Duration of symptomatology and median segmental sensory latency in 993 carpal tunnel syndrome hands (668 cases)

According to median sensory nerve action potential onset-latency to index finger in a 140 mm fixed distance, 993 carpal tunnel syndrome (CTS) hands from 668 patients were grouped into MIld (3.0 to 3.5 ms, 384 hands), MOderate (3.6 to 4.4 ms, 332 hands), SEvere (> 4.4 ms, 135 hands) and UNrecordable (142 hands) and correlated with CTS symptomatology duration. All patients have sensory antidromic median-radial latency difference (MRD) e > or = 1.0 ms without any doubt about CTS diagnosis. Patients with systemic disease, trauma or previous surgery were excluded. There is a remarkable cumulative percentage increase from 1 to 12 months in group UN (3.5% to 38.7%, 11 folds), much less than the group MI (13.8% to 54.6%, 3.9 folds). There is also a remarkable non-cumulative percentage increase in group UN, from 1 to 4-12 months; the group MI had a relatively uniform distribution in all symptomatic duration groups from 1 to > 60 months. The conclusion is that median nerve compression at carpal tunnel can lead to unrecordable potentials in a relatively short period from 1 to 12 months of evolution, suggesting acute/subacute deterioration. Electrophysiological evaluation must be done periodically in patients that underwent clinical treatment, since cumulative 38.7% of group UN was found in 12 months period

Concentric Needle Jitter in 97 Myasthenia Gravis Patients

Objectives: To estimate the jitter parameters (single-fiber electromyography) in myasthenia gravis patients mostly by electrical activation in Frontalis, Orbicularis Oculi, and Extensor Digitorum muscles using a concentric needle electrode. Methods: Between 2009 and 2019, a total of 97 myasthenia gravis patients, 52 male, and mean age 54 years were included. Results: Any abnormal jitter parameter in individual muscles was 90.5% (Frontalis), 88.5% (Orbicularis Oculi), and 86.6% (Extensor Digitorum). Any jitter parameter combining Orbicularis Oculi and Frontalis muscle was abnormal in 100% for the ocular, and in 92.9% for the generalized myasthenia gravis. The most abnormal muscle was Orbicularis Oculi for the generalized, and Frontalis for the ocular myasthenia gravis. The decrement was abnormal in 78.4%, 85.9% for the generalized, and 25% for the ocular myasthenia gravis. The mean jitter ranged from 14.2 to 86 mu s (mean 33.3 mu s) for the ocular myasthenia gravis and from 14.4 to 220.4 mu s (mean 66.3 mu s) for the generalized myasthenia gravis. The antibody titers tested positive in 86.6%, 91.8% for the generalized, and 50% for the ocular myasthenia gravis. Thymectomy was done in 48.5%, thymoma was found in 19.6%, and myasthenic crisis occurred by 21.6%. Conclusion: The jitter parameters achieved a 100% abnormality in ocular myasthenia gravis if both the Orbicularis Oculi and Frontalis muscles were tested. There was a high jitter abnormality in generalized myasthenia gravis cases with one muscle tested, with about a 2% increase in sensitivity when a second is added. Concentric needle electrode jitter had high sensitivity similar to the single fiber electrode (93.8%), followed by antibody titers (86.6%), and abnormal decrement (78.4%)

Carpal tunnel syndrome: age, nerve conduction severity and duration of symptomatology Síndrome do túnel do carpo: correlação de idade, anormalidade de condução nervosa e tempo de sintomatologia

Median sensory and motor distal latencies (SDL/MDL) were correlated with age and duration of symptomatology in 1498 carpal tunnel syndrome (CTS) patients (17-90 years old, 87.6% female). Patients were distributed in four groups according to distal latencies severity. There was an increase in age as long as SDL/MDL became more severe, ranging from 47.5 to 67 years old (mild to severe-absence potentials in both hands groups, respectively). There was a less dramatic increase in duration of complaints as long as SDL/MDL became more severe, ranging from 12 to 30.7 months (mild to severe-absence potentials in both hands groups, respectively). Aging correlates more positively than duration of complaints with severity of SDL/MDL in CTS. The effects of increasing median blockage in CTS are more severe as long as patients become older regardless duration of symptomatology.<br>Latências distais sensitivas e motoras (LDS/LDM) do nervo mediano foram correlacionadas com idade e duração da sintomatologia em 1498 pacientes com síndrome do túnel do carpo (STC); a idade variou de 17 a 90 anos e 87,6% eram do sexo feminino. Os casos foram distribuídos em quatro grupos de acordo com a gravidade das latências distais. Houve aumento de idade proporcional ao aumento de LDS/LDM, variando de 47,5 a 67 anos nos grupos leve e grave-ausência de potenciais nas duas mãos, respectivamente. Houve aumento menos dramático na duração da sintomatologia proporcional ao aumento de LDS/LDM, variando de 12 a 30,7 meses nos grupos leve e grave-ausência de potenciais nas duas mãos, respectivamente. O aumento da idade correlaciona-se melhor que a duração da sintomatologia com o aumento de LDS/LDM. Os efeitos do aumento do bloqueio do nervo mediano no STC são mais graves com o avanço da idade, independentemente da duração da sintomatologia

