偏瘫患者的肌腱振动提示肌梭Ia、Ⅱ类传入纤维在下肢肌肉痉挛反射中的作用  

Reflex contribution of spindle group Ia and II afferent input to legmuscle spasticity as revealed by tendon vibration in hemiparesis

作　　者：Nardone A. Schieppati M. 郭中孟 

机构地区：[1]Department of Experimental Medicine , University of Pavia, Centro Studi Attivit' a Motorie (CSAM), I- 27100 Pavia, Italy

出　　处：《世界核心医学期刊文摘（神经病学分册）》2005年第10期12-13,共2页Digest of the World Core Medical Journals:Clinical Neurology

摘　　要：Objective: Foot dorsiflexion evokes a short- (SLR) and a medium- latency EM G response (MLR) in the soleus of standing subjects. SLR is mediated by spindle group Ia, while group II fibres contribute to MLR through an oligosynaptic circu it. We studied the effects of Achilles’ tendon vibration on both responses in spastic patients to disclose any abnormal excitability of these pathways. Method s: SLR and MLR were evoked in 11 hemiparetics and 11 normals. The vibration- in duced changes in both responses were correlated to the Ashworth score of the aff ected leg. Results: There were no differences between normals and patients in th e size of control SLR or MLR. Vibration decreased SLR to 70% in normal subject s, but increased it to 110% in patients, in both affected and unaffected leg. Vibration did not affect MLR in normals, but increased it to 165% on the affec ted and 120% on the unaffected side of patients. Ashworth score was solely cor related with the degree of vibration- induced increase of MLR. Conclusions: Whi le the lack of inhibitory effect of vibration on SLR confirms a reduced inhibiti bility of the monosynaptic reflex, the increased MLR indicates a disin hibition of group II pathway in patients, connected to the loss of descending control on group II interneurones. Spastic hypertonia depends on release of gro up II rather than group Ia reflex pathways. Significance: These findings give a neurophysiological support for the pharmacological treatment of spastic hyperton ia and suggest a method for the assessment of its effects.Objective: Foot dorsiflexion evokes a short- (SLR) and a medium- latency EM G response (MLR) in the soleus of standing subjects. SLR is mediated by spindle group Ia, while group II fibres contribute to MLR through an oligosynaptic circu it. We studied the effects of Achilles’ tendon vibration on both responses in spastic patients to disclose any abnormal excitability of these pathways. Method s: SLR and MLR were evoked in 11 hemiparetics and 11 normals. The vibration- in duced changes in both responses were correlated to the Ashworth score of the aff ected leg. Results: There were no differences between normals and patients in th e size of control SLR or MLR. Vibration decreased SLR to 70% in normal subject s, but increased it to 110% in patients, in both affected and unaffected leg. Vibration did not affect MLR in normals, but increased it to 165% on the affec ted and 120% on the unaffected side of patients. Ashworth score was solely cor related with the degree of vibration- induced increase of MLR. Conclusions: Whi le the lack of inhibitory effect of vibration on SLR confirms a reduced inhibiti bility of the monosynaptic reflex, the increased MLR indicates a disin hibition of group II pathway in patients, connected to the loss of descending control on group II interneurones. Spastic hypertonia depends on release of gro up II rather than group Ia reflex pathways. Significance: These findings give a neurophysiological support for the pharmacological treatment of spastic hyperton ia and suggest a method for the assessment of its effects.

关 键 词：IA 患侧下肢 下肢肌肉 肌梭 单突触反射 背屈 神经生理学 比目鱼肌 痉挛性 肌痉挛 

分 类 号：R741[医药卫生—神经病学与精神病学]