The epilepsy medication Phenytoin is an effective anticonvulsant in protecting against the development of focal seizures with complex symptomatology (psychomotor and temporal lobeseizures).

The medication is also effective in controlling partial seizures with autonomic symptoms due to its advantage of single daily administration.

Its popularity however is in decline, partly because of perception of adverse effects that include cerebellar toxicity.

About Phenytoin

Phenytoin, sold under the brand name Dilantin, is an anti seizure medication. It is useful for the prevention of tonic-clonic seizures and partial epilepsy.

Dilantin may accumulate in the cerebral cortex over long periods of time which can cause atrophy of the cerebellum. The degree of cerebellar toxicty is related to the duration of Dilantin treatment and is not related to dosage of the anti-seizure medication.

What is Cerebellar Toxicity?

The cerebellum is the area of the brain responsible for controlling muscle coordination. If it becomes inflamed or damaged, a person may suddenly lose coordination.

Damage, degeneration or loss of nerve cells in the part of the brain that controls muscle coordination (cerebellum), results in cerebellar ataxia (unsteadiness).

The cerebellum comprises two ping pong-ball-sized portions of folded tissue situated at the base of the brain near the brainstem. The right side of the cerebellum controls coordination on the right side of the body; the left side of the cerebellum controls coordination on the left.

Diseases that damage the spinal cord and peripheral nerves that connect your cerebellum to the muscles also may cause cerebellar ataxia. Common cerebellar toxicity or ataxia causes include:

• Head trauma
• Stroke
• Cerebral palsy
• Multiple sclerosis
• Chickenpox
• Tumor

Additionally, cerebellar toxicity or ataxia causes can be triggered by a rare toxic reaction to a specific mediation such as phenytoin (Dilantin).

Possible Long-Term Side Effects of Phenytoin Use

Another side effect of long term use of phenytoin is cerebellar toxicity.  While cerebellar toxicity is rarely fatal, it can cause neurologic symptoms ranging from nystagmus to cerebellar ataxia to coma.

Symptoms of phenytoin cerebellar toxicity include:

• Fast, uncontrollable eye movements or double vision
• Dizziness, drowsiness, or confusion
• Lack of coordination of fingers, hands, arms, legs, or body
• Slurred speech
• Nausea or vomiting
• Decreased appetite, decreased activity, abdominal bloating, or irregular jerky movements in children or the elderly

Treatment Options for Cerebellar Toxicity

There’s no treatment specifically for cerebellar toxicity or ataxia. In some cases, treating the underlying cause resolves the ataxia.

In other cases, such as ataxia causes from chickenpox or other viral infection, it’s likely to resolve on its own over time.

Patients may benefit from adaptive devices or physical, occupational or speech therapies to help with cerebellar toxicity symptoms.

If you or a loved one suffered a type of focal cerebral atrophy known as cerebellar ataxia or phenytoin toxicity after long term use of phenytoin or Dilantin, you may be eligible to join a phenytoin lawsuit/Dilantin lawsuit investigation and pursue compensation for your injuries.