Electromyography and clinical neurophysiology (Electromyogr Clin Neurophysiol )


Incorporated into Clinical Neurophysiology (1388-2457)

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Publications in this journal

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    ABSTRACT: In Asia, many activities of daily living (ADL) are performed while sitting cross-legged on the floor. This sitting posture rotates the pelvis in a more dorsal direction and lumbar lordosis is more flattened than while sitting on a chair. Sitting cross-legged induces a greater load on the intervertebral discs and spine, especially when in a slumped position that is known to increase disc pressure even more and to aggravate chronic low back pain (CLBP). Therefore, it is very important to instruct Asian people about the correct sitting posture. In addition, it is known that co-contraction of the deep spine-stabilizing muscles enhances lumbar segmental stability and the sacroiliac joint. However, little is known about the influence of co-contraction of the trunk deep muscles on spinal curvature while sitting cross-legged on the floor. The purpose of this study was to compare EMG (electromyographic) activity of the trunk muscles while slump cross-legged sitting with that during co-contraction of the trunk muscles and to investigate how this co-contraction influences spinal curvature. Ten healthy male volunteers (21.7 +/- 2.5 years old) without CLBP participated in the study. Bipolar surface electrodes were attached to the rectus abdominis, the obliquus externus abdominis, the obliquus internus abdominis, the lower back extensor muscles (L3) and the multifidus on the right side. EMG signals were continuously recorded while slump sitting cross-legged and during co-contraction of the trunk muscles. They were amplified, band-pass filtered, digitized and stored by a data acquisition system. The average muscle activity values over the five-second sample for each sitting posture were normalized to maximal voluntary contractions (%MVC). While the subjects performed both sitting postures, the curvature of the spine was measured using a skin-surface and hand-held device, the "Spinal Mouse". More significant activities of the trunk muscles, with the exception of the rectus abdominis, were observed during co-contraction of the trunk muscles than while slump sitting cross-legged. The co-contraction of the trunk muscles resulted in significantly less thoracic and lumbar curvature and more sacral angle than while slump sitting cross-legged. The results of this study indicated that co-contraction of the trunk muscles while sitting cross-legged could bring about the correct thoracic and lumbar curvature, and effectively stabilize the lumbopelvic region, and decrease focal stress on passive structures.
    Electromyography and clinical neurophysiology 07/2013; 50(3-4):187-92.
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    ABSTRACT: 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.
    Electromyography and clinical neurophysiology 03/2010; 50(2):67-73.
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    ABSTRACT: The present study investigated the influence of a regular Physical Therapy program with emphasis on proprioceptive stimulation, on the center pressure trajectory and muscle adjustments necessary to maintain balance on orthostatic position. After medical assessment, 29 subjects (63.06 +/- 2.84 years) were submitted to electromyographic and baropodometric evaluation and, subsequently, to a program of 12 weeks of physical therapy intervention focusing on proprioceptive stimulation. The oscillation of the pressure center (Pressure platform-MatScanTekscan) was evaluated concomitantly to electromyographic signal envelopment and median frequency assessment of anterior tibial and gastrocnemius muscles (signal conditioner module--MCS 1000-V2-LYNX ). The Wilcoxon test was used for comparison of means, with the significance level of 5%. The pressure center trajectory unipodal position with open eyes (UO) decreased significantly after physical therapy intervention. In this position, there was a reduction of the electromyographic signal envelopment and an increase on median frequency of the gastrocnemius muscle, while the anterior tibial muscle showed increased median frequency after intervention. For the unipodal position with closed eyes (UC), the anterior tibial muscle showed significant electromyographic signal envelopment decrease and increase of median frequency, which also increased for the gastrocnemius muscle. It is concluded that the physical therapy intervention promoted decrease of body oscillation, recruitment improvement and adjustment of the gastrocnemius and anterior tibial muscles, contributing to the postural balance improvement in orthostatic position on senior population.
    Electromyography and clinical neurophysiology 03/2010; 50(2):113-9.
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    ABSTRACT: 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. 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. The statistical analysis revealed a reduction in pain, but there was no significant difference in electromyographic activity (p < 0.05). It was concluded that massage therapy was effective on pain symptoms, but was not capable of altering the electrical activity of the masseter muscle.
