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Electrodiagnostic medicine is a specific area of physical medicine and rehabilitation in which a physiatrist uses clinical history, physical examination, and the techniques of electrophysiologic study to diagnose and treat neuromuscular disorders. The roles of electrodiagnosis include (1) determining the localization and distribution of a lesion and severity of a disease, (2) characterizing the evolution of a disease, (3) estimating prognosis, (4) differentiating neuropathy and myopathy, and (5) monitoring the response to a treatment. For these to be achieved, a logical approach during every step of testing is needed, followed by data interpretation and clinical correlations.

To investigate the immediate effects of bilateral upper-extremity sanding exercises on conduction and morphologic characteristics of the median and ulnar nerves at the wrist in hemiparetic subjects and control subjects.Case control study using a pretest-post-test design.Inpatient rehabilitation department affiliated with a teaching hospital.Thirty hemiparetic subjects and 21 matched control subjects who met our inclusion criteria and had no history of diseases that may have predisposed them to peripheral neuropathies were recruited for this study.Bilateral nerve conduction tests and ultrasonographic evaluations were performed on each subject before and immediately after a 30-minute bilateral sanding exercise with a frequency of 5 repetitions per minute.The effects of exercises on bilateral median and ulnar wrist nerves were assessed with the use of sensory and motor nerve conduction velocity tests and by width/thickness ratios in ultrasonographic evaluations.In the hemiparesis group, the pre-exercise amplitude of the motor component for the median and ulnar nerves were respectively lower than the corresponding values in the control group (P.05), whereas the pre-exercise amplitude and velocity of the sensory component were lower than the corresponding values in the control group (P.01). After the exercise, the assessments for the affected side showed reductions in the conduction velocity of the sensory component and an increase in the width/thickness ratio for the median nerve (P.05).The median and ulnar nerves at the wrist in hemiparetic subjects before sanding exercises showed different conduction characteristics compared with control subjects. Their affected side also demonstrated significant conduction and morphologic changes after the exercises. These subclinical findings may be attributed to different mechanisms such as overuse, spasticity, and demyelinating changes. Prevention of these subclinical changes is recommended to enhance exercise safety in hemiparetic patients.

Chang C-W, Chang K-Y, Chen Y-R, Kuo P-L. Electrophysiologic evidence of spinal accessory neuropathy in patients with cervical myofascial pain syndrome. Objective To evaluate whether or not spinal accessory neuropathy exists in patients with cervical myofascial pain syndrome (MFPS). Design Prospective study. Setting A neurophysiologic laboratory in a university hospital. Participants Patients with cervical MFPS (n=25) and healthy controls (n=20). Interventions Not applicable. Main Outcome Measures We performed nerve conduction studies (NCSs) in bilateral spinal accessory nerves, and electromyography and stimulated single-fiber electromyography in the trapezius muscles of all patients and controls. Parameters including nerve conduction velocities (NCVs), amplitudes and areas of compound muscle action potentials (CMAPs), and mean consecutive differences (MCDs) in single-fiber electromyography were measured, analyzed, and compared with the disease durations of the patients. Results Spinal accessory NCSs showed normative NCVs but with prominently reduced CMAP amplitude in the patients with cervical MFPS, which is recognized as an axonal neuropathy of the spinal accessory nerves. Electromyography showed prominent evidence of denervation and reinnervation patterns in 48% of the MFPS patients. The abnormal MCDs in single-fiber electromyography indicated a synaptic delay of motor endplates in the motor units, and may signify evolving instability of neuromuscular transmission in the spinal accessory nerves innervating trapezius muscles of the patients. Conclusions This study demonstrates electrophysiologic evidence of neuroaxonal degeneration and neuromuscular transmission disorder in a significant proportion of patients with cervical MFPS. We suggest that spinal accessory neuropathy may be associated with cervical MFPS.

