Pick and Alzheimer diseases: a rare comorbidity presenting as corticobasal syndrome

We describe a patient with corticobasal syndrome in whom neuropathological examination on autopsy revealed Pick and Alzheimer diseases in comorbidity. Corticobasal degeneration is a tauopathy usually associated with asymmetric parkinsonism, parietal lobe involvement, and cognitive impairment. Corticobasal syndrome is the clinical presentation of corticobasal degeneration without neuropathological confirmation. A 66-year-old right-handed man slowly developed speech difficulties, right-hand clumsiness, and forgetfulness. His speech apraxia progressed to mutism with preserved comprehension, and his clumsiness progressed to severe apraxia involving both hands. He developed behavioral changes and severe amnesia. All of these features were consistent with corticobasal syndrome. His loss of episodic, verbal, and visuospatial memory suggested Alzheimer disease; however, beyond his frontotemporal neuropsychological profile, he had few symptoms characteristic of frontal lobe dementia. Magnetic resonance imaging scans showed worsening temporal, frontal, and parietal atrophy, predominant in the left hemisphere. Neuropathological examination at autopsy revealed abundant neuritic plaques and neurofibrillary tangles consistent with fully developed Alzheimer disease, as well as numerous intraneuronal Pick bodies in the frontotemporal lobes. Our findings confirm the importance of clinical and neuropathological correlations in patients with atypical neurodegenerative dementias.