Natural history of muscle cramps in amyotrophic lateral sclerosis.
BACKGROUND
Muscle cramping is a common symptom in amyotrophic lateral sclerosis (ALS) that lacks efficacious treatment. The natural history of this symptom is unknown, which hampers efforts to design optimal clinical trials.


METHODS
We surveyed early stage ALS patients about their experience with cramps each month by phone for up to 21 months.


RESULTS
Cramps developed in 95% of patients over the course of their disease. The number of cramps experienced by an individual varied widely from month-to-month and trended lower after the first year of illness (P = 0.26). Those with limb-onset and age >60 years had more cramps than bulbar-onset (P < 0.0001) and younger patients (P < 0.0001).


CONCLUSIONS
The high variability of the number of cramps experienced suggests that clinical trials will need to use crossover designs or large numbers of participants, even when the treatment effect is substantial.
Department of Neurology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA.
James B
JB
Caress
Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, USA.
Stephanie L
SL
Ciarlone
Neurology Associates, Hattiesburg, Mississippi, USA.
Elizabeth A
EA
Sullivan
Department of Biostatistical Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA.
Leah P
LP
Griffin
Department of Neurology, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA.
Michael S
MS
Cartwright
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009120:Muscle Cramp / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D011795:Surveys and Questionnaires
amyotrophic lateral sclerosis; cramps; muscle spasms; natural history; pain