Electromyography and clinical neurophysiology最新文献

Introduction: Orofacial pain and pain in the muscles of mastication are frequent symptoms of temporomandibular disorder. The masseter is the closet masticatory muscle to the surface and has the function of raising and retracting the mandible. This muscle has considerable strength and is one of the main muscles involved in the shredding of food It is therefore of utmost importance in the masticatory cycle and generally the most affected by pain and spasms.

Objectives: The aim of the present study was to analyze the effect of manual therapy with transversal and circular movements on pain and spasm in the masseter muscle, using electromyography and a visual analogue pain scale (VAPS). Eight women who experienced pain upon palpation of the masseter greater than 6 on the VAPS were selected for participation in the study, which employed electromyography and a VAPS for assessment, followed by manual oral physiotherapy and reevaluation.

Results: The statistical analysis revealed a reduction in pain, but there was no significant difference in electromyographic activity (p < 0.05).

Conclusion: It was concluded that massage therapy was effective on pain symptoms, but was not capable of altering the electrical activity of the masseter muscle.

Lack of sensitivity in clinical evaluation and imaging techniques often result in the potential misdiagnosis of the nerve root compromise in patients with non specific low back pain (NSLBP). H-reflex is reliable, valid, and sensitive electrophysiological procedure in detecting neural impingement in patients with low back pain of neurological origin and, thus, could be used to detect nerve root compromise in NSLBP To date, this has not been studied. The purpose of this study was to estimate the proportion of patients with NSLPB and neural compromise using the soleus H-reflex. Soleus H-reflex was measured bilaterally in 30 NSLBP patients with no radicular symptoms during prone lying and standing upright relaxed postures. Five traces were measured and averaged. Side-to-side amplitude (HIH) ratios were then calculated. Inference statistic estimated the proportion and 95% confidence intervals of patients with NSLBP and neural involvement. Soleus H-reflex asymmetry was detected in 17% and 20% of patients with NSLBP during lying and standing, respectively. In some patients, NSLBP may be associated with small degree of nerve root compromise, although the neural compromise is insufficient to cause distal radiculopathy. For these patients, treatment strategies to address such possible underlying mechanism of pain should be considered.

Purpose: The purpose of the present investigation was to determine the linearity and reliability of the electromyographic (EMG) amplitude versus dynamic torque relationships for the vastus lateralis (VL), rectus femoris (RF), and vastus medialis (VM).

Methods: Nine healthy men (mean +/- SD age = 25.3 +/- 4.7 years) and eleven healthy women (mean +/- SD age = 22.0 +/- 1.3 years) performed a series of randomly ordered, submaximal to maximal, concentric isokinetic muscle actions of the leg extensors at 30 degrees x s(1) on two occasions separated by at least 48 hours. During each muscle action, surface EMG signals were detected from the VL, RF and VM of the dominant thigh with bipolar surface electrode arrangements.

Results: The coefficients of determination for the EMG amplitude versus dynamic torque relationships ranged from r2 = 0.75-0.98 and 0.64-0.99 for the VL, r2 = 0.79-0.99 and 0.60-0.98 for the RFE and r2 = 0.44-0.98 and 0.51-0.98 for the VM for trials 1 and2, respectively. In some cases, the linear EMG amplitude versus torque slope coefficient for trial 1 was significantly different from that for trial 2 for the VL and RF, but not for the VM. The intraclass correlation coefficients for the linear EMG amplitude versus torque coefficients were 0.730 (VL), 0.709 (RF), and 0.888 (VM).

Conclusion: These results indicated that the EMG amplitude versus dynamic torque relationships for the superficial quadriceps femoris muscles did not demonstrate enough linearity and reliability to be used for examining the contributions of neural versus hypertrophic factors to training-induced strength gains.

Objective: The aim of this study was to compare the behavior of the major chewing muscles (anterior temporalis, masseter and suprahyoid muscles) by using two commercial chewing gums (A and B) and two insipid materials (cotton ball and Parafilm M) through analysis of electromyographic signals.

