Phenytoin cerebellar ataxia is one of the most serious complications associated with Dilantin (phenytoin) side effects, which has been cited in several studies.

Also known as cerebellar atrophy, phenytoin cerebellar ataxia is described as a condition where certain parts of the brain deteriorate due to issues like drug toxicity or degenerative disease.

One of the more recent studies observing the alleged phenytoin cerebellar ataxia connection was published in the 2013 issue of the Indian Journal of Pharmacology, observing a case study of a teenage male epileptic patient.

After being admitted to the hospital for fever and weakness, diagnostic testing revealed that he had been taking phenytoin for the past ten years. The patient was diagnosed with cerebellar ataxia, after observing certain symptoms and MRI scans revealing cerebellum deterioration.

At this point in time, the exact cause of cerebellar ataxia is not known, but it has been linked to diseases like Alzheimer’s disease or traumatic incidents like head injuries. Drug toxicity has also been attributed as a potential cause for cerebellar ataxia, with phenytoin being one of the most commonly reported medications in conjunction.

Overview of Phenytoin Cerebellar Ataxia Correlation

Phenytoin is one of the most popularly prescribed antiepileptic medications in the United States, treating patients by helping manage the brain’s electrical signals. By streamlining the electrical signals, epileptic episodes are ultimately prevented and the patient’s quality of life is increased.

This medication, however, has been linked to a number of serious complications, including phenytoin cerebellar ataxia. Cerebellar ataxia can either be focal or generalized, but is typically associated with damage to the cerebellum.

The cerebellum is located under the cerebrum, behind the brain stem. It is divided into two hemispheres that are primarily responsible for movement and speech. Due to the nature of phenytoin cerebellar ataxia damage, patients experiencing this condition will often exhibit the following symptoms:

• Unsteady or Lurching Walking Gait
• Slow or Unsteady Jerky Movements in Arms or Legs
• Slow and Slurred Speech
• Nystagmus (small rapid eye movements)

Phenytoin cerebellar ataxia was first cited in a 1994 study, after researchers discovered significant damage to the cerebellum in phenytoin patients.

The study was initially conducted to observe the treatment effects of the medication on the patient’s brain, but researchers discovered the Dilantin patient group had significantly smaller cerebelli compared to non exposed patients.

In this 1994 study, 36 patients with partial epilepsy on long term phenytoin prescriptions were observed from a consecutive sample of patients from an epilepsy treatment center. Diagnostic images revealed that patients with greater phenytoin exposure levels had sustained more severe damage to the cerebellum.

The study concluded the potential phenytoin cerebellar ataxia link needed to be further explored, and that the severity of the damage could be linked to the phenytoin levels. If cerebellar ataxia is not treated promptly, it can induce potentially permanent brain damage and chronic movement problems for the patient.

Even though phenytoin cerebellar ataxia can be devastating for patients, Pfizer Inc. and generic manufacturers may not have adequately warned patients against this correlation.