Seizures & Epilepsy (Clinical)
Sort provoked from unprovoked, then run the fixed status and counseling playbook
Provoked seizures vs epilepsy
Provoked (acute symptomatic) seizures come from a reversible insult: hypoglycemia, hyponatremia (Na <120), hypocalcemia, alcohol or benzodiazepine withdrawal, uremia, drugs such as cocaine, eclampsia, or meningitis. Fix the cause; no chronic antiseizure medication (ASM) is needed. An unprovoked seizure has no acute trigger. A seizing patient with a sodium of 116 needs careful sodium correction, not lifelong levetiracetam.
Epilepsy (ILAE definition) is any of: two unprovoked seizures more than 24 hours apart; one unprovoked seizure with a ≥60% 10-year recurrence risk (an epileptiform EEG or a structural lesion on MRI); or a recognized epilepsy syndrome.
Recurrence and when to treat. About 40% of first unprovoked seizures recur within 2 years. Risk is higher with an abnormal EEG, an MRI lesion, a nocturnal seizure, or a focal seizure. Start an ASM after a first seizure only when recurrence risk is high; otherwise wait for a second seizure. One typical unprovoked seizure with a normal workup and clear precipitants such as sleep loss and heavy drinking calls for counseling, not a drug.
Evaluating a first seizure
Workup. Check glucose, electrolytes (Na, Ca, Mg), toxicology, and a pregnancy test. Image the brain: non-contrast CT in the ED to exclude bleeding or a mass, with MRI preferred for the full evaluation. Obtain an EEG. Perform a lumbar puncture if the patient is febrile, immunosuppressed, or meningitis is suspected.
A normal EEG never excludes epilepsy; yield rises with sleep deprivation and repeated or prolonged recordings.
| Feature | Generalized seizure | Syncope | Psychogenic nonepileptic seizure |
|---|---|---|---|
| Onset | Abrupt, possible aura if focal onset | Prodrome of lightheadedness, pallor, sweating | Often gradual, with an emotional trigger |
| Event | Tonic-clonic activity, lateral tongue bite, incontinence | Brief loss of consciousness; a few jerks possible | Eyes closed, side-to-side head movement, pelvic thrusting |
| Recovery | Prolonged postictal confusion | Rapid return to baseline | Variable; no true postictal state |
| Confirm with | EEG, imaging | ECG and cardiac workup | Video-EEG |
Seizure types and syndromes
Focal vs generalized onset. Focal seizures start in one hemisphere: focal aware (consciousness intact) or focal impaired awareness (formerly complex partial), and they can evolve to bilateral tonic-clonic seizures. Generalized seizures involve both hemispheres at once: absence, myoclonic, tonic-clonic, and atonic. Onset type drives drug choice.
| Syndrome | Clinical clues | EEG | First-line |
|---|---|---|---|
| Temporal lobe (focal impaired awareness) | Rising epigastric aura, lip-smacking automatisms, postictal confusion | Anterior temporal spikes | Lamotrigine, levetiracetam, or carbamazepine |
| Childhood absence | ~10-second staring spells, many per day, eyelid flutter, no aura or postictal state | 3-Hz generalized spike-and-wave, provoked by hyperventilation | Ethosuximide (T-type calcium channel blocker); valproate if tonic-clonic seizures coexist |
| Juvenile myoclonic epilepsy | Adolescent with morning myoclonic jerks and tonic-clonic seizures, worse with sleep loss | 4–6 Hz polyspike-and-wave | Valproate (broad-spectrum) or levetiracetam |
Narrow-spectrum sodium-channel drugs (carbamazepine, phenytoin) can WORSEN generalized absence and myoclonic seizures, so avoid them unless the seizures are clearly focal.
Status epilepticus
A 5-minute clock. Status epilepticus is ≥5 minutes of continuous seizure, or recurrent seizures without recovery of consciousness between them. It is a neurologic emergency: secure the airway, give oxygen, check glucose (give thiamine with dextrose if alcohol use is possible), and start the drug ladder immediately while establishing IV access.
- BenzodiazepineIV lorazepam 0.1 mg/kg, or IM midazolam 10 mg if there is no IV.
- Second-line ASM loadLevetiracetam, valproate, or fosphenytoin; ESETT showed all three roughly equal.
- RefractoryIntubate and start an anesthetic infusion (propofol or midazolam).
Repeated benzodiazepine boluses are not a substitute for step 2. A patient who does not wake up after convulsions stop needs continuous EEG to exclude nonconvulsive status.
Choosing and living with antiseizure drugs
Match the drug to the seizure type. For focal seizures use lamotrigine, levetiracetam, or carbamazepine. For generalized epilepsy, valproate is the broad-spectrum workhorse, with lamotrigine and levetiracetam as alternatives; lamotrigine can worsen myoclonic seizures, so levetiracetam is the preferred alternative in juvenile myoclonic epilepsy. Failure of two appropriate drugs defines drug-resistant epilepsy and prompts referral for surgical evaluation.
| Drug | Notable adverse effects |
|---|---|
| Valproate | Hepatotoxicity, pancreatitis, thrombocytopenia, hyperammonemia, weight gain, tremor, alopecia; most teratogenic |
| Lamotrigine | Stevens-Johnson syndrome, so titrate slowly |
| Levetiracetam | Irritability and mood change |
| Carbamazepine | Hyponatremia (SIADH), agranulocytosis, SJS, CYP450 induction |
| Phenytoin/fosphenytoin | Gingival hyperplasia, hirsutism, nystagmus and ataxia; hypotension and arrhythmia with IV loading |
| Ethosuximide | GI upset, fatigue |
Pregnancy. Valproate carries the highest risk (neural tube defects, ~10% major malformations, lower child IQ), so avoid it in anyone who could become pregnant when alternatives exist and switch toward lamotrigine or levetiracetam before conception. Give folic acid, use monotherapy at the lowest effective dose, and NEVER stop drugs abruptly: convulsions cause fetal hypoxia and harm mother and fetus more than the medication.
Driving and safety. After a seizure with impaired awareness, patients may not drive until the state-mandated seizure-free interval passes (commonly 3–6 months). Counsel against swimming alone, unprotected heights, and operating heavy machinery until seizures are controlled.