Factors that predict diagnostic stability in neurodegenerative dementia.


Department of Neurology, Memory and Aging Center, UCSF Weill Institute for Neurosciences, University of California, San Francisco, 675 Nelson Rising Lane, Box 1207, Suite 190, San Francisco, CA, 94158, USA. [Email]


OBJECTIVE : To determine the frequency and characteristics of clinical diagnostic change in frontotemporal dementia (FTD)-spectrum syndromes and Alzheimer's disease (AD)-type dementia.
METHODS : We reviewed records and categorized diagnostic changes in patients seen ≥ 2 times with behavioral variant FTD (bvFTD, n = 99), nonfluent and semantic variant primary progressive aphasia (nfvPPA, n = 32; svPPA, n = 59), corticobasal syndrome (CBS, n = 40), progressive supranuclear palsy-Richardson syndrome (PSP-RS, n = 34), and AD-type dementia (n = 49). For bvFTD, we compared patients with and without diagnostic change, and assessed predictors of diagnostic change by logistic regression.
RESULTS : Initial diagnoses changed infrequently at subsequent visits in svPPA (6.8%), PSP-RS (8.8%), and nfvPPA (12.5%), with rare changes largely involving clinicopathological overlap or diagnostic ambiguity. Changes in AD-type dementia (30.6%) and CBS (37.5%) were more common, but reflected greater specificity, predicted co-pathology, or overlapping syndromes. Diagnostic change in bvFTD was also common (32.3%), but more diverse, including motor neuron disease development, alternative neurodegenerative syndromes, and non-neurodegenerative diseases. Diagnostic change occurred more often in those who met possible rather than probable bvFTD criteria (70.6% vs 15.3%, p < 0.001). Patients with stable diagnoses showed greater overall impairment, bvFTD behavioral severity, and atrophy in core right-hemisphere bvFTD regions. Patients with diagnostic change had more severe depression (p < 0.05) and more frequent contributing, secondary diagnoses (p = 0.01), such as cerebrovascular disease. By logistic regression, the accuracy of predicting stable bvFTD diagnoses using first-visit data was 80%.
CONCLUSIONS : bvFTD displays more diverse diagnostic change than other neurodegenerative syndromes. First-visit bvFTD diagnoses may waver if based on meeting possible criteria only.


Alzheimer’s disease,Corticobasal degeneration,Frontotemporal dementia,Progressive supranuclear palsy,