Epilepsy in Adults
Epilepsy, being the fourth most common neurological disease diagnosed, will affect an additional 150,000 Americans this year. Interestingly, the incidence significantly grows after the age of 55 due to the fact patients are at an increased risk of developing vascular insults, tumors and neurodegenerative disorders. Mood disorders and behavioral changes are also commonly associated with epilepsy. Early evaluation and treatment are associated with better outcomes.
Approximately 10% of people will have at least one episode of seizure during their lifetime; most of them will subsequently learn to avoid the identified provoking triggers. For example, people older than 50 will often present with various types of pain or discomfort. The use of narcotics or certain anti-depressants may be associated with a higher risk of seizures. Therefore, it is important to always report to physicians all the prescribed medications. When a patient is suspected of recurrent seizure disorder, clinicians must first obtain a detailed medical history on semiology, potential provoking factors, family history, etc., as all these factors may significantly alter management and prognosis. Brain MRI and routine EEG are usually used for evaluation.
When seizures are potentially recurrent without apparent provoking factors, oral anti-epileptic drugs (AED) are needed to control these events. About 70% of people with epilepsy can control seizures by using medicine only. Some people also choose to try diet control (ketogenic diet) to control seizures. Eventually, people with uncontrolled seizures might have to undertake surgical interventions to reach satisfactory seizure control. Other than medicinal treatment, people with epilepsy often benefit from family support. When a person loses consciousness during a seizure, driving or operating heavy machinery is prohibited.
The selection of AEDs for each patient is often based on the type of epilepsy and the side effect profile of different medications. It is crucial for a neurologist to meticulously choose the first one or two (if necessary) antiseizure drugs, as anything beyond the third seizure medication will offer little to no benefits to the patient. If the primary care physician or general neurologist cannot help control the seizures completely, a referral to epileptologist for further management may be beneficial. An epileptologist has specialized training to help with correct diagnosis of certain epilepsy syndrome, finding the most appropriate AED, and the possibility of working with a functional neurosurgeon to assess necessity for surgical intervention.
Surgical treatment of partial epilepsy is to remove the epileptogenic brain tissue by resection or a newly-used, less invasive way, laser ablation. About 20% of patients screened for surgical intervention are determined appropriate for removal of a certain amount of epileptogenic tissue. For people with multifocal epilepsy, when cure is less likely, neuromodulation may be used to minimize seizure occurrence. Vagus nerve stimulation, a responsive brain stimulator, or deep brain stimulator can be used for neuromodulation. This management can often bring satisfactory seizure control so that AEDs can be cut down. Subsequently, people with intractable epilepsy can have fewer side effects from AEDs and have better function in daily life. This is especially important for older patients.
One of the most controversial topics lately regarding epilepsy management involves applications of cannabinoids. In June of 2018, the FDA approved cannabidiol (CBD) Epidiolex oral solution as the treatment for two epilepsy syndromes, Lennox-Gastaut syndrome and Dravet syndrome. Note that CBD (cannabidiol) is the cannabinoid with non-psychotropic actions, which is extracted from Cannabis Sativa (hemp). This compound’s intrinsic neuroprotective roles are still at its earliest phase of investigations in patients who are refractory to conventional AEDs. Though there have been cases at LSU Health Shreveport where patients observe significant improvement with CBD applications, we still advise clinicians to exercise caution as the mechanism by which CBD interacts with other medications (especially AEDs) is still largely unknown. In addition, it is important to know that medical marijuana refers to medicine containing a significant amount of tetrahydrocannabinol (THC), the psychoactive component of marijuana. It is believed that THC is the chemical triggering seizures.
Jimmy Young, MD is a third-year resident in the Department of Neurology at LSU Health Shreveport.