Rigid spine syndrome (vacuolar variant). A quantitative electromyograhic study.
BACKGROUND
Quantitative electromyography (EMG) using different needle techniques was performed as part of a complete systems review on 9 patients diagnosed with the vacuolar variant of rigid spine syndrome (RSS).


OBJECTIVE
To establish statistically: (1) correlations between clinical features (patient age, disease duration, degree of weakness) and quantitative EMG; (2) correlation between different EMG parameters; (3) differences in quantitative EMG comparing patients with a healthy control group; and (4) correlate EMG with muscle pathology findings.


METHODS
Nerve conduction studies and needle EMG (motorunit analysis, MacroEMG, SFEMG) were performed on Mm. triceps brachii and tibialis anterior according to standard techniques on 9 RSS patients.


RESULTS
Nerve conduction studies were normal. Overall, clinical parameters did not correlate well with motorunit analysis and MacroEMG results. Motorunit analysis and MacroEMG results were significantly different comparing patients with controls. Motorunit analysis and MacroEMG correlated well with muscle biopsy findings. SFEMG results were within normal limits.


CONCLUSIONS
Comprehensive EMG study results were compatible with a benign myopathic process. Results were consistent amongst patients within the study group, but differed significantly from the control group. Stable neuromuscular junction physiology did not accurately reflect evidence of muscle fiber degeneration and regeneration observed on muscle biopsies.
Stübgen
J P
JP
Department of Neurology, Weill Medical College, Cornell University, New York, NY 10021, USA.
D000293:Adolescent; D000328:Adult; D002648:Child; D004576:Electromyography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009046:Motor Neurons; D018908:Muscle Weakness / Q000175:diagnosis* / Q000503:physiopathology*; D009431:Neural Conduction; D012600:Scoliosis / Q000175:diagnosis* / Q000503:physiopathology*; D012720:Severity of Illness Index; D013122:Spinal Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D013577:Syndrome