional decline in elderly essential tremor patients: An exporatory-comparative study with Parkinson’s and Alzheimer’s disease patients. Journal of American Medical Directors Association, 10, 238–242.Google Scholar
Gainotti, G., Quaranta, D., & Vita, M. (2014). Neuropsychological predictors of conversion from mild cognitive impairment to Alzheimer’s disease. Journal of Alzheimer’s Disease, 38(3), 481–495. doi:10.3233/JAD-130881 Google Scholar
Ganguli, M., Bilt, J.V., Lee, C.W., Snitz, B.E., Chang, C.C., Loewenstein, D.A., & Saxton, J.A. (2010). Cognitive test performance predicts change in functional status at the population level: The MYHAT Project. Journal of the International Neuropsychological Society, 761–770.Google Scholar
Gasparini, J., Bonifati, V., Fabrizio, E., Fabbrini, G., Brusa, L., Lenzi, G.L., & Meco, G. (2001). Frontal lobe dysfunction in essential tremor: A preliminary study. Journal of Neurology, 248, 399–402.Google Scholar
Gauthier, S., Reisberg, B., Zaudig, M., Peterson, R.C., Ritchie, K., Broich, K., Hampel, H. (2006). Mild cognitive impairment. The Lancet, 367(9518), 1262–1270.Google Scholar
Goldman, J., & Litvan, I. (2012). Mild cognitive impairment in Parkinson’s disease. Minerva Medica, 102(6), 441–459.Google Scholar
Goldman, J., Holden, S., Ouyang, B., Bernard, B., Goetz, C.G., & Stebbins, G.T. (2015). Diagnosing PD-MCI by MDS Task Force criteria: How many and which neuropsychological tests? Movement Disorders, 30, 402–406.Google Scholar
Goodglass, H., & Kaplan, E. (1983). Clock Drawing Test: Assessment of aphasia and related disorders (Vol. 2). Philadelphia: Lea and Febiger.Google Scholar
Grober, E., & Buschke, H. (2009). Genuine memory deficits in dementia. Developmental Neuropsychology, 3, 13–36.Google Scholar
Higginson, C., Wheelock, V., Levine, D., King, D., Pappas, C., & Sigvardt, K. (2008). Cognitive deficits in essential tremor consistent with frontosubcortical dysfunction. Journal of Clinical and Experimental Neuropsychology, 30, 760–765.Google Scholar
Holster, J., Corsun-Ascher, C., Olivier, T., & Golden, C. (2012). An evaluation of the CVLT-II substitution on the WMS-IV amongst a mixed clinical and nonclinical population. Archives of Assessment Psychology, 2(1).Google Scholar
Janicki, S.C., Cosentino, S., & Louis, E.D. (2013). The cognitive side of essential tremor: What are the therapeutic implications? Therapeutic Advances in Neurological Disorders, 6, 353–368.Google Scholar
Josephs, K.A., Whitwell, J.L., Weigand, S.D., Senjem, M.L., Boeve, B.F., Knopman, D.S., Petersen, R.C. (2011). Predicting functional decline in behavioural variant frontotemporal dementia. Brain, 134, 432–448.Google Scholar
Kaplan, E., Goodglass, H., & Weintraub, S. (1983). Boston Naming Test. Philadelphia, PA: Lea & Febiger.Google Scholar
Kertesz, A., Davidson, W., & Fox, H. (1983). Frontal behavioral inventory: Diagnostic criteria for frontal lobe dementia. Canadian Journal of Neurological Sciences, 24(1), 29–36.Google Scholar
Kim, J.S., Song, I.U., Shim, Y.S., Park, J.W., Yoo, J.Y., Kim, Y.I., & Lee, K.S. (2009). Cognitive impairment in essential tremor without dementia. Journal of Clinical Neurology, 5, 81–84.Google Scholar
Koepsell, T.D., Gill, D.P., & Chen, B. (2013). Stability of clinical etiologic diagnosis in dementia and mild cognitive impairment: Results from a multi-center longitudinal database. American Journal of Alzheimer’s Disease & Other Dementias, 28(8), 750–758.Google Scholar
Koziol, L.F., & Budding, D.E. (2009). Familiarity and novelty - Evaluating the frontostriatal system. In Subcortical structures and cognition: Implications for neuropsychological assessment (pp. 233–234). New York: Springer.Google Scholar
