Epilepsy in the Elderly: Why is it Different? Brenda Y. Wu, M.D., Ph.D.
Incidence of New Diagnosis of Epilepsy > 60y/o, ~25% Pohlmann-Eden B, Acta Neurol Scand 2005(suppl);181:40-46
Etiology in Patients age 60 Ramsay, et al. Neurology 2004; 62 (5 suppl 2).
Causes of Epilepsy Annegers JF. The epidemiology of epilepsy. In: Wyllie E, ed. The treatment of epilepsy: principles and practice.3rd Ed, 2001:165-72
Seizure Precipitants Metabolic and electrolyte imbalance Stimulant/other pro-convulsant intoxication: cocaine, anticholinergics, dopamine blockers, clozapine, immuno-suppressants, antibiotics, certain narcotics (e.g. Dilaudid) Sedative or ethanol withdrawal Severe sleep deprivation Antiepileptic medication reduction or inadequate AED treatment Hormonal variations or immunocompromise (e.g. platelets) Stress Fever or systemic infection Concussion and/or closed head injury
Seizure Types in Patients age 60 Ramsay, R. E. et al. Neurology2004;62:24-29S
Under-diagnosed Epilepsy in Elderly • Obscured by multiple medical problems • ‘Atypical’ symptoms from commonly discussed seizure types, often interpreted as caused by aging or depression • Living alone, not being closely observed • Half of delays—Patient did not seek for help. • After 1st seizure, < 50% diagnosed (GTC—usually immediately versus only 20% for CPS) • Only < 73% ultimately diagnosed by primary care physicians
Typical Seizures for All Age Groups • Generalized: absence, tonic-clonic, atonic • Staring, shaking, incontinence, tongue bite, unresponsive • Partial-onset epilepsy: simple or complex • Aura • Confusion, incoherent speech • Oral or manual automatism • Head turning
Symptoms in Late-onset Epilepsy • Auras are less common • Often non-specific auras: e.g. dizziness • Less automatism • Prolonged post-ictal confusion • Common initial presentations (1 or more): altered mental status (41.8%), blackout/syncope/recurrent falls (29.3%), memory impairment (17.2%), dizziness (10.3%) & dementia (6.9%) • New onset sleep walking/sleep talking; vivid dreams with arousal (Night terror ? REM behavior sleep disorder? frontal lobe epilepsy); jerks in sleep
Diagnosis • Detailed history • Clinical symptoms; • Circumstances of event • Past medical, neurological & psychiatric history, medications • Physical Exam, lateralizing neurological signs, cognitive function • Lab & Diagnostic studies: • ECG • Laboratory tests: immediately after events, supportive only • Routine EEG (short) –low yield • Long-term Video EEG monitoring—especially helpful, “gold-standard”
Epileptiform Activities on EEG Drury I. et al. Epilepsia. 1999; 40 • First routine (short) EEGs (> age 60): • Only seen in 35% with pre-existing epilepsy • Only seen in 26% with late-onset epilepsy (onset after age 60) • Past medical, neurological & psychiatric history, medications • Long-term video EEG: • More than 50% in patient with vague or non-specific clinical symptoms whose routine EEGs are normal or inconclusive if episodes are not captured.
Challenges • Clinical • More severe injuries • More prolonged postictal confusion • Impact on quality of life • Less impact on employment • Driving • Competency of living independently • Treatment: more intolerance issues
Nonlinear pharmacokinetics of Phenytion Birnbaum A., et al. Neurology. 2003; 60.
Treatment of Epilepsy in Elderly Is it the symptoms of the disease? Medication(s) make me sick?
Treatment of Epilepsy in Elderly • Drug of choice • Drug interaction • Adverse effect: imbalance, mood swing, sedation, sleep pattern; weight changes; • Co-existing medical problems: liver, kidney failure; • Dosage • Speech impairment from AED adverse effect versus uncontrolled seizures • Compliance • Management of precipitating factors: Sleep disorder (OSA etc), conditions affecting sleep quality, stress management, chronic infections, hormonal and electrolyte disturbance
Summary Epilepsy in elderly: high incidence but under-diagnosed Epileptic symptoms may be ‘atypical’ in elderly patients. Detailed history and descriptions will be helpful for diagnosis. Routine (short) EEG usually has low yield. Long term video EEG is more helpful to confirm the diagnosis. Pharmacological treatment plan should be individualized for better tolerance and compliance.