Post traumatic epilepsy or seizures after head trauma

Post Traumatic Epilepsy

Nitin K Sethi, MD

Assistant Professor of Neurology

New York-Presbyterian Hospital

Weill Cornell Medical Center

New York, NY 10065

 

In this post I shall discuss the entity called post traumatic epilepsy/ post traumatic seizure disorder.  Epilepsy is a condition characterized by two or more seizures in a person’s lifetime. Broadly speaking epilepsy can be of two kinds:

1. Primary Epilepsy

2. Secondary Epilepsy

Patients who have primary epilepsy have seizures usually due to an underlying genetic predisposition. They do not have a secondary cause for their seizures and neuroimaging is usually normal.  On the other hands patients who have secondary epilepsy usually have seizures secondary to something (example secondary to brain tumor, secondary to an abscess in the brain, after a stroke and so forth). Under this category of secondary epilepsies is included post traumatic epilepsy (as the name suggests patients have seizures secondary to brain trauma).

Let me explain with the aid of an example.  Let us assume our patient (we shall call him Philip) is a 27-year-old healthy male with no significant medical or surgical history. Bikes are his passion especially Harleys.  Have you seen the ones they show on American Chopper. But we are digressing from our story line. Philip loves to ride them fast. A bright sunny Sunday morning finds him zipping down FDR drive at 80 mph.  With a bike under me, I felt like a real man. And then disaster strikes. Philip’s bike gets clipped by a speeding SUV. Philip is flung from the bike and hits the ground hard. Did I mention he was not wearing a helmet at this time. He is rushed to the nearest hospital. A lacerated spleen, couple of broken ribs and a fractured collar bone. Not too bad you might say. He shall live to ride another day. But all is not so rosy. Philip does not regain consciousness and does not respond to verbal commands.  A quick CT scan yields the answer. Philip has suffered extensive bleeding in the brain (neuro trauma). He is admitted to the neurological ICU. Recovery is painfully slow and after a months stay in the hospital, Philip is discharged to a sub-acute rehab facility. Alls well that ends well? Not quite done yet, I am afraid. Six months after his motorbike accident, Philip is again rushed back to the hospital after a witnessed tonic clonic convulsion. He is evaluated by a neurologist (like me) and a diagnosis of post traumatic epilepsy is made.

So what exactly is post traumatic epilepsy? As the name suggests epilepsy develops after head injury. Seizures can occur anytime after head injury. If they occur immediately after head injury it is referred to as immediate post traumatic epilepsy (also called impact seizures, as seizures occur at the time of impact to head).  If seizures occur within the first month after head injury it is referred to as early post traumatic epilepsy. Patients may have their first seizure as long as 18 months after head trauma. This is referred to as late post traumatic epilepsy.

Patients develop post traumatic epilepsy as a result of scarring of brain tissue.  They usually have convulsions. The treatment of post traumatic epilepsy is essentially the same as that of any other type of epilepsy. Once the seizure type is characterized, the right anti-epileptic drug is usually effective in controlling the seizures.