Lafo, J.A., Jones, J.D., Okun, M.S., Bauer, R.M., Price, C.C., & Bowers, D. (2015). Memory similarities between essential tremor and Parkinson’s disease: A final common pathway? Clinical Neuropsychology, 29(7), 985–1001. doi:10.1080/13854046.2015.1118553 Google Scholar
Lawton, M., & Brody, E. (1969). Assessment of older people: Self-maintaining and isntrumental activities of daily living. The Gerontologist, 9(3), 179–186.Google Scholar
Litvan, I., Goldman, J.G., Tröster, A.I., Schmand, B.A., Weintraub, D., Petersen, R.C., Emre, M. (2012). Diagnostic criteria for mild cognitive impairment in Parkinson’s disease: Movement Disorder Society Task Force Guidelines. Movement Disorders, 27(3), 349–356.Google Scholar
Lombardi, W., Woolston, D.J., Roberts, J.W., & Gross, R.E. (2001). Cognitive deficits in patients with essential tremor. Neurology, 57, 785–790.Google Scholar
Louis, E.D. (2009). The essential tremors: A family of neurodegenerative disorders? Archives of Neurology, 66, 1202–1208.Google Scholar
Louis, E.D. (2010). Functional correlates of lower cognitive test scores in essential tremor. Movement Disorders, 25, 481–499.Google Scholar
Louis, E.D. (2014a). Re-thinking the biology of essential tremor: From models to morphology. Parkinsonism & Related Disorders, 20(Suppl. 1), S88–S93.Google Scholar
Louis, E.D., & Rao, A.K. (2014b). Tandem gait performance in essential tremor patients correlates with cognitive function. Cerebellum & Ataxias, 1, 19.Google Scholar
Louis, E.D., Benito-León, J., Vega-Quiroga, S., Bermejo-Pareja, F., & NEDICES Study Group. (2010). Cognitive and motor functional activity in non-demented community-dwelling essential tremor cases. Journal of Neurology, Neurosurgery, and Psychiatry, 81(9), 997–1001.Google Scholar
Louis, E.D., Collins, K., Rohl, B., Morgan, S., Robakis, D., Huey, E.D., & Cosentino, S. (2016). Self-reported physical activity in essential tremor: Relationship with tremor, balance, and cognitive function. Journal of the Neurological Sciences, 336, 240–245.Google Scholar
Louis, E.D., Ford, B., & Bismuth, B. (1998). Reliability between two observers using a protocol for diagnosign essential tremor. Movement Disorders, 13, 287–293.Google Scholar
Louis, E.D., Kellner, S., Morgan, S., Collins, K., Rohl, B., Huey, E.D., & Cosentino, S. (2017). Cognitive dysfunction is associated with greater imbalance and falls in essential tremor. Frontiers in Neurology, 8, 154.Google Scholar
Louis, E.D., Ottman, R., & Hauser, W.A. (1998). How common is the most common adult movement disorder? estimates of the prevalence of essential tremor throughout the world. Movement Disorders, 13(1), 5–10.Google Scholar
Louis, E.D., Ottman, R., Ford, B., Pullman, S., Martinez, M., Fahn, S., & Hauser, W.A. (1997). The Washington Height-Inwood Genetic Study of Essential Tremor: Methodologic issues in essential-tremor research. Neuroepidemiology, 16, 668–673.Google Scholar
Louis, E.D., Wendt, K.J., Albert, S.M., Pullman, S.L., Yu, Q., & Andrews, H. (1999). Validity of a performance-based test of function in essential tremor. Archives of Neurology, 56, 841–846.Google Scholar
Mameli, F., Tomasini, E., Scelzo, E., Fumagalli, M., Ferrucci, R., Bertolasi, L., & Priori, A. (2013). Lies tell the truth about cognitive dysfunction in essential tremor: An experimental deception study with the guilty knowledge task. Journal of Neurology, Neurosurgery, and Psychiatry, 84(9), 1008–1013.Google Scholar
