Alzheimer’s Disease Manifesting as Corticobasal Degeneration – Case Report

Summary

Corticobasal degeneration is a rare neurodegenerative disease that belongs to the group of tauopathies is clinically manifested as a combination of extrapyramidal symptoms and cortical dysfunction affecting mainly the parietal areas. The definite diagnosis of corticobasal degeneration is based on neuropathological findings. For this reason, the term corticobasal syndrome tends to be used in surviving patients. The objective of our paper is to present a case of a patient with corticobasal syndrome as a peculiar manifestation of neuropathologically confirmed Alzheimer’s disease. Our patient showed significant cognitive impairment in visuospatial functions, apparent apraxia, frontal signs as well as early episodic memory impairment. Asymmetrical extrapyramidal features with left-sided prevalent akinesia and rigidity, apraxia on the left upper extremity and occasional myoclonus were also present. The pattern of neuropathological changes met the criteria of a fully developed neocortical stage of an early Alzheimer’s disease without any evidence of corticobasal degeneration. The main features evoking Alzheimer’s disease-associated corticobasal syndrome and enabling its differentiation from corticobasal degeneration were lower age at onset and myoclonus. In contrast to previously published data, our patient presented with an early episodic me­mory impairment suggesting a predominant involvement of the hippocampal and entorhinal 
cortices.

Key words:
corticobasal syndrome – corticobasal degeneration – Alzheimer’s disease –  tauopathies