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Introduction: Essential tremor (ET) patients may exhibit a variety of non-motor features, including cognitive decline and depressive symptoms. Studies of several neurodegenerative diseases link depression to cognitive decline, suggesting depression is an early marker of dementia. We examined whether baseline depressive symptoms predict incident dementia in elders with ET., Methods: Hundred and forty-one ET cases aged 70 years or older at baseline, enrolled in a prospective study of cognitive performance, took part in evaluations at baseline and at 18, 36, 54, and 72 months. Participants completed the Geriatric Depression Scale (GDS), a 30-item self-report measure of depressive symptoms, and a battery of neuropsychological tests and functional assessments, from which we derived cognitive diagnoses at each evaluation. Cox proportional hazards regression equations determined incident dementia risk based on participants' baseline depression scores., Results: Mean baseline age was 81.5 ± 6.7 years. Higher baseline GDS scores were associated with increased risk of dementia in an unadjusted model (hazards ratio [HR] = 1.11, 95% confidence interval [CI] = 1.02-1.20, p = 0.01) and after controlling for baseline age, education, number of medications, and tremor onset age (HR = 1.13, 95% CI = 1.02-1.25, p = 0.02)., Conclusion: Baseline depression scores predicted incident dementia in elders with ET. With each one-point increase in baseline depression score, there was a 13% increase in incident dementia risk. Given the published data that reported depression may be twice as high in elders with ET compared to controls, this association is particularly worrisome in the ET population., (© 2024 S. Karger AG, Basel.)

Background: Cognitive impairment is a feature of essential tremor (ET). There are no studies of the genetic drivers of this association. We examined whether the microtubule-associated protein tau (MAPT) H1 haplotype is associated with cognitive performance in ET., Methods: ET cases genotyped for the MAPT H1 and H2 haplotypes completed a battery of neuropsychological tests at baseline and four follow-up evaluations. Chi-square, t-tests, and analyses of covariance examined associations between the presence of the MAPT H1 haplotype, cognitive diagnoses of normal, mild cognitive impairment (MCI), and dementia, and performance in specific cognitive domains., Results: We observed no evidence of cognitive differences as a function of the presence of the MAPT H1 haplotype. Specifically, cases with (n = 57) and without (n = 42) this haplotype did not differ with respect to the prevalence of diagnoses of MCI or dementia, p ≥ 0.87. Moreover, cases with vs without this haplotype did not differ in either the age or point in the disease course at which observed conversions to MCI or dementia occurred, p 's ≥ 0.51. Finally, no haplotype-related differences were observed in performance in the cognitive domains of attention, executive function, language, memory, visuospatial or global ability, p 's ≥ 0.21, or in changes in performance in these domains across time, p 's ≥ 0.08., Discussion: The study in an ET cohort revealed no influence of MAPT haplotypes on cognitive performance. This study serves as a valuable foundation for future studies to expand our understanding of the genetic drivers of cognitive impairment in ET., Highlights: This study found no evidence of cognitive differences between individuals with and without the MAPT H1 haplotype. Our work provides a valuable foundation for future work to expand our knowledge of the genetic drivers of cognitive impairment in ET., Competing Interests: The authors have no competing interests to declare., (Copyright: © 2023 The Author(s).)

Background: Misidentification of dementia in Medicare claims is quite common., Objective: We examined potential race/ethnic disparities in misidentification of dementia in Medicare claims in a diverse cohort of older adults who underwent careful clinical assessment., Methods: Participants were enrolled in the Washington Heights-Inwood Columbia Aging Project (WHICAP), a multiethnic, population-based, prospective study of cognitive aging in which dementia status was assessed using a rigorous clinical protocol. ICD-9-CM and ICD-10-CM diagnosis codes in all available Medicare claims (1999-2019) were compared to clinical dementia diagnosis and categorized into three mutually exclusive groups: 1) congruent-, 2) over-, and 3) under- identification during the study period. Multinomial logistic regression model was used to examine the relationship between race (White, African American/Black, other) and ethnicity (Hispanic/Latinx, non-Hispanic/Latinx) and congruency of dementia identification after controlling for clinical (cognition, function, comorbidities) and demographic characteristics (age, sex, education), and inpatient and outpatient utilization., Results: Across all person-years, 88.4% had congruent identification of dementia compared to clinical diagnosis, in 4.1% of the times participants were over-identified with dementia, and 7.5% of the times the participants were under-identified. Rates of misidentification was higher in minority participants than in White, non-Hispanic participants. Multivariable estimation results showed that the probability of over-identification with dementia was 2.2% higher for African American/Black than White (p = 0.05) and 2.7% higher for Hispanic participants than non-Hispanics (p = 0.03) participants. Differences in under-identification by race/ethnicity were not statistically significant., Conclusions: African American/Black and Hispanic participants were more likely over-identified with dementia in Medicare claims.