This study was done to evaluate the effect of rising temperature on nerve conduction parameters in 22 patients with carpal tunnel syndrome (CTS). We wanted to find out whether diseased nerves responded to temperature rise in a different manner from normal controls. For this purpose a group of 20 healthy individuals were also tested. With rising temperature motor nerve conduction velocities increased, whereas latencies, amplitudes and duration of the compound muscle action potential decreased in both groups. These changes were not statistically significant between the two groups. Sensory nerve conduction parameters yielded basically similar findings except for a significantly smaller reduction in amplitude of the compound nerve action potential (CNAP) in the CTS group (p < 0.005). We conclude that there is a different response in the sensory CNAP amplitude between normal and CTS groups, but the same nerve conduction correction formulae for temperature can be used in CTS patients as in normal individuals in the event of low skin temperature.

OBJECTIVE. We investigated how verbal instructions and target location interacted to influence reaching movement of the less-affected limb in participants with and without unilateral cerebrovascular accidents (CVAs). METHOD. Using a counterbalanced repeated-measures design, 26 people with CVA and 24 age-matched healthy people performed the reaching tasks under 4 conditions formed by the crossing of verbal instructions (speed and accuracy emphasis) and target locations (ipsilateral and contralateral to the performing hand). RESULTS. In the control groups, speeded instructions and ipsilateral reaches elicited significantly more preprogrammed movements than did accuracy instruction and contralateral reaches, respectively. Similar patterns of performance in response to task constraints were found in the CVA groups except for movement initiation in the right CVA group. CONCLUSION. Instruction and locations interacted to constrain reaching movements in both control and CVA groups. The combination of speeded instruction and ipsilateral reach may optimize movement performance of the less-affected limb in stroke patients.

Background and PurposeThe purpose of this study was to compare the use of 3 mobilization techniques—end-range mobilization (ERM), mid-range mobilization (MRM), and mobilization with movement (MWM)—in the management of subjects with frozen shoulder syndrome (FSS).SubjectsTwenty-eight subjects with FSS were recruited.MethodsA multiple-treatment trial on 2 groups (A-B-A-C and A-C-A-B, where A=MRM, B=ERM, and C=MWM) was carried out. The duration of each treatment was 3 weeks, for a total of 12 weeks. Outcome measures included the functional score and shoulder kinematics.ResultsOverall, subjects in both groups improved over the 12 weeks. Statistically significant improvements were found in ERM and MWM. Additionally, MWM corrected scapulohumeral rhythm significantly better than ERM did.Discussion and ConclusionIn subjects with FSS, ERM and MWM were more effective than MRM in increasing mobility and functional ability. Movement strategies in terms of scapulohumeral rhythm improved after 3 weeks of MWM.

Objective To demonstrate a method of sensory nerve conduction study (NCS) for the medial calcaneal nerve (MCN) and confirm the medial calcaneal neuropathy in patients with plantar fasciitis (PF). Methods Twenty-six patients with clinical and ultrasonographic diagnosis of PF participated in the present study. An antidromic method for sensory NCS of MCN was performed in each patient and in 30 controls. The conduction latency, sensory nerve conduction velocity (SNCV) and amplitude of the sensory nerve action potential (SNAP) were measured and the correlation of the SNCV of MCN with both body weight and body mass index (BMI) was studied. Results The mean conduction latency obtained in the MCN was greater in the PF patients than in the normal controls. Mean SNCV and SNAP amplitude of the MCN were significantly less in the PF patients than in the normal controls. Body weight and BMI were greater in PF patients than in controls. Six patients were identified as having a medial calcaneal neuropathy by using the criteria of the lowest normal values of the NCS of MCN from the normal controls. Conclusions Medial calcaneal neuropathy is associated with PF. The present method of sensory NCS is useful and objective in the diagnosis of the medial calcaneal neuropathy. Significance Medial calcaneal neuropathy was confirmed by the sensory NCS of MCN and shown to be associated with PF.

Understanding the control of movement requires an awareness of how tasks constrain movements. The present study investigated the effects of two types of task constraints—spatial accuracy (effector size) and target location—on reaching kinematics. 15 right-handed healthy young adults (7 men, 8 women) whose mean age was 23.6 yr. ( SD = 3.9 yr.) performed the ringing task under six conditions, formed by the crossing of effector size (larger vs smaller size) and target location (left, right, or a central position). Significant main effects of effector size and target location were found for peak velocity and movement time. There was a significant interaction for the percentage of time to peak velocity. The findings suggested that task constraints may modulate movement performance in specific ways. Effects of effector size might be a consequence of feedforward and feedback control, and location effects might be influenced by both biomechanical and neurological factors.