Marras, C., Armstrong, M., Meaney, C., Fox, S., Rothberg, B., Reginold, W., Duff-Canning, S. (2013). Measuring mild cognitive impairment in patients with Parkinson’s disease. Movement Disorders, 28(5), 626–633. doi:10.1002/mds.25426 Google Scholar
McCrae, R., & Costa, P. (2010). NEO inventories for the NEO Personality Inventory-3 (NEO-PI-3), NEO Five-Factor Inventory-3 (NEO-FFI-3), NEO Personality Inventory-Revised (NEO PI-R): Professional manual. Lutz, FL: PAR.Google Scholar
Middleton, F., & Strick, P. (2000a). Basal ganglia and cerebellar loops: Motor and cognitive circuits. Brain Research. Brain Research Reviews, 31, 236–250.Google Scholar
Middleton, F., & Strick, P. (2000b). Basal galgia output and cognition: Evidence from anatomical, behavioral, and clinical studies. Brain Cognition, 42, 183–200.Google Scholar
Middleton, F., & Strick, P. (2001). Cerebellar projections to the prefrontal cortex of the primate. Journal of Neuroscience, 21, 700–712.Google Scholar
Miller, J.B., Axelrod, B.N., Rapport, L.J., Hanks, R.A., Bashem, J.R., & Schutte, C. (2012). Substitution of California Verbal Learning Test, second edition for Verbal Paired Associates on the Wechsler Memory Scale, fourth edition. The Clinical Neuropsychologist, 26(4), 599–608. doi:10.1080/13854046.2012.677478 Google Scholar
Montgomery, E., Baker, K., Lyons, K., & Koller, W. (2000). Motor initiation and execution in essential tremor and Parkinson’s disease. Movement Disorders, 15, 511–515.Google Scholar
Morris, J. (1993). The clinical dementia rating (CDR): Current version and scoring rules. Neurology, 43(11), 2412–2414.Google Scholar
Morris, J. (1997). Clinical dementia rating: A reliable and valid diagnostic and staging measure for dementia of the Alzheimer type. International Psychogeriatrics, 9(Suppl. 1), 173–176; discussion 177–178.Google Scholar
Nasreddine, Z., Phillips, N., Bedirian, V., Charbonneau, S., Whitehead, V., Collin, I., & Chertkow, H. (2005). The Montreal Cognitive Assessment, MoCA: A brief screening tool for mild cognitive impairment. Journal of the American Geriatrics Society, 53(4), 695–699. doi:10.11/j.1532-5415.2005.5322.x Google Scholar
Passamonti, L., Novellino, F., Cerasa, A., Chiriaco, C., Rocca, F., Matina, M., Quattrone, A. (2011). Altered cortical-cerebellar circuits during verbal working memory in essential tremor. Brain, 134, 2274–2786.Google Scholar
Peterson, R. (1999). Mild cognitive impairment: Clinical characterization and outcome. Archives of Neurology, 56(3), 303–308.Google Scholar
Puertas-Martin, V., Villarejo-Galende, A., Fernandez-Guinea, S., Romero, J., Louis, E.D., & Benito-Leon, J. (2016). A comparison study of cognitive and neuropsychiatric features of essential tremor and Parkinson’s disease. Tremor and Other Hyperkinetic Movements, 6, 431. doi:10.7916/D86H4HRN Google Scholar
Rao, A.K., Gillman, A., & Louis, E.D. (2014). Balance confidence and falls in nondemented essential tremor patients: The role of cognition. Archives of Physical Medicine and Rehabilitation, 95(10), 1832–1837.Google Scholar
Rao, A.K., Uddin, J., Gillman, A., & Louis, E.D. (2013). Cognitive motor interference during dual-task gait in essential tremor. Gait & Posture, 38(3), 403–409.Google Scholar
Reitan, R.M., & Wolfson, D. (1993). The Trail-making Test (Vol. 2). Tucson, AZ: Neuropsychology Press.Google Scholar
Sahin, H., Terzi, M., Ucak, S., Yapici, O., Basoglu, T., & Onar, M. (2006). Frontal functions in young patients with essential tremor: A case comparison study. Journal of Neuropsychiatry and Clinical Neuroscience, 18, 64–72.Google Scholar
