Brain stem electrical responses in cerebello-pontine angle tumours

Area of Science:

• Neuroscience
• Neurosurgery
• Audiology

Background:

• Cerebello-pontine angle (CPA) tumors present diagnostic challenges.
• Brain-stem electrical responses (BSER) are a valuable tool for assessing auditory pathway integrity.

Purpose of the Study:

• To evaluate the diagnostic utility of BSER in patients with CPA lesions.
• To characterize BSER abnormalities in various CPA pathologies.

Main Methods:

• Thirty patients with CPA tumors underwent BSER testing.
• BSER parameters including wave latencies and inter-aural time differences were analyzed.
• Tumor types included acoustic neuromas, meningiomas, lymphoma, chordoma, arteriovenous malformations, and aneurysms.

Main Results:

• All 30 patients exhibited pathological BSER findings.
• Eight cases showed no evoked BSER waves.
• Thirteen cases with Wave V present demonstrated significant delay; prolonged I-V intervals and IT5 were noted.
• Nine cases showed only early components (I and III), often with missing Wave II.

Conclusions:

• BSER is a sensitive indicator of CPA lesions.
• Abnormalities in BSER, including wave absence and latency delays, are characteristic of CPA pathologies.
• BSER aids in the diagnosis and localization of CPA abnormalities.