Case 3: Alzheimer's Disease— Behavioral Variant

Alzheimer's disease (AD) is a heterogeneous illness including "atypical" clinical presentations dominated by visual, aphasic, "frontal" (behavioral), or apraxic symptoms. Initial description of atypical phenotypes of AD was based on clinicopathologic studies, but there is a growing body of evidence coming from in vivo molecular biomarkers describing the topography of neurodegeneration or amyloid and tau pathology. In frontal presentation the severity of behavioral symptoms is lower than in behavioral Frontotemporal dementia (bvFTD), but cognitive impairment might be more evident, often showing similar memory deficit as in typical AD and worse executive functioning than patients with either bvFTD or typical AD.