Study design: A study of the clinical features, physical activity, muscle enzyme, electromyography and histopathological alternations of muscles in patients with post-polio syndrome (PPS). Objective: To assess the varied patterns of PPS in Taiwan. Setting: Taiwan. Methods: Thirty-one patients who fulfill the inclusion criteria of PPS were selected for study. Clinical features, physical activity scale, serum concentrations of creatine kinase, electromyography and histopathological alterations of muscles were assessed and correlated to the causes of PPS patients. Results: Patients with PPS in Taiwan are relatively young, with a mean age of 39.3 years. Elevated concentration of creatine kinase was found predominantly in male patients with higher physical activities. Electromyographic examinations as well as histological tests of affected muscles revealed prominent evidence of chronic and active denervation with reinnervation in PPS patients. Conclusion: Patients with PPS in Taiwan are young. Thus, PPS should not be attributed to aging. Physical attrition with degradation of nerve terminals is considered the main cause of this disease. Sponsorship: This study was supported by the National Science Council, Republic of China under grant no. NSC-83-0412-B002-302. Spinal Cord (2001) 39, 526–531.

Objectives : To evaluate the primitive reflexes by electrophysiological assessments and their correlation with the cognitive and physical functioning of stroke patients. Methods : Electrophysiological studies of primitive reflexes including jaw jerk, snout reflex, glabellar reflex, and corneomandibular reflexes were performed in 38 stroke patients and 26 normal controls. Cognitive function of patients was assessed by Modified Mini-Mental State (3MS) Examination and logical memory test. The Chinese Functional Independence Scale (CFIS) was used to evaluate the physical functioning and social domains of stroke patients. Results : The presence rate of primitive reflexes was higher in stroke patients than in normal controls. Wave amplitude of snout and corneomandibular reflexes obtained from stroke patients was greater than those from controls. No definite difference in reflex conduction latencies was observed between the two groups. A regression relationship was noted between the wave amplitude of snout reflexes and the 3MS and CFIS scores of stroke patients. Conclusion : Primitive reflexes can be measured by electrophysiological assessments. The results may serve as an objective and useful parameter in evaluation of cognition and physical functioning of stroke patients.

We report a 47-year-old male stroke patient with nasopharyngeal cancer (NPC) and protein C deficiency. The patient was diagnosed with NPC and received a complete course of radiotherapy. Infarction stroke occurred 28 months after radiotherapy and magnetic resonance imaging of the brain confirmed the diagnosis. Carotid duplex sonography showed 50–79% stenosis in his left internal carotid artery. Coagulation profiles indicated protein C deficiency. After medical treatment and rehabilitation, the patient regained the ability to walk and he could perform most of his daily activities. Radiotherapy-induced carotid stenosis is an exacerbating feature of stroke in patients with protein C deficiency. We suggest early carotid duplex sonography and survey of the coagulation profile to prevent a stroke in patients with NPC.

Neuronal degradation accompanied by axonal degeneration has been known to occur in lower motor neurons following a stroke. In the present study, the functional integrity of neuromuscular transmission was assessed, utilizing a sensitive electrodiagnostic method consisting of stimulated single-fiber electromyography (SFEMG), along with axonal microstimulation, in paralytic muscles of stroke patients. Neuromuscular jitter was measured in the hemiplegic side extensor digitorum communis (EDC) as well as in anterior tibial (AT) muscles for 28 stroke patients and also for 13 age-matched controls. The disease duration, i.e. from the onset of stroke until the stimulated SFEMG examination, extended from 2 months to 8 years. Mean jitters obtained in EDC and AT muscles of stroke patients were found to be significantly greater than those in normal controls. Mean jitters obtained in severely weak muscles of stroke patients were greater than those in moderately weak muscles. Positive correlations were noted between the increased jitter and the disease duration from the onset of stroke until the time of the stimulated SFEMG test. These findings demonstrate a dysfunction of neuromuscular transmission in the paralytic muscles of stroke patients and suggests that trans-synaptic degeneration of motor neurons may occur in stroke. Furthermore, the neuronal degradation in stroke was positively correlated with the course duration of the disease.

