Eye movement and vestibular dysfunction in mitochondrial A3243G mutation
Studying eye movements and vestibular function would provide insights into brain networks that are vulnerable in mitochondrial disorders. We sought eye movement and vestibular abnormalities in three Korean patients with a mitochondrial A3243G point mutation. The patients suffered from vertigo and imbalance during the stroke-like and seizure episodes from lesions involving the posterior cerebral cortex, which were accompanied by bilateral saccadic hypermetria and horizontal gaze-evoked nystagmus. Furthermore, two patients showed bilateral impairments of the vestibulo-ocular reflex during head impulses for the horizontal and posterior canals on both sides in the absence of caloric paresis. Cerebellar atrophy was prominent on MRIs in two patients and was less marked in the other patient. These findings imply that the cerebellum is susceptible to neuronal energy deficiency due to mitochondrial A3243G point mutation.
KeywordsMitochondria Head impulse test Cerebellum Vestibular function test
S.-H. K. and Z. A. A., as the first author, contributed to analysis and interpretation of the data and drafting of the manuscript. I. J. contributed to collection and interpretation of the data. J.-S. K., as the corresponding author, contributed to design of the study, interpretation of the data, and critical revision of the manuscript.
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Conflict of interest
The authors declare that they have no conflict of interest.
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