Dilantin (phenytoin) is commonly used to prevent tonic-clonic seizures in epileptic patients. Despite its long history of use as an anticonvulsant, Dilantin may increase the risk of developing cerebellar ataxia.

Cerebellar Ataxia Causes

There are many different types of possiblecerebellar ataxia causes. Cerebellar ataxia can result from viral infections like Epstein-Barr, or from bacterial infections like Lyme disease. Head trauma or bleeding in the cerebellum can also lead to cerebellar ataxia. Certain toxins like lead or mercury can also be cerebellar ataxia causes.

Several decades’ worth of studies also point to a link between cerebellar ataxia and the use of phenytoin to treat tonic-clonic seizures. A case study from 1980 concluded that Dilantin, and not just the hypoxia associated with seizures, could be the cause of cerebellar atrophy.

A more recent study from 2003 found that cerebellar atrophy is frequently associated with long-term use of Dilantin. Cerebellar atrophy is a type of focal cerebral atrophy related to the cerebellar toxicity that comes with phenytoin use; it can lead to cerebellar ataxia or other motor and visual dysfunctions.

Dilantin is an antiepileptic drug with a long history, despite its association with cerebellar ataxia. In its current form as Pfizer’s brand-name drug Dilantin, it was approved by the FDA in 1953. It’s now approved as a preventive treatment for tonic-clonic seizures and psychomotor seizures.

Symptoms of Cerebellar Ataxia

Perhaps the most visible symptoms of cerebellar ataxia are the abnormalities of posture and gait. Patients may find themselves falling or staggering when trying to run or walk. They may also have trouble maintaining balance on moving surfaces like elevators or boat decks. Their impaired control of movement may demand a greater than normal expenditure of energy that can lead to increased fatigue.

A loss of fine motor coordination may also inhibit the patient’s ability to take care of many everyday tasks like writing, preparing food, typing, or buttoning clothes. Some patients’ speech becomes slurred or indistinct. Difficulty with swallowing may cause them to choke on food or liquids. Visual abnormalities may manifest as blurred or double vision, making it difficult to read, track moving objects, or change gaze from one object to another.

Some patients also report problems with cognition and mood. These may manifest as problems recalling information or decision-making tasks like making plans and keeping thoughts in order. Persons with cerebellar ataxia more frequently exhibit personality and mood disorders than do those without.

Cerebellar Ataxia Treatment

Generally, cerebellar ataxia treatment requires a multi-modal approach to address the condition from all sides. One approach is to establish a multi-disciplinary team to coordinate care. This team will likely include a neurologist and a physiotherapist, and possibly other specialists.

Symptoms can be addressed through various types of physical and occupational therapy. Speech and language therapy uses repeated exercises to address problems with speech and swallowing.

Cerebellar ataxia treatment may also include regular physiotherapy to address motor problems. The physiotherapist can teach the patient exercises to help improve movement of the arms and legs.

Occupational therapy can help the patient mitigate the effects of cerebellar ataxia on their ability to perform regular daily activities. The patient may need to learn how to use a wheelchair or other assistive device. An occupational therapist can also advise the patient on modifications that can be made to their home or workspace to make tasks less difficult.