Retrospective case study.Report a rare case of cervical myelopathy induced by calcium pyrophosphate dehydrate (CPPD) deposition in multiple cervical levels.An area teaching hospital in Taiwan.A patient with cervical myelopathy was evaluated by computerized tomography (CT) scan and magnetic resonance (MR) image. CPPD deposition known as pseudogout was diagnosed and approved by a polarized microscope.A prominent hypertrophy of ligmentum flavum and a retro-odontoid bulging mass induced cord compression were found in CT scan and MR image. CPPD deposition was confirmed by the histological examinations in the ligamentum flavum at the spinal levels of C3-C6. After decompression surgery of spine and comprehensive rehabilitation, the patient's neurological symptoms subsided and her neurological functions improved leading to a good prognosis.CPPD deposition in cervical spine occurring at multiple levels is rare. Image studies with CT scan and MR are complementary in the diagnosis of CPPD-induced myelopathy. Surgical decompression is always required and expected to have a good outcome.

Study Design A prospective motor-evoked potential study with measurement of spinal cord motor conduction velocity in the thoracolumbar cord was performed before and after decompression surgery in 30 patients with cervical spondylotic myelopathy. Objectives To evaluate the neurofunctional integrity of the spinal motor pathways in cervical spondylotic myelopathy in patients compared with age-matched control subjects; to assess any changes after posterior surgical decompression; and to correlate such changes with functional outcomes so that the predictability of preoperative motor-evoked potentials could be determined. Summary of Background Data Previous studies evaluating neurologic function and predictability of surgical results in cervical spondylotic myelopathy patients always depended on the morphologic changes of the cord and spinal structures. The recently developed motor-evoked potential study and noninvasive measurement of spinal cord motor conduction velocity may provide an objective method to evaluate physiologic motor function in cervical spondylotic myelopathy patients. Methods Spinal cord motor conduction velocity in the thoracolumbar cord was measured using percutaneous magnetic stimulation over the motor cortices and F-wave studies in median and peroneal nerves. Motor function of cervical spondylotic myelopathy patients was graded according to evaluation of signs of cord involvement, ambulation, and degree of dependence in activities of daily living. Evaluation was performed at 6 months, 1 year, and 2 years after decompression surgery. Results Motor functional improvement accompanied by increased spinal cord motor conduction velocity occurred in Grade I patients with a mild neurologic dysfunction but not in Grade II or III patients with a moderate-to-severe neurologic deficit. Neurologic improvement does not appear to occur until 6 months after surgery. Conclusions Measurement of spinal cord motor conduction velocity may provide an objective and quantitative approach to assessing the motor functional integrity of the spinal cord and serving as a predictor in evaluating surgical outcome in patients with cervical spondylotic myelopathy.

Objective To investigate the relative and absolute reliabilities of the myotonometer. Design Psychometric study. Setting Three medical centers. Participants Patients with stroke (N=61). Interventions Not applicable. Main Outcome Measures Muscle tone, elasticity, and stiffness of relaxed affected deltoid, triceps brachii, biceps brachii, extensor digitorum, flexor carpi radialis, and flexor carpi ulnaris were measured twice, 30 minutes apart, using the myotonometer. Intraclass correlation coefficient, a relative reliability index, was calculated for 3 muscular properties and for each muscle to examine the degree of consistency and agreement between the 2 test sessions. Absolute reliability indices, including the SEM, smallest real difference, and Bland-Altman limits of agreement, were used to quantify measurement errors and check systematic biases of the 2 test sessions. Results The intraclass correlation coefficients were .83 to .95 for muscle tone, elasticity, and stiffness of all muscle groups. The SEM and the smallest real difference of muscle tone, elasticity, and stiffness of the biceps were the smallest among the 6 muscles tested. The Bland-Altman analyses showed no systematic bias between most of the repeated measurements. Compared with other muscles, biceps had narrower limits-of-agreement ranges, indicating that the myotonometric measurements of the biceps had higher stability and less variation over time. Conclusions The myotonometer reliably measures muscular properties, with good relative and absolute reliabilities. These findings are useful for clinicians and researchers to assess muscle properties reliably and determine whether a real change has occurred in groups and on individual levels of patients with stroke.

