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A 16-year-old girl is brought by her mother after two early-morning episodes in the last month: she spilled her tea from sudden jerks of both arms, and on one occasion this was followed by a generalised tonic-clonic seizure on waking. Her EEG shows generalised polyspike-and-wave discharges, photosensitive on stimulation. Her older sister has epilepsy. She has recently started the combined oral contraceptive pill for menorrhagia. She asks whether she will need lifelong treatment and whether she can drive.
Questions
a) Diagnosis and the single most diagnostic feature (2 marks)
The diagnosis is juvenile myoclonic epilepsy (JME). The single most diagnostic feature is the generalised polyspike-and-wave EEG with photosensitivity, in the setting of early-morning myoclonic jerks and generalised tonic-clonic seizures on waking in a teenager — the classic JME tetrad. (1 mark diagnosis, 1 mark EEG signature.)
b) First-line drug and the key counselling point (3 marks)
- First-line drug: sodium valproate is the most effective agent for idiopathic generalised epilepsy and JME. (1 mark)
- However, valproate is TERATOGENIC (neural tube defects, cardiac defects) and lowers offspring IQ; in a 16-year-old on contraception it should only be used if a Pregnancy Prevention Programme is in place (highly effective contraception, negative pregnancy test, annual review, signed acknowledgement of risk). (1 mark)
- If valproate is inappropriate, levetiracetam is the alternative first-line for JME. Carbamazepine and phenytoin must be AVOIDED — they can worsen myoclonus. (1 mark)
c) Contraception interaction (2 marks)
Valproate, levetiracetam, lamotrigine and ethosuximide do not reduce the efficacy of the combined oral contraceptive pill, so her current pill is fine. (If she were on an enzyme-inducing AED — carbamazepine, phenytoin, phenobarbitone, topiramate, perampanel — the pill could fail and a higher-dose oestrogen or a non-hormonal method would be needed.) (1 mark for no interaction with valproate/levetiracetam; 1 mark for naming the enzyme-inducers that DO interact.)
d) Driving and prognosis counselling (3 marks)
- Driving: she must stop driving immediately and notify the licensing authority. In India (RTO) she must be seizure-free for typically at least 1 year before resuming a private licence; in the UK (DVLA group 1) at least 1 year seizure-free, or 1 year of established sleep-only seizures. (1 mark)
- Prognosis: JME responds very well to treatment with valproate, with most patients achieving seizure freedom — but JME is LIFELONG: seizures recur in the great majority if the AED is withdrawn, even after years of freedom. She should be advised she will likely need lifelong treatment. (1 mark)
- Lifestyle triggers to avoid: sleep deprivation, excess alcohol, and flickering lights (given her photosensitivity). Good adherence is the single best protection against seizures and against SUDEP (sudden unexpected death in epilepsy), which should be discussed sensitively. (1 mark)