Serious Dilantin side effects have been attributed to the “grandfather” epilepsy drug when taken over a long-standing period of time. These Dilantin side effects include shrinkage to an area of the brain known as the cerebellum.

The cerebellum under the influence of phenytoin—the generic name for the seizure disorder medication developed in the first decade of the twentieth century—has been shown to lose its size due to the death of brain cells and the connections between them.

Despite these Dilantin side effects, the epilepsy drug is still listed on the World Health Organization’s List of Essential Medicines, according to a reputable online resource.

Where it had once only been used to control convulsions related to electroshock therapy, it was found to be generally useful in treating seizures as early as 1936 and paved the way for many of the newer, more advanced and effective medications in use today.

Presently in the U.S., phenytoin is rarely a first choice among neurologists to treat various forms of epilepsy but remains tried and true among general physicians and emergency rooms. It is also one of the most affordable treatments–when that is a key concern–selling at about $30 for a month’s supply.

Is it Epilepsy or Dilantin Side Effects?

Ironically, seizure disorders themselves can produce cerebellar atrophy. So, the problem with identifying whether shrinkage of this area of the brain is related to the original disease or Dilantin side effects presents a dilemma.

The first study to look at the connection between phenytoin and the loss of focal (regional) brain mass was in 1994. This study controlled for the fact that seizures can produce this effect. The study found epilepsy patients being treated with phenytoin versus another medication choice had overall smaller cerebellums.

Where is the Cerebellum and What is its Function?

The cerebellum lies beneath the main mass of what we consider the brain. It is situated behind the brain stem. While the brain stem intersects with the spinal chord and is responsible for our autonomic life processes like heartbeat, respiration, swallowing and digestive processes, the cerebellum is responsible for the control of voluntary movement.

The cerebellum works to coordinate movement among several different muscle groups so that the result is smooth. It helps maintain our sense of our body in space and signals us to make small adjusts to maintain balance.

The critical brain lobe helps us to learn and retain the knowledge necessary to use our muscles to perform certain trained physical tasks like roller skating, riding a bike, or skiing. The cerebellum coordinates our vision and is also related—although the mechanism is unknown—to mood stability.

What are the Symptoms of Cerebellar Atrophy?

The most common symptoms of cerebellar shrinkage are difficulty walking, speaking and coordinating muscle movements. Sufferers are often mistaken for being inebriated. It is not uncommon for them to have unusual eye movements and to experience headaches on a regular basis.

Sometimes transitioning to a different seizure medication can alleviate symptoms. Other times, the Dilantin side effects are more permanent. It is very important to consult the prescribing physician before changing any drug regimen.