Electromyography and clinical neurophysiology最新文献

Background: The usual presentation of herpes zoster (HZ) is a self-limiting vesicular rash, often accompanied by post-herpetic neuralgia. However, HZ can give rise to other complications, that have unusual presentations and serious sequelae like segmental motor paralysis of the limbs that is a relatively rare complication.

Case: A 68-year-old man presented with foot drop on the right side had a history of HZ infection on and around the knee and the popliteal fossa. He was treated with acyclovir by a dermatologist and 10 days after the inital symptoms he developed weakness on the right ankle and on the muscles distal to the knee. In a few days foot drop has developed and he was unable to walk without help. Three months later he was admitted to the neurology out patient clinic. On his electrophysiological examination common peroneal nerve could not be stimulated on the right side. The distal latency of the tibial nerve has prolonged, CMAP amplitude has diminished and the nerve conduction velocity has slowed down. Latency of the sural nerve has prolonged with a small SNAP amplitude and a slow nerve conduction velocity on the right side. Electromyography revealed denervation on the muscles inervated by tibialis anterior and common peroneal nerves distal to the knee.

Conclusion: The double mononeuropathy of the tibial and common peroneal nerves secondary to HZ was not found in the published data. HZ should be considered as a possible cause of the paralysis of peripheral nerves and more attention should be paid to it.

Purpose: [corrected] Compare the symmetry of the activity and masticatory muscles in individuals with TMD and asymptomatic.

Methods: The study included 50 women, while 31 had temporomandibular disorders (TMD) and 19 were asymptomatic (control group), aged between 19 and 40 years. The volunteers were subjected to clinical examination of the diagnostic criteria in research with TMD (RDC/TMD) with the aim of diagnosing volunteers with or without TMD, and evaluate the electromyographic activity of the right temporalis muscle (TR) and left (TL), right masseter (MR) and left (ML), in situations of rest, isometric contraction of the muscles of the jaw elevators. We obtained the rates of activity and asymmetry in each situation and for the collection and TMD control groups.

Results: For the index of activity for the rest there was significant difference (p = 0.0008) between the control group and the TMD group, with predominance of temporal muscle, was not observed difference between groups for the index of activity during the isometric contraction (p = 0.1069). For the index of asymmetry no difference between groups during rest, for the masseter muscles (p = 0.4182) and the temporal (p = 0.7614), and also during the isometry for both masseter muscles (p = 0.8691) and for time (p = 0.6643).

Conclusions: The control group showed prevalence of TMD and temporal muscle during rest, which did not occur in the isometry, and no difference for the index of asymmetry between the groups for the masseter and temporal muscles.

The aim of this study was to investigate the influence of gender on the EMG signal of the muscles of the quadriceps femoris and the physical performance in high-intensity, short-term exercise. Fourteen volunteers (7 men = 29.1 +/- 2.8 years and 7 women = 22.6 +/- 2.9 years) performed a Wingate Test (WT) with a load of 7.5% of body mass. The variables analyzed during the WT were the Relative Peak Power (W.Kg(-1)) (RPP), Relative Mean Power (W.Kg(-1)) (RMP), Fatigue Index (%) (FI) and Peak Power Instant (s) (PPI). EMG signals of the superficial muscles of the quadriceps femoris (QF) from the right leg: rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM) were analyzed through root mean square (RMS) values and the normalized median frequency (MNF) determined using the Fast Fourier Transform (FFT). The RPP and the RMP were significantly higher in men when compared to women (9.99 +/- 0.96 vs. 7.66 +/- 1.00 W.kg(-1); 7.23 +/- 0.49 vs. 5.65 +/- 0.61 W.kg(1), P < 0.05; respectively). No significant difference between genders was found on RMS and NMF during WT (P > 0.05). Although RPP and RMP were influenced by gender, the RMS and the NMF of the superficial muscles of the QF did not show the same behavior, suggesting that other mechanisms, not related to motor unit recruitment and speed of nervous stimuli in the muscle fiber may be associated to the lower performance of women in high-intensity, short-term exercise.

