Accuracy of repetitive nerve stimulation for diagnosis of the cramp-fasciculation syndrome

• Published in: Muscle & nerve Vol. 35; no. 6; pp. 776 - 780
• Main Authors: Harrison, Taylor B., Benatar, Michael
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.06.2007; Wiley
• Subjects: Action Potentials - physiology; Adult; Age Factors; Biological and medical sciences; Cohort Studies; Diseases of striated muscles. Neuromuscular diseases; Electric Stimulation - methods; Electrodiagnosis - instrumentation; Electrodiagnosis - methods; Electromyography - instrumentation; Electromyography - methods; fasciculations; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Medical sciences; Middle Aged; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; muscle cramps; Muscle, Skeletal - innervation; Muscle, Skeletal - physiopathology; Neural Conduction - physiology; Neurology; Neuromuscular Diseases - diagnosis; Neuromuscular Diseases - physiopathology; peripheral nerve hyperexcitability; Peripheral Nerves - physiopathology; Peripheral Nervous System Diseases - diagnosis; Peripheral Nervous System Diseases - physiopathology; Predictive Value of Tests; Reproducibility of Results; Retrospective Studies; ROC curve; sensitivity; Sex Factors; specificity; Vertebrates: nervous system and sense organs; Human; Peripheral nerve; Fasciculation; fasciculations; Excitability; Afterdischarge; Retrospective; Motor unit; Cramp; Striated muscle disease; Accuracy; Sensitivity; muscle cramps; Hyperexcitability; Repetitive stimulus; Receiver operating characteristic curves; specificity; peripheral nerve hyperexcitability; Diagnosis; ROC curve
• ISSN: 0148-639X; 1097-4598
• DOI: 10.1002/mus.20774

The goal of this retrospective cohort study was to test the hypothesis that the cramp–fasciculation syndrome (CFS) represents a disorder of peripheral nerve hyperexcitability and to evaluate the accuracy of repetitive nerve stimulation (RNS) for its diagnosis. A consecutive series of 108 patients were evaluated with posterior tibial RNS at 1, 2, and 5 HZ. Abnormal peripheral nerve excitability was defined by the presence of afterdischarges, cramp potentials, or continuous motor unit activity. RNS demonstrated abnormal nerve hyperexcitability in 29 of 36 subjects (81%) with CFS, defined operationally by the presence of both muscle cramps and fasciculations. Based on receiver operating characteristic (ROC) curve analysis, tibial RNS correctly classified the presence or absence of CFS in 75% of subjects. These results suggest that CFS represents a form of peripheral nerve hyperexcitability and, furthermore, that RNS is a clinically useful test for CFS. Muscle Nerve, 2007