Clinical Management of Late-Onset Unexplained Epilepsy

Diagnosis

Epilepsy is a common condition in older adults. Older adults have a higher incidence of developing new-onset epilepsy than do people at any other time of life. Seizures in older adults may not look like a “classic” grand mal (generalized tonic-clonic) seizure, but may consist solely of transient sensory symptoms or confusion. Physicians should have a high level of suspicion for seizures in patients with fluctuating neurological symptoms and episodes of mental fogginess or confusion. Abnormalities on EEG and clinical response to anti-seizure medication may help to confirm the diagnosis of epilepsy.

Workup

Adults with new known or suspected seizures should have a comprehensive workup that includes the following:

  • High quality brain MRI, to evaluate structural causes of epilepsy.
  • Scalp EEG, to evaluate epileptiform activity, or in some cases, capture a typical clinical event for definitive diagnosis.  Note that epileptiform abnormalities in many older adults tend to occur primarily during sleep, so it is important that the EEG adequately record the patient’s sleep.  When available, an overnight ambulatory EEG may help capture abnormalities not present on a routine EEG.   
  • Based on other symptoms, screening for cognitive impairment, sleep apnea, vascular risk factors, infection, or toxic/metabolic abnormalities may also be indicated.

Treatment

Older adults may be more sensitive to side effects of anti-seizure medications compared to younger adults with epilepsy.  Moreover, lower doses of anti-seizure medications are often sufficient to control seizures in older adults, compared to younger adults. Whenever possible, anti-seizure medications should be started at a low dose, and increased slowly as needed.  Enzyme inducing anti-seizure medications (such as phenobarbital and phenytoin) should be avoided in older adults, to maintain bone health and to avoid interactions with other commonly used medications in this age group (such as warfarin).

Lamotrigine and levetiracetam are anti-seizure medications that are commonly used and often well-tolerated in older adults.  

Causes

Common causes of epilepsy in older adults include stroke, brain tumor, neurodegenerative disease, and traumatic brain injury.  However, a large number of cases are unexplained. 

Some risk factors for late-onset epilepsy include hypertension, diabetes, smoking, sleep apnea, and the apolipoprotein E4 genotype.

Counseling

Several studies show at individuals with late-onset epilepsy have a 2-3 fold increased risk for subsequent development of stroke and dementia. Patients should be counseled on strategies to optimize their brain health, especially in controlling vascular risk factors.  Aerobic exercise, staying socially and intellectually engaged, and a healthy diet are also advisable for maintaining good brain health.

Additional Resources

Articles

Seizures and Epilepsy in the Elderly:  A Focus on Multidisciplinary Care 
Written by Dr. Rani Sarkis and colleagues (Practical Neurology, 2018)
View article

Late-Onset Epilepsy
Written by Dr. Rani Sarkis (Practical Neurology, 2022)
View article

Management of epilepsy in older adults: A critical review by the ILAE Task Force on Epilepsy in the Elderly
(Piccenna et al., Epilepsia, 2022)
View article 

Webinars

Seizures and Epilepsy In Older Adults
Epilepsy Foundation Webinar Series, for healthcare professionals caring for older adults with epilepsy.  Featuring Dr. Alice Lam (October 30, 2019)
View webinar