What is Hereditary Olivopontocerebellar Atrophy & How is it Treated?

Hereditary olivopontocerebellar atrophy (OPCA) is a condition that affects the nerves in the brain. There are two distinct types of individuals suffering from olivopontocerebellar atrophy (OPCA). One is non-inherited sporadic olivopontocerebellar atrophy which is now considered as a form of multiple system atrophy (MSA) and other type is hereditary olivopontocerebellar atrophy. Generally, men are more likely to be affected by this disorder than women.

Hereditary olivopontocerebellar atrophy is an increasing neurological disorder. Hereditary olivopontocerebellar atrophy, is a bloodline disorder caused through inheritance of a defective gene. It causes degeneration of neurons of the pons, inferior olives and cerebellum. The pons is responsible for coordinating nerve signals between structures of the brain and the inferior olive is involved in balance, coordination, and motor activity.

It is important to understand the functions of the cerebellum because hereditary olivopontocerebellar atrophy mostly affects this part of the brain. Cerebellum weighs only ten percent of the total weight of human brain but it contains approximately half of the brain’s neurons.

• The cerebellum is responsible for receiving information from the sensory systems, spinal cord etc. and regulates the motor movements.
• This part of the brain also coordinates voluntary movements like speech, movements other balanced muscular activities.

The main cause of hereditary olivopontocerebellar atrophy is the inheritance of at least two defective genes. It is still not known how these defective genes cause degeneration or death of the neurons in that particular region of the brain.

Hereditary olivopontocerebellar atrophy can be caused by the inheritance of autosomal dominant, autosomal recessive, or X linked recessive genes.

Since it is pre-conditioned by the genetic disorder the presence of hereditary olivopontocerebellar atrophy in family history increases the risk for an individual to be affected. The cause of hereditary olivopontocerebellar atrophy, which is the defective gene can be inherited from either parent. But, it is also observed in some patients that a new mutation (changes in genes) can cause the disorder also.

The symptoms of hereditary olivopontocerebellar atrophy are related to the damage of the neurons and the affected nerves. Degeneration of neurons of that portion of the brain in a progressive manner leads to severe ataxia (loss of coordination). This is the most common symptom of hereditary olivopontocerebellar atrophy in the early stages and is noted as the patients lose balance while walking. In the beginning ataxia may be misinterpreted as clumsiness but in fact it is an indicating symptom of hereditary olivopontocerebellar atrophy.

The symptoms of hereditary olivopontocerebellar atrophy vary from one person to another. In some the progression of neuron degeneration may be fast, while in some it is very slow. In most cases, symptoms of hereditary olivopontocerebellar atrophy are noted after the age of 50 but can also be observed in late 20s in some cases.

Common symptoms of hereditary olivopontocerebellar atrophy include

• Dysarthria (Slurred speech or speech difficulty)
• Tremors in hands
• Stiffness of muscles
• Dysphagia (Difficulty in swallowing)
• Involuntary urination and stool.
• Nystagmus (abnormal movement of eyes).
• Sudden abnormal movements such as jerking, twisting or writhing.
• Over reaching for an object with hand

Diagnosis of hereditary olivopontocerebellar atrophy is made after necessary investigations. Careful neurological examination, CT scans cross-sectional and detailed X-rays with magnetic resonance image (MRI) may show brain damage to determine the amount of loss of tissues in the distinctive brain regions.

But it is difficult to diagnose hereditary olivopontocerebellar atrophy in the earlier stages due to variable symptoms. Genetic tests or other advanced tests may be ordered, if appropriate.

Treatment of hereditary olivopontocerebellar atrophy is not available. In most cases, only the symptoms are treated to provide relief. Hence, medications to treat the ataxia, tremor, and rigidity are given.

The main aim of management of this disorder is to provide relief to the patient for daily management. Exercise stretching may help the patient to some extent to keep their balance and strength intact as long as possible. Occupational and physical therapy can help to maintain strength, balance and co-ordination. Obtaining some devices or appliances to assist in walking and other daily activities will also help.

Speech therapy helps the patient to improve speech. Learning the technique of swallowing food to prevent any nutritional deficiencies is also a part of the therapies.
Other treatment of hereditary olivopontocerebellar atrophy is directed at specific symptoms like spasms, sleep disorders, depression etc. may be improved with medication. For example the walking aids, such as canes or walkers and mechanical wheelchairs is some of the appliances or devises which help the patient suffer from the disorder.

Commonly used treatment of hereditary olivopontocerebellar atrophy includes

• Using Dopaminergic agents, such as levodopa, bromocriptine, or amantadine, have shown some minimal benefit.
• Propranolol has been used for tremor with a minimum response.
• Related to the fact that some serotonin modulate the serotonergic motor output from the cerebellum, such as tandospirone or buspirone, as a treatment for ataxia.
• Parents with a history of hereditary olivopontocerebellar atrophy are advised to go for genetic counselling before planning for a baby.

There is no cure for this medical condition. The life expectancy after diagnosis of hereditary olivopontocerebellar atrophy is approximately 15 years, although this is an average and cannot be used to predict the lifespan of any individual person. The disorder is slowly progressive.

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