Information about NAF, HA &
OPCA
National Ataxia Foundation (NAF)
- What is the National Ataxia
Foundation?
- The National Ataxia Foundation is a
nonprofit organization established in 1957 with the primary
mission of encouraging and supporting research into Hereditary
Ataxia, a group of neurological disorders which are chronic and
progressive conditions affecting coordination. There are more than
45 affiliated chapters and support groups throughout the U.S. and
Canada.
-
- Who is NAF
for?
- An estimated 150,000 people in the
United States are affected by the hereditary and sporadic ataxias.
They strike without regard to age, gender, or race. NAF's members
include:
-
- people with hereditary or sporadic
ataxia, their families,
- physicians and other health
professionals who treat people with ataxia,
- physicians and scientists involved in
research into the causes of ataxia,
- others interested in the fight against
ataxia or in disability issues.
- (For people who have ataxia as a symptom
of other medical conditions such as head injury, stroke, MS, or
alcoholism, we recommend that you contact the organization related
to your specific condition for the most up-to-date information. We
will be happy to provide you with appropriate addresses and
telephone numbers if needed.)
-
- What does NAF
do?
- NAF's programs, funded through
contributions and membership dues, include:
-
- Encouraging and supporting research
efforts to identify the causes and mechanisms of the hereditary
ataxias, improving diagnosis, and developing treatment models.
- Locating families affected by ataxia or
at risk for ataxia in order to offer information and education.
- Identifying needs and services for
purposes of referral.
- Creating and making available
educational programs for ataxia families, health care
professionals, and the general public.
- Increasing public awareness of
hereditary ataxia.
- NAF keeps its members informed through
its quarterly publication, GENERATIONS.
Also, by providing access to ELECTRONIC
NAF, offers additional support
and information resources.
HEREDITARY ATAXIA
(HA)
To
See a short video about HA & NAF go here
An estimated 150,000 people in the United
States are affected by the hereditary and sporadic ataxias, a group
of neurological disorders having ataxia (incoordination) as a common
symptom. Hereditary ataxia affects the cerebellum and spinal cord and
is passed from one generation to the next through a defective gene.
The two most prevalent types of hereditary ataxia are Friedreich's
(recessive) ataxia and Marie's (dominant) ataxia. Also common are the
sporadic ataxias which occur spontaneously in individuals with no
known family history of ataxia. You may consult a more complete
ataxia
classification, provided by the
Department
of Neurology at Washington
University, School of Medicine.
-
- Olivopontocerebellar
Atrophy (OPCA)
-
- Background: In 1900, Dejerine and
Thomas first introduced the term olivopontocerebellar atrophy
(OPCA). Since then, the classiication of idiopathic acquired
ataxias has evolved a great deal. The initial cases of Dejerine
and Thomas involved 2 middle-aged patients with chronic
progressive cerebellar degeneration and autopsy findings of gross
atrophy of the pons, cerebellum, middle cerebellar peduncle, and
inferior olives.
-
- OPCA has not been proven to be a single
entity. The nosology of these disorders has been extremely
confusing, as the OPCAs overlap with spinocerebellar atrophies
(SCAs) and multiple system atrophies (MSAs). Clinical distinction
of these entities is based on the dominant feature, which may be
cerebellar ataxia (observed in OPCA, SCA, and MSA), parkinsonism
(observed in MSA), or autonomic failure (observed in MSA). The
term OPCA has been retained to describe a form of progressive
ataxia distinguished by pontine flattening and cerebellar atrophy
on brain imaging studies and at autopsy. Thus defined, OPCA also
may qualify as an SCA or as an MSA.
While MSAs are sporadic by definition,
the genetic bases of the SCAs are increasingly well defined. Since
OPCA may exist as a sporadic or inherited disease, categorizing
sporadic OPCA as MSA and inherited OPCA s SCA may be appropriate.
Differences between sporadic and inherited OPCA in microscopic
pathology support this division.
- When faced with an adult having
progressive ataxia suggestive of OPCA, the role of the clinician
includes (1) excluding readily treatable alternative diagnoses,
(2) discussing the value of genetic testing with patients in whom
such testing is informative, (3) managing symptoms, and (4)
advising the patient and family regarding natural history and the
need to plan for the future. No definitive therapy for OPCA
exists.
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.
A personal note: There are more
Subdivisions being classified all the time, this treatise is
forshortened because these classifications represent a majority of
the disorder Subdivisions, though the type of OPCA plauging my family
is yet to be found, and thus we wait for the discovery of the gene
which is responsible for my disease. Which will lead to tests which
can be done on my two children and perhaps a cure.
CAUSES
Copyright (C) 1988, 1990, 1994, 1997, 1998
National Organization for Rare Disorders, Inc
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 other normal gene and resulting in the
appearance of the disease. The risk of transmitting the disorder from
affected parent to offspring is 50 percent 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 (for that particular
trait).)
