Behavioral Variant Frontotemporal Dementia with Corticobasal Degeneration Pathology: Phenotypic Comparison to bvFTD with Pick’s Disease

Abstract

Patients with corticobasal degeneration (CBD) pathology present with diverse clinical syndromes also associated with other neuropathologies, including corticobasal syndrome, progressive nonfluent aphasia, and an Alzheimer’s-type dementia. Some present with behavioral variant frontotemporal dementia (bvFTD), though this subtype still requires more detailed phenotypic characterization. All patients with CBD pathology and clinical assessment were reviewed (N=17) and selected if they initially met criteria for bvFTD [bvFTD(CBD): N=5]. Available bvFTD patients with Pick’s [bvFTD(Pick’s): N=5] were selected as controls. Patients were also compared to healthy older controls [N=53] on neuropsychological and neuroimaging measures. At initial presentation, bvFTD(CBD) showed few neuropsychological or motor differences from bvFTD(Pick’s). Neuropsychiatrically, they were predominantly apathetic with less florid social disinhibition and eating disturbances, and were more anxious than bvFTD(Pick’s) patients. Voxel-based morphometry revealed similar patterns of predominantly frontal atrophy between bvFTD groups, though overall degree of atrophy was less severe in bvFTD(CBD), who also showed comparative preservation of the frontoinsular rim, with dorsal > ventral frontal atrophy, and sparing of temporal and parietal structures relative to bvFTD(Pick’s) patients. Despite remarkable overlap between the two patient types, bvFTD patients with underlying CBD pathology show subtle clinical features that may distinguish them from patients with Pick’s disease neuropathology.

The association of aphasia and right-sided motor impairment in corticobasal syndrome

“…Our data suggest that the diagnostic accuracy could be increased by focusing on higher cortical functions [3,5,9,10,20]. Future studies are needed to Cases that did not fulfill all sets of criteria are printed in Italics.…”

A clinicopathological approach to the diagnosis of dementia

“…For instance, in comparison with bvFTD patients who have Pick disease, those with CBD pathology tend to have more dorsal than ventral frontal atrophy, and relative preservation of the frontoinsular rim. Consequently, executive dysfunction and anxiety are more prominent than disinhibition, emotional dysregulation, social misconduct and changes in eating behaviour 150 . bvFTD associated with C9orf72 expansion also has distinct clinical features and patterns of neurodegeneration 151 (BOX 3).…”

Diagnosis and Management of Behavioral Variant Frontotemporal Dementia

“…This dementia shares many symptoms with primary psychiatric disorders including schizophrenia, obsessive-compulsive disorder, borderline personality disorder and bipolar disorder. In addition, neurodegenerative diseases with prominent movement abnormalities including progressive supranuclear palsy (PSP),(9, 10) corticobasal degeneration (CBD),(11, 12) and amyotrophic lateral sclerosis (ALS) often present as bvFTD or nfvPPA. (13)…”