Lower Brainstem Changes in Herpes Oticus with Facial Palsy
Fifteen patientswith facial palsy (five herpes zoster and ten idiopathic) were subjected to auditory brainstem evoked response (ABR) to evaluate the possible brainstem changes in terms of interpeak latency for wave I–III and wave III–V in response to a 60- or 80-dB SL stimulus within the 1st week of the onset. The idiopathic group consisted of ten patients (mean age, 31.8 years) and the herpes zoster group consisted of five patients (mean age, 32.2 years). The right side was affected more (seven idiopathic and four herpes). The herpes group only exhibited hearing loss as a symptom in two patients on audiometry including another patient; three showed mild to moderate loss (40–55 dB). Two patients who showed no hearing loss and two others with 50–55 dB loss (i.e., four patients) showed prolongation of wave I–III IPL only when compared to normative values, i.e., more than normative mean plus 2 SD, suggesting involvement of the 8th nerve and lower brainstem. On the other hand, Bell’s palsy (idiopathic) patients showed normal values (I–III= 1.99 ms; III–V= 1.82 ms).