Prolonged I-III interwave interval in cerebellar astrocytoma.
We are reporting the case of a 41-year-old female diagnosed with a cerebellar astrocytoma. The tumor was detected after the patient was referred for MRI scan because of an abnormal ABR. The ABR was unusual as the I-V interwave intervals (IWIs) were within normal limits bilaterally, but the I-III IWI was prolonged by .40 msec on the left ear in comparison to the right ear. This case report illustrates the importance of the I-III IWI in the detection of retrocochlear pathology and the nonsequential generation of the components of the ABR.
Sostarich
M E
ME
Otolaryngic-Head and Neck Surgery Foundation, University of Kansas Medical Center, KS 66160-7380.
Ferraro
J A
JA
Karlsen
E A
EA
D000161:Acoustic Stimulation; D000328:Adult; D001254:Astrocytoma / Q000175:diagnosis / Q000473:pathology* / Q000532:radiotherapy; D001299:Audiometry; D001933:Brain Stem / Q000000981:diagnostic imaging / Q000503:physiopathology; D002528:Cerebellar Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000532:radiotherapy; D002531:Cerebellum / Q000473:pathology*; D004584:Electronystagmography; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006801:Humans; D010470:Perceptual Masking; D011859:Radiography; D014717:Vertigo / Q000175:diagnosis / Q000503:physiopathology