Cramps part 2

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TETANY

In tetany, all of the nerve cells in the body are activated, which then

stimulate the muscles. This reaction causes spasms or cramps throughout the

body. The name tetany is derived from the effect of the tetanus toxin on the

nerves. However, the name is now commonly applied to muscle cramping from

other conditions, such as low blood levels of calcium and magnesium. Low

calcium and low magnesium, which increase the activity of nerve tissue

non-specifically, also can produce tetanic cramps. Often, such cramps are

accompanied by evidence of hyperactivity of other nerve functions in addition

to muscle stimulation. For instance, low blood calcium causes not only spasm

of the muscles of the hands and wrists, but also a sensation of numbness and

tingling around the mouth and other areas.

Sometimes, tetanic cramps are indistinguishable from " true " cramps. The

accompanying changes of sensation or other nerve functions may not be

apparent.

CONTRACTURES

Contractures result when the muscles are unable to relax. The constant spasms

are caused by a depletion of adenosine triphosphate (ATP), an energy chemical

within the cell. This prevents muscle fiber relaxation. The nerves are

inactive in this form of muscle spasm.

Contractures can be inherited (e.g., McArdle’s disease -- a defect of the

breakdown of glycogen to sugar within the muscle cell) or acquired (e.g.

hyperthyroid myopathy -- a muscle disease that is associated with an

overactive thyroid). Cramps of this category are uncommon.

DYSTONIC CRAMPS

The final category is dystonic cramps, in which muscles that are not needed

for the intended movement are stimulated to contract. Muscles that are

affected by this type of cramping include those that ordinarily work in the

opposite direction of the intended movement, and/or others that exaggerate

the movement. Some dystonic cramps usually affect small groups of muscles

(eyelids, jaws, neck, larynx, etc.) The hands and arms may be affected during

the performance of repetitive activities such as those associated with

handwriting (writer’s cramp), typing, playing certain musical instruments,

and many others. Each of these repetitive activities may also produce " true "

cramps from muscle fatigue. Dystonic cramps are not as common as " true "

cramps.

Do all muscle cramps fit into the above categories?

No. Not all cramps are readily categorized in the preceding manner since

these categories best apply to cramps that are the major muscle problem a

patient has. Many cramps are a relatively minor part of nerve and muscle

diseases; other muscle symptoms are usually more prominent in these diseases.

Examples include amyotrophic lateral sclerosis (Lou Gehrig’s disease) with

weakness and muscle wasting; radiculopathy (spinal nerve irritation or

compression from various causes) with pain, distortion or loss of sensation,

and/or weakness; diseases of the peripheral nerves, such as diabetic

neuropathy, with distorted and diminished sensation and weakness; and a

number of primarily dystonic muscle diseases.

Can medications cause muscle cramps?

Numerous medicines can cause cramps. Potent diuretic medications, such as

furosemide (LASIX), or the vigorous removal of body fluids even with less

potent diuretics can induce cramps by depleting body fluid and sodium.

Simultaneously, diuretics often cause the loss of potassium, calcium, and

magnesium, which can also cause cramps.

Medications such as donepezil (ARICEPT -- used for Alzheimer’s disease) and

neostigmine (PROSTIGMINE and others -- used for myasthenia gravis) as well as

raloxifene (EVISTA – used to prevent osteoporosis in postmenopausal women)

have caused cramps. Tolcapone (TASMAR -- used for Parkinson’s disease)

reportedly causes muscle cramps in at least 10% of patients. " True " cramps

are reported with nifedipine (PROCARDIA and others -- used for angina and

high blood pressure, and other conditions) and the asthma drugs terbutaline

(BRETHINE)and albuterol (PROVENTIL, VENTOLIN, and others). Some medicines

used to lower cholesterol, including clofibrate (ATROMID-S) and lovastatin

(MEVACOR), can also lead to cramps.

Cramps are sometimes noted in addicted individuals during withdrawal from

medications and substances that have sedative effects, including alcohol,

barbiturates and other sedatives, anti-anxiety agents such as benzodiazepines

(e.g. VALIUM and XANAX), narcotics, and other drugs.

Can vitamin deficiencies cause muscle cramps?

Several vitamin deficiency states may directly or indirectly lead to muscle

cramps. These include deficiencies of thiamine (B1), pantothenic acid (B5),

and pyridoxine (B6). The role of deficiency of these vitamins in causing

cramps is unknown.

Can poor circulation cause muscle cramps?

Poor circulation to the legs, which results in inadequate oxygen to the

muscle tissue, can cause severe pain in the muscle. This commonly occurs in

the calf muscles. While the pain feels virtually identical to that of a

severely cramped muscle, the pain does not seem to be a result of the actual

muscle cramping. This pain may be due to accumulation of lactic acid and

other chemicals in the muscle tissues.

What are the symptoms of common muscle cramps and how are they diagnosed?

Characteristically, a cramp is painful, often severely so. Usually, the

sufferer must stop whatever activity is underway and seek relief from the

cramp; the person is unable to use the affected muscle while it is cramping.

Severe cramps may be associated with soreness and swelling, which can

occasionally persist up to several days after the cramp has subsided. At the

time of cramping, the knotted muscle will bulge, feel very firm, and may be

tender.

There are no special tests for cramps. Most people know what cramps are and

when they have one. If present during a cramp, the doctor, or any other

bystander, can feel the tense, firm bulge of the cramped muscle.