Treatment strategies targeting abnormal shoulder kinematics may prevent pathology or if the pathology develops, shorten its duration. We examined the effectiveness of the end-range mobilization/scapular mobilization treatment approach (EMSMTA) in a subgroup of subjects with frozen shoulder syndrome (FSS). Based on the kinematics criteria from a prediction method, 34 subjects with FSS were recruited. Eleven subjects were assigned to the control group, and 23 subjects who met the criteria were randomly assigned to the criteria-control group with a standardized physical therapy program or to the EMSMTA group. Subjects attended treatment sessions twice a week for 8 weeks. Range of motion (ROM), disability score, and shoulder complex kinematics were obtained at the beginning, 4 weeks, and 8 weeks. Subjects in the EMSMTA group experienced greater improvement in outcomes compared with the criteria-control group at 4 weeks (mean difference=0.2 of normalized hand-behind-back reach) and 8 weeks (mean difference=22.4 degrees humeral external rotation, 0.31 of normalized hand-behind-back reach, 7.5 disability, 5 degrees tipping and 0.32 rhythm ratio). Similar improvements were found between the EMSMTA group and control group. The EMSMTA was more effective than a standardized physical therapy program in a subgroup of subjects who fit the criteria from a prediction method.

The Tromner sign is commonly used as a clinical neurological examination for upper motor neuron lesions above the fifth or sixth cervical segments of the spinal cord. This study aims to assess and quantify the Tromner signs utilizing electrophysiological test, and correlate to the severity of cord compression in cervical spondylotic myelopathy (CSM). We enlisted 46 CSM patients, and 30 healthy persons as controls. Manual Tromner and Hoffmann signs were tested in all subjects. By using a self-designed instrument, we performed electrophysiological assessments for the Tromner signs in patients and controls. Parameters of conduction latencies and amplitude of muscle action potentials were measured and compared with the cord compression ratios in CSM patients. The results showed a greater diagnostic sensitivity for the quantified Tromner signs in comparison to those of manual Tromner signs and Hoffmann signs. We found a positive correlation between the amplitude of muscle action potentials obtained in the Tromner signs and the cord compression ratios in the patients with CSM. In conclusion, the Tromner signs can be measured by electrophysiological assessments. We demonstrate a new quantification method for an established neurological sign. Not only is Tromner sign a highly sensitive test in clinical neurological examination, the electrophysiological assessment of this sign can also serve as an objective marker for evaluation of the severity of cervical cord compression.

Physical therapy is an intervention commonly used in the treatment of subjects with frozen shoulder symptoms, with limited proven effect. The purpose of this study was to identify the kinematic features of patients with frozen shoulder who are more likely to respond to physical therapy. Thirty-four subjects presenting frozen shoulder syndrome were studied to determine altered shoulder kinematics and functional disability. Subjects received the same standardized treatment with passive mobilization/stretching techniques, physical modalities (i.e. ultrasound, shortwave diathermy and/or electrotherapy) and active exercises twice a week for 3 months. Initially, subjects were asked to perform full active motion in 3 tests: abduction in the scapular plane, hand-to-neck and hand-to-scapula. During the test, shoulder kinematics were measured using a 3-D electromagnetic motion-capturing system. In the initial and follow-up sessions, the self-reported Flexilevel Scale of Shoulder Function (FLEX-SF) was used to determine functional disability from symptoms. Improvement with treatment was determined using percent change in FLEX-SF scores over three months of treatment [(final score-initial score)/initial score x 100,20% improvement and= 20% nonimprovement]. Shoulder kinematics were first analysed for univariate accuracy in predicting improvement and then combined into a multivariate prediction method. A prediction method with two variables (scapular tipping8.4 degrees during arm elevation, and external rotation38.9 degrees during hand to neck) were identified. The presence of these two variables (positive likelihood ratio=15.71) increased the probability of improvement with treatment from 41% to 92%. It appears that shoulder kinematics may predict improvement in subjects with frozen shoulder syndrome. Prospective validation of the proposed prediction method is warranted.

