Abstract Details

Title Expanding the Clinical Phenotypes of Corticobasal Degeneration

Topic Movement Disorders

Presentation(s) S21 - Movement Disorders: Clinical Characteristics and Epidemiology of Movement Disorders (4:18 PM-4:30 PM)

Poster/Presentation
Number 005

Background CBD is a rare, progressive neurodegenerative disease associated with a variety of cognitive and motor features. International consensus criteria define five clinical phenotypes of CBD. It is unknown whether there are other “atypical” presentations of CBD and whether these atypical presentations have unique neuroanatomic and/or neuropathologic features.

Objective To determine whether atypical presentations of corticobasal degeneration (CBD) exist, and if so, examine such presentations and identify neuroanatomic and histopathologic features that could account for such presentations.

Design/Methods We identified all patients evaluated at Mayo Clinic with a pathological diagnosis of CBD. Medical records were screened to determine if clinical presentations were consistent with one of the five criteria phenotypes. Statistical parametric mapping (SPM) was used to compare grey/white matter volume loss in atypical CBD to CBD patients who had a classic corticobasal syndrome (CBS) presentation. Phosphorylated tau deposition was assessed using digital pathology in cortical and basal ganglia regions in atypical CBD and CBD-CBS.

Results Of 100 CBD patients, seven could not be classified (4 females, mean age at death = 71.1 years, mean disease duration = 6.3 years, like the other 93 CBD patients). Presenting features of the atypical patients included unclassified aphasia, apperceptive agnosia, Gerstmann syndrome, and topographagnosia. Over time, limb apraxia developed in three, but none met probable CBS criteria before death. SPM analysis showed greater temporal lobe, but less motor cortex, volume loss compared to CBD-CBS. Average tau immunoreactive lesion size was greater in all cortical regions, but not basal ganglia, in atypical CBD. Number of dystrophic neurites and their burden was greater in atypical CBD.

Conclusions We have identified unique presentations of CBD not captured by the current consensus criteria. Such presentations were related to a transference of neurodegeneration away from motor cortex and towards temporal lobe, as well as tau lesion differences.

Authors/Disclosures
Emma L. Wetmore, MD PRESENTER	Dr. Wetmore has nothing to disclose.
Gokhan Uruk-Contreras, MD, PhD	Dr. Uruk-Contreras has nothing to disclose.
Nha Trang Thu Pham (Mayo Clinic)	Nha Trang Thu Pham has received personal compensation for serving as an employee of Mayo Clinic.
Bradley F. Boeve, MD, FAAN (Mayo Clinic)	Dr. Boeve has received personal compensation in the range of $10,000-$49,999 for serving as an officer or member of the Board of Directors for Rainwater Charitable Foundation. The institution of Dr. Boeve has received research support from Alector. The institution of Dr. Boeve has received research support from EIP Pharma. The institution of Dr. Boeve has received research support from Transposon. The institution of Dr. Boeve has received research support from Cognition Therapeutics. Dr. Boeve has received publishing royalties from a publication relating to health care.
Ronald C. Petersen, MD, PhD, FAAN (Mayo Clinic)	Dr. Petersen has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Roche. Dr. Petersen has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Genentech. Dr. Petersen has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Eli Lilly and Co.. Dr. Petersen has received personal compensation in the range of $0-$499 for serving as a Consultant for Eisai, Inc.. Dr. Petersen has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novo Nordisk. Dr. Petersen has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis. Dr. Petersen has received publishing royalties from a publication relating to health care. Dr. Petersen has received publishing royalties from a publication relating to health care. Dr. Petersen has received publishing royalties from a publication relating to health care. Dr. Petersen has a non-compensated relationship as a Board of Directors with American Brain Foundation that is relevant to AAN interests or activities.
Dennis W. Dickson, MD (Mayo Clinic)	Dr. Dickson has nothing to disclose.
Jennifer Whitwell, PhD (Mayo Clinic)	Dr. Whitwell has nothing to disclose.
Keith A. Josephs, Jr., MD, FAAN (Mayo Clinic)	Dr. Josephs has nothing to disclose.

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