Epilepsy in the Elderly

Until recently the topic of epilepsy in the elderly has not been the focus of clinical research.  The elderly make up the fastest-growing segment of the population in the United States.  In Calumet County, the demographic shift to increased elderly is much more marked than other areas in the state.  Epilepsy has assumed major importance over the last five years in the elderly.  There are many different issues to be considered when dealing with epilepsy in this age group.  These issues relate to diagnosis, etiology, treatment and quality of life, all of which require different considerations, based on age.

Since more studies have been initiated regarding epilepsy in the elderly, it has become clear that the problem is under-diagnosed.  In fact, may clinicians have difficulty recognizing elderly patients with new onset epilepsy. The great majority of these patients so not have generalized tonic-clinic seizures.  The most common presentation is with a complex partial seizure.  As such, these episodes can easily be mistaken for confusional states, dementia, cardiac disease, TIA or encephalopathy.  Indeed, these seizures are often very subtle and can easily be dismissed as a "senior moment."  Undoubtedly, we underestimate the number of elderly patients with epilepsy.  In the coming years, it will be important to educate the various practitioners that treat elderly patients-family physicians, geriatricians, psychiatrists, stroke specialists, hosptialtis-regarding the clinical presentation of seizures in the elderly.  Furthermore, practitioners will need to understand the correct us and limitation of routine EEG studies in improving diagnostic accuracy.  Prolonged video/EEG monitoring, a "Holter of the brain" frequently leads to a correct diagnosis.

The most common cause of epilepsy in the elderly is cerebrovascular disease, accounting for 40-50% of those identified.  It has been well described that stroke associates with seizures in the acute state is less likely to cause epilepsy.  Epileptic seizures occurring months after acute stroke, however, do cause epilepsy.  There have been studies associating otherwise unexplained seizures occurring late in life with significant increase in the risk of subsequently stroke, such that patients presenting with seizures late in life without obvious cause should be screened for vascular factors and aggressively treated.

Other causes of epilepsy in the elderly include head trauma, tumor, dementia, degenerative disease and systemic and metabolic diseases.  Alzheimer's disease is a defined risk factor for new onset seizures in the elderly.  It typically occurs late in the Patient illness with a 10% prevalence.  Despite advances in neuroimaging, as many as 45% of patients over the age of 60 with seizures have no structural abnormality defined.  There may be age-dependent changes in genes relating to susceptibility to seizures in the elderly.  This is a current area of research.

The difference in clinical presentation and the altered metabolism of antiepileptic medications, along with the risk of adverse events, have been common issues when discussing elderly patients with epilepsy.  It is frequently more difficult to determine quality-of-life effects of anticonvulsant medications in post-stroke patients or demented patients, particularly when they are on other medications.  Treatment in this population is focused on preventing morbidity related to secondarily generalized tonic-clonic seizures.

Finally, a staggering 10% of nursing home patients are on antiepileptic medications.  It is not uncommon for patients to receive an anticonvulsant medication because of jerking, reduced responsiveness or incontinence.  The exact determination of these symptoms as being caused by an epileptic event is frequently not pursued.  These patients maybe treated after a single event and have limited subsequent investigation and follow-up.  Further more, many of these patients have a remote history of epilepsy and have been maintained on anticonvulsant medications unnecessarily without being re-evaluated.

As the elderly become the fastest-growing segment of our population, we will find ourselves in a more urgent position to improve our diagnostic and therapeutic interventions for these patients.  Elderly patients requiring screening and treatment can be referred to the seizure clinic at the Neuroscience Group.  The neurologists, led by Dr. Gizell Larson, are experienced with long term video EEG monitoring, use of the newest AEDs, screening for potential epilepsy and improved treatment options, such as vagal nerve stimulation (VNS).  Patient education efforts are led by Kristine Twomey, RN.  For further information, please contact Dr. Gizell Larson at gizell.larson@neurosciencegroup.com