Electromyography and clinical neurophysiology
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Autonomic neuropathy is a complication of diabetes mellitus (DM) in substantial proportion of cases and may cause definite autonomic symptoms. Because conventional electrophysiological methods do not assess the autonomic nervous system, simple reproducible tests were developed. One of them is sympathetic skin response (SSR) which provides useful information about the status of sympathetic postganglionic function. ⋯ An absent response in at least one tested lower extremity (50%) and prolonged foot with normal hand latency (20%). 6 patients (30%) demonstrated no abnormalities. Foot and hand latencies in diabetics did not differ significantly from those of normal controls (p: 0.4, p: 0.1) and no correlation could be found with latencies and duration of sickness, patient's age and HbA1c values. We believe latency measurement is an objective measure of conduction in multineural pathways and can detect subclinical involvement of sympathetic nervous system in diabetics who do not manifest symptoms or signs referable to autonomic system dysfunction.
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Electromyogr Clin Neurophysiol · Apr 2002
Inhibitory and excitatory circuits of cerebral cortex after ischaemic stroke: prognostic value of the transcranial magnetic stimulation.
The motor cortex excitatory responses and inhibitory effects after transcranial magnetic stimulation were studied in 20 patients with hemiparesis after ischaemic stroke in the MCA territory within 24 hours from the beginning of the symptomatology, in order to evaluate prognostic utility of these techniques and to compare they with the conventional MEP examination. Central motor conduction time was abnormal in two patient. ⋯ The motor cortex threshold measurement is easily performed and the most sensitive parameter in our group of patients with hemispheric infarct. Our study suggested that the evaluation of the modifications in the intrinsic excitatory properties rather than in the inhibitory cortical circuits may offer a prognostic tool for predicting functional outcome following ischaemic stroke.
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Electromyogr Clin Neurophysiol · Dec 2000
Case ReportsThe lumbar multifidus muscle in polysegmentally innervated.
We conducted a prospective case study to determine whether the lumbar multifidus muscle is polysegmentally innervated. A 49-year-old man with chronic mechanical low back pain underwent bilateral percutaneous radiofrequency neurotomy of the medial branches of the L3 dorsal rami. ⋯ This study provides electrophysiological evidence in the human lumbar spine that the medial branch of the lumbar root innervates the multifidus muscle at multiple levels, i.e., the lumbar multifidus muscle is polysegmentally innervated. As a result, electromyography of the multifidus cannot identify a specific level of lumbar radiculopathy.
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Electromyogr Clin Neurophysiol · Jun 2000
Comparative StudyTwo consecutive fasciculation potentials having different motor unit origins are an electromyographically pathognomonic finding of ALS.
To electrophysiologically diagnose amyotrophic lateral sclerosis (ALS), fasciculation potentials (FPs) were evaluated in each wasted muscle in 12 ALS and 14 other neurogenic disorders (non-ALS patients). Various types of FPs were observed in ALS. ⋯ Although nine of 12 ALS patients showed two consecutive FPs having different motor unit origins, non-ALS patients did not show such FPs. Since the two consecutive FPs having different motor unit origins reflect an involvement of both upper and lower motor neurons, these potentials are an electrophysiologically pathognomonic finding to ALS.
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Electromyogr Clin Neurophysiol · Mar 2000
Intrasession and intersession reliability of the soleus H-reflex in supine and standing positions.
The Hoffmann reflex (H-reflex) is a measure of motoneuron pool excitability, which is valuable in determining muscle inhibition caused by joint damage (arthrogenic muscle inhibition). In order to detect changes in H-reflex due to injury, the reliability of such a measurement must be established. The purpose of this study was to establish the intrasession and intersession reliability of soleus H-reflex in a supine and standing position. ⋯ These results indicate that the H-reflex measured using our protocol in a supine and standing position is a reliable assessment within sessions and between sessions. Five measurements are sufficient to observe reliable measurements within a single session. Most importantly, this data shows that the H-reflex is a reliable assessment that may be used to measure small changes in motoneuron pool excitability over time.