Essential Tremor (ET), by definition, is a disorder of movement. Yet over the years, epidemiologic, clinical, pathologic, and neuroimaging studies have converged to reveal a cognitive side of ET. The cognitive symptoms in ET are heterogeneous and are likely to reflect heterogeneous underlying mechanisms. In this chapter, we review and synthesize a diverse set of studies from both population-based settings to cohorts with more detailed investigations into cognition to consider the various mechanisms by which cognitive symptoms may emerge in a subset of individuals with ET. As part of our analysis, we consider questions surrounding ET diagnosis and the possibility of comorbid disease as potential factors that, upon closer examination, appear to strengthen the argument in favor of ET as a risk factor for dementia. Importantly, we also consider the clinical relevance of cognitive impairment in ET. While ET is not universally characterized by significant cognitive deficits, the data from epidemiological, cognitive, neuroimaging, and postmortem neuropathologic studies converge to reveal an increased risk for cognitive impairment and dementia among individuals with ET. We conclude by offering directions for future research, and a neurocognitive framework with which to consider existing findings and to use in the design of novel studies dedicated to clarifying the basis, nature, and course of cognitive impairments in ET., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: There is evidence that the risk of mortality is increased in patients with essential tremor (ET), however, there are few longitudinal, prospective data on the predictors of mortality in ET. There is also evidence that ET is associated with cognitive impairment; yet, it is unknown whether this is associated with elevated risk of mortality., Methods: In a longitudinal, prospective study of 194 elders with ET, an extensive neuropsychological test battery was performed at three time points: baseline, 18 months, and 36 months, and cognitive diagnoses (normal, mild cognitive impairment [MCI], and dementia) were assigned during consensus conferences. We used Cox proportional hazards models to estimate hazard ratios (HR) for death., Results: The mean baseline age was 79.1 ± 9.7 years. During follow-up, 52 (26.8%) died. In initial univariate models, a variety of baseline factors were associated with increased risk of mortality, including demographic variables (i.e., older age), cognitive variables and gait and balance variables. In the final multivariate Cox model, baseline dementia (HR = 2.66, p = 0.006), older baseline age (HR = 1.18, p < 0.001), and more reported falls at baseline (HR = 1.10, p < 0.001) were independently associated with increased risk of mortality. Amnestic MCI was marginally associated with increased risk of mortality (HR = 1.93, p = 0.08) in primary analyses and significantly (p < 0.05) in several sensitivity analyses., Conclusions: In this longitudinal, prospective study, baseline dementia resulted in a 2- to 3-times increase in risk of mortality in ET, further highlighting the clinical significance of cognitive impairment, specifically dementia, in this population., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Objective: Leukocyte telomere length (LTL) is a widely hypothesized biomarker of biological aging. Persons with shorter LTL may have a greater likelihood of developing dementia. We investigate whether LTL is associated with cognitive function, differently for individuals without cognitive impairment versus individuals with dementia or incipient dementia., Method: Enrolled subjects belong to the Long Life Family Study (LLFS), a multi-generational cohort study, where enrollment was predicated upon exceptional family longevity. Included subjects had valid cognitive and telomere data at baseline. Exclusion criteria were age ≤ 60 years, outlying LTL, and missing sociodemographic/clinical information. Analyses were performed using linear regression with generalized estimating equations, adjusting for sex, age, education, country, generation, and lymphocyte percentage., Results: Older age and male gender were associated with shorter LTL, and LTL was significantly longer in family members than spouse controls (p < 0.005). LTL was not associated with working or episodic memory, semantic processing, and information processing speed for 1613 cognitively unimpaired individuals as well as 597 individuals with dementia or incipient dementia (p < 0.005), who scored significantly lower on all cognitive domains (p < 0.005)., Conclusions: Within this unique LLFS cohort, a group of families assembled on the basis of exceptional survival, LTL is unrelated to cognitive ability for individuals with and without cognitive impairment. LTL does not change in the context of degenerative disease for these individuals who are biologically younger than the general population.

