Chronic inflammation of the internal auditory canal as a rare etiology of episodic vestibular syndrome: a case report

Abstract

Episodic vestibular syndrome (EVS) commonly results from vestibular migraine and benign paroxysmal positional vertigo, but other causes can be challenging for clinicians to diagnose. We present the case of a 72-year-old patient who sought medical attention for a one-month history of EVS associated with right peripheral facial palsy and ipsilateral sensorineural hearing loss. Initial imaging studies suggested a diagnosis of right vestibular schwannoma, and vestibular function tests indicated ipsilateral vestibular hypofunction. The patient was initially managed with corticosteroids, showing a good clinical response. Follow-up imaging excluded schwannoma diagnosis, revealing a persistent linear inflammation of the right internal auditory canal, leading to the exclusion of secondary causes such as lymphoma, sarcoidosis, IgG4 disease, and other inflammatory conditions. Over a two-year follow-up period, the patient exhibited fluctuations in audiovestibular symptoms and occasional fa­cial fasciculations. Inflammatory and neoplastic pathologies were ruled out, and the final diagnosis was chronic inflammation of the internal auditory canal with an unspecified etio­logy. This case highlights the diagnostic challenges in identifying the underlying etiology of EVS in this patient. It establishes a rare etiological diagnosis and underscores the limited information available in the literature regarding this condition.