Mild cognitive impairment and dementia in motor manifest Huntington's disease: Classification and prevalence

Authors

Parunyou Julayanont, Division of Behavioral and Cognitive Neurology, Department of Neurology, University of Florida College of Medicine, Gainesville, FL, USA. Electronic address: p.julayanont@ttuhsc.edu.
Nikolaus R. McFarland, Center for Movement Disorders and Neurorestoration, Department of Neurology, University of Florida College of Medicine, Gainesville, FL, USA. Electronic address: mcfarland@neurology.ufl.edu.
Kenneth M. Heilman, Division of Behavioral and Cognitive Neurology, Department of Neurology, University of Florida College of Medicine, Gainesville, FL, USA; Malcom Randall Veterans Affairs Medical Center, Gainesville, FL, USA. Electronic address: heilman@neurology.ufl.edu.

Document Type

Article

Abstract

OBJECTIVES: To identify the characteristics and prevalence of mild cognitive impairment in patients with motor-manifest Huntington's disease (HD) and to propose a new mild cognitive impairment (HD-MCI) classification for HD. METHODS: We included 307 motor-manifest HD participants from the ENROLL-HD study who completed the evaluation in four neurocognitive domains including executive functions, processing speed, language, and memory. Cognitive impairment in each domain was determined by age- and education-adjusted cutoffs (> 1.5 standard deviations below the mean). HD-MCI was defined as an impairment in at least one cognitive domain without a loss of functional independence (Function Independence Scale, FIS ≥85). Dementia (HD-Dem) was defined as at least two domains of cognitive impairment with functional impairment (FIS ≤80). RESULTS: At the onset of motor symptoms, MCI was present in 84% and dementia in 5% of patients. After 5 years of motor symptoms, 24% of participants met the criteria for MCI and 69% for dementia. Executive dysfunction was the most common impairment, being present in 70% of participants, followed by slowed processing speed in 67%. Language impairment was reported in 55% and memory deficits in 53%. MCI subtypes were classified as "Executive-predominant" (executive impairment and slowed processing speed), "Representational-predominant" (impaired language and memory) and "Mixed Executive-Representational". Executive-predominant MCI comprised 30%, Representational-predominant 15% and Mixed 55% of this cohort. CONCLUSION: MCI is highly prevalent in the early stage of motor-manifest HD. Three MCI subgroups are defined suggesting at the earlier stage of this disease the frontal-striatal-executive and/or the temporoparietal-representational functional network can be impaired.

Medical Subject Headings

Adolescent; Adult; Aged; Aged, 80 and over; Cognitive Dysfunction (classification, diagnosis, epidemiology); Cohort Studies; Dementia (classification, diagnosis, epidemiology); Executive Function (physiology); Female; Humans; Huntington Disease (classification, diagnosis, epidemiology); Male; Mental Status and Dementia Tests; Middle Aged; Neuropsychological Tests; Prevalence; Young Adult

Publication Date

1-15-2020

Publication Title

Journal of the neurological sciences

E-ISSN

1878-5883

Volume

408

First Page

116523

PubMed ID

31678902

Digital Object Identifier (DOI)

10.1016/j.jns.2019.116523

Recommended Citation

Julayanont, Parunyou; McFarland, Nikolaus R.; and Heilman, Kenneth M., "Mild cognitive impairment and dementia in motor manifest Huntington's disease: Classification and prevalence" (2020). Neurology. 1240.
https://scholar.barrowneuro.org/neurology/1240