Background Work-related upper limb amputations account for a significant number of occupational injuries. This study analyzes the nationwide incidence of work-related amputations of upper limbs in Taiwan by using the workers' compensation database. Methods A total of 2,950 cases were retrieved and analyzed from the database of workers' compensatory disability claims between the years 1999 and 2001. Results The cases were workers with an average age of 39.1 years, of whom 23.0% were female, the highest percentage of cases was in the 30–49 age group, but the incidence based on insured population was the highest for those under 20 years old. About 96% of the cases involved finger amputation, and 85% of all amputations were related to common powered machines. The average annual incidence of disability claims due to occupational amputation of upper extremities was 12.5 per 100,000 workers. Claims were most prevalent among manufacturing workers and male workers. The male to female risk ratios ranged from 2.62 for manufacturing workers to 9.05 for transport, storage and communication workers by the Poisson regression analysis. Conclusions Young male manufacturing workers were at high risk of occupational amputation of upper extremities in Taiwan. These results provide an epidemiological base for developing a prevention strategy. Am. J. Ind. Med. 46:649–655, 2004. © 2004 Wiley-Liss, Inc.

To evaluate the chronodispersion and tacheodispersion of F waves in patients with spinal cord injury and to determine whether these parameters are more sensitive than those of standard F waves.F chronodispersion and F tacheodispersion as well as F wave latencies, amplitude, and persistence were measured in tibial nerves of 23 male patients with different scales of spinal cord injury and 23 normal subjects. Spasticity was measured and correlated with F chronodispersion in spinal cord injury patients.F chronodispersion of 6.4 +/- 1.9 msec (mean +/- SD) obtained in spinal cord injury patients was found to be significantly greater than the results of 3.9 +/- 1.6 msec in normal controls (P0.05). F chronodispersion was greater in spinal cord injury patients with complete cord lesion. A positive correlation was found between F chronodispersion and Ashworth Scores in spinal cord injury patients. There were no significant differences in minimal latency, amplitude, persistence of F waves, and F tacheodispersion between spinal cord injury patients and normal subjects.Measurement of F chronodispersion may provide a useful and sensitive electrophysiologic assessment in evaluation of spinal cord injury and serve as an evident tool for differentiating pathologic from normal state motoneuron excitability in spinal cord lesion.

A motor evoked potential (MEP) study with percutaneous magnetic stimulation over the motor cortices and an F-wave study in peripheral nerves were performed to measure spinal cord motor conduction velocity (SCMCV) in 25 patients with herniated disc-induced cervical myelopathy (HDICM). Grading of motor function and assessment of SCMCV were performed before and 2 years after microsurgical discectomy. The results show that functional motor improvement accompanied by an increase in SCMCV occurred in grade I patients with mild neurological impairment after surgery, whereas no definite change was seen in grade II and grade III patients with moderate and severely neurological impairment. This finding suggests that measurement of SCMCV by MEP study with a noninvasive method may provide an objective and quantitative method to assessment of the functional integrity of the spinal motor pathway and that the results of such studies may serve as a predictor in evaluation of surgical outcome in patients with HDICM.

Single nerve lesion or mononeuropathy caused by extrinsic compression of hematoma or hemarthrosis is consistently reported for hemophilic patients. To study the manifestation of peripheral nerve lesions, an extensive nerve conduction study of peripheral nerves and specific nerves in correlation with clinical involvement was carried out on 126 hemophilic patients. We found 24 patients with 34 peripheral nerve lesions. The frequency of nerve lesion positively correlated with the severity of hemophilia (p < 0.01) and increasing age (p < 0.05). Nerve lesions occurred more commonly in lower extremities than in upper extremities. The femoral nerve was most commonly involved. Seven patients were identified to have mononeuropathy multiplex with 2 or more nerve lesions involving more than one extremity. All of these patients had chronic condition. Our findings suggest that mononeuropathy multiplex may occur in hemophilic patients.