Vestibular nerve in Meniere's disease

Area of Science:

• Neurology
• Otolaryngology
• Neuroscience

Background:

• Meniere's disease is a disorder of the inner ear.
• Vestibular nerve pathology is implicated in Meniere's disease.
• Surgical interventions aim to alleviate severe symptoms.

Purpose of the Study:

• To investigate the microscopic changes in vestibular nerves of patients with severe Meniere's disease.
• To correlate histological findings with surgical outcomes.

Main Methods:

• Microscopic examination of biopsy specimens from vestibular nerves (eighth cranial nerve).
• Analysis of 40 patients with severe Meniere's disease.
• Correlation with surgical procedures: translabyrinthine eighth nerve transection (17 patients) and middle fossa vestibular neurectomy (23 patients).

Main Results:

• Observed thickened, deformed, and degraded myelin sheaths in nerve fibers.
• Identified thinly myelinated fibers and absence of macrophages.
• In six patients, distinct areas with astrocyte processes and basement membranes were noted, associated with persistent vertiginous symptoms post-surgery.

Conclusions:

• Microscopic findings reveal significant myelin abnormalities in the vestibular nerves of Meniere's disease patients.
• A subset of patients with persistent symptoms may have an atypical neuropathy distinct from common Meniere's disease etiologies.
• Further research is warranted to understand this distinct neuropathic condition.