Seizure Causes: Common Underlying Conditions

A seizure is a transient surge of abnormal neuronal activity. Identifying the etiology guides treatment. Major categories:

Neurological

• Epilepsy: Recurrent unprovoked seizures. Etiologies: genetic, structural (mesial temporal sclerosis, cortical dysplasia), metabolic, immune, infectious, unknown.
• Stroke: Acute (early) or remote (late) seizures; cortical involvement increases risk.
• Traumatic brain injury: Immediate, early (<1 week), or late (>1 week) post-traumatic seizures.
• Brain tumors: Glioblastoma, meningioma, metastases—especially frontal/temporal lobes.
• CNS infections: Encephalitis (HSV, enterovirus), meningitis, abscess, neurocysticercosis.
• Neurodegenerative: Alzheimer's, dementia with Lewy bodies.

Metabolic/Toxic

• Electrolyte disturbances: hyponatremia, hypocalcemia, hypomagnesemia.
• Glucose: hypoglycemia, hyperglycemic hyperosmolar state.
• Uremia, hepatic encephalopathy.
• Drugs: withdrawal (alcohol, benzodiazepines), overdose (tricyclics, bupropion, tramadol), antibiotic neurotoxicity.
• Alcohol withdrawal seizures (6–48 hrs post-cessation).

Other Medical Conditions

• Autoimmune: lupus cerebritis, anti-NMDA receptor encephalitis.
• Renal/liver failure.
• Eclampsia (pregnancy).
• Genetic syndromes: tuberous sclerosis, Down syndrome, Angelman syndrome.

Urgent Evaluation

First seizure, status epilepticus, focal deficit, immunocompromise, pregnancy, or fever → emergent neuroimaging, EEG, labs, lumbar puncture as indicated.