Seizures and Head Injury / Brain Injury
Unfortunately, seizures may develop immediately after an injury to the brain or may develop in delayed fashion, showing up months or years after the initial trauma. Generally speaking, the risk of post traumatic seizures is related to the severity of the injury- the greater the injury, the higher the risk of developing seizures. Even mild to moderate injuries can result in seizures.
There are many kinds of seizures and seizures are not an uncommon condition among persons without head injuries. It is thought that a head injury disrupts the pathways of the brain and that an epileptic seizure can be viewed as a sort of short circuit of the brain's electrical functioning. During the seizure the electrical fields in the brain are overloaded, resulting in seizures.
The most commonly seen seizures related to traumatic brain injury are "generalized" seizures, which are also called "Tonic-Clonic" or "Grand Mal" seizures. The classification of different types of seizures is beyond the scope of this website.
Persons who have had head trauma are twelve times as likely as the general population to suffer seizures (Willmore, 1992). Patients with acute intra cranial hematomas also have a high rate of epilepsy. While there are contradictory studies, the more recent study (Lee, 1992) showed that of 4,232 persons suffering mild closed head injury, 53% had early post-traumatic epilepsy. Approximately 57% of head injured individuals developed epilepsy within one-year of injury. Longer onset epilepsy beginning more than four years after the trauma occurs in 20% of patients who developed epilepsy. It is estimated that 30% of all individuals suffering head trauma developed post-traumatic seizures and 80% of the time they occur within the first 24-months (Bakay, 1980).
The primary tool used to diagnose epilepsy is the Electroencephalograph (EEG), which is a device that captures and plots the electrical activity of the brain. EEGs show abnormality in over 80% of epileptic patients.
If someone has a traumatic brain injury or is even suspected of having same, most prudent physicians will prescribe a preventive course of medication. Fortunately, the current anti-seizure medications on the market are very effective and in a vast majority of cases will largely or completely control the epileptic seizures (examples include Phenytoin, Valproate, Phenobarbital, Dilantin, Felmabate and others).
Unfortunately, recent studies have show that suffering seizures, in and of itself, can shorten one's life and can contribute to brain damage. There are, of course, other dangers such as falling injuries, problems driving and the risk of choking.
There is another, more controversial, type of seizure know as "Complex Partial-Seizure Disorder." A majority of the persons suffering these more subtle types of seizure (in which one's perception is changed, sensors are altered, blanking out occurs and other more subtle things occur) would have normal findings on the EEG. However, all of the patients in the studies confirming this disorder had evidence of cerebral dysfunction on neuropsychological testing.
There is a controversial diagnosis as pseudo-seizures or non-epileptic seizures, which is given to patients who outwardly exhibit signs of a seizure but that do not have abnormal EEG readings. The reason this diagnosis is so controversial is that it implies that the origin of the seizure activity is psychological rather than organic. Persons suffering from pseudo-seizures have other psychological problems and needs unrelated to any head injury. However, there are studies showing that almost 1/3 to 1/2 are suffering from true organic EEG confirmed seizures also suffer from some sort of pseudo-seizure. If you are confronted with this diagnosis, be very careful and get a second opinion. Some of the recent studies in the field indicate the following:A video EEG was carried out in 60 patients, neurologist were asked to determine whether they were true epileptics or pseudo-seizures. They were accurate in only 67% of the cases. The abstract states "these data suggests that pseudo-seizures occur frequently in patients being evaluated for epilepsy or suspected epilepsy. The clinical differentiation between epileptic seizures and pseudo seizures is often inaccurate." (King, DW 1982). The 1999 study in the European Journal of Neurology studied over 1,000 patients and said that their study "exposed the difficulties involved in the diagnoses of psychogenic pseudo epileptic seizures," pointing out again the overlap between true seizures and pseudo seizures. A recent article on seizure (deTimary, T. 2002) recently once again pointed out the difficulty in distinguishing between epileptic seizures and non epileptic seizures. An article published in the American Academy of Child and Adolescence Psychiatry by Dr. Bloom et al. 2001 entitled "Lifetime and Novel Psychiatric Disorders After Pediatric Traumatic Brain Injury" stated that "a wide variety and high rate of novel psychiatric disorders were identified and that 74% of those disorders persisted in 48% of the injured children." They found that the findings were consistent with previous research demonstrating a high rate of novel psychiatric disorders following pediatric TBI. Finally, there is a body of research which indicates the existence of "subclinical" types of seizures, also know as Partial Complex Seizures (J. R. Roberts, 1992). Subclinical seizures would be those which are not found even on EEG at the time of the event. This condition is also called Atypical Psychosis, episodic dyscontrol, post traumatic temporal lobe dysfunction or multiple partial seizure like symptoms without stereotype spells. Another attempt to name the phenomenon by Springer and others is called an "Epilepsy Spectrum Disorder" (ESD). Animal and other research shows there may be abnormal electro discharges from the limbic system which can only be detected with implanted electrodes and thus most patients would have normal EEG tracings.