Establishing a correct diagnosis

The adolescent period is an important time to review the diagnosis of both epilepsy (differentiating it from other paroxysmal but non-epileptic disorders/conditions) and the epilepsy syndrome, and to consider any underlying cause. Common misdiagnoses at this age include vasovagal attacks, migraine with aura (“classic” migraine), non-epileptic (pseudo-epileptic) attacks, and substance abuse (including recreational drugs). Cocaine, heroin, and 3–4 methylenedioxymethamphetamine (“ecstasy”) are known to cause convulsions; cannabis is less likely to have this effect.5 6 The false diagnosis rates of epilepsy and the epilepsy syndrome could be at least 10% and 6%, respectively.3 Juvenile myoclonic epilepsy is the most commonly unrecognised and misdiagnosed epilepsy syndrome; a history of myoclonic seizures, which are the defining seizure type in this syndrome, needs to be sought specifically because teenagers either fail to recognise them or consider that the early morning jerks are a normal part of waking up.7 Brain tumours and temporal lobe epilepsy (caused by hippocampal atrophy/mesial temporal sclerosis) may present at this time. Finally, the onset of seizures in adolescence may, rarely, herald the onset of a neurodegenerative disorder including subacute sclerosing panencephalitis, Unverricht-Lundborg or Lafora body disease (both progressive myoclonic epilepsies), or juvenile Huntington’s disease.

Repeat electroencephalogram (EEG) monitoring and neuroimaging with magnetic resonance imaging may be indicated, particularly if seizures have an onset at this time, if seizures change in frequency or character, or if …