athetosis 227the ability to walk for 10 to 15 years after symp-
toms begin and maintain limited independence
with assisted mobility (such as a wheelchair) for
another 10 years or longer.
See also AMYOTROPHIC LATERAL SCLEROSIS (ALS);
CEREBRAL PALSY; COGNITIVE FUNCTION AND DYSFUNC-
TION; GENETIC COUNSELING; INHERITANCE PATTERN; NYS-
TAGMUS; PARKINSON’S DISEASE; VIRUS.
athetosis Slow, writhing, involuntary, often con-
tinuous movements of the hands and fingers and
occasionally the upper extremities. Athetosis
occurs as a result of damage to the basal ganglia,
NERVEstructures deep in the BRAINthat regulate
voluntary movement. Athetosis occurs in about
5 percent of people who have CEREBRAL PALSY
and also as a consequence of hepatic ENCEPHALOPA-
THY(damage to the structures of the brain result-
ing from LIVER FAILURE) or encephalopathy due
to drug toxicity (including ANTIPSYCHOTIC MEDICA-
TIONS and medications to treat PARKINSON’S DIS-
EASE), ENCEPHALITIS (INFLAMMATION of the brain),
and HUNTINGTON’S DISEASE. Athetosis often occurs
in combination with CHOREA(choreoathetosis).
The diagnostic path relies on physician observa-
tion in combination with health history. Imaging
procedures such as MAGNETIC RESONANCE IMAGING
(MRI) and SINGLE-PHOTON EMISSION COMPUTED TOMOG-
RAPHY(SPECT) sometimes show the lesion (dam-
aged tissue) within the brain. Treatment for
athetosis depends on the underlying cause and
may include- MUSCLE RELAXANT MEDICATIONSsuch as diazepam
(Valium) and clonazepam (Klonopin) - OCCUPATIONAL THERAPYto teach adaptive skills
and improve MUSCLEcontrol - DEEP BRAIN STIMULATION, which alters the electri-
cal output of the basal ganglia and related
structures - RHIZOTOMY, a surgical OPERATION in which the
neurosurgeon selectively severs root fibers of
the SPINAL NERVESthat serve the affected areas of
the body
Outcome also depends on the underlying
cause. Surgery is often effective at eliminating
athetosis when the cause is cerebral palsy. A com-
bination of methods often achieves relief when
other causes are responsible.
See also DYSTONIA; TIC; TOURETTE’S SYNDROME;
TREMOR DISORDERS.