D–G

dislocations Separations of the structures within
a JOINT, typically as a result of traumatic injury.
The digits (fingers and toes), shoulders, and hips
are particularly vulnerable to dislocation. Trau-
matic dislocation is very painful. Generally a doc-
tor should reduce the dislocation (restore the
bones to their correct positions) and evaluate the
injury for any damage that would require addi-
tional treatment; however, people tend to “pop”
dislocations back into place themselves. Such self-
treatment can cause further trauma, depending on
the circumstances. Splinting the joint and apply-
ing ice to the area can reduce swelling and PAIN
until the doctor can realign the structures. Some-
times a dislocation reflects an abnormality of the
joint that requires a doctor’s assessment and treat-
ment to prevent subsequent dislocations.
See alsoFRACTURE; RICE; SPRAINS AND STRAINS.

dwarfism See SKELETAL DYSPLASIA.

dystonia Extended contractions of the muscles
that hold the body in unnatural postures. Dysto-
nia may occur as a primary disorder of movement,
typically a hereditary disorder, or as an undesired
SIDE EFFECTof certain medications to treat PARKIN-
SON’S DISEASE, PSYCHOSIS, SCHIZOPHRENIA, and SEIZURE
DISORDERS that affect DOPAMINE binding in the
BRAIN. Dopamine is a key NEUROTRANSMITTER for
movement as well as for mood. Sometimes,
though unfortunately not always, stopping the
medication ends DRUG-related dystonia. Inherited
forms of primary dystonia may be spastic (involve
rigid, distorted postures) or repetitious, often
rhythmic, involuntary movements such as gri-
maces, twitches, and jerking.
There are no treatments for primary dystonia
that are certain to stop the MUSCLEcontractions.

Some people experience relief with high doses of

anticholinergic drugs that affect acetylcholine, a

neurotransmitter important to fine motor move-

ments. When the dystonia occurs in a localized or

regional part of the body, BOTULINUM THERAPY

(injections of weakened botulinum toxin) some-

times can paralyze the muscles enough to signifi-

cantly reduce or eliminate the dystonia. The

effects of botulinum therapy are temporary, how-

ever, with repeat treatments required about every

six months.

See also BLEPHAROSPASM; SPASM; TIC; TORTICOLLIS.

epicondylitis INFLAMMATIONof the TENDONat the

elbow end of the humerus (long BONEof the upper

arm). Epicondylitis may be lateral or medial. Lat-

eral epicondylitis, commonly called tennis elbow,

affects the outer side of the elbow (little finger

side). Bending the wrist back or applying pressure

to the bony projection (the humeral epicondyle)

on the outside of the elbow causes PAINat the

elbow. Painting and plastering are common occu-

pational causes of lateral epicondylitis. Medial epi-

condylitis, commonly called baseball elbow or

golfer’s elbow, affects the inner side of the elbow

(thumb side). Bending the wrist toward the palm

of the hand or squeezing a ball held in the palm of

the hand causes pain at the base of the elbow.

The doctor makes the diagnosis on the basis of

symptoms and personal history of overuse or a

blow to the elbow. Diagnostic procedures are usu-

ally not necessary. Treatment combines NON-

STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS) or

injections of CORTICOSTEROID MEDICATIONS, which

reduce inflammation and pain, with alternating

heat and cold to the area. A brace or band worn

over the humeral epicondyle provides relief for

some people. Epicondylitis generally goes away in

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