Diagnosing and Treating Epilepsy in the Elderly
Diagnosing and Treating Epilepsy in the Elderly
Q: Why does epilepsy in the elderly warrant its own discussion?
Alan B Ettinger, MD: From the clinician s point of view there may be an inclination to think about epilepsy as a uniform disorder throughout all groups. The truth is that the assessment, etiologies, diagnoses, and, most importantly, treatments associated with epilepsy are different in childhood from those in middle age and, in turn, from the considerations in the elderly. As our population gets older, and people are increasingly living to older ages, the subject of seizures in the elderly will become a vital area with which clinicians will need to be comfortable.
It is intuitive to think of epilepsy as a childhood disease. We often think of the incidence of new cases of epilepsy to be highest in childhood, but actually a number of studies over the years have shown that reported cases of epilepsy climb to the highest levels in the elderly.1 This means that over time the discussion of epilepsy may become even more focused on the elderly than on younger age groups.
Another very important fact is that the elderly with epilepsy are much more likely to have associated comorbid illnesses, which has important implications for the diagnosis and management of epilepsy in this age group.
What symptoms should lead the clinician to consider epilepsy in the differential diagnosis?
There are diverse symptoms that should lead to the consideration of epilepsy. For example, mental status change is a very common symptom in the elderly and the clinician may be inclined to think that this has been caused by a toxic metabolic disorder. Seizures may be easily missed due in part to different manifestations of seizures in the elderly compared with the classic presentation in younger age groups. In younger people, temporal lobe epilepsy is common. In this condition, there are classic automatisms such as psychic symptoms (e.g. déjà vu), and repetitive movements such as lip smacking. With secondary generalization, obvious convulsive activity occurs. In the elderly, seizures often originate from extra-temporal sites manifestations may be quite different and subtle. For example, small degrees of eye twitching may be the only clinical evidence of a seizure in a patient with altered mentation but no other obvious signs of seizure activity. This means that family members or other observers may not recognize that these patients are exhibiting any symptoms at all, least of all seizures. This, in turn, contributes to a potentially serious delay in getting a patient proper medical attention and diagnosis. Even when the patient does reach the doctor there is the additional problem that the doctor may not recognize these very subtle symptoms.
A separate entity known as non-convulsive status epilepticus (NCSE) may occur in all age groups, but can be particularly elusive in the elderly. It should be an important consideration in the differential diagnosis of mental status changes in the elderly because it is commonly missed. NCSE is characterized by a waxing and waning state of prolonged seizures, unassociated with major motor activity such as convulsions. With this possibility in mind, one should strongly consider ordering an electroencephalogram (EEG) and, where indicated, even consider using extended recording such as video EEG monitoring.
In the elderly, postictal effects, for example Todd s paralysis which involves deficits in strength or changes in mental status can last much longer than in younger age groups. A patient presenting with mental status changes may be in a prolonged postictal stage lasting for hours to days. The EEG would not show any obvious seizure activity, would likely display nonspecific slow-wave activity, and may not even reveal evidence of interictal epileptiform activity. All of this could confound the diagnosis.
We used to believe that seizures were really only harmful to the brain if you reached the point of generalized convulsions of prolonged duration: status epilepticus. However, there may be complications from more subtle seizures, as well as the risk that patients could harm themselves because of their altered awareness. Furthermore, in the process they may be treated for erroneous conditions while any underlying etiology remains untreated.
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