    Electromyography and clinical neurophysiology 03/2010; 50(2):107-12.
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    ABSTRACT: 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. 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). 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. 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.
    Electromyography and clinical neurophysiology 03/2010; 50(2):121-7.
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    ABSTRACT: Standing and walking balance decreases in many kinds of neuromuscular, musculoskeletal and sensory disorders, and in elderly people because of age-related physiologic diminution. Recent studies have shown that contact cues from a cane or a fingertip provide information that leads to reduced postural sway in subjects. The first purpose of this study was to investigate the influence of light and forceful fingertip contacts with a wall on the postural sway while standing upright. The second purpose was to investigate the influence of fingertip contact on the EMG activity of the soleus muscle. Twelve healthy male volunteers (20.8 +/- 0.7 years old) participated in this study. Standing balance or postural sway was measured by sway of the center of pressure (COP) under three conditions: (1) standing without touching a wall, (2) standing with the right index fingertip lightly touching (< 1N) to a wall (3), and standing with the right index fingertip forcefully touching (5 approximately 10N) to a wall. Bipolar surface electrodes were placed over the right soleus muscle to measure EMG activity associated with anterior-posterior sway. More significant length, and rectangular and environmental areas of the COP were observed while standing without touching a wall than while standing while lightly or forcefully touching a wall, but there was no significant difference between the two touching conditions. No significant difference in the EMG activity of the soleus muscle was observed among the three conditions. The results of this study suggested that the fingertip touch contact with a wall decreased sway during static standing but did not influence the EMG activity of the soleus muscle.
    Electromyography and clinical neurophysiology 01/2010; 50(5):229-33.
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    ABSTRACT: The neurological manifestations of Crohn's disease are rare, dominated by multiple mononeuropathies, peripheral neuropathies (PN) of axonal and demyelinating types, myopathies and the abnormalities of the white matter. In our study, we aimed to report electrophysiological follow-up of a patient with chronic polyradiculoneuritis associated with newly diagnosed active Crohn's disease. A 32-year-old male patient was admitted with the complaints of abdominal pain and diarrhea for three years and an ascending weakness of all four extremities since two years. On his medical history he did not have any other disease and none of the members of his family had similar complaints. The neurological examination revealed a weakness of the especially distal muscles (2-3/5) with areflexia, hypotonia and distal atrophia in all extremities. He also had a glove and stocking hypoestesia. Routine biochemical and hematological examination were in normal ranges except C-reactive protein. The analysis of the cerebrospinal fluid showed an albumino-cytological dissociation. Our results suggest that peripheral neurological findings could be regarded as a possible extraintestinal manifestation of Crohn's disease. It is important to remember that inflammatory bowel diseases may be a reason for a newly diagnosed polyneuropathy (acute or chronic demyelinated polyneuropathy) and therefore detailed examinations are needed if the patients do not have the commonly observed reasons for the development of polyneuropathy and be careful in inflammatory disease patient to develop polyneuropathy.
    Electromyography and clinical neurophysiology 01/2010; 50(3-4):181-5.
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    ABSTRACT: Temperature affects distal sensory & motor latencies & nerve conduction velocity but not necessarily at the same degree. Purpose of this study is to see which one is affected less and thus could be more reliable in cold conditions. A total of 32 healthy individuals with age range of 18-28 years (mean 22.25 +/- 2.2) participated in this study. Skin Temperature was recorded at wrist. Distal median motor & sensory latencies and transcarpal median NCV were recorded before and after immersion in cold water. Statistical analysis was performed using paired t-test with SPSS. All parameters were affected by cold but the effect was less dramatic in transcarpal NCV. Transcarpal median NCV is least affected parameter by cold, so it may be more reliable than sensory & motor latencies at wrist.
    Electromyography and clinical neurophysiology 01/2010; 50(5):235-8.