Objectives: The main objective of this study was to estimate effects of dementia on Medicaid expenditures in an ethnically diverse community., Methods: The sample included 1,211 Medicare beneficiaries who did not have any Medicaid coverage and 568 who additionally had full Medicaid coverage enrolled in the Washington Heights-Inwood Columbia Aging Project (WHICAP), a multiethnic, population-based, prospective study of cognitive aging in northern Manhattan (1999-2010). Individuals' dementia status was determined using a rigorous clinical protocol. Relationship between dementia and Medicaid coverage and expenditures were estimated using a two-part model., Results: In participants who had full Medicaid coverage, average annual Medicaid expenditures were substantially higher for those with dementia than those without dementia ($50,270 vs. $21,966, p < .001), but Medicare expenditures did not differ by dementia status ($8,458 vs. $9,324, p = .19). In participants who did not have any Medicaid coverage, average annual Medicare expenditures were substantially higher for those with dementia than those without dementia ($12,408 vs. $8,113, p = .02). In adjusted models, dementia was associated with a $6,278 increase in annual Medicaid spending per person after controlling for other characteristics., Discussion: Results highlight Medicaid's contribution to covering the cost of dementia care in addition to Medicare. Studies that do not include Medicaid are unlikely to accurately reflect the true cost of dementia., (Published by Oxford University Press on behalf of The Gerontological Society of America 2019.)

Background: Essential tremor (ET), among the most common neurological diseases, is associated with cognitive dysfunction. Yet, nearly all knowledge of ET-related cognitive impairment is static and cross-sectional (e.g., prevalence), with virtually no dynamic information (i.e., course and progression, conversion rates, and clinical outcomes)., Objectives: To quantify the rate of progression from mild cognitive impairment (MCI) to dementia in a cohort of elderly ET cases., Methods: 167 ET cases, enrolled in a prospective, longitudinal, clinical-pathological study, underwent an extensive neuropsychological testing battery at baseline (T1), 1.5 years (T2), and 3 years (T3). Results of these assessments informed clinical diagnoses of normal cognition (ET-NC), MCI (ET-MCI), and dementia (ET-D)., Results: At baseline, 26 cases (82.7 ± 7.7 years) were diagnosed with ET-MCI and were available for follow-up at T2. At T2, three of 26 (11.5%) had converted to ET-D. At the start of T2, 23 cases (83.6 ± 7.7 years) were diagnosed with ET-MCI and were available for follow-up at T3. At T3, six of 23 (26.1%) converted to ET-D. The average annual conversion rate from ET-MCI to ET-D was 12.5%., Conclusions: The study of cognitive impairment in ET is a nascent field, with limited data. We show that the conversion rate from ET-MCI to ET-dementia was 12.5%. Available studies on historical controls have reported conversion rates of 2.6-6.3%. Data such as these systematically fill gaps in knowledge, creating a scientifically-derived knowledge base to guide physicians and patients in clinical settings., Competing Interests: Declaration of competing interest There are no conflicts of interest or competing financial interests., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background: Research studies have shown an association between essential tremor (ET) and dementia, although dementia in ET is not often regarded as a clinically important issue., Phenomenology Shown: We present three tangible visual records of patients with ET who have developed concurrent, comorbid dementia., Educational Value: ET is a risk factor for dementia. This non-motor feature of the disease has substantial effects on the lives of patients and their families., Competing Interests: Funding: NINDS R01NS086736. Conflicts of Interest: The authors report no conflicts of interest. Ethics Statement: This study was performed in accordance with the ethical standards detailed in the Declaration of Helsinki. The authors’ institutional ethics committee has approved this study and all patients have provided written informed consent. All patients that appear on video have provided written informed consent; authorization for the videotaping and for publication of the videotape was provided.