Coordination Dynamics Therapy (CDT) has been shown to be able to partly repair CNS injury. The repair is based on a movement-based re-learning theory which requires at least three levels of description: the movement or pattern (and anamnesis) level, the collective variable level, and the neuron level. Upon CDT not only the actually performed movement pattern itself is repaired, but the entire dynamics of CNS organization is improved, which is the theoretical basis for (re-) learning transfer. The transfer of learning for repair from jumping on springboard and exercising on a special CDT and recording device to urinary bladder functions is investigated at the neuron level. At the movement or pattern level, the improvement of central nervous system (CNS) functioning in human patients can be seen (or partly measured) by the improvement of the performance of the pattern. At the collective variable level, coordination tendencies can be measured by the so-called 'coordination dynamics' before, during and after treatment. At the neuron level, re-learning can additionally be assessed by surface electromyography (sEMG) as alterations of single motor unit firings and motor programs. But to express the ongoing interaction between the numerous neural, muscular, and metabolic elements involved in perception and action, it is relevant to inquire how the individual afferent and efferent neurons adjust their phase and frequency coordination to other neurons to satisfy learning task requirements. With the single-nerve fibre action potential recording method it was possible to measure that distributed single neurons communicate by phase and frequency coordination. It is shown that this timed firing of neurons is getting impaired upon injury and has to be improved by learning The stability of phase and frequency coordination among afferent and efferent neuron firings can be related to pattern stability. The stability of phase and frequency coordination at the neuron level can therefore be assessed integratively at the (non-invasive) collective variable level by the arrhythmicity of turning (coordination dynamics) when a patient is exercising on a special CDT device. Upon jumping on springboard and exercising on the special CDT device, the intertwined neuronal networks, subserving movements (somatic) and urinary bladder functions (autonomic and somatic) in the sacral spinal cord, are synchronously activated and entrained to give rise to learning transfer from movements to bladder functions. Jumping on springboard and other movements primarily repair the pattern dynamics, whereas the exactly coordinated performed movements, performed on the special CDT device for turning, primarily improve the preciseness of the timed firing of neurons. The synchronous learning of perceptuomotor and perceptuobladder functioning from a dynamical perspective (giving rise to learning transfer) can be understood at the neuron level. Especially the activated phase and frequency coor

Introduction & objective: Nerve conduction study is the most sensitive test for diagnosis of carpal tunnel syndrome (CTS). This test is normal in some patients with mild CTS. Median nerve conduction study evaluation after a provocative test (e.g. wrist flexion) may be helpful for diagnosis of mild CTS. This study aimed to determine the effect of wrist flexion on median nerve conduction in patients suspected to CTS and in healthy subjects.

Materials & methods: In this case-control study, 20 patients (20 hands) with clinical signs of CTS and normal routine electrodiagnosis test results and 20 healthy subjects were investigated. Measured parameters included: median nerve distal sensory latency (DSL), nerve conduction velocity (NCV) across wrist, compound nerve action potential (CNAP), distal motor latency (DML) and compound muscle action potential amplitude CAMPAMP). The above noted parameters were measured before and after 5 minutes of full wrist flexion. Data were analyzed using paired T-test.

Results: Distal Sensory Latency increment and NCV decrimental after 5 minutes of wrist flexion in the patients group were statistically significant (p > 0.05). The same parameters did not show significant incremental or detrimental changes in the control group.

Conclusion: Median nerve DSL and NCV measurement after 5 minutes of wrist flexion may be helpful in determining more sensitive parameters in the electrodiagnosis of CTS.

The purpose of this study was to determine the most sensitive diagnostic test for nerve conduction study (NCS) of the foot for early detection of diabetic polyneuropathy. We compared the sensitivities for diagnosis of sensory polyneuropathy of four different nerve conduction techniques in the same nerves: nerve conduction studies of the medial plantar nerve with surface electrodes using three different techniques and a nerve conduction study of the digital and interdigital nerves of the foot using a near-nerve needle technique. In 25 patients with diabetic polyneuropathy with normal routine NCS, diagnosis of sensory neuropathy was confirmed by medial plantar NCS in 5 patients (20.0%) using Guiloff's method, in 5 patients (20.0%) using Ponsford's method and in 9 patients (36.0%) using Hemmi's method. In digital and interdigital NCS of the foot, a definite neuropathy pattern was observed in 15 patients (60.0%). The most common abnormality was low amplitude of sensory nerve action potential, indicating axonal degeneration. This study demonstrated that digital and interdigital NCS using the near-nerve needle technique is a more sensitive method for detection of early-stage diabetic polyneuropathy.

Background: Visual processing in migraine has been targeted indicating that the visual pathways are involved in the migraine pathophysiology. We aimed to assess the nature of visual evoked potential (VEP) changes in migraine patients and to evaluate the role of VEP in the diagnosis of migraine.

