Nocturnal leg cramps in children: Incidence and clinical characteristics

The records of 2527 healthy children seen in on ambulatory care clinic were evaluated For nocturnal leg cramps in the preceding 12 months, frequency a nd duration of the cramps, whether the cramps affected one leg or both legs at a time, whether there was associated muscle 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 pres ent in 185 children for an overall incidence of 7.3%. Leg cramps were noted only in children aged greater than or equal to 8 years. The incidence incr eased at 12 years and peaked at 16 to 18 years of age. A majority (81.6%) o f 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 9 8.9% 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 th e 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-1 day). We conclude that nocturnal leg cramps are common in children aged >12 year s. A majority of the affected children have leg cramps 1 to 4 times per yea r. The cramps are usually unilateral and occur when the children are asleep . Normal duration of the leg cramp is <2 minutes. Residual tenderness is pr esent in approximately 30% of the affected children. Residual tenderness, i f present, usually lasts for half an hour.