Long-term outcomes of symptomatic electrodiagnosed carpal tunnel syndrome

This study was done to evaluate the long-term patient's satisfaction after carpal tunnel syndrome (CTS) electrodiagnostic done between 1989 and 1994 (5 to 10 years follow-up). Mail contact was made to 528 consecutive cases with a questionnaire to be filled; 165 patients responded after 19 exclusions. CTS severity was graded from 0 (incipient) to 4 (severe) after a combination of median sensory distal latency, sensory median-radial latency difference and amplitude of the median compound muscle action potential. Current symptoms ("cure", improved, unchanged or worsed) and the therapy utilized, either surgical or conservative, were analyzed to the initial CTS severity, age and duration of symptomatology. Surgical release was done in 114 cases (69%). Patient's satisfaction after surgical and non-surgical were respectively, 77.6% and 16% ("cure"), 13.6% and 52% (much improved), 5.4% and 9.3% (little improved), 2.7% and 16% (unchanged), 0.7% and 6.7% (worsed). The frequency of "cure" versus unchanged/worsed or "cure"/much improved versus unchanged/worsed was highly significative (Fisher, P-value < 0.001) and was not influenced by the CTS electrophysiological severity. There was no relationship between the outcome after surgery and duration of symptomatology, age or CTS severity. Conservative benefice was more prevalent in those with shorter symptomatology and older age; the majority of conservative failure cases had mild initial CTS. We concluded the excellent surgical benefice described by patients and the absence of any predictive factors based on CTS severity, age or duration of symptomatology for outcome

Guidelines for single fiber EMG

This document is the consensus of international experts on the current status of Single Fiber EMG (SFEMG)and the measurement of neuromuscular jitter with concentric needle electrodes (CNE - CN-jitter). The panel of authors was chosen based on their particular interests and previous publications within a specific area of SFEMG or CN-jitter. Each member of the panel was asked to submit a section on their particular area of interest and these submissions were circulated among the panel members for edits and comments. This process continued until a consensus was reached. Donald Sanders and Erik Stalberg then edited the final document. (C) 2019 Published by Elsevier B.V. on behalf of International Federation of Clinical Neurophysiology

Guidelines for single fiber EMG

This document is the consensus of international experts on the current status of Single Fiber EMG (SFEMG)and the measurement of neuromuscular jitter with concentric needle electrodes (CNE - CN-jitter). The panel of authors was chosen based on their particular interests and previous publications within a specific area of SFEMG or CN-jitter. Each member of the panel was asked to submit a section on their particular area of interest and these submissions were circulated among the panel members for edits and comments. This process continued until a consensus was reached. Donald Sanders and Erik Stalberg then edited the final document

Wrist and palm indexes in carpal tunnel syndrome Índices de palma/punho e síndrome do túnel do carpo

According to median sensory latency > or = 3.7 ms (wrist-index finger [WIF], 14 cm), median/ulnar sensory latency difference to ring finger > or = 0.5 ms (14 cm) or median midpalm (8 cm) latency > or = 2.3 ms (all peak-measured), 141 Brazilian symptomatic patients (238 hands) have CTS confirmation. Wrist ratio (depth divided by width, WR) and a new wrist/palm ratio (wrist depth divided by the distance between distal wrist crease to the third digit metacarpophalangeal crease, WPR) were measured in all cases. Previous surgery/peripheral neuropathy were excluded; mean age 50.3 years; 90.8% female. Control subjects (486 hands) have mean age 43.0 years; 96.7% female. The mean WR in controls was 0.694 against 0.699, 0.703, 0.707 and 0.721 in CTS groups of progressive WIF severity. The mean WPR in controls was 0.374 against 0.376, 0.382, 0.387 and 0.403 in CTS groups of WIF progressive severity. Both were statistically significant for the last two groups (WIF > 4.4 ms, moderate, and, WIF unrecordable, severe). BMI increases togetherwith CTS severity and WR. It was concluded that both WR/WPR have a progressive correlation with the severity of CTS but with statistically significance only in groups moderate and severe. In these groups both WR and BMI have progressive increase and we believe that the latter could be a risk factor as important as important WR/WPR.<br>Um grupo de 141 pacientes (238 mãos) com síndrome do túnel do carpo (STC) sintomático foi estudado após confirmação por condução nervosa: latência distal sensitiva do nervo mediano (LDS-M) > ou = 3,7 ms (punho -- II dedo, 14 cm), diferença de latência sensitiva mediano-ulnar > ou = 0,5 ms (punho -- IV dedo, 14 cm) e/ou latência palma-punho do nervo mediano > ou = 2,3 ms (8 cm); as latências foram medidas no pico do potencial. Todos os casos tiveram as seguintes medidas calculadas: 1. Índice do punho (IP, espessura dividido pela largura do punho); 2. Índice punho-palma (IPP, espessura do punho dividido pela distância entre a prega distal do punho e a prega mais proximal do III dedo); a média de idade foi de 50,3 anos com 90,8% do gênero feminino. Foram realizadas mesmas medidas em 486 mãos do grupo controle (GC) cuja idade média foi 43,0 anos e 96,7% do gênero feminino. O IP médio do GC foi de 0,694 contra 0,699/0,703/0,707/0,721 do grupo STC (valores relativos a casos incipiente/leve/moderado/grave). O IPP médio do GC foi de 0,374 contra 0,376/0,382/0,387/0,403 do grupo STC. Ambos os índices apresentaram significância estatística na comparação com STC mais grave (moderado: LDS-M > 4,4 ms e grave: LDS-M não obtida). O índice de massa corporal aumentou de acordo com a gravidade do STC e o IP. Conclui-se que tanto o IP como o IPP apresentam correlação progressiva com a gravidade do STC porém com significância estatística apenas nos grupos moderado e grave. Neste grupos tanto o IP como o índice de massa corporal tiveram aumento progressivo e acreditamos que o último possa representar risco tão importante quanto IP/IPP