Nocturnal muscle cramps are a common lower extremity condition that produces pain and can disrupt sleep.
In the general population, they are present in 40 percent of those over the age of 50, have an increased frequency with age, show no sex preference, and are associated with sleep disturbance and overall poor health.
CLINICAL FEATURES
Nocturnal muscle cramps generally share the following characteristics:
● Symptoms – Nocturnal muscle cramps are characterized by sudden muscle tightness, usually painful, and most commonly in the calf, foot, or thigh. Calf cramping may induce extreme plantar flexion of the foot and toes.
● Duration – Nocturnal muscle cramps typically last from seconds to many minutes and are relieved by forceful stretching of the affected muscles.
● Timing – Nocturnal muscle cramps typically occur while in bed, but patients may be awake or asleep. Most individuals have such cramps only at night. In one study, cramps occurred exclusively at night in most (73 percent), but they occurred both during the day and night in 20 percent of patients and only during the daytime in 7 percent.
● Residual soreness – Following resolution of the acute cramp, there may be persistent soreness that typically lasts for several hours. Nocturnal muscle cramps affecting the thigh are more commonly associated with prolonged soreness than cramps affecting the calf and foot.
● Frequency – Roughly 40 percent of those with nocturnal muscle cramps report having such symptoms at least three times per week, and 5 to 10 percent report nightly cramping.
● Sleep disturbance – Nocturnal muscle cramps are associated with sleep disturbance, and patients may present to their clinician with a complaint of insomnia. Daytime fatigue is sometimes reported.
● Seasonal variation – Nocturnal muscle cramps are more common in winter than in summer. The basis for these observations is not known.
EVALUATION
A detailed assessment is generally conducted only for patients with recurrent symptoms despite initial preventative therapies.
Identifying risk factors associated with nocturnal muscle cramps
Laboratory evaluation — Laboratory tests are not necessary to establish a diagnosis of nocturnal muscle cramps. However, laboratory testing may be indicated in certain situations.
● Hypokalemia in patients receiving diuretics
● Electrolyte abnormalities in patients on dialysis
● Hypomagnesemia during pregnancy
● Hypocalcemia in a patient with diffuse, recurrent, or severe muscle cramping.
● Elevated thyroid-stimulating hormone in patients with hypothyroidism
DIAGNOSIS
The diagnosis of nocturnal muscle cramps is established clinically. To be diagnosed with nocturnal muscle cramps, patients should meet all three of the following criteria:
● A painful sensation in the leg or foot associated with sudden, involuntary muscle hardness or tightness, indicating a strong muscle contraction.
● The painful muscle contractions occur during the time in bed, although they may arise from either wakefulness or sleep.
● The pain is relieved by forceful stretching of the affected muscles, thus releasing the contraction.
MANAGEMENT
Treatment of acute leg cramps:
● Stretching
● Alternate therapies – If stretching is not effective, try the following:
- Walking or leg jiggling followed by leg elevation
- A hot shower
- Ice massage
Initial preventive therapies:
Stretching exercises for all patients – We suggest that all patients with recurrent nocturnal muscle cramps perform posterior leg muscle stretching exercises:
- The posterior leg stretches are performed while standing
- The patient leans forward with the legs kept straight and the feet kept flat on the floor
- The position is held for 10 to 20 seconds
Additional interventions for select patients – Patients who have a partial response to stretching exercises may wish to add some of the interventions listed below:
- Increase exercise
- Keeping the bed covers at the foot of the bed loose and not tucked in
- Avoid drugs, alcohol, caffeine, exercise in extreme heat or on concrete floors
Initial drug therapies
Supplements – We recommend mineral and vitamin supplementation before using prescription medications.
Vitamin B complex (three times daily, containing 30 mg of Vitamin B6) or Vitamin E (800 international units before bed).
● Calcium channel blocker – In patients in whom the measures above are ineffective, we prescribe a calcium channel blocker.
● Gabapentin or pregabalin can be prescribed if the above measures have failed. These medications must be used cautiously.
● Tonic water before bedtime, which contains approximately 15 mg of quinine. Patients should limit their use of tonic water to once nightly; after the nocturnal muscle cramps improve, patients should try reducing their use of tonic water to the minimum frequency required to control their symptoms. A trial of a month is generally adequate to determine if there is a reduction in the severity of attacks.
When to refer patients to a Specialist
Patients in whom pharmacotherapy is ineffective, and who experience distress associated with nocturnal muscle cramps, should be referred to a sleep specialist to determine if the patient has an underlying sleep disorder (eg, restless legs syndrome [RLS], periodic limb movements of sleep [PLMS], or obstructive sleep apnea).
If you have any questions or concerns, please call the office at (707) 938-1255 and we can set you up for an appointment with Dr. Guy.
