Seizures, Epileptic

Incidence of epilepsy estimated to be 0.5–2.3%.

30–40% of pts with epilepsy will develop intractable seizures (>1/mo refractory to two or more medications).

Approx 400,000 people in USA have medically uncontrolled epilepsy.

Epilepsy has causality with a variety of syndromes throughout multiple systems.

Various psychiatric disorders are assoc with epilepsy (e.g., migraines, depression, psychosis), and antiepileptic drugs are associated with mood, behavior, or cognition disturbances.

2 cases per 1000 pt-years result in sudden death associated with epilepsy.

Many antiepileptic drugs induce hepatic enzymes (p450) or inhibitors which may affect blood levels of drugs such as warfarin, tricyclic antidepressants, statins, chemotherapeutic agents, and antivirals. Specific to anesthesia are NDMRs.

Different anesthetic effects on seizure threshold.

Antiepileptic drug therapy-induced resistance to NDMRs and opioids.

Anticonvulsant-induced blood dyscrasia (carbamazepine and others), hepatitis (valproate and others), Stevens-Johnson syndrome, toxic epidermal necrolysis (lamotrigine and others; 10× greater risk for carbamazepine with Chinese ancestry), and hyponatremia (oxcarbazepine).

Rapid IV administration of IV phenytoin can cause profound hypotension.

Acidosis in pts following a ketogenic diet as part of an anticonvulsant regimen.

Epilepsy can lead to significant reduction in pt ADLs.

Cognitive decline can be worsened by organic damage from refractory epilepsy, side effects of an anticonvulsant regimen, and increased social isolation from societal misunderstanding of the disease.

Newer AEDs are generally well tolerated, but most still have significant side effects.

Seizures are categorized as partial (simple, complex, or with generalization), generalized (convulsive or nonconvulsive), absence, nonepileptic (pseudoseizures), or unclassified. Up to 56% of comatose neurologic ICU pts have seizure activity.

Congenital often associated with other syndromes such as tuberous sclerosis, neurofibromatosis, multiple endocrine adenomatosis, and Jervell-Lange-Nielsen syndrome.

Acquired associated with traumatic brain injury, stroke, brain tumor, Alzheimer, or idiopathic causes.