Epilepsy — Causes, Symptoms, Diagnosis & Treatment Guide — Symptoms, Causes & Treatment | MyMedicPlus

Epilepsy is a chronic neurological disorder characterised by recurrent, unprovoked seizures resulting from abnormal excessive or synchronous neuronal discharge in the brain. A diagnosis of epilepsy requires either two or more unprovoked seizures occurring more than 24 hours apart, or one unprovoked seizure with a probability of further seizures exceeding 60% (e.g., after cortical malformation, remote structural brain injury, or an epileptiform EEG pattern), or a diagnosis of an epilepsy syndrome (ILAE 2014 definition). Epilepsy is classified by seizure type (focal, generalised, combined, or unknown) and by epilepsy type and syndrome. It affects approximately 50 million people globally (0.6% of the world population). Approximately 70% of people with epilepsy can become seizure-free with appropriate antiseizure medication (ASM). About 30% have drug-resistant epilepsy.

Epilepsy causes vary by age of onset: structural (cortical dysplasia, hippocampal sclerosis, brain tumours, stroke, traumatic brain injury, encephalitis, tuberous sclerosis complex); genetic (SCN1A mutations in Dravet syndrome; KCNQ2, DEPDC5, and hundreds of identified epilepsy genes); metabolic (pyridoxine-dependent epilepsy, GLUT1 deficiency); immune (autoimmune encephalitis — anti-NMDA receptor, anti-LGI1 antibodies); and infectious (cerebral malaria, neurocysticercosis — leading cause worldwide in developing countries; HIV encephalopathy; herpes encephalitis). In older adults, stroke is the most common cause. In children, genetic and structural causes predominate. Approximately 50% of epilepsy cases remain of unknown cause despite thorough investigation. Autoimmune epilepsies — caused by antibodies against neuronal antigens (LGI1, CASPR2, NMDAR) — are an increasingly recognised and treatable cause of new-onset seizures in adults, responding to immunotherapy.

Focal (partial) seizures — arise in one hemisphere: focal aware (previously simple partial — consciousness preserved; motor, sensory, autonomic, or psychic symptoms); focal impaired awareness (previously complex partial — consciousness altered, automatisms such as lip-smacking, picking at clothes); focal to bilateral tonic-clonic seizure (secondary generalisation). Generalised seizures — involve both hemispheres from onset: tonic-clonic (grand mal — loss of consciousness, rhythmic convulsions, post-ictal confusion), absence (brief 5-20 second staring with 3 Hz spike-wave EEG pattern — predominantly in childhood), myoclonic (brief jerks, often morning), atonic (drop attacks), and tonic seizures. Status epilepticus — continuous seizure activity lasting more than 5 minutes (convulsive) or 10-30 minutes (non-convulsive) — is a neurological emergency requiring immediate benzodiazepine treatment.

Diagnosis is clinical, based on a detailed seizure history (including eyewitness account), followed by investigations to confirm and classify epilepsy. EEG (electroencephalogram) is the primary diagnostic tool — records brain electrical activity; interictal epileptiform discharges (IEDs) support epilepsy diagnosis but a normal EEG does not exclude it (30-40% of epilepsy patients have normal routine EEG). Sleep-deprived EEG or prolonged ambulatory EEG increases yield. Video-telemetry EEG (simultaneous video and EEG recording) is the gold standard for capturing seizures and classifying seizure type, essential before epilepsy surgery. MRI brain (3T epilepsy protocol with dedicated sequences): identifies structural causes — hippocampal sclerosis, cortical malformations, tumours, vascular malformations. Metabolic panel, glucose, electrolytes, and toxicology screen exclude acute symptomatic causes (provoked seizures). Genetic testing for suspected genetic epilepsy syndromes. Autoimmune antibody panel (NMDA-R, LGI1, CASPR2, GABA-B) for suspected autoimmune encephalitis.

Antiseizure medications (ASMs) are the mainstay of treatment — tailored by seizure type, epilepsy syndrome, co-morbidities, drug interactions, and patient factors (pregnancy, fertility, age). Focal epilepsy first-line: levetiracetam, lamotrigine, carbamazepine, oxcarbazepine. Generalised epilepsy first-line: sodium valproate (most effective broad-spectrum ASM but teratogenic — avoid in women of childbearing potential), levetiracetam, lamotrigine. Absence seizures: ethosuximide, valproate, lamotrigine. Childhood epileptic spasms (West syndrome): vigabatrin and ACTH. Drug-resistant epilepsy (failure of 2 appropriate ASMs): refer to specialist epilepsy centre for video-EEG telemetry and surgical evaluation. Resective epilepsy surgery (temporal lobe resection for hippocampal sclerosis): seizure freedom in 60-70% of carefully selected patients. Vagus nerve stimulation (VNS), deep brain stimulation (DBS of the anterior nucleus of the thalamus), and responsive neurostimulation (RNS) are neuromodulation options for non-resectable epilepsy. Ketogenic diet (very high fat, low carbohydrate): established efficacy in drug-resistant childhood epilepsy. Status epilepticus: IV/IM lorazepam or buccal midazolam first-line; IV levetiracetam, phenytoin, or valproate second-line; anaesthesia (thiopental, propofol, midazolam infusion) for refractory status.

Sudden unexpected death in epilepsy (SUDEP) occurs in approximately 1 in 1,000 people with epilepsy annually — rising to 1 in 150 in drug-resistant epilepsy — most often during sleep from respiratory or cardiac arrest. Status epilepticus (seizure lasting more than 30 minutes) causes brain injury and has 20-30% mortality in convulsive form. Traumatic injuries from uncontrolled falls (head injuries, fractures, burns) and drowning (all epilepsy patients should shower rather than bathe alone) are major risks. Cognitive impairment accumulates from repeated seizures or hypoxic episodes. Loss of driving licence and employment restrictions, combined with social stigma, cause depression in 30-40% of people with epilepsy and significantly impair quality of life.

Prevent known triggers: sleep deprivation (the most common seizure trigger — maintain 7-9 hours/night), alcohol excess, missed ASM doses, fever/infections, physical or emotional stress, photosensitivity (avoid flashing lights — only 3% of epilepsy patients are photosensitive). Take all ASMs consistently at the same time daily. Driving restrictions: must be seizure-free for the required period (1 year in UK for standard licence; 10 years for Group 2 — HGV/bus). Women with epilepsy: preconception counselling essential — folic acid 5 mg daily; valproate is teratogenic (avoid in women of childbearing potential unless no alternative); many ASMs have pharmacokinetic interactions with combined oral contraceptive. Bathing (shower rather than bath), swimming supervision, working at heights, and contact sports — assess individual risk. Wear a medical alert bracelet. Rescue medication (buccal midazolam) prescribed for prolonged seizures.

Call emergency services immediately for a first seizure, any seizure lasting more than 5 minutes, repeated seizures without recovery between them (status epilepticus), a seizure in water, or a seizure in someone not known to have epilepsy. Attend A&E urgently after any first seizure even if the person has recovered fully. Contact your neurologist or epilepsy nurse promptly for breakthrough seizures after a period of control, medication side effects, consideration of pregnancy, or any new neurological symptoms. A first unprovoked seizure warrants urgent neurology assessment, MRI brain, and EEG to establish diagnosis and risk of recurrence. Any adult experiencing a first seizure should have urgent brain MRI and EEG within 24 hours to exclude an acute structural or metabolic cause before outpatient epilepsy assessment.