Epilepsy and Clinical Neurophysiology: Semiology First
Classify the seizure before choosing the drug
Seizure questions test whether you can classify semiology and match it to treatment. Use the modern framework: onset (focal, generalized, unknown), level of awareness, and motor versus nonmotor features.
Semiology clues. A focal seizure may show automatisms, head version, or aphasic posturing with preserved awareness. Absence seizures are brief staring spells with immediate recovery, typically with 3 Hz generalized spike-and-wave on EEG, and are provoked by hyperventilation. Juvenile myoclonic epilepsy presents in adolescence with morning myoclonic jerks, sometimes followed by generalized tonic-clonic seizures; sleep deprivation is a trigger. Focal impaired awareness seizures arising from the temporal lobe often begin with an aura such as a rising epigastric sensation or deja vu.
Status epilepticus. Convulsive status is defined operationally at 5 minutes of continuous seizure or recurrent seizures without recovery. First-line treatment is a benzodiazepine (intramuscular midazolam, intravenous lorazepam). Second-line options are levetiracetam, valproate, or fosphenytoin, which perform comparably; refractory cases require anesthetic infusion and continuous EEG.
Drug selection traps. Valproate is effective across generalized epilepsies but carries teratogenicity and should be avoided in women of childbearing potential when alternatives exist. Carbamazepine and other sodium channel blockers can worsen Dravet syndrome and some generalized epilepsies. Lamotrigine requires slow titration because of rash risk.
EEG patterns to know. Hypsarrhythmia with infantile spasms, periodic sharp-wave complexes in Creutzfeldt-Jakob disease, lateralized periodic discharges in structural lesions, burst suppression in severe encephalopathy, and generalized periodic discharges in toxic-metabolic states.
Rule of thumb: treat convulsive status at 5 minutes, and never delay a benzodiazepine while waiting for an EEG.