Muscle Cramps - Clinical Methods - NCBI Bookshelf

Technique

Muscle cramps are ubiquitous yet tend to be little more than a benign nuisance to the sufferer. On occasion, though, the physician encounters either patients who complain of "cramps" or might want to inquire as to their presence while evaluating a related symptom.

There is nothing unique in taking a history of cramps, the aims being both to characterize the complaint fully and to extract clues that might reveal its cause. This can be accomplished by having the patient describe the symptom, then asking directed questions as necessary to elaborate information as to the quality, location, duration, precipitating and relieving maneuvers, course of the symptom, and associated features.

Many patients who complain of "cramps" actually have some other related phenomenon. What characteristics, then, can be helpful in making the correct diagnosis?

• Quality. It is useful to find out about onset (abrupt or slow?), sensation (painful? stiff?), and appearance (if an abnormal posture is described, have the patient demonstrate it). With true cramps, the onset is sudden, the muscle feels taut and painful, and usually it is visibly and palpably knotted (although this may not be readily apparent if only part of the muscle is involved).
• Location. Determine if muscles are involved singly or in groups, if certain muscles are consistently involved, and if the cramps remain limited or spread. While ordinary cramps often affect the leg (especially calf) muscles, other locations may point to a specific syndrome such as carpopedal spasms in tetany or unilateral facial involvement in hemifacial spasms.
• Duration. Ordinary cramps last from seconds to several minutes if severe. Fleeting twitches or prolonged contractions suggest another type of disorder.
• Precipitating or relieving maneuvers. Attempt to uncover any relation to exercise; specifically, find out not only if occurrence is at rest or during or after exercise but also the duration and intensity of exercise that may initiate cramps. Moreover, clarify if the cramps appear only sporadically or can be predictably expected at a certain level of exertion. One may also want to ask about other potential triggers such as movement, sensory or emotional stimuli, hyperventilation, cold, or fasting. Assess if anything alleviates the cramps.
• Course of symptoms. A relatively recent onset suggests the possibility of an acquired intercurrent illness, whereas affliction since youth may point to an inherited disorder.

It is important to recognize several entities that may be confused with cramps. With disorders of muscle relaxation, as in myotonia and hypothyroidism, the patient may perceive an uncomfortable but painless muscle tightness or stiffness, often made worse in the cold. One can get a clue to myotonia if the patient admits to difficulty releasing a grip (be it a handshake, doorknob, or cooking pan) that improves with repeated contractions. Other rare ailments can produce a sensation of stiffness via various mechanisms (see Table 53.1).

Table 53.1

The Cramp History.

Focal dystonias share certain similarities and may easily be mistaken for cramps. Dystonia refers to a movement disorder manifest by the assumption of involuntary abnormal postures. Patients may relate spasmodic, even painful, bending or twisting movements of an extremity, neck, face or trunk that remain in a persistent attitude (e.g., overextended/overflexed posture of hand, inversion of foot, pulling of the head to one side). Sometimes the spasms occur in relation to and interfere with a specific skilled motor act, as in so-called writer's cramp. The slower onset, inappropriate contraction of many opposing muscles, and unusual postures evoked help to distinguish dystonia.

Far and away a more common patient complaint is that of a "crampy" feeling, by which is meant an aching discomfort in the muscles without any visible or palpable hardening. These myalgias are common in childhood. They can also be seen in a variety of neuromuscular and systemic illnesses, as well as in the context of generalized pervasive fatigue without objective muscle weakness in depressed patients.

It should be emphasized, though, that the above conditions, along with other abnormal muscle contractions, may occur in conjunction with actual muscle cramps. Patients as historians can be "lumpers" or "splitters"—they may complain of cramps as one of many symptoms, or include a number of different phenomena under the rubric of "cramps."

Once one has fully characterized the symptoms, the next step is to probe for associated features that may disclose an etiology. Appropriate queries might include: Is there any weakness, numbness, or paresthesias present that may indicate an underlying neuromuscular disorder? Has muscle twitching been noted? Fasciculations (spontaneous visible muscle twitches due to contraction of a motor unit) can be seen in several neuropathic disorders associated with cramping. They can also appear as a benign condition with muscle cramps, particularly in people with large muscles.

Do bouts of myoglobinuria occur? This sign, reflecting muscle fiber breakdown, can be ascertained by asking if the urine ever becomes cola colored. Be careful—patients frequently say their urine becomes dark (concentrated) but rarely admit that it actually turns brownish.

Are there any concurrent illnesses or medications? Spontaneous muscle cramps are associated with a number of conditions and medications (see Table 53.2).

Table 53.2

Clinical Settings of Muscle Cramps.

Is there a family history of cramps?