HUNTINGTON'S DISEASE
Philip A. Hanna, M.D.
Parkinson's Disease and Movement Disorders Center
New Jersey Neuroscience Institute
Edison, New Jersey
Chorea describes involuntary, continuous, abrupt, nonsustained,
irregular movements which flow in a random fashion from one body part
to another. Patients can temporarily suppress the chorea and
incorporate the involuntary movements into activities which appear
purposeful. Patients have difficulty maintaining voluntary
contractions such as tongue protrusion or sustaining a grip which may
result in clumsiness. Their walking typically appears
"dance-like" in nature.
In addition to chorea, the other two features of the Huntington's
disease (HD) triad include a decline in cognition and
psychiatric/neurobehavioral symptoms such as personality change, loss
of interest, withdrawal from social situations, impulsiveness,
irritability, depression, mania, paranoia, and hallucinations.
Cognitive changes, primarily a loss of recent memory, poor judgment,
and impaired concentration occur in nearly all patients yet some
patients with late-onset chorea do not develop dementia.
Nearly 10% of patients have symptom onset prior to age 20 (juvenile
HD), but the usual age of onset is in the 4th or 5th decade. Juvenile
HD usually presents with parkinsonism (slowness of movement),
dementia, clumsiness and seizures, while adult HD usually has more
gradual onset of clumsiness and fidgety movements which may appear as
"nervousness". HD is inherited via an autosomal dominant
pattern, such that each offspring of an individual with HD has a 50%
chance of inheriting the HD gene. The gene on chromosome 4p encodes a
protein which has been named "huntingtin" [DiFiglia, 1997].
At present only symptomatic treatment is available, tailored to the
patient's main symptoms. Psychosis may improve with certain
anti-psychotic medications but many of these may cause tardive
dykinesia (potentially permanent involuntary movements). Tetrabenazine
(or reserpine) are very effective in reducing chorea, but they can
cause slowness of movement, worsened depression or fatigue.
Anti-excitatory drugs, including remacemide, coenzyme Q10 and
nicotinamide are being studied and may be neuroprotective.
Transplantation studies are also in progress.
Huntington's Disease Society of America
140 W. 22nd Street
New York, NY 10011-2420
Tel: 800-345-HDSA; 212-242-1968. Fax: 212-243-2443
Penney JB, Young AB. Huntington's disease. In: Jankovic J, Tolosa E,
eds, Parkinson's Disease and Movement Disorders, 3rd ed. Williams and
Wilkins, 1998:341-355.
Hanna PA, Cardoso F, Jankovic J. Basal Ganglia and Movement Disorders.
In: Rolak LA, ed. Neurology Secrets, 2nd ed. New York: Hanley and
Belfus, 1998:137-169.
DiFiglia M, Sapp E, Chase KO, et al. Aggregation of huntingtin in
neuronal intranuclear inclusions and dystrophic neurites in brain.
Science 1997;227:1990-1993.
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