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    ABSTRACT: The study of brain activity has been studied with the use of various techniques like electroencephalography (EEG), magnetic resonance imaging (MRI), positron emission topography (PET) and magneto-encephalography (MEG). These techniques are unsuitable because of restriction of moving of subject's body while playing "shogi (Japanese Chess)" matching However, optical topography (OT) is possible to measure. Therefore, brain activity is here studied with use of OT. The measurement and analyses of the activity of brain is carried out by cerebral blood flow with use of OT. The equipment of OP is 16-channel maximum OMM-2000 device (Shimadzu, Tokyo, Japan). Two subjects play the game, and the cerebral blood flow of only one subject is measured, since the capacity of the equipment is limited. When the subject does decision-making for a matter of chance during the game, the right side of frontal part (Fp2) proves more activity than that of left side (Fp1), and proves that the activity of both parts of visual field (O1, O2) communicates each other. The present study with use of OT is highly useful for observing brain activity during play of shogi game.
    Electromyography and clinical neurophysiology 01/2010; 50(3-4):137-48.
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    ABSTRACT: 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.
    Electromyography and clinical neurophysiology 01/2010; 50(1):29-31.
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    ABSTRACT: PROPOSE: Compare the symmetry of the activity and masticatory muscles in individuals with TMD and asymptomatic. 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. 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). 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.
    Electromyography and clinical neurophysiology 01/2010; 50(7-8):333-8.
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    ABSTRACT: 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. 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. 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. 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.
    Electromyography and clinical neurophysiology 01/2010; 50(1):47-53.
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    ABSTRACT: This study used a within-subjects design. The purpose of this study was to examine cross-talk among monopolar surface electromyographic (EMG) signals from the superficial quadriceps femoris muscles. The "efficiency of electrical activity" technique for assessing muscle function uses monopolar EMG. Thus, knowledge of the potential for cross-talk among the superficial quadriceps femoris muscles when using monopolar recording will be valuable in rehabilitative settings. Fourteen healthy men (mean +/- SD age = 22.0 +/- 3.9 years) volunteered to perform submaximal to maximal isometric muscle actions of the dominant leg extensors in 10% increments from 10% to 100% of the maximum voluntary contraction (MVC). During each muscle action, monopolar surface EMG signals were detected from the superficial quadriceps femoris muscles. Three separate cross-correlations were performed to examine cross-talk among the vastus lateralis and rectus femoris, vastus medialis and rectus femoris, and vastus lateralis and vastus medialis. The peak cross-correlation coefficients ranged from R(x,y) = 0.182-0.944, with the greatest cross-talk occurring between the vastus lateralis and vastus medialis. In addition, the cross-correlation coefficients generally increased with force. These findings showed moderate to large degrees of crosstalk among monopolar surface EMG signals from the superficial quadriceps femoris muscles. Thus, the monopolar EMG signals from these muscles should be interpreted carefully and with the understanding that at least a portion of the signal from each muscle is due to cross-talk.
    Electromyography and clinical neurophysiology 01/2010; 50(5):245-50.
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    ABSTRACT: 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. 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. 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.
    Electromyography and clinical neurophysiology 01/2010; 50(7-8):322-5.
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    ABSTRACT: Hearing level in some children may be abnormal due to conductive or sensorineural causes. In Kuwait, the hearing screening test is not conducted for newborns at public hospitals. We evaluated the hearing level of 159 Kuwaiti school children (age 6-12 years) at the Audiology Clinic of Ahmadi hospital to determine the extent and causes of hearing loss in these children. Each child was evaluated by otoscopic examination, tympanogram, acoustic reflex threshold (ART), audiogram, and distortion product oto-acoustic emission (DPOAE). 120 children were found to have normal ear conditions, while 39 children had abnormal results. The abnormalities were 21 children with ear wax, 16 children with secretory otitis media (SOM), and 2 children with sensorineural hearing loss (SNHL). In the children with ear wax, 3 had normal hearing level, while 18 had mild conductive hearing loss in the 250-500 Hz frequency range. In the children with SOM, 3 had normal hearing level, 9 had mild conductive hearing loss in the 250-500 Hz frequency range, while 4 had moderate conductive hearing loss in the 250-2000 Hz frequency range. The children with SNHL had moderate hearing loss in the 4000-8000 Hz frequency range. Wax in the ear canal and SOM were the main factors associated with hearing loss in these Kuwaiti school children. It is necessary to establish a national program of school entry hearing screening in Kuwait.
    Electromyography and clinical neurophysiology 01/2010; 50(6):309-18.