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A recent RCPCH guideline appraisal asserted: “There is no need for an EEG following a first simple afebrile seizure”.1 This is puzzling. A “simple afebrile seizure” is not an entity recognised in the ILAE diagnostic scheme.2 More importantly, we disagree both with the recommendation and the contention that it is based on grade B evidence.
The recommendation is principally based on a meta-analysis by Gilbert and Buncher, which found the sensitivity and specificity of EEG in helping to predict recurrence after a first seizure to be too low to justify its routine use.3 However, they concluded: “EEG should be ordered selectively, not routinely, after first unprovoked seizure in childhood”, which is different from, “There is no need for ...”. Moreover, the principle purpose of performing an EEG after a first seizure is not to predict recurrence.
There are many different disorders in which a seizure may be the first symptom. While it may be useful for statistical purposes to lump these together, clinically this is indefensible. There are many common scenarios when, following an initial generalised tonic-clonic seizure (GTCS), an EEG may be helpful for diagnostic, therapeutic, and/or prognostic purposes. This may be the case if one suspects a benign focal seizure disorder, a photically induced seizure, or an idiopathic generalised epilepsy in which the first GTCS may have been preceded by hundreds of unrecognised minor seizures.
The guideline might be better worded: “An EEG following a first definite seizure may not yield useful information regarding recurrence risk, but may provide useful information regarding syndrome diagnosis, the role of precipitating factors, and management. The need for an EEG should be determined following clinical evaluation by a clinician with expertise in seizure disorders”. In this the guideline would reflect other evidence based guidelines that EEG should be “... part of the neurodiagnostic evaluation of the child with an apparent first unprovoked seizure”.4