Assessment of Vestibular Functional Recovery Using Video Head Impulse Test in Vestibular Neuritis / 대한평형의학회지

OBJECTIVE: The video head impulse test (vHIT) is useful for evaluation of high frequency vestibulo-ocular reflex. There are a few reports regarding the recovery of head impulse test in vestibular neuritis (VN) but the factors for the recovery were not studied. The study aimed to identify the recovery patterns of vHIT in VN and the factors influencing the recovery. METHODS: Among 31 patients with acute VN, 18 patients with identified recovery pattern were selected. We conducted serial checks of subjective vertigo and spontaneous nystagmus until discharged (1-8 days), and scheduled vHITs. We found three patterns in serial vHITs during follow-ups and analyzed the relationship of initial vestibular function tests, serial check-ups of subjective vertigo, bedside neuro-otologic tests, and vHITs. RESULTS: Five patients showed normal vHIT gain in acute stage (non-damaged pattern) and 8 patients' gains were recovered after 30 days after symptom onset (early recovered pattern). Poor recovery pattern was found in 5 patients (poorly recovered pattern). There were relationship between vHIT recovery patterns and the severity of vestibular dysfunctions. Duration of spontaneous nystagmus (until grade 1), degree of subjective visual vertical tilt, ocular vestibular myogenic potential abnormalities, and abnormality of rotatory chair test were all related to poorly recovered vHIT patterns. All poor recovery patients had residual symptom at 30 days after symptom onset. CONCLUSION: The vHIT may give clinicians useful hints in predicting prognosis in VN, and the recovery of vHIT would be delayed if the damage were more extensive.

Percutaneous Endoscopic Interlaminar Discectomy for L5-S1 Disc Herniation: Axillary Approach and Preliminary Results

OBJECTIVE: The purpose of this study was to describe a surgical technique of axillary approach of percutaneous endoscopic interlaminar discectomy for L5-S1 disc herniation and its preliminary results. METHODS: From July 2002 to September 2003, 101 patients with lumbar radiculopathy due to L5-S1 disc herniation, who were treated by percutaneous interlaminar endoscopic discectomy, were retrospectively reviewed. There were 57 males and 44 females with a mean age of 44.8 years (range, 18 to 62 years). The surgery consisted of needle insertion into the epidural space via the interlaminar space, sequential dilatation, and endoscopic discectomy through the axillary area of the S1 root. RESULTS: The mean follow-up period was 14.5 months and the average surgical time was 41 min. According to the modified Macnab criteria, 44 patients (43.6%) had excellent outcomes, 49 (48.5%) had good results and only 8 (7.8%) had fair or poor outcomes. Four patients had a revision microdiscectomy due to incomplete removal of disc fragment. There were no major complications related to this surgical approach. CONCLUSION: Axillary approach of percutaneous endoscopic interlaminar discectomy is safe and effective procedure for the treatment of L5-S1 disc herniation. It combines the advantages of MED and conventional percutaneous endoscopic discectomy.