Olivopontocerebellar Atrophy
Introduction

Olivopontocerebellar atrophy (OPCA) is almost certainly not a single disease, but a group of diseases. In this brochure, we discuss OPCA that has occurred "sporadically", which means that no one else in the family has ever had the same disorder. In the brochure "Hereditary Olivopontocerebellar Atrophy", we describe forms of ataxia that are known to run in families.

Many people do not receive a diagnosis of OPCA until they have seen many different physicians. Physicians also use different terms when they diagnose OPCA. Here is a list of some of the terms, or diagnoses, that physicians may use:

* olivopontocerebellar atrophy or degeneration
* olivocerebellar atrophy or degeneration
* multisystem atrophy
* ataxia
* Marie's ataxia
* Holmes ataxia
* Menzel's ataxia
* ataxia with Parkinsonism, autonomic neuropathy, corticospinal features or dementia
* spastic ataxia

In addition many patients with sporadic OPCA may have been diagnosed as having Parkinson's disease, multiple sclerosis, or other neurologic conditions before the diagnosis of OPCA becomes clear.

What are the symptoms of OPCA?

The symptoms of OPCA are different from one person to the next, which is one reason why the diagnosis may be hard to make. Most patients with sporadic OPCA develop difficulty with balance and coordination of the legs and arms (ataxia), and many develop slurred speech (dysarthria). If the ataxia becomes severe, it can interfere with the person's ability to work at his job, to walk independently, to write or feed himself.

Many patients with sporadic OPCA develop symptoms in addition to ataxia; occasionally these symptoms come on earlier or are most obvious than the ataxia. These symptoms may include weakness, stiffness of the muscles, or muscle spasms; numbness or tingling of the hands or feet; tremor (shaking) of the hand or arm, slowness of movements, and decreased movements; loss of thinking or memory skills; and difficulty controlling the bladder or bowels, or feeling faint when standing up. Some patients with sporadic OPCA have troubles with sleep; others note fatigue as a troublesome symptom.

The symptoms of OPCA usually come on in mid-adult life and progress slowly over a course of many years.

What causes OPCA?

There are probably many different causes for OPCA, because OPCA is really a number of different disorders. When a person with symptoms suggesting OPCA sees a physician, the physician may do a large number of tests to look for medical and neurologic diseases that we already know about that can cause these symptoms. Among the medical and neurologic diseases that can cause or be associated with ataxia and/or some of the other symptoms described above are:

* cancer (particularly lung and ovarian)
* chronic alcohol use or abuse
* Vitamin B12, thiamine, or Vitami n E deficiency
* hypothyroidism
* certain drugs, in particular drugs to treat epilepsy
* strokes, tumors, or cysts in the cerebellum or brainstem
* hydrocephalus
* residual effects of encephalitis or suffocation
* exposure to certain toxins, such as heavy metals (lead, thallium)
* a number of rare "enzyme" or "metabolic" disorders
* multiple sclerosis
* peripheral neuropathy (various types)

You can see why it may take a long time and a number of tests before all these possibilities are considered and a diagnosis of OPCA is made. Sometimes the diagnosis may never be entirely certain. There is no single test that proves that a person has sporadic OPCA; rather, the diagnosis is usually made in a patient with a appropriate symptoms in whom other conditions have been "ruled out."

Commonly, a person who has OPCA will undergo a number of blood tests, imaging of the brain and/or spinal cord by CT (computerized tomography) or MRI (magnetic resonance imaging), and (depending on the specific symptoms) evaluation for cancer, multiple sclerosis, or peripheral neuropathy before a diagnosis is made.

For the full text of this article please contact the National Ataxia Foundation at naf@ataxia