Objectives: To examine how misidentification of dementia affects estimation of Medicare costs in a largely minority cohort of participants for whom accurate in-person diagnoses are available., Design: Prospective cohort study., Setting: Washington Heights-Inwood Columbia Aging Project, a multiethnic, population-based, prospective study of cognitive aging of Medicare beneficiaries aged 65 and older., Participants: Individuals clinically diagnosed with dementia (n=495) and individuals clinically diagnosed without dementia (n=1,701)., Measurements: Medicare claims-identified dementia was defined according to the presence of any International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes for Alzheimer's disease and related dementias in all available claims during the study period. Participant characteristics associated with claims misidentification of dementia were estimated using logistic regression. Effects of dementia misidentification on Medicare expenditures were estimated using generalized linear models., Results: Medicare claims correctly identified 250 of the 495 (51%) dementia cases and 1,565 of the 1,701 (92%) nondementia cases. Sensitivity of claims-identified dementia was 0.51, and specificity was 0.92. Average annual Medicare expenditures were $14,721 for a beneficiary with a clinical diagnosis of dementia, and $18,208 for a beneficiary with claim-identified dementia, suggesting an overestimation of $3,487 per person per year when Medicare claims were used to identify dementia. Total annual expenditures for all beneficiaries with claims-identified dementia were $258,707 lower than that for all those who were clinically diagnosed, suggesting an overall underestimation of total Medicare expenditures if Medicare claims were used to identify dementia. Different types of misidentification have different effects on dementia-related cost estimates. Average annual expenditures per person were highest for false positives., Conclusion: Misidentification of dementia in Medicare claims is common. Using claims to identify dementia may result in significantly biased estimates of the cost of dementia. J Am Geriatr Soc 67:269-276, 2019., (© 2018, Copyright the Author Journal compilation © 2018, The American Geriatrics Society.)

Objective: The objective of this study was to examine whether reduced awareness of memory deficits in individuals with dementia is associated with more frequent need for Medicare home health care services., Methods: Cross-sectional analyses were conducted in a multicenter, clinic-based cohort. In total, 192 participants diagnosed with dementia and their informants were independently asked whether or not the participant demonstrated cognitive symptoms of dementia related to memory and word-finding. Participant self-awareness was measured as the discrepancy between participant and caregiver report of these symptoms. Annual Medicare home health benefit use data was obtained from Medicare claims matched by year to the Predictors study visit., Results: Participants that used home health services had lower awareness scores than those who did not. Awareness remained independently associated with home health use in a logistic regression adjusted for age, gender, education, caregiver relationship, global cognition, dementia subtype, and medical comorbidities., Implications: Reduced self-awareness of memory deficits in individuals with dementia is associated with more frequent use of Medicare home health services. The disproportionate use of in-home assistance as a function of awareness level may reflect dangers faced by patients, and challenges faced by caregivers, when patients have limited awareness of their memory deficits. Current results have implications for clinical care, caregiver education, and models of health care utilization.

Background: Few studies have examined how dementia and comorbidities may interact to affect healthcare expenditures., Objective: To examine whether effects of dementia severity on Medicare expenditures differed for individuals with different levels of comorbidities., Methods: Data are drawn from the Washington Heights-Inwood Columbia Aging Project (WHICAP). Comprehensive clinical assessments of dementia severity were systematically carried out at ∼18 month intervals. Dementia severity was measured by Clinical Dementia Rating (CDR). Comorbidities were measured by a modified Elixhauser comorbidities index. Generalized linear models examined effects of dementia severity, comorbidities, and their interactions on Medicare expenditures (1999-2010)., Results: At baseline, 1,280 subjects were dementia free (CDR = 0, 66.4%), 490 had very mild dementia (CDR = 0.5, 25.4%), 108 had mild dementia (CDR = 1, 5.6%), and 49 had moderate/severe dementia (CDR = 2/3, 2.5%). Average annual Medicare expenditures for individuals with moderate/severe dementia were more than twice as high as those who were dementia free (CDR = 0: $9,108, CDR = 0.5/1: $11,664, CDR≥2: $19,604, p < 0.01). Expenditures were approximately 10 times higher among those with≥3 comorbidities than among those with no comorbidities ($2,612 for those with no comorbidities, to $6,109 for those with 1, $10,656 for those with 2, and $30,244 for those with≥3 comorbidities, p < 0.001). Dementia severity was associated with higher expenditures, but comorbidities were the most important predictor of expenditures. We did not find strong interaction effects between number of comorbidities and dementia severity., Conclusions: Increasing dementia severity and higher comorbidities are associated with higher Medicare expenditures. Care of individuals with dementia should focus on management of comorbidities.

