Eye movement and vestibular dysfunction in mitochondrial A3243G mutation

Area of Science:

• Neuroscience
• Ophthalmology
• Genetics

Background:

• Mitochondrial disorders can affect brain networks, impacting neurological functions.
• Eye movement and vestibular system assessments offer insights into neuronal vulnerability.

Observation:

• Three Korean patients with the mitochondrial A3243G point mutation presented with vertigo and imbalance.
• Neurological episodes involved posterior cerebral cortex lesions, accompanied by bilateral saccadic hypermetria and horizontal gaze-evoked nystagmus.

Findings:

• Two patients exhibited bilateral vestibulo-ocular reflex impairments in horizontal and posterior canals without caloric paresis.
• Cerebellar atrophy was observed on MRI, correlating with mutation severity.

Implications:

• The cerebellum appears susceptible to neuronal energy deficiency caused by the mitochondrial A3243G mutation.
• Eye movement and vestibular dysfunction are key indicators of mitochondrial disease progression.