Muscle Cramps

Muscles alternately contract and relax as the person moves the limbs. When a muscle or some fibers of the muscle involuntarily contracts, this is called a "spasm". When a spasm is forceful and sustained, it is called a "cramp". A muscle cramp can be described as an involuntarily and forcibly contracted muscle which does not relax. The cramp may be related to part of a muscle, the entire muscle or a group of muscles. It may occur several times till it goes away. The duration of a muscle cramp may be a few seconds or a quarter of an hour. At times there may be simultaneous contraction of muscles that move body parts in opposite directions. Statistically, 95% individuals experience cramps at some time in their life. Although, they are very common in adults and increase with age, they can be experienced in childhood. The muscles under the voluntary control are called "skeletal muscles". Any skeletal muscle can cramp. Muscle cramps of the legs and feet and particularly the calf are prevalent. Involuntary muscles like the blood vessel wall, intestinal tract and urine passages are also susceptible to cramps.

Types of muscle cramps
The categorization is as per the causes and muscle groups affected.

True cramps
These are the most common types of skeletal muscle cramps. The reason of occurrence is the hyperexcitability of the nerves that stimulate the muscles. They may occur due to injury, vigorous activity, dehydration, body fluid shifts, low blood calcium and magnesium or low potassium.

Contractures
In this, the muscles are unable to relax. There is a depletion of adenosine triphosphate, which is an energy chemical in the cell that prevents muscle fiber relaxation. In this sort of muscle cramp, the nerves remain inactive. When contractures are inherited, they are called McArdle's disease. This is a defect of the breakdown of glycogen to sugar in the muscle cell. If the contracture is acquired, it is called Hyperthyroid myopathy. This is linked with overactive thyroid. Contractures are uncommon.

Tetany
All the nerve cells in the body are activated and these stimulate the muscles. This reaction leads to cramps all over the body. The term tetany is usually applied to muscle cramps due to conditions like low blood level of calcium and magnesium. Low blood calcium leads to cramps of the hands and the wrists and a feeling of numbness and tingling around the mouth and some other regions.

Dystonic cramps
Muscles that are not required for the intended movement are stimulated to contract. Muscles that are usually affected by such cramps are those that work in the opposite direction of the intended movement or those that exaggerate the movement. Sometimes small groups of muscles like eyelids, neck, jaws, larynx are affected. Dystonic cramps are not very common.

Some other types of muscle cramps also exist due to amyotrophic lateral sclerosis, radiculopathy, diabetic neuropathy and primarily dystonic muscle diseases.

Causes

• Deficiency of vitamins : thiamine (B1), pantothenic acid (B5) and pyridoxine (B6)
• poor blood circulation to the legs causing dearth of oxygen to the muscle tissue

Treatment

• The muscle has to be stretched. This is done by standing up and walking around
• In case of a calf muscle cramp, one should stand 2 or 2.5 feet from the wall, lean towards the wall, place the forearms against the wall, keep knees and back straight and heels in contact with the floor or pull the toes upwards towards the head, while lying in bed and keeping the leg straight as possible
• for cramps like writer's cramp, press the hand on a flat surface
• gently massage the muscle or apply warmth with a hot soak or heating pad
• fluid and electrolyte (sodium and potassium) replacement
• injections of therapeutic doses of botulism toxin are used for dystonic muscle disorders

Prevention

• stretching before and after vigorous physical activity accompanied by sufficient warm-up and cool down
• good hydration and replacement of lost electrolytes of sodium and potassium
• avoiding excessive fatigue
• intake of supplements of calcium and magnesium
• for dystonic cramps, use wrist supports, avoid high heels, adjust chair position, take activity breaks, avoid excessive tension
• for rest/night cramps, perform stretching exercises before bed
• intake of 400 units of vitamin E

Muscle cramps and elderly people
Elderly people generally have some kidney dysfunction. If supplemental magnesium is ingested, then this may lead to toxic levels of magnesium. So, the magnesium blood level must be periodically checked.

There is usually a vitamin D deficiency amongst elderly people. This vitamin is necessary for normal absorption of calcium from food. An intake of 800 units of vitamin D is considered to be adequate. Minimum 400 units are prescribed.

For hypertension and heart failure, diuretics are used. Diuretics cause loss of calcium and magnesium. However, hydrochlorothiazide (Hydrodiuril) and related thiazide diuretics result in calcium and magnesium retention.

With increase in age, the feeling of thirst decreases. So, elderly people are not well hydrated and this state aggravates with the use of diuretics. So, six to eight glasses per day fluid intake is desirable. Drinks containing caffeine must be ignored as they work on kidneys to raise fluid loss.

For overcoming night cramps, regular stretching, proper fluid intake, proper calcium and vitamin D intake, supplemental vitamin E and magnesium intake are essential.

Medication
Quinine is used to decrease the excitability of the muscles. However, it leads to birth defects and miscarriages. Infrequently, it causes hypersensitivity reactions and scarcity of platelets. Use of quinine leads to symptoms like vomiting, nausea, deafness and headaches. This medication can be purchased only by prescription in the United States and the general dose is 325 milligrams per night.