Szmulewicz David J, Seiderer Linda, Halmagyi G Michael, Storey Elsdon, Roberts Leslie
University of Melbourne, Royal Victorian Eye and Ear Hospital, Melbourne, Victoria, Australia.
Muscle Nerve. 2015 Apr;51(4):600-3. doi: 10.1002/mus.24422. Epub 2015 Jan 5.
Cerebellar ataxia with neuropathy and bilateral vestibular areflexia syndrome (CANVAS) is a recently described multisystem ataxia defined by the presence of cerebellar ataxia, bilateral vestibulopathy, and a somatosensory deficit. The characteristic clinical sign is an abnormal visually enhanced vestibuloocular reflex. The somatosensory deficit contributes to a significant level of disability in CANVAS.
This study was a neurophysiological investigation of 14 patients with CANVAS.
Findings revealed uniformly absent sensory nerve action potentials in all limbs, abnormal blink reflexes in 13 of 14 patients, and abnormal masseter reflexes in 6 of 11 patients. Tibial H-reflexes were absent in 11 of 14 patients. Somatosensory evoked potentials were abnormal in 10 of the 11 patients tested, and brainstem auditory evoked responses were abnormal in 3 of 8. Cutaneous silent period responses were abnormal in 7 of 14 patients.
We suggest that a sensory neuronopathy should be sought in cerebellar and/or vestibular ataxias, particularly where the degree of ataxia is out of proportion to the clinically identified cerebellar and/or vestibular dysfunction.
伴有神经病变和双侧前庭无反射综合征的小脑性共济失调（CANVAS）是一种最近描述的多系统共济失调，其定义为存在小脑性共济失调、双侧前庭病变和躯体感觉缺陷。特征性临床体征是视觉增强的前庭眼反射异常。躯体感觉缺陷导致CANVAS患者出现显著程度的残疾。
本研究对14例CANVAS患者进行了神经生理学调查。
研究结果显示，所有肢体的感觉神经动作电位均一致缺失，14例患者中有13例眨眼反射异常，11例患者中有6例咬肌反射异常。14例患者中有11例胫神经H反射缺失。11例接受测试的患者中有10例体感诱发电位异常，8例中有3例脑干听觉诱发电位异常。14例患者中有7例皮肤静息期反应异常。
我们建议，在小脑性和/或前庭性共济失调中应寻找感觉神经元病，尤其是在共济失调程度与临床确定的小脑和/或前庭功能障碍不成比例的情况下。