Sanchez-Ferraro, A., Benito-Leon, J., Louis, E., Cantador, I., Hernandez-Gallego, J., Puertas-Martin, V., & Bermejo-Pareja, F. (2017). Cognition in non-demented Parkinson’s disease vs essential tremor: A population-based study. Acta Neurologica Scandanavia, 136(5), 393–400. doi:10.1111/ane.12752 Google Scholar
Sinoff, G., & Badarny, S. (2014). Mild cognitive impairment, dementia, and affective disorders in essential tremor: A prospective study. Tremor and Other Hyperkinetic Movements (New York, N.Y.), 4, 227.Google Scholar
Smith, A. (1982). Symbol Digit Modalities Test. Los Angeles: Western Psychological Services.Google Scholar
Thawani, S.P., Schupf, N., & Louis, E.D. (2009). Essential tremor is associated with dementia: Prospective population-based study in New York. Neurology, 73(8), 621–625.Google Scholar
Thiruselvam, I., Vogt, E.M., & Hoelzle, J.B. (2015). The interchangeability of CVLT-II and WMS-IV Verbal Paired Associates Scores: A slightly different story. Archives of Clinical Neuropsychology, 30(3), 248–255.Google Scholar
Traykov, L., Rigaud, A.S., Cesaro, P., & Boller, F. (2007). Le déficit neuropsychologique dans la maladie d’Alzheimer débutante. L’Encéphale, 33(3), 310–316. doi:ENC-6-2007-33-3-0013-7006-101019-200730033 Google Scholar
Tremont, G., Halpert, S., Javorsky, D., & Stern, R. (2000). Differential impact of executive dysfunction on verbal list learning and story recall. Clinical Neuropsychology, 14(3), 295–302. doi:10.1076/1385-4046(200008)14:3;1-P;FT295 Google Scholar
Tröster, A.I., Woods, S.P., Fields, J.A., Lyons, K.E., Pahwa, R., Higginson, C.I., & Koller, W.C. (2002). Neuropsychological deficits in essential tremor: An expression of cerebello-thalamo-cortical pathophysiology? European Journal of Neurology, 9(2), 143–151.Google Scholar
Vendrell, P., Junqué, C., Pujol, J., Jurado, M., Molet, J., & Grafman, J. (1995). The role of prefrontal regions in the Stroop task. Neuropsychologia, 33(3), 341–352. doi:10.1016/0028-3932(94)00116-7 Google Scholar
Watson, G., & Leverenz, J. (2010). Profile of cognitive impairment in Parkinson disease. Brain Pathology, 20(3), 640–645. doi:10.1111/j.1750-3639.2010.00373.x Google Scholar
Wechsler, D. (1987). Wechsler Memory Scale - Revised. San Antonio, TX: Psychological Corporation.Google Scholar
Wechsler, D. (1997). Manual for the Wechsler Adult Intelligence Scale (3rd ed.). San Antonio, TX: The Psychological Corporation.Google Scholar
Wechsler, D. (2001). Wechsler Individual Achievement Test (2nd ed.). San Antonio, TX: Harcourt Assessment.Google Scholar
Wechsler, D. (2008). Wechsler Memory Scale (4th ed.). San Antonio, TX: Pearson.Google Scholar
Williams, B.R., & Donovick, P.J. (2008). Questioning the rule of thumb: Can verbal tasks be administered during the CVLT-II delay interval? The Clinical Neuropsychologist, 22(5), 807–812.Google Scholar
Williams, B.R., Sullivan, S.K., Morra, L.F., Williams, J.R., & Donovick, P.J. (2014). The similar effects of verbal and non-verbal intervening tasks on word recall in an elderly population. The Clinical Neuropsychologist, 28(3), 505–513.Google Scholar
Williams, M.M., Roe, C.M., & Morris, J.C. (2009). Stability of the Clinical Dementia Rating: 1979–2007. Achives of Neurology, 66(6), 773–777.Google Scholar
Wilson, R.S., Gilley, D.W., Bennett, D.A., Beckett, L.A., & Evans, D.A. (2000). Person-specific paths of cognitive decline in Alzheimer’s disease and their relation to age. Psychology and Aging, 15(1), 18–28.Google Scholar
Yesavage, J., Poon, L., Crook, T., Davis, K., Eisdorfer, C., Gurland, B., Thompson, L. (1986). Handbook of clinical memory assessment of older adults. Washington, DC: American Psychiatric Press.Google Scholar