Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q8IXL6 (RNS)
 1,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Electrical and mechanical responses to single shocks, slow and fast nerve stimulation (RNS), quantitated EMG, anti-acetylcholine receptor (AChR) and anti-striated muscle (SM) antibodies (ab) were determined in 145 patients with myasthenia gravis (MG). Anti-AChR ab were found in 93% of the myasthenic sera. Decrement of muscle and mechanical responses occurred in 72% and 49%, respectively, the diagnostic yield being positively related to severity of MG. Anti-AChR ab were found in 81% of patients without RNS abnormalities. Decrement at RNS occurred in 33% of the cases without anti-AChR ab compared with 78% of those with elevated titres. Regional curare test (RCT) was diagnostic in 75% of cases with normal RNS. As the combined diagnostic yield of RNS and anti-AChR ab was 96%, RCT and single fibre EMG are rarely indicated. Post-tetanic facilitation and exhaustion, and an abnormal staircase phenomenon occurred in 25%, 44% and 37%, respectively. None of these parameters correlated with severity, type or onset of MG. EMG evidence of myopathy, positively correlated with the presence of anti-SM ab, occurred in 19% of patients examined, 3 times more frequent in those with late onset of MG than in those with early onset; thus myopathy of possible autoimmune origin may coexist with MG. An adequate electrophysiological diagnostic strategy for MG patients is proposed.
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PMID:Neurophysiological evaluation in myasthenia gravis. A comprehensive study of a complete patient population. 768 5

We compared changes in amplitude and area of surface recorded compound motor action potentials (CMAPs) during 20-Hz repetitive nerve stimulation and after maximum voluntary contraction in patients with the Lambert-Eaton myasthenic syndrome (LEMS), myasthenia gravis (MG), and normal controls. There was greater potentiation of CMAP amplitude after voluntary contraction than during 20-Hz stimulation in 10 of 14 LEMS patients; CMAP area increased more after exercise than during 20-Hz stimulation in all LEMS patients. Although abnormal potentiation of CMAP area and amplitude was seen in equal numbers of LEMS patients, more LEMS patients demonstrated a greater than 100% potentiation of CMAP area than of CMAP amplitude. We conclude that maximum voluntary contraction is preferable to brief 20-Hz RNS to demonstrate potentiation in LEMS because it is at least as sensitive and is less painful. Measurement of CMAP area in LEMS patients is not better than measuring the change in CMAP amplitude in demonstrating abnormal potentiation. Testing of a single hand muscle for potentiation in LEMS does not demonstrate abnormal potentiation in all LEMS patients.
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PMID:Repetitive nerve stimulation studies in the Lambert-Eaton myasthenic syndrome. 750 83

We performed RNS and SFEMG studies of the same muscle in 46 patients with myasthenia gravis. Maximum decrement to 3-5-Hz stimulation before and after maximum voluntary exercise, percentage of action potential pairs with increased jitter and blocking, and mean MCD in each study were compared. A significant decrement (> 10% decrease in CMAP area or amplitude between the first and fourth response) was never found without increased jitter and impulse blocking on SFEMG. Increased jitter, blocking, and mean MCD were each correlated with maximum decrement (r > 0.61, P < 0.0001). We conclude that decrement to RNS and impulse blocking on SFEMG result from the same physiologic phenomenon, and that SFEMG is more sensitive at detecting disordered neuromuscular transmission given its ability to detect impulse blocking at levels below the resolution of RNS and increased neuromuscular jitter when there is not blocking.
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PMID:Single fiber EMG and repetitive stimulation of the same muscle in myasthenia gravis. 811 86