Method: Ten female young adult subjects, aged from 18 to 27 years, with normal occlusion and no history of craniomandibular disorder were studied The masticatory activity was performed with the subjects comfortably sat so that the Frankfurt plane was parallel to the floor. Electromyographic exams were carried out using bipolar surface passive mini-electrodes positioned on the anterior temporalis, masseter, and suprahyoid muscles. The subjects were guided to chew bilaterally and simultaneously each one of the materials, in aleatory sequence. For the study of the masticatory activity the electromyographic signals were processed through rectification, linear envelope and normalization, so that the coefficient of variation obtained from the procedure was comparatively analyzed. All data were submitted to analysis of variance (uni- and multi-varied).

Results: The results of this study indicated that the best materials for electromyographic studies on the chewing were Parafilm and cotton ball because they demonstrated the smallest coefficients of variation.

Conclusion: In addition, Parafilm showed the best palatability. In a general way, these materials are indicated for the accomplishment of electromyographic exams, since they demonstrated a smaller coefficient of variation as compared to the other materials.

The goal of this study was to establish how increased ventilation modifies postural stability, as characterized by body sway and leg muscle activities. Twelve healthy subjects had to perform six 30-second postural tests: one pre-exercise test while breathing gently and then one test every minute for the five minutes immediately following a maximum-intensity, incremental cycling exercise test. Subjects were asked to maintain an upright stance on a force plate for 30 s, with their eyes open. Movement of the centre of pressure in the sagittal plane was monitored in the time and spectral domains. Myoelectric activities of the soleus and tibialis anterior muscles were recorded using surface electromyography. Ventilatory parameters were measured with a portable, telemetric device. Postural changes related to respiratory variations were quantified by coherence analysis. The results showed that hyperventilation induced by exercise was accompanied by a significant increase in postural parameters, indicating a reduction in postural stability following a change in ventilatory drive. Coherence analysis confirmed the ventilatory origin of the postural oscillations. The results suggest that ventilation may be an important factor in postural disturbance during physical activity. The observed increases in leg muscle activities were most likely related to musculo-articular stiffening.

Objectives: The proposal of the present study is based on mobilizing the nervous system of the upper hemiplegic limb of stroke victims using the Upper Limb Neurodynamic Test (ULNT 1) and electromyographic analysis of the biceps brachii muscle.

Methods: A pre-experimental study was carried out with pretest and posttest repeated measurements on five stroke victims (4 men and 1 woman; mean age: 52.8 +/- 11 years), with Grade 1 and + 1 spasticity, according to the modified Ashworth scale. Electromyographic analysis of the biceps brachii muscle was performed with the elbow flexed at 90 degrees, following by complete extension.

Results: The neurodynamic test led to a decrease in electromyographic activity in the biceps brachii muscle (p < or = 0.05).

Conclusion: Neural mobilization was efficient in reducing myoelectric activity in the biceps brachii muscle in patients with stroke and may used by physiotherapists as an efficient method for treating patients with this pathology.

1. Single-nerve fibre action potentials (APs) were recorded with 2 pairs of wire electrodes from lower sacral nerve roots during surgery in patients with spinal cord injury and in a brain-dead human. Conduction velocity distribution histograms were constructed for afferent and efferent fibres, nerve fibre groups were identified and simultaneous impulse patterns of alpha and gamma-motoneurons and secondary muscle spindle afferents (SP2) were constructed. Temporal relations between afferent and efferent APs were analyzed by interspike interval (II) and phase relation changes to explore the coordinated self-organization of somatic and parasympathetic neuronal networks in the sacral micturition centre during continence functions under physiologic (brain-dead) and pathophysiologic conditions (spinal cord injury). 2. In a paraplegic with hyperreflexia of the bladder, urinary bladder stretch (S1) and tension receptor afferents (ST) fired already when the bladder was empty, and showed a several times higher bladder afferent activity increase upon retrograde bladder filling than observed in the brain-dead individual. Two alpha2-motoneurons (FR) innervating the external bladder sphincter were already oscillatory firing to generate high activity levels when the bladder was empty. They showed activity levels with no bladder filling, comparable to those measured at a bladder filling of 600 ml in the brain-dead individual. A bladder storage volume of 600 ml was thus lost in the paraplegic, due to a too high bladder afferent input to the sacral micturition center, secondary to inflammation and hypertrophy of the detrusor. 3. In a brain-dead human, 2 phase relations existed per oscillation period of 160 ms between the APs of a sphincteric oscillatory firing alpha2-motoneuron, a dynamic fusimotor and a secondary muscle spindle afferent fibre. Following stimulation of mainly somatic afferent fibres, the phase relations changed only little. 4. In a paraplegic with dyssynergia of the urinary bladder also 2 phase relations (less stable) existed per oscillation period of 110 ms in a functional unit between the APs of a sphincteric alpha-motoneuron, a fusimotor and a secondary spindle afferent fibre. The phase relations changed with time following stimulation of mainly somatic afferents. A second functional unit organized by phase related interactions was phase related to the first functional unit. 5. Following painful bladder catheter pulling, the parasympathetic division was transiently activated several times in the paraplegic. At times of activation of the parasympathetic division, 3 broad phase relations occurred within and between the two functional units, indicating that the parasympathetic division in the sacral micturition and defecation center channeled an additional input to the somatic oscillatory firing neuronal networks driving motoneurons which innervate the external bladder and/or anal sphincters. 6. It is conceivable that the mutual inhibitory ac

