神经电生理对腓总神经卡压的诊断价值

目的 观察神经电生理检测对腓总神经卡压的诊断价值。方法 对腓总神经卡压的临床特征及病因进行分析，并作神经传导速度和肌电图检测和分析。结果 21条患病神经中1条神经波形消失。其余有不同程度的传导速度减慢，尤其是跨腓骨小头段，波幅降低，传导时间延长，42块腓总神经支配的肌肉中有30块出现失神经电位。结论 神经电生理检查在腓总神经卡压的诊断中有重要意义。     

脊髓损伤大鼠的阴茎海绵体肌电图研究

目的探讨海绵体肌电图诊断脊髓性勃起功能障碍的价值。方法将24只成年雄性SD大鼠(300～400 g)分成:对照组、T9和L6损伤组(每组8只)。损伤脊髓1周后,用肌电图仪采集注射阿朴吗啡前后阴茎肌电数据,采集频率20～3 000 Hz、扫描速度5 ms／d、灵敏度10 μV／d。用t检验方法分析统计数据。结果对照组使用阿朴吗啡10 min均方根振幅为(5．60±0．89)μV, 大于T9损伤组(3．60±1．14)μV(P<0．05);使用阿朴吗啡前、使用后5 min和10 min高／低功率比均为0．05±0．03,小于L6损伤组0．13±0．04、0．15±0．07、0．13±0．07(P<0．05)。T9损伤组使用阿朴吗啡后5 min和10 min平均频率分别为(122．40±47．99)、(151．80±76．42)Hz,较L6损伤组(278．83±118．66)、(265．00±81．35)Hz低(P<0．05)。结论海绵体肌电图对脊髓性勃起功能障碍有诊断价值。     

Exploration simplifiée des atteintes plexiques par réduction aux atteintes nerveuses et radiculaires connues

The anatomic complexity of the brachial plexus makes its electrophysiological exploration difficult. Electrodiagnosis nevertheless plays a crucial role in assessing brachial plexopathies, particularly in the perspective of post-traumatic surgical reconstructions. The evaluation aims to locate as precisely as possible injuries within the plexus, as well as to determine their severity and capacity for recovery. This requires various sensory nerve conduction studies and needle EMG recordings of “marker” muscles. Plexopathies differ from radiculopathies by altered sensory nerve responses and unaltered functional innervation of paracervical muscles. We propose to simplify the exploration of brachial plexopathies by following some practical rules derived from a reanalysis of the brachial plexus anatomic sketch. Two main simplification rules can be deduced from an analysis of the anatomic sketch. First it would be judicious to associate the plexopathies involving a single element of the brachial plexus with distinct etiological and symptomatic patterns according to the altered element, as one does for peripheral nerve and root pathologies. The second proposal relies on the observation that each supraclavicular “truncal” element (upper, middle, or lower) of the brachial plexus results from reunion of cervical root nerves and behaves like a “super-root” for the upper limb, while each infraclavicular “cord” element (posterior, lateral, or medial) is the sum of two or more peripheral nerves and behaves like a “super-nerve”. Accordingly, the motor and sensory abnormalities associated with the lesion of a single plexus branch may occupy a clinical and electrophysiological territory that recovers those of its constituants. Except the unaltered paracervical muscles, it is useful to reduce the topographical semiology of truncal lesions to well-known cervical radiculopathies (upper trunk neuropathy to C5 and C6 associated radiculopathies, middle trunk neuropathy to C7 radiculopathy, lower trunk neuropathy to C8 and T1 associated radiculopathies); and that of cord lesions to well-known mononeuropathies of the upper limb (for example, a posterior cord neuropathy may be considered as a full radial mononeuropathy associated with an axillary one). This method of simplification allows to demystify the brachial plexopathies and to facilitate their comprehension and exploration.     

Advances in processing of surface myoelectric signals: Part 1

During sustained voluntary or electrically elicted muscle contractions the surface myoelectric signal is nonstationary and it undergoes progressive changes reflecting the modifications of the motor unit action potentials and their propagation velocity. In particular, during sustained electrical stimulation, the evoked signals show progressive amplitude, time scaling and shape modification. The quantitative evaluation of these changes is important for non-invasive muscle characterisation and may be performed in either the time or frequency domain using parametric and nonparametric spectral analysis as well as alternative methodologies. The paper introduces the detection techniques, reviews and compares the methods of spectral estimation based on FFT and autoregressive models, and discusses their applications and limitations in extracting information from the surface myoelectric signal with particular regard to myoelectric manifestations of localised muscle fatigue during sustained contractions.     

Fear and the startle reflex: Blink modulation and autonomic response patterns in animal and mutilation fearful subjects

The present study was designed to examine the pattern of startle reflex modulation and autonomic responses for individuals high in animal or blood-injury fear when viewing pictures of their feared objects. Sixteen individuals in each fear group and 16 low-fear control individuals viewed 32 color slides depicting fear-relevant, unpleasant but fear-unrelated, neutral, and pleasant scenes. Free viewing times were assessed in a second phase of the procedure as an index of avoidance behavior. Exposure to pictures of feared objects resulted in a consistent startle reflex potentiation and behavioral avoidance in both fear groups. This activation of the basic aversive system was independent of the autonomic pattern of the fear responses, which differed for the high-fear groups. These results suggest that the probe startle response indexes the organism's basic motivational disposition and add new information to the assessment of fear.     

Primary orthostatic tremor is an exaggeration of a physiological response to instability.

Primary orthostatic tremor (POT) is a rare disorder characterised by an intense sense of unsteadiness upon standing and a 16-Hz tremor in which the timing between tremor bursts in different muscles (unilateral and bilateral) remains constant. Hitherto, similar EMG activity has not been described in healthy subjects and it has been postulated that the oscillations seen in POT are primarily pathological. In this study, EMG was recorded from tibialis anterior in healthy subjects who were made unsteady through vestibular galvanic stimulation or leaning backwards. Under these conditions, a peak at approximately 16 Hz was seen in the coherence between the left and right tibialis anterior. This bilateral coherence was absent when the subjects activated the same muscles when not unsteady. These data indicate the existence of a physiological system involved in organising postural responses under circumstances of imbalance and characterised by a highly synchronised output at approximately 16 Hz. In addition, the results suggest that the core abnormality in POT may be an exaggerated sense of unsteadiness when standing still, which then elicits activity from a 16-Hz oscillator normally engaged in postural responses.     

TOCP染毒母鸡的神经电生理研究

对TOCP染毒母鸡进行为期7周的神经电生理监测,结果表明,TOCP主要影响远端周围神经,导致坐骨神经远端MCV和SCV减慢及腓肠肌EMG失神经样改变,而胫后神经H反射及重复电刺激无明显异常。     

Neuromuscular transmission as a function of motor unit size in patients with prior poliomyelitis.

We studied neuromuscular transmission in 16 patients with prior poliomyelitis by measuring single fiber electromyographic (SFEMG) jitter. This was compared with 3 indirect methods of assessing reinnervation: SFEMG fiber density, macro EMG, and the presence of fiber type grouping on muscle biopsy. In patients with acute poliomyelitis before the age of 10, there was a positive correlation between the extent of neuromuscular transmission impairment, demonstrated by increased SFEMG jitter, and the enlargement of the motor unit, as indicated by increased fiber density, increased macro EMG signals, and fiber type grouping on muscle biopsy. However, there was no correlation between any of these parameters and the presence or absence of new symptoms of weakness. These findings suggest that impaired neuromuscular transmission is most common in patients with prior poliomyelitis whose motor units have been maximally enlarged by axonal sprouting, but is independent of the presence or absence of new symptoms of weakness.