Materials and methods: We examined 31 female and 10 male patients with a migraine headache diagnosis according to the criteria of the International Headache Society. Control subjects had neither migraine and other types of primary headache nor familial history. VEP were elicited using a checkerboard by monocular and binocular pattern reversal stimulation. The latencies of N75, P100 and N145 and peak-to-peak amplitude of N75-P100 were measured. We compared VEP latencies and amplitudes of the monocular and binocular stimulation within each population.

Results: The N75 and P100 latencies were found to be significantly longer in the study group than the control group (p = 0.014 and p = 0.034, respectively) while the amplitudes in the study group were lower (p = 0.014). N145 latency was found to be longer in patients with longer duration of disease (p < 0.05). P100 latency was found to be significantly longer in patients with aura than the patients without aura (p = 0.029). N75 latency, recorded by left monocular stimulation, was elongated and the amplitude was diminished with left hemicranial headache.

Conclusion: Measurement of VEP latency and amplitude is a valuable and reliable test for the diagnosis of migraine. Our results reflect a persisting dysfunction of precortical visual processing which might be relevant in the pathogenesis of migraine.

The aim of the present study was to analyze the electromyographic (EMG) signals of the rectus femoris (RF), vastus lateralis (VL), tibialis anterior (TA) and soleus (SO) muscles in young healthy adults with and without the use of an experimental ankle-foot-orthosis (AFO) designed for patients with hemiparesis. Twenty-eight individuals with an average age of 22 +/- 3.63 years participated in the study. An electromyograph, surface electrodes and two force plates were used. There was a non-significant increase in the TA activity with the use of the AFO (6.04 +/- 2.81) when compared to non-use (5.91 +/- 2.49) (p > 0.5); the same was true for the other muscles evaluated. There was a positive correlation (r = 0.37) between TA and SO activity (p < 0.05). The results demonstrate that the AFO did not affect the gait pattern of healthy young adults.

The purpose of the present study was to examine the acute effects of passives stretching versus prolonged vibration on the active and passive properties of voluntary and evoked muscle actions of the plantar flexors. Eleven healthy men performed the isometric maximal voluntary contractions (MVCs) and passive range of motion (PROM) assessments before and after 20 min of passive stretching (PS), vibration (VIB), and control (CON) conditions. In addition, percent voluntary activation was calculated from superimposed and potentiated doublets during the MVCs. Voluntary peak torque (PT) decreased by 11% and 4%, while surface electromyographic (EMG) amplitude decreased by 8% and 16% for the PS and VIB, respectively, with no changes during the CON The electromechanical delay (EMD) decreased and PROM increased following the PS, but was unchanged during the VIB and CON conditions. Musculotendinous stiffness (MTS) decreased at all joint angles following the PS, but decreased only at the furthest joint angle following the VIB. There were no changes in peak twitch torque (PTT), M-wave amplitude, and EMG amplitude during the PROM assessments for all conditions. Both PS and VIB elicited similar decreases in muscle activation, which may be the same centrally-mediated mechanism (i.e., y loop impairment). Changes in the EMD were inversely proportional to the changes in MTS, which occurred only following PS. The present findings indicated that the stretching- and vibration-induced force deficits may have resulted in part from similar centrally-mediated neural deficits, while an elongation of the series elastic component may also have affected the stretching-induced force deficit.

Objective: This study reports cognitive, P300 and MRI changes in the patients undergoing open heart surgery.

Design: 18 patients undergoing open heart surgery were included who were aged > or = 18 years of age and educated at least up to 5th standard. Patients with preoperative neuropsychiatric, and metabolic illnesses were excluded. The operative and post operative events wer recorded Cognitive tests included Mini Mental State examination (MMSE), forward and backward digit span, trail making test (TMT), motor speed and precision test (MSPT), Luria's 3 step, Benton visual retention test (BVRT) and hospital anxiety and depression (HAD). P300 study was carried out using auditory oddball paradigm and recording from Cz, Fz and Pz referred to mastoids. Clinical psychometry, MRI and P300 studies were repeated after 6 weeks.

Results: The median age of the patients was 51 years and 7 were females. Coronary artery bypass graft (15) was done off pump and valve replacement (7) and atrial septal defect (2) were done on pump. Clinical psychometric tests did not change significantly after surgery except BVRT and MSPT were improved significantly after the surgery. The pre and post surgical P300 latency and amplitude were also not different. Follow up MRI in 10 patients also did not reveal any additional findings.

Conclusion: Cognitive decline was not observed after open heart surgery as assessed by clinical psychometry and P300 studies.