Objectives: The Sit-to-Stand test (SST) is accepted and utilized during functional assessments of COPD patients, along with the 6-Minute Walk test (6MWT). Since there is a lack of evidence in literature regarding the neurophysiological effectiveness of SST compared to 6MWT, the present study is justified with the purpose of assessing the neurophysiological effectiveness of SST in comparison to the 6MWT during the functional assessment of such patients, once it is known that both tests are good predictors of functional state.

Methods: Fourteen patients with moderate to severe COPD randomly performed the 6MWT and the SST with a 30-minute interval in between tests. Blood lactate was collected along with the median frequency (MDF), obtained with the electromyography of the muscles rectusfemoris (RF), vastus lateralis (VL), tibialis anterior (TA), and soleus (SO) for the comparison of the neurophysiological effectiveness.

Results: The results of the blood lactate concentration during rest and at the end of the functional tasks along with the results from the angular coefficient (AC) obtained from the median frequency were analyzed with the Student t test. The initial and final values obtained from SST and 6MWT were compared within each activity, along with the comparison between the initial and final values for each functional test. A significant difference (p = 0.0005) was only verified between the initial and final values of SST.

Conclusion: We found neurophysiological correlation between both tests which enabled us to suggest that SST may determine functional status as easily as the 6MWT in regard to neurophysiological effectiveness.

Diabetic neuropathy is one of the most common causes of peripheral neuropathy. Conventional electrodiagnostic evaluation or even magnetic resonance imaging (MRI) of lumbosacral vertebrae cannot confirm radiculopathy (e.g S1-root irritation) in diabetic neuropathic patients definitely. The purpose of the present study was to evaluate spinal nerve pathway of H-reflex in diabetic neuropathic patients by the central loop of H-reflex when its conventional pathway was impaired. No similar study, however, has been done on this subject. Forty two diabetic neuropathic patients with impaired conventional H-reflex were studied by the central loop of H-reflex bilaterally. The central loop of H-reflex was elicited by monopolar needle stimulation of S1 nerve root at the level of S1 foramen and recorded in the half way of the line from popliteal crease to the medial malleolus. In 82 out of 84 (97.6%) limbs with impaired conventional H-reflex, the central loop of H-reflex was measurable with latency less than 8 ms. Therefore the central loop of H-reflex was a more reliable approach for investigating S1-root in these patients with significant statistical difference (P < 0.001). The central loop of H-reflex latency in this study was 6.34 +/- 0.96 ms with the range of 4.3-7.85 ms. In conclusion the presence of central loop of H-reflex with latency less than 8 ms can be used as a complementary approach for assessment of S1-root sparing in diabetics.

Peripheral neuropathy is one of the most frequently reported neurological extra-intestinal manifestations of the Crohn disease. Former studies have showed sympathetic neuropathy as early manifestation of CD by physical tests. The aim of this study is to examine sympathetic neuropathy in CD by using sympathetic skin response (SSR). We performed SSR on 6 Patients (4 male, 2 female) that were diagnosed as CD. Their age was between 26 till 68 years with the mean of (43.3 +/- 17.1) years. The duration of their disease was at least 4 years (mean: 9.0 +/- 8.4) and none of the patients had any symptoms or signs related to autonomic nervous system dysfunction. Hand and foot latencies in CD patients were prolonged relative to controls and the difference of hand latencies was statistically significant. Two patients demonstrated total abnormal results. In conclusion, there is some sub-clinical sympathetic dysfunction in CD patient. This suggests that SSR can be useful in detecting early autonomic changes in these patients.