Epilepsy syndromes by age — branching viva

Opening

Examiner: A seven-month-old is referred to your clinic with two weeks of clustering brief flexion jerks on waking and loss of babbling. The EEG shows hypsarrhythmia. Talk me through your assessment and plan. ^[2]

Candidate: This is West syndrome — infantile spasms — defined by the triad of epileptic spasms in clusters, hypsarrhythmia on the EEG, and psychomotor regression with the loss of babbling. The peak age is four to eight months, which fits. Because this is a developmental and epileptic encephalopathy, the epileptic activity itself is driving the regression, so I would treat promptly rather than watch and wait, and I would refer urgently to paediatric neurology. ^[2]

Branch 1 — syndrome-directed treatment

Examiner: What is your first-line treatment and why? ^[5]

Candidate: First-line is vigabatrin or hormonal therapy with ACTH or high-dose prednisolone. The Cochrane review found hormonal therapy more effective than vigabatrin for short-term spasm cessation in non-tuberous-sclerosis cases, while vigabatrin is preferred when the cause is tuberous sclerosis. The skin examination is normal here and there is no clinical evidence of tuberous sclerosis, so I would favour hormonal therapy. I would start it promptly, because time-to-treatment is a major determinant of developmental outcome. ^[5]

Examiner (probe): Why does time-to-treatment matter so much here? ^[2]

Candidate: Because the hypsarrhythmia and the ongoing spasms constitute an epileptic encephalopathy — the abnormal electrical activity is actively eroding the developing brain. Resolving the electroencephalographic burden is treatment of the developmental problem, not just seizure control. The longer the encephalopathy persists, the greater the developmental cost, so early treatment is one of the few modifiable determinants of cognition. ^{[2] [5]}