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$Unique_ID{BRK04061}
$Pretitle{}
$Title{Olivopontocerebellar Atrophy}
$Subject{Olivopontocerebellar Atrophy Ataxia Spinal Cerebellar Atrophy
Olivopontocerebellar Atrophy I (SCA1; OPCA I, Menzel Type OPCA)
Olivopontocerebellar Atrophy II (OPCA II, Fickler-Winkler Type)
Olivopontocerebellar Atrophy III (OPCA III; OPCA With Retinal Degeneration)
Olivopontocerebellar Atrophy IV (OPCA IV; Schut-Haymaker Type OPCA)
Olivopontocerebellar Atrophy V (OPCA V; OPCA With Dementia and Extrapyramidal
Signs) Friedreich's Ataxia Marie's Ataxia Ataxia Telangiectasia
Charcot-Marie-Tooth Disease}
$Volume{}
$Log{}

Copyright (C) 1988, 1990 National Organization for Rare Disorders, Inc.

495:
Olivopontocerebellar Atrophy

** IMPORTANT **
It is possible the main title of the article (Olivopontocerebellar
Atrophy) is not the name you expected.  Please check the SYNONYMS listing on
the next page to find alternate names, disorder subdivisions, and related
disorders covered by this article.

Synonyms

     Ataxia
     Spinal Cerebellar Atrophy

DISORDER SUBDIVISIONS

     Olivopontocerebellar Atrophy I (SCA1; OPCA I, Menzel Type OPCA)
     Olivopontocerebellar Atrophy II (OPCA II, Fickler-Winkler Type)
     Olivopontocerebellar Atrophy III (OPCA III; OPCA With Retinal
Degeneration)
     Olivopontocerebellar Atrophy IV (OPCA IV; Schut-Haymaker Type OPCA)
     Olivopontocerebellar Atrophy V (OPCA V; OPCA With Dementia and
Extrapyramidal Signs)

Information on the following diseases can be found in the Related
Disorders section of this report:

     Friedreich's Ataxia
     Marie's Ataxia
     Ataxia Telangiectasia
     Charcot-Marie-Tooth Disease

General Discussion

** REMINDER **
The information contained in the Rare Disease Database is provided for
educational purposes only.  It should not be used for diagnostic or treatment
purposes.  If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.

Olivopontocerebellar Atrophy (OPCA) is a group of inherited forms of
Ataxia characterized by progressive neurological degeneration affecting the
olivopontocerebellar area of the brain.  These inherited forms include Menzel
type I, Fickler-Winkler type II, retinal degeneration type III, Schut-
Haymaker type IV, and ophthalmoplegia (paralysis of facial and eye muscles)
type 5 OPCA.  However, cases have occurred which have defied classification
in any of these five categories.

Symptoms

Olivopontocerebellar Atrophy (OPCA) is characterized by loss of nerve cells
(neurons) in the cortex of the brain, base of the pons section of brainstem
(basis pontis), and inferior olivary nuclei which is a prominence on the
surface of the lower part of the brain (medulla oblangata).  Loss of these
neurons results in impaired muscle coordination (ataxia), tremor, involuntary
movement, and a speech disturbance (dysarthria).  Five clinical types of OPCA
have been described, depending on additional findings, such as sensory loss,
retinal degeneration, ophthalmoplegia, and extrapyramidal signs.  However,
cases have occurred which have defied classification in any of these five
categories.  A wide variation in severity and age of onset may be found in
any of the five recognized classifications of Olivopontocerebellar Atrophy.

Olivopontocerebellar Atrophy I (Menzel type OPCA) usually begins in the
third or fourth decades of life, with an average onset at thirty years of
age.  In addition to cerebellar degeneration, other areas of the body become
affected with speech abnormalities and/or tremors.  Involuntary movements
(chorea) may also occur.

Olivopontocerebellar Atrophy II (OPCA II, Fickler-Winkler or Dejerine-
Thomas type) differs from OPCA type I by a lack of involuntary movements.
Onset of this disorder usually begins at approximately fifty years of age.
The exact nature of this form of cerebellar atrophy is not well understood.

Olivopontocerebellar Atrophy III (OPCA III; OPCA with retinal
degeneration) is characterized by retinal degeneration.  This form of OPCA
usually begins during middle age, although it can begin at any age.  It is
also marked by blindness, tremor, weakness and impaired muscle coordination.

Olivopontocerebellar Atrophy IV (OPCA IV; Schut-Haymaker type OPCA) is
characterized by a form of paralysis (spastic paraplegia).  The atrophy seems
to be limited to the inferior olivary nucleus and cerebellum with varying
involvement of the pons area of the brain.  Abnormalities of the spinal cord
and some of the cranial nerves may also occur.  Symptoms usually begin at
approximately twenty-five years of age.

Olivopontocerebellar Atrophy V (OPCA V; OPCA with dementia and
extrapyramidal signs) is characterized by cerebellar atrophy, tremors, ataxia
and abnormal sensation, rigidity and mental deterioration.  This disorder
usually begins during adult life.  Walking, writing and speech often become
difficult as the disorder progresses.

Causes

Four of the five identified forms of Olivopontocerebellar Atrophy (OPCA) are
inherited as autosomal dominant traits.  OPCA II is inherited as an autosomal
recessive trait.

Human traits including the classic genetic diseases, are the product of
the interaction of two genes for that condition, one received from the father
and one from the mother.

In dominant disorders, a single copy of the disease gene (received from
either the mother or father) will be expressed "dominating" the normal gene
and resulting in appearance of the disease.  The risk of transmitting the
disorder from affected parent to offspring is 50% for each pregnancy
regardless of the sex of the resulting child.)

In recessive disorders, the condition does not appear unless a person
inherits the same defective gene from each parent.  If one receives one
normal gene and one gene for the disease, the person will be a carrier for
the disease, but usually will show no symptoms.  The risk of transmitting the
disease to the children of a couple, both of whom are carriers for a
recessive disorder, is twenty-five percent.  Fifty percent of their children
will be carriers, but healthy as described above.  Twenty-five percent of
their children will receive both normal genes, one from each parent and will
be genetically normal.)

Affected Population

Olivopontocerebellar Atrophy is a group of rare disorders which usually
affect males and females in equal numbers.

Related Disorders

Symptoms of the following disorders can be similar to those of
Olivopontocerebellar Atrophy.  Comparisons may be useful for a differential
diagnosis:

Ataxia means walking with an unsteady gait caused by the failure of
muscular coordination or irregularity of muscular action.  There are many
forms of Ataxia.  Some ataxias are hereditary, some have other causes and
sometimes ataxia can be a symptom of other disorders.  To locate information
about other types of ataxias, choose "Ataxia" as your search term in the Rare
Disease Database.

Friedreich's Ataxia is a hereditary neuromuscular syndrome characterized
by slow degenerative changes of the spinal cord and the brain.  Dysfunction
of the central nervous system affects coordination of the muscles in the
limbs.  Speech can be affected and numbness or weakness of the arms and legs
may develop.  Various transitional and overlapping forms of Friedreich's
Ataxia can occur.  Although no specific treatment can stop the progression of
this disorder, some symptoms can be alleviated with proper treatment.  In a
few cases, spontaneous remissions may occur which can last five to ten years
or sometimes longer.  This syndrome appears to be the most common of the many
different forms of hereditary Ataxia.  It usually begins during childhood or
the teen years.  (For more information on this disorder, choose "Friedrich"
as your search term in the Rare Disease Database).

Marie's Ataxia is a neuromuscular syndrome inherited as a dominant trait.
Also known as Pierre Marie's Disease or Hereditary Cerebellar Ataxia, it is
characterized by a later onset of neurological and coordination disturbances.
The syndrome usually begins between thirty and forty years of age and may not
be as disabling as Friedreich's Ataxia.  Initially, those affected may walk
unsteadily and tend to fall frequently.  Loss of coordination in the arms and
speech disturbances may also occur.  In later stages slight loss of vision,
and loss of pain or touch sensations, may also occur.  Tremors may develop
when conscious motion is attempted.  Swallowing and clearing of secretions
may eventually become difficult if the throat muscles are affected.  (For
more information on this disorder, choose "Marie" as your search term in the
Rare Disease Database).

Charcot-Marie-Tooth Disease (CMT) is a hereditary neurological disorder
characterized by weakness and atrophy, primarily in the legs.  Disappearance
of the fatty shield surrounding the nerve cells (segmental demyelination of
peripheral nerves), and associated degeneration of part of the nerve cells
(axons) characterize this disorder.  (For more information on this disorder,
choose "CMT" as your search term in the Rare Disease Database).

Ataxia Telangiectasia, also known as Louis-Bar Syndrome, is an inherited
progressive cerebellar ataxia that usually begins during infancy.  It
involves progressive loss of coordination in the limbs, head and eyes with a
below-normal immune response to infections.  In later stages, dilated blood
vessels (telangiectasias) appear in the eyes and skin.  Individuals with this
form of Ataxia are more susceptible to sinus and lung infections and tend to
have tumors (neoplasms).  Ataxia Telangiectasia may be misdiagnosed as
Friedreich Ataxia until dilated blood vessels appear in the skin
(telangiectasias).  (For more information on this disorder, choose "Louis-
Bar" as your search term in the Rare Disease Database).

Therapies:  Standard

Treatment of Olivopontocerebellar Atrophy is symptomatic and supportive.
Continuous medical supervision to avoid potential complications involving the
heart, lungs, spine, bones and muscles is recommended.  Prevention of
infection is a challenge in the care of people in the advanced stages of
Olivopontocerebellar Atrophy.  Physical therapy may be recommended by a
physician.

Drugs may be useful in treating some symptoms.  Propranolol may be
effective against static tremors, and less often against intention tremors.
Static tremors can occur when the affected individual is not moving, whereas
intention tremors occur when the patient makes intentional movements.
Dantrolene sodium may help some patients with muscle spasms of the legs.
These drugs should be carefully monitored by a physician to limit the
possibility of toxicity.  Genetic counseling is recommended for patients and
their families.  Other treatment is symptomatic and supportive.

Therapies:  Investigational

Olivopontocerebellar Atrophy patients may be treated for spasticity using the
drug baclofen.  Genetic investigators are trying to identify the gene which
causes this syndrome.  Other experimental drugs, cell cultures, and analysis
of central nervous system tissues are also under study.

This disease entry is based upon medical information available through
March 1990.  Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.

Resources

For more information on Olivopontocerebellar Atrophy, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     [phone]

     National Ataxia Foundation
     750 Twelve Oaks Center
     15500 Wayzata Blvd.
     Wayzata, MN  55391
     [phone]

     NIH/National Institute of Neurological Disorders & Stroke (NINDS)
     9000 Rockville Pike
     Bethesda, MD  20892
     [phone]
     [phone]

For information on genetics and genetic counseling referrals, please
contact:

     March of Dimes Birth Defects Foundation
     1275 Mamaroneck Avenue
     White Plains, NY  10605
     [phone]

     Alliance of Genetic Support Groups
     35 Wisconsin Circle, Suite 440
     Chevy Chase, MD  20815
     (800) 336-GENE
     [phone]

References

MENDELIAN INHERITANCE IN MAN, 7th ed.:  Victor A. McKusick; Johns Hopkins
University Press, 1986.  Pp. 537-539, 874.

OLIVOPONTOCEREBELLAR ATROPHY WITH DEMENTIA, BLINDNESS, AND CHOREA.
RESPONSE TO BACLOFEN:  D.A. Trauner; Arch Neurol (August 1985, issue 42(8)).
Pp. 757-758.

OLIVOPONTOCEREBELLAR ATROPHY.  A REVIEW OF 117 CASES:  J. Berciano; J
Neurol Sci (February 1982, issue 53 (2)).  Pp. 253-272.

AN APOLOGY AND AN INTRODUCTION TO THE OLIVOPONTOCEREBELLAR ATROPHIES:
R.C. Duvoisin; Adv Neurol (1984, issue 41).  Pp. 5-12.