"Tonic-absence seizures": an unusual seizure phenotype, but not necessarily in that order

Video telