Pretarsal blepharospasm: Clinical and electromyographic characteristics

ObjectiveTo describe the clinical and electromyographic characteristics of blepharospasm caused by selective involvement of the pars pretarsalis of the orbicularis oculi muscle.MethodsClinical assessment and simultaneous electromyographic recordings from levator palpebrae superioris and pars orbitaria and pretarsalis of orbicularis oculi muscles were performed in patients with blepharospasm and primary failure to botulinum toxin injections. Patients with selective abnormal electromyographic activity of the pars pretarsalis of the orbicularis oculi muscle were identified and treated with selective pretarsal injections of botulinum toxin.ResultsWe found 24 patients with pretarsal blepharospasm confirmed by the electromyographic assessment. All of them were functionally blind. Three clinical-electromyographic patterns were identified: (a) Impairment of eyelid opening; (b) Increased blinking; (c) Spasms of eye closure combined with varying degrees of excessive blinking and impairment of eye-opening. Pretarsal injections of botulinum toxin induced a significant improvement in all patients and 50 % regained normal or near-normal vision. The clinical improvement was sustained after repeated pretarsal injections.ConclusionsPretarsal blepharospasm can be suspected on clinical grounds and it can be confirmed by electromyographic recordings.SignificanceRecognition of this type of blepharospasm is important because of its excellent response to botulinum toxin injections applied into the pretarsal part of the orbicularis oculi muscle.     

表面肌电生物反馈疗法结合吞咽训练治疗脑卒中患者吞咽障碍的疗效

目的:观察表面肌电生物反馈治疗结合吞咽训练治疗脑卒中患者吞咽障碍的效果。方法:选择2018年2月至2019年12月在广州市第一人民医院康复医学科和神经科接受治疗的65例脑卒中后吞咽障碍患者,根据患者意愿分为吞咽训练组33例和肌电生物反馈组32例。吞咽训练组采用吞咽训练,肌电生物反馈组在吞咽训练的基础上采用表面肌电生物反馈疗法。在患者接受治疗前后均采用标准吞咽功能评估法(SSA)及视频吞咽造影功能障碍量表(VDS)对患者的吞咽功能进行测定,并比较两组疗效。结果:与治疗前比较,治疗后两组SSA及VDS评分均降低(P<0.05),肌电生物反馈组降低更明显(P<0.05)。肌电生物反馈组有效率高于吞咽训练组(87.5%比60.6%,P<0.05)。结论:表面肌电生物反馈疗法结合吞咽训练能有效改善脑卒中患者吞咽障碍,且效果明显优于单纯吞咽训练。     

Activity of inferior head of human lateral pterygoid muscle during standardized lateral jaw movements

OBJECTIVE: (a) To describe the changes in electromyographic (EMG) activity from selected jaw muscles during a standardized lateral jaw movement with the teeth together, and (b) to investigate the effects on jaw muscle activity of changes in both the rate of lateral jaw movement and the relative magnitude of jaw-closing force. DESIGN: In 16 healthy volunteers, recordings were made using a jaw-tracking system, of mid-incisor point (MIPT) movements, as well as EMG activity from the contralateral inferior head of the lateral pterygoid muscle (IHLP), and bilateral anterior and posterior temporalis, masseter and submandibular muscles, during lateral jaw movement tasks at two speeds and two closing force levels with the teeth together. RESULTS: The IHLP was the only muscle to show a consistent increase in activity in association with the outgoing phase of the task and a decrease during the return phase. Under high closing force at slow speed, the EMG activities of the IHLP and bilateral anterior temporalis and masseter muscles were significantly (p < 0.05) higher than those under a low closing force, while there was no significant change (p > 0.05) in bilateral posterior temporalis and submandibular muscles. The change from slow to fast lateral movement at low force did not significantly (p > 0.05) alter the mean activity except for the IHLP (increase in activity) and the contralateral anterior temporalis (decrease in activity). CONCLUSIONS: The data suggest that the IHLP is one of the principal jaw muscles involved in a lateral jaw movement with the teeth together while the other jaw muscles may play a contributory or facilitatory role.     

局部注射A型肉毒毒素后远隔部位F波的改变

目的探讨局部注射A型肉毒毒素(BTX-A)后其远隔部位F波的改变及其可能机制。方法对19例偏侧面肌痉挛(HFS)患者、5例Meige综合征患者及2例痉挛性斜颈(TS)患者行BTX-A注射，并在注射前、注射后1周及注射后12～24周时分别检测其尺神经及胫神经F波的各项参数变化。结果①注射后1周，有3例患者共5条尺神经未引出肯定波形。②与注射前比较，尺、胫神经F波平均潜伏期以及尺神经F波时限在注射1周后显著延长，且这种改变与注射剂量无明显相关性；注射12～24周时，上述两参数与注射前比较，差异均无显著性意义。结论F波平均潜伏期和时限是评价BTX-A远隔效应的敏感指标；BTX-A的远隔效应似与检查部位和注射部位间的距离有关，而与注射剂量无明显相关性。     

重复经颅磁刺激对截瘫后脊髓兴奋性作用的实验研究

目的观察重复经颅磁刺激对脊髓损伤大鼠脊髓兴奋性的影响并探讨其机制。方法利用重物撞击法制备成年SD大鼠T10脊髓损伤模型，造模8周后脊髓损伤磁刺激组给予0．5Hz阈上强度经颅定位磁刺激，每天500个脉冲，共4周。另设脊髓损伤组及正常对照组。各组大鼠不同时点行后肢F波检测，观察F与M波幅比值；免疫组化法观察5-羟色胺（5-HT）在脊髓损伤区头尾端的变化情况。结果脊髓损伤后8周F波幅增高，M波幅恒定，与正常对照组比较，F／M波幅比值明显升高（P〈0．01）；磁刺激后，F／M波幅比值降低，与脊髓损伤组比较有非常显著性差异（P〈0．01）；脊髓损伤8周时，损伤头、尾端5-HT密度明显降低（P〈0．01）；磁刺激后，损伤头、尾端表达均明显升高（P〈0．01）。结论重复经颅磁刺激可以降低慢性下胸段脊髓不全损伤大鼠脊髓兴奋性，其机制可能与通过残存5-HT能下行传导束增加递质分泌，改善脊髓上位中枢对脊髓损伤尾端的控制有关。     

Effects of Repetitive Facilitative Exercise on Spasticity in the Upper Paretic Limb After Subacute Stroke

Background

Repetitive facilitative exercise is an effective method for recovery of the affected limb in stroke patients. However, its effects on spasticity are unknown. We aimed to determine the effects of repetitive facilitative exercise on spasticity using the Modified Ashworth Scale (MAS) and the F-wave, and to determine the relationship between the changes in spasticity and functional recovery of the hemiplegic upper limb.

Effect of whole body vibration on spasticity in hemiplegic legs of patients with stroke

Background: Several reports have focused on the effects of whole body vibration (WBV) on spasticity with differing results. Most studies used modified Ashworth scale (MAS) for qualitative measurements, but the effect was small.

Objective: To investigate the effect of WBV on spasticity in hemiplegic legs of patients with stroke using F-wave parameters.

Methods: Sixteen patients with stroke (mean age, 54.7 ± 13.5 years: time after stroke, 28.0 ± 26.3 months) were enrolled in a comparative before-and-after intervention trial. WBV was applied at 30 Hz (4–8 mm amplitude) for 5 min on the hamstrings, gastrocnemius, and soleus muscles in a sitting position. Spasticity was assessed according to the F-wave parameters, MAS, and active and passive range of motion (A-ROM and P-ROM, respectively). These assessments were obtained before, immediately after, and 20 min after each intervention.

Results: The F-wave parameters, MAS score, and P-ROM improved significantly after the WBV and remained below the baseline level, even after 20 min; no such change was noted in the unaffected limb via the F-wave parameters. The WBV also improved volitional movement immediately after intervention, as indicated by the A-ROM.

Conclusions: These results confirmed a significant reduction of motor neuron excitability until 20 min after the WBV, as indicated by F-wave parameters.     

基于嵌入式的多路肌电信号采集系统的设计

采用直接内存存取(direct memory access,DMA)和双口随机存取存储器(dual-port random access memory,dual-port RAM)相结合的方式设计了基于嵌入式的多路肌电信号采集系统。该系统由现场可编程门阵列(field-programmable gate array,FPGA)控制模数转换器(ADC)器件的采样时序;ARM作为主控器件采用DMA方式的数据采集机制,实现了上下位机的高速通信。本研究给出了数据采集接口设计方案,以及Linux操作系统下的DMA驱动程序和控制指令。实验表明该系统在采集肌电信息的同时对肌电信息进行算法处理并实时传输,明显提升了多路肌电信号采集系统的性能。