Fiorio M, Tinazzi M, Scontrini A, Stanzani C, Gambarin M, Fiaschi A, Moretto G, Fabbrini G, Berardelli A
Dipartimento di Scienze Neurologiche e della Visione, Sez. Neurologia Riabilitativa, Universitè di Verona, Via Casorati 43, 37131 Verona, Italy.
J Neurol Neurosurg Psychiatry. 2008 Jul;79(7):796-8. doi: 10.1136/jnnp.2007.131524. Epub 2007 Nov 6.
Blepharospasm is an adult-onset focal dystonia that causes involuntary blinking and eyelid spasms. Studies have shown the presence of sensory deficits associated with dystonia.
To rule out any confounding effect of muscle spasms on sensory performance in affected and unaffected body regions of patients with blepharospasm and with hemifacial spasm.
Participants (19 patients with blepharospasm, 19 patients with hemifacial spasm and 19 control subjects) were asked to discriminate between two stimuli that were either simultaneous or sequential (temporal discrimination threshold, TDT). Pairs of tactile stimuli were delivered with increasing or decreasing inter-stimulus intervals from 0 to 400 ms (in 10-ms steps) to the hands or on the skin over the orbicularis oculi muscle.
Tactile stimuli elicited similar TDTs in control subjects and patients with hemifacial spasm, but significantly higher TDTs in patients with blepharospasm, regardless of whether stimuli were applied to the orbicularis muscle or the hand.
As TDT was abnormal in unaffected body regions of patients with blepharospasm, and patients with hemifacial spasm processed tactile stimuli normally, TDT deficits in blepharospasm depend on central rather than peripheral factors. This study further supports the link between focal dystonia and impaired temporal processing of somatosensory inputs.
睑痉挛是一种成人起病的局灶性肌张力障碍，可导致不自主眨眼和眼睑痉挛。研究表明存在与肌张力障碍相关的感觉缺陷。
排除睑痉挛和半面痉挛患者患侧和未患侧身体部位肌肉痉挛对感觉功能的任何混杂影响。
要求参与者（19例睑痉挛患者、19例半面痉挛患者和19名对照者）辨别两个同时或相继出现的刺激（时间辨别阈值，TDT）。以0至400毫秒（以10毫秒为步长）递增或递减的刺激间隔，将成对的触觉刺激施加于手部或眼轮匝肌上方的皮肤。
触觉刺激在对照者和半面痉挛患者中引发相似的TDT，但在睑痉挛患者中显著更高，无论刺激是施加于眼轮匝肌还是手部。
由于睑痉挛患者未患侧身体部位的TDT异常，而半面痉挛患者正常处理触觉刺激，睑痉挛中的TDT缺陷取决于中枢而非外周因素。本研究进一步支持局灶性肌张力障碍与体感输入时间处理受损之间的联系。
