Therapeutic Implications of Peripheral Nerve Hyperexcitability in Muscle Cramping: A Retrospective Review.
OBJECTIVE
Muscle cramping due to peripheral nerve hyperexcitability (PNH) is poorly characterized. This retrospective study examines the prevalence of PNH and response to treatment.


METHODS
The Duke EMG Database was queried to identify patients with muscle cramping tested for PNH from 2010 to 2015. Peripheral nerve hyperexcitability was defined by compound muscle action potential after-discharges on repetitive nerve stimulation. Response to treatment was determined by the treating physician's clinical impression 6 months after diagnosis or last documented visit.


RESULTS
Seventy-two patients met inclusion criteria. Twenty-three (32%) patients had electrodiagnostic evidence of PNH. Of the patients with PNH, 74% had a good response to treatment whereas 37% of treated patients in the PNH-negative group (P = 0.0258). Carbamazepine and gabapentin were the most frequently used treatments with response rates of 70% and 77%, respectively.


CONCLUSIONS
Muscle cramps associated with PNH respond well to symptomatic treatment, particularly with carbamazepine and gabapentin.
*Neuromuscular Division, Department of Neurology, University of South Florida, Tampa, Florida, U.S.A.; and †Neuromuscular Division, Department of Neurology, Duke University, Durham, North Carolina, U.S.A.
Rebecca L
RL
Hurst
Lisa D
LD
Hobson-Webb
D000588:Amines / Q000627:therapeutic use; D018712:Analgesics, Non-Narcotic / Q000627:therapeutic use; D000906:Antibodies / Q000097:blood; D002220:Carbamazepine / Q000627:therapeutic use; D003509:Cyclohexanecarboxylic Acids / Q000627:therapeutic use; D004599:Electric Stimulation Therapy / Q000379:methods; D004568:Electrodiagnosis; D004576:Electromyography; D005260:Female; D000077206:Gabapentin; D006801:Humans; D008297:Male; D009120:Muscle Cramp / Q000150:complications* / Q000628:therapy*; D010523:Peripheral Nervous System Diseases / Q000097:blood / Q000209:etiology* / Q000628:therapy*; D024642:Potassium Channels, Voltage-Gated / Q000276:immunology; D012189:Retrospective Studies; D005680:gamma-Aminobutyric Acid / Q000627:therapeutic use
D000588:Amines; D018712:Analgesics, Non-Narcotic; D000906:Antibodies; D003509:Cyclohexanecarboxylic Acids; D024642:Potassium Channels, Voltage-Gated; D002220:Carbamazepine; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin