neurologic disorders
Muscle Cramps
Introduction
A muscle cramp (charley horse) is a sudden, brief, involuntary, painful contraction of a muscle or group of muscles. Cramps commonly occur in healthy people (usually middle-aged and older adults), sometimes during rest, but particularly during or after exercise or at night (including during sleep). Sleep-related leg cramps usually occur in the calf and cause plantar flexion of the foot and toes, but cramping of other muscle groups is also possible. Other disorders can simulate cramps: Dystonias None Tetanycan cause muscle spasm, but spasm is usually more sustained (often with repetitive brief muscle twitches); it is usually bilateral and diffuse, but isolated carpopedal spasm may occur. Muscle ischemiaduring exertion in patients with peripheral arterial disease (claudication) may cause calf pain, but this pain is due to inadequate blood flow to muscles, and the muscles do not contract as with a cramp. Illusory crampsare the sensation of cramps in the absence of muscle contraction or ischemia. Cramping is more likely when people do things that they are not prepared for (eg, using muscles not commonly used to do a physical task, doing an exercise never done before). 