Jackson Lance E, Morgan Barry, Fletcher Jeffrey C, Krueger Wesley W O
Ear Institute of Texas, San Antonio, TX 78240, USA.
Otol Neurotol. 2007 Feb;28(2):218-22. doi: 10.1097/01.mao.0000247825.90774.6b.
Evaluate the frequency and characteristics of benign paroxysmal positional vertigo (BPPV) arising from involvement of the anterior semicircular canal (AC) as compared with the posterior canal (PC) and horizontal canal (HC).
Prospective review of patients with BPPV.
Tertiary referral center.
A total of 260 patients who were evaluated for vertigo were identified as experiencing BPPV.
Standard vestibular assessment including the use of electrooculography (EOG) or video-oculography (VOG) was completed on all patients. Based on EOG/VOG findings, the BPPV origin was attributed to AC, PC, or HC involvement secondary to canalithiasis versus cupulolithiasis. Treatment was performed with canalith repositioning maneuvers (CRMs) appropriate for type of canal involvement.
For the 260 patients, the positionally induced nystagmus patterns suggested the canal of origin to be AC in 21.2%, PC in 66.9%, and HC in 11.9%. Cupulolithiasis was observed in 27.3% of the AC, 6.3% of the PC, and 41.9% of the HC patients. Head trauma was confirmed in the history preceding the onset of vertigo in 36.4% of the AC, versus 9.2% of the PC and 9.7% of the HC patients (p < 0.001). The number of CRMs completed to treat the BPPV did not differ between canals involved (1.32 for AC, 1.49 for PC, and 1.34 for HC).
The direction of subtle vertical-beating nystagmus underlying the torsional component is critical in differentiating AC versus PC origin; EOG/VOG aids in accurate assessment of the vertical component for the diagnosis of canal involvement. AC involvement may be more prevalent than previously appreciated, particularly if the examiner does not appreciate the vertical component of the nystagmus or the diagnosis is made without the assistance of EOG/VOG. Head trauma history is significantly more frequent in AC versus other forms of BPPV, and patients with a history of head trauma should be examined closely for AC involvement. CRM is as successful for treatment of AC BPPV as for other types of BPPV.
评估与后半规管（PC）和水平半规管（HC）受累相比，前半规管（AC）受累引起的良性阵发性位置性眩晕（BPPV）的发生率及特征。
对BPPV患者进行前瞻性回顾。
三级转诊中心。
共有260例因眩晕接受评估的患者被确诊为BPPV。
对所有患者完成包括使用眼震电图（EOG）或视频眼震图（VOG）在内的标准前庭评估。根据EOG/VOG检查结果，将BPPV的起源归因于管结石症或嵴帽结石症继发的AC、PC或HC受累。根据半规管受累类型采用相应的管结石复位手法（CRM）进行治疗。
在260例患者中，位置性眼震模式提示起源半规管为AC的占21.2%，PC的占66.9%，HC的占11.9%。嵴帽结石症在27.3%的AC患者、6.3%的PC患者和41.9%的HC患者中被观察到。在眩晕发作前的病史中，36.4%的AC患者被证实有头部外伤史，而PC患者为9.2%，HC患者为9.7%（p<0.001）。治疗BPPV完成的CRM次数在受累半规管之间无差异（AC为1.32次，PC为1.49次，HC为1.34次）。
扭转成分背后细微的垂直性眼震方向对于区分AC与PC起源至关重要；EOG/VOG有助于准确评估垂直成分以诊断半规管受累情况。AC受累可能比之前认识到的更为普遍，特别是当检查者未察觉到眼震的垂直成分或在没有EOG/VOG辅助的情况下做出诊断时。与其他形式的BPPV相比，AC受累患者的头部外伤史明显更常见，有头部外伤史的患者应仔细检查是否存在AC受累情况。CRM治疗AC型BPPV与治疗其他类型BPPV同样成功。
