Progression of acute cochleovestibulopathy into anterior inferior cerebellar artery infarction

Antemortem diagnosis of isolated inner ear infarction remains a diagnostic challenge since current imaging techniques do not permit differentiation of isolated labyrinthine infarction from other more benign disorders involving the inner ear. An 81-year-old woman with diabetes, hypertension and hypercholesterolemia presented with vertigo and hearing loss. Initial examination revealed findings of left cochleovestibular labyrinthitis without brainstem or cerebellar signs. MRIs including the diffusion-weighted images were normal. Five days later, however, she developed dysarthria, and decreased facial sensation, subtle facial palsy, and dysmetria in the left side. Follow-up MRI was consistent with acute infarctions in the territory of anterior inferior cerebellar artery (AICA), involving the left lateral pons, left middle cerebellar peduncle, and inferolateral cerebellum. AICA infarction should be considered in acute audiovestibular syndrome, especially in aged patients with vascular risk factors, even though the classic brainstem or cerebellar signs are absent.