NOCTURNAL LEG CRAMPS IN CHILDREN:
INCIDENCE AND CLINICAL
CHARACTERISTICS
Alexander K.C. Leung, MBBS, FRCP, FRCPCH, FRCPC, FAAP, Byron E. Wong, MD, FRCPC,
Paul Y.H. Chan, MD, and Helen Y.H. Cho, MD
Calgary, Alberta, Canada
The records of 2527 healthy children seen in an ambulatory care clinic were evaluated for
nocturnal leg cramps in the preceding 12 months, frequency and duration of the cramps,
whether the cramps affected one leg or both legs at a time, whether there was associated mus-
cle cramps in feet, whether the cramps occurred when the child was awake or asleep, and
whether there was residual tenderness in the affected muscles. Nocturnal leg cramps were pre-
sent in 185 children for an overall incidence of 7.3%. Leg cramps were noted only in children
aged >8 years. The incidence increased at 12 years and peaked at 16 to 18 years of age. A
majority (81.6%) of the affected children had nocturnal leg cramps 1 to 4 times per year. The
mean duration of episodes was 1.7 minutes. Leg cramps were unilateral in 98.9% of cases and
the ipsilateral foot also was involved in 18.9% of cases. One hundred thirty-five (73%) children
had leg cramps while asleep, and the remaining 23 (12.4%) children had leg cramps in either
state. Fifty-seven (30.8%) children had residual tenderness in the affected muscles. The mean
duration of residual tenderness was 33.2 minutes (range: 2 minutes-i day). We conclude that
nocturnal leg cramps are common in children aged > 1 2 years. A majority of the affected chil-
dren have leg cramps 1 to 4 times per year. The cramps are usually unilateral and occur when
the children are asleep. Normal duration of the leg cramp is 12 years. Our study
cramps five to eleven times per year, and 81.6% had shows that the clinical characteristics of nocturnal
cramps one to four times per year. It is likely that chil- leg cramps in children are significantly different
dren experience less frequent nocturnal leg cramps from those observed in the adult population.
than adults.
The duration of nocturnal leg cramps is rarely Acknowledgments
mentioned in the literature. In a study of elderly We thank Ms Dianne Leung for secretarial assistance and Mr
patients, Naylor et a19 found that the mean duration Sulakhan Chopra of the University of Calgary Medical Library
for assistance in preparating the manuscript.
of the cramp episodes was 9 minutes. In the present
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