The defective gene that causes
Olivopontocerebellar Atrophy I (Spinocerebellar Ataxia Type I
[SCA1]) is thought to be located on the short arm of
chromosome 6 (p23). Some studies suggest that this defective gene may
be very unusual. It may produce varying amounts of extra genetic
material (trinucleotide repeats) that may be responsible for the
severity of symptoms as well as the age of onset. Research suggests
that people who have symptoms of this disease early in life may have
a larger gene size than those with late-onset disease.
The defective gene that causes
Olivopontocerebellar Atrophy II (Spinocerebellar Ataxia Type II
[SCA2]) is thought to be located on the short arm of
chromosome 6 (6p23).
The defective gene that causes
Olivopontocerebellar Atrophy III is believed to be located on the
short arm of chromosome 3 (3p21.1-p12).
The defective gene believed to cause
Spinocerebellar Ataxia Type IV (SCA4) is located on the long arm of
chromosome 16 (16q22.1).
The defective gene believed to cause
Spinocerebellar Ataxia Type V (SCA5) is located on the centromeric
region of chromosome 11 (11p11-q11).
The defective gene believed to cause
Spinocerebellar Ataxia Type VI (SCA6) is located on the short arm of
chromosome 19 (19p13).
The defective gene believed to cause
Spinocerebellar Ataxia Type VII (SCA7) is located on the short arm of
chromosome 3 (3p12-p13).
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.)
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- Standard Therapies
-
- 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.
-
- There are genetic tests available for
some types of Spinocerebellar Ataxia. The diagnosis of
Spinocerebellar Ataxia Types I, II, and III can be confirmed with
a standard blood test. Genetic testing may be developed for other
types of SCA.
-
- Drugs may be useful in treating some
symptoms. Propranalol 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.
-
- Investigational
Therapies
-
- Research on genetic disorders and their
causes is ongoing. The National Institutes of Health (NIH) is
sponsoring the Human Genome Project which is aimed at mapping
every gene in the human body and learning why they sometimes
malfunction. It is hoped that this new knowledge will lead to
prevention and treatment of genetic and familial disorders in the
future.
-
- Olivopontocerebellar Atrophy patients
may be treated for spasticity using the drug baclofen. Other
experimental drugs, cell cultures, and analysis of central nervous
system tissues are also under study.
-
- Researchers at the National Institutues
of Health are conducting clinical trials to locate the genes
responsible for a group of neurodegenerative disorders called the
hereditary ataxias.
-
- NORD does not promote, endorse or
encourage participation in any specific medical research study.
This information is presented to further scientific understanding
that could lead to prevention, treatment, and/ or cure of rare
disorders. NORD recommends that anyone interested in participating
in a clinical research program seek the advice or counsel of his
or her own personal physician(s).
-
- This disease entry is based upon medical
information available through 03 Jan 2002. 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.
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- Resources
-
-
- Some of this information was provided by
the National Organization for Rare Disorders, P.O. Box 8923, New
Fairfield, CT 06812-8923, phone: (203) 746-6518, web site:
www.rarediseases.org,
e-mail: orphan@rarediseases.org.
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- For more information on
Olivopontocerebellar Atrophy, please contact:
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- National Ataxia Foundation
(NAF)
- 2600 Fernbrook Lane
- Suite 119
- Minneapolis, MN 55447
- (763) 553-0020 Phone
- (763) 553-0167 Fax
- e-mail :
naf@ataxia.org
- Home Page:
http://www.naf.org
-
- CLIMB (Children Living with Inherited
Metabolic Diseases)
- The Quadrangle
- Cheshire Intl CW1 6UR
- 1270 250221
- e-mail: Lesley@climb.org.uk
- Home Page:
http://www.CLIMB.org.uk
-
- WE MOVE (Worldwide Education and
Awareness for Movement Disorders)
- Mt. Sinai Medical Center
- New York NY 10029
- 2122418567
- 8004376682
- e-mail: wemove@wemove.org
- Home Page:
http://www.wemove.org
-
- March of Dimes Birth Defects
Foundation
- 1275 Mamaroneck Avenue
- White Plains NY 10605
- 9144287100
- 8886634637
- e-mail: resourcecenter@modimes.org
- Home Page:
http://www.modimes.org
-
- NIH/National Institute of
Neurological Disorders and Stroke
- "Brain Resources and Information
Network" (BRAIN)
- Bethesda MD 20824
- 3014965751
- 8003529424
- e-mail: N/A
- Home Page:
http://www.ninds.nih.gov/
-
- Metabolic Information Network
(PHYSICIAN CALLS ONLY)
- P.O. Box 670847
- Dallas TX 75367-0847
- 2146962188
- 8009452188
- e-mail: mizesg@ix.netcom.com
- Home Page: N/A
-