Epilepsy in the Elderly: Why is it Different?

Brenda Y. Wu, M.D., Ph.D.

Incidence of New Diagnosis of Epilepsy

Pohlmann-Eden B, Acta Neurol Scand 2005(suppl);181:40-46

> 60y/o, ~25%

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

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 Precipitants

Ramsay, R. E. et al. Neurology 2004;62:24-29S

Seizure Types in Patients age 60

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

Under-diagnosed Epilepsy in Elderly

Generalized: absence, tonic-clonic, atonicStaring, shaking, incontinence, tongue bite,

unresponsive

Partial-onset epilepsy: simple or complexAura

Confusion, incoherent speech

Oral or manual automatism

Head turning

Typical Seizures for All Age Groups

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

Symptoms in Late-onset Epilepsy

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”

Diagnosis

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.

Epileptiform Activities on EEG

Drury I. et al. Epilepsia. 1999; 40

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

Challenges

Nonlinear pharmacokinetics of Phenytion

Birnbaum A., et al. Neurology. 2003; 60.

Treatment of Epilepsy in Elderly

Medication(s) make me sick?

Is it the symptoms of the

disease?

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

Treatment of Epilepsy in Elderly

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.

Summary