Individuals with late-onset essential tremor (ET) (e.g., older adults) seem to have an increased prevalence of mild cognitive impairment and dementia, and a higher risk of incident dementia. It is well-known that education has a protective role against dementia in individuals without a pre-existing neurologic disorder, but evidence regarding the maintenance of this effect during the premotor and motor phases of ET is unknown. Our aim was to determine the influence of education on the risk of dementia in a population-based cohort of ET patients and controls. In a prospective study (Neurological Disorders in Central Spain), participants ≥65 years old were evaluated twice: at baseline (1994-1995) and at follow-up (1997-1998). There were 3 groups: premotor (i.e., participants first diagnosed with incident ET at follow-up), prevalent ET (i.e., participants diagnosed with ET at baseline and at follow-up), and controls. Participants were stratified into lower education (≤primary studies) versus higher education (≥secondary studies) categories. Dementia risk was estimated using Cox proportional-hazards models (higher education control group = reference category). Among the participants, 3878 had a mean duration of follow-up of 3.2 years. Eight (16.7%) of 48 lower education premotor ET patients developed incident dementia versus 1 (3.3%) of 30 higher education premotor ET patients, 9 (7.1%) of 126 lower education prevalent ET patients, 7 (8.8%) of 80 higher education prevalent ET patients, and 92 (4.9%) of 1892 lower education controls (P < 0.001). In comparison to the higher education controls, the adjusted hazard ratios for incident dementia were 5.84 (lower education premotor ET, P < 0.001); 1.36 (higher education premotor ET, P = 0.76); 2.13 (lower education prevalent ET, P = 0.04); 2.79 (higher education prevalent ET, P = 0.01); and 1.66 (lower education controls, P = 0.01). Our results suggest that a higher educational attainment may ameliorate the risk of incident dementia during the premotor phase of ET, but not in the motor phase.

Background: Few studies have examined patterns of health care utilization and costs during the period around incident dementia., Methods: Participants were drawn from the Washington Heights-Inwood Columbia Aging Project, a multiethnic, population-based, prospective study of cognitive aging of Medicare beneficiaries in a geographically defined area of northern Manhattan. Medicare utilization and expenditure were examined in individuals with clinically diagnosed dementia from 2 years before until 2 years after the initial diagnosis. A sample of non-demented individuals who were matched on socio-demographic and clinical characteristics at study enrollment was used as controls. Multivariable regression analysis estimated effects on Medicare utilization and expenditures associated with incident dementia., Results: During the 2 years before incident dementia, rates of inpatient admissions and outpatient visits were similar between dementia patients and non-demented controls, but use of home health and skilled nursing care and durable medical equipment were already higher in dementia patients. Results showed a small but significant excess increase associated with incident dementia in inpatient admissions but not in other areas of care. In the 2 years before incident dementia, total Medicare expenditures were already higher in dementia patients than in non-demented controls. But we found no excess increases in Medicare expenditures associated with incident dementia., Conclusions: Demand for medical care already is increasing and costs are higher at the time of incident dementia. There was a small but significant excess risk of inpatient admission associated with incident dementia., (Published by Oxford University Press on behalf of the Gerontological Society of America 2015.)

Objectives: The aim of this study is to examine the relative contribution of functional impairment and cognitive deficits on risk of hospitalization and costs., Methods: A prospective cohort of Medicare beneficiaries aged 65 and older who participated in the Washington Heights-Inwood Columbia Aging Project (WHICAP) were followed approximately every 18 months for over 10 years (1805 never diagnosed with dementia during study period, 221 diagnosed with dementia at enrollment). Hospitalization and Medicare expenditures data (1999-2010) were obtained from Medicare claims. Multivariate analyses were conducted to examine (1) risk of all-cause hospitalizations, (2) hospitalizations from ambulatory care sensitive (ACSs) conditions, (3) hospital length of stay (LOS), and (4) Medicare expenditures. Propensity score matching methods were used to reduce observed differences between demented and non-demented groups at study enrollment. Analyses took into account repeated observations within each individual., Results: Compared to propensity-matched individuals without dementia, individuals with dementia had significantly higher risk for all-cause hospitalization, longer LOS, and higher Medicare expenditures. Functional and cognitive deficits were significantly associated with higher risks for hospitalizations, hospital LOS, and Medicare expenditures. Functional and cognitive deficits were associated with higher risks of for some ACS but not all admissions., Conclusions: These results allow us to differentiate the impact of functional and cognitive deficits on hospitalizations. To develop strategies to reduce hospitalizations and expenditures, better understanding of which types of hospitalizations and which disease characteristics impact these outcomes will be critical., (Copyright © 2014 John Wiley & Sons, Ltd.)

Background: Clock drawing is part of the Montreal Cognitive Assessment (MoCA) test but may have administration and scoring limitations. We assessed (1) the reliability of the MoCA clock criteria relative to a published error scoring approach, (2) whether command-only administration could distinguish dementia from cognitively intact individuals and (3) the value of adding a clock copy condition to the MoCA., Methods: Three novice raters and clocks from dementia and control participants were used to assess the 3 aims., Results: MoCA interrater and intrarater reliability were low (i.e. intraclass correlation coefficient = 0.12-0.31) and required repeat training. Clocks drawn to command classified dementia at chance. Inclusion of a copy condition demonstrated expected dementia subgroup patterns., Conclusion: Reliable clock scoring with MoCA criteria requires practice. Supplementing a clock copy to the standard MoCA test (takes <1 min) will improve dementia assessment., (Copyright © 2011 S. Karger AG, Basel.)

In patients with dementia, leukoaraiosis (LA) was hypothesized to result in differential patterns of impairment on a verbal serial list-learning test. Using a visual rating scale, 144 dementia patients with ischemic scores <4 were re-categorized as having mild (n = 73), moderate (n = 44), or severe LA (n = 27). Mild LA was predicted to be associated with an amnestic list-learning profile, while severe LA was predicted to be associated with a dysexecutive profile. List-learning performances were standardized to a group of healthy older adults (n = 24). Analyses were conducted on a set of four factors derived from the list-learning paradigm, as well as error scores. Data indicate that LA severity is an important marker for understanding list learning in dementia.

The neuropsychological substrate of scripts, routines which guide much of human behavior, is unclear. We propose a model of script comprehension characterized by the interaction of semantic knowledge for script content, and executive resources that organize this knowledge into goal directed behavior. We examined these neuropsychological components by asking participants with Alzheimer's disease (AD) and frontotemporal dementia (behavioral disorder/dysexecutive syndrome (BDD) and semantic dementia (SD) subtypes), to judge the coherence of four-phrase scripts. The BDD group detected significantly fewer sequencing errors than semantic errors; the AD and SD groups detected these errors with equal frequency. Independent semantic measures predicted both semantic and sequencing script errors, while executive measures predicted sequencing errors only. Findings support a multi-component model of script comprehension., (Copyright (c) 2006 APA, all rights reserved.)

Anosognosia, disordered awareness of cognitive and behavioral deficits, is a striking and common symptom of Alzheimer's disease (AD), yet its etiology, clinical correlates, and prognostic value are unclear. Historically, disordered awareness has been a conceptually challenging phenomenon, evidenced by the numerous and diverse theories that aim to explain the manner in which this syndrome arises. We review many of these theories, focusing on the neuroanatomic substrates of awareness, and highlighting the potential roles of critical regions such as the right prefrontal and parietal cortices in enabling self-awareness. We then address methodological limitations such as use of subjective measurement tools that likely contribute to the conceptual ambiguity surrounding anosognosia. We argue that metacognitive techniques used in healthy adults, such as the Feeling of Knowing task, offer models for dissecting awareness into clear and identifiable cognitive components in patients with AD. We critique several studies that have pioneered such tasks in AD, and offer guidelines for future implementation of such methods. A final goal of this review is to advocate for a multidimensional approach to studying metacognitive skills that will facilitate the objective investigation of deficit awareness as it relates to a variety of disease variables such as prognosis, neuropsychological profile, neuropathological distribution, psychiatric symptoms, and clinical course.

Objectives: A clock drawing test scoring system is presented to explore the neuropsychological/neuroanatomic components underlying clock drawing in patients initially diagnosed with Alzheimer disease, ischemic vascular dementia associated with white matter alterations, and Parkinson disease., Methods: Fourteen clock drawing test errors were scored to create 4 clock drawing test subscales that assess different underlying cognitive operations., Results: In the command condition, errors on the Time subscale were correlated with impairment on executive control measures. In the copy condition, errors on the Perseveration/Pull to Stimulus subscale was also correlated with executive control measures. Patients presenting with mild (low) magnetic resonance imaging white matter alterations, significant (high) white matter alterations, and Parkinson disease were compared. In the command condition, the low white matter alterations group made fewer total errors than the Parkinson disease group. In the copy condition, the low white matter alterations group made fewer errors on the Time, Spatial Layout, and Perseveration/Pull to Stimulus clock drawing test subscales than the high white matter alterations or Parkinson disease groups. Few differences were noted between the high white matter alterations and Parkinson disease groups., Discussion: Our data suggest that heavy demands on executive control associated with the interruption of large-scale cortical-subcortical neural networks underlie impairment in clock drawing in mild dementia.