Neurology: What causes sudden seizures?

Sudden seizures—characterized by involuntary, abnormal electrical activity in the brain—can arise from a wide range of underlying causes and require prompt clinical evaluation. Common etiologies include epilepsy (a chronic neurological disorder defined by recurrent unprovoked seizures), acute metabolic disturbances (e.g., severe hyponatremia, hypoglycemia, hypocalcemia, or uremia), acute structural brain lesions (such as stroke, intracranial hemorrhage, tumor, or encephalitis), withdrawal syndromes (particularly from alcohol or benzodiazepines), and febrile illness in young children. Less common but critical considerations include autoimmune encephalitis, mitochondrial disorders, genetic channelopathies, and non-epileptic events such as psychogenic nonepileptic seizures (PNES) or syncope with myoclonus. A thorough history—including seizure semiology, duration, triggers, postictal state, prior neurological history, medications, substance use, and family history—is essential. Neuroimaging (typically MRI) and electroencephalography (EEG) are cornerstone diagnostic tools, often supplemented by blood tests (electrolytes, glucose, renal and liver function, toxicology screen) and lumbar puncture when infection or inflammation is suspected. Immediate management focuses on ensuring airway protection, safety, and cessation of ongoing seizure activity—especially in status epilepticus, which constitutes a neurological emergency requiring urgent benzodiazepine administration and escalation to second-line antiseizure medications if needed.