Episodic aphasia with residual effects in a patient with progressive dementia resulting from a mitochondrial cytopathy (MELAS)

This paper describes an unusual case of aphasia, not previously reported in the literature, in a patient diagnosed with MELAS, a mitochondrial cytopathy. The patient (KS, a 22-year-old right-handed Polish female) presents with episodic aphasia against the background of progressive dementia, with the successive episodes leaving a residual effect that has slowly but steadily accumulated. A variety of standardised neurolinguistic and neuropsychological instruments (including WAIS-R, WMS-R, WAB, BNT, CNAB-R) were used to develop a dynamic, holistic clinical picture of K.S.'s disturbances, in terms of both semantic and pragmatic performance. She experiences dramatic but brief episodic aphasia (including severe anomia) occurring in the course of repeated "stroke-like episodes", which typically end with rapid (but incomplete) spontaneous remission. At the same time, she exhibits progressive dementia and steadily deteriorating communication skills on the pragmatic level. The authors discuss the possible reasons for the configuration of aphasia symptoms in this patient and their association with the course of the disease, and the implications of the results for aphasiological theory and practice.