Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, Maryland 21287, USA.
Otol Neurotol. 2012 Oct;33(8):1386-91. doi: 10.1097/MAO.0b013e318268d20d.
To determine postoperative hearing outcomes after surgical plugging via middle cranial fossa approach for superior semicircular canal dehiscence syndrome (SCDS).
Clinical review.
Tertiary care medical center.
Forty-three cases of SCDS based on history, physical examination, vestibular function testing, and computed tomography imaging confirming the presence of a dehiscence. All patients underwent surgical plugging of the superior semicircular canal via middle cranial fossa approach.
Pure tone audiometry was performed preoperatively and at 7 days and at least 1 month postoperatively.
Change in air-bone gap (ABG) and pure tone average (PTA).
Preoperative average ABG across 0.25, 0.5, 1, and 2 kHz was 16.0 dB (standard deviation [SD], 7.5 dB). At 7 days postoperatively, average ABG was 16.5 dB (SD, 11.1; p = 0.42), and at greater than 1 month was 8.1 dB (SD, 8.4; p < 0.001). 53% (95% confidence interval, 33-69) of affected ears had greater than 10 dB increase in their 4-frequency (0.5, 1, 2, and 4 kHz) PTA measured by bone-conduction (BC) threshold 7 days postoperatively and 25% (95% confidence interval, 8-39) at greater than 1 month postoperatively. Mean BC PTA of affected ears was 8.4 dB hearing loss (HL) (SD, 10.4) preoperatively. Compared with baseline, this declined to 19.2 dB HL (SD, 12.6; p < 0.001) at 7 days postoperatively and 16.4 dB HL (SD, 18.8; p = 0.01) at greater than 1 month. No significant differences in speech discrimination score were noted (F = 0.17).
Low-frequency air-bone gap decreases after surgical plugging and seems to be due to both increased BC thresholds and decreased AC thresholds. Surgical plugging via a middle cranial fossa approach in SCDS is associated with mild high-frequency sensorineural hearing loss that persists in 25% but no change in speech discrimination.
通过经中颅窝入路对上半规管裂综合征（SCDS）进行手术填塞，以确定术后听力结果。
临床回顾。
三级护理医疗中心。
43 例 SCDS 患者，依据病史、体格检查、前庭功能检查和计算机断层扫描成像，证实存在裂孔。所有患者均通过中颅窝入路行上半规管手术填塞。
术前及术后 7 天和至少 1 个月行纯音测听。
气骨导差（ABG）和纯音平均听阈（PTA）的变化。
0.25、0.5、1 和 2 kHz 时的术前平均 ABG 为 16.0 dB（标准差[SD]，7.5 dB）。术后 7 天平均 ABG 为 16.5 dB（SD，11.1；p = 0.42），术后 1 个月以上时为 8.1 dB（SD，8.4；p < 0.001）。术后 7 天，53%（95%置信区间，33-69）受影响的耳朵通过骨导（BC）阈值测量的 4 个频率（0.5、1、2 和 4 kHz）的 PTA 增加了 10 dB 以上，术后 1 个月以上时为 25%（95%置信区间，8-39）。受影响耳朵的平均 BC PTA 术前为 8.4 dB 听力损失（HL）（SD，10.4）。与基线相比，术后 7 天下降至 19.2 dB HL（SD，12.6；p < 0.001），术后 1 个月下降至 16.4 dB HL（SD，18.8；p = 0.01）。言语辨别评分无显著差异（F = 0.17）。
手术填塞后低频气骨导差减小，这似乎是由于 BC 阈值升高和 AC 阈值降低所致。SCDS 经中颅窝入路手术填塞后可引起轻度高频感音神经性听力损失，25%患者持续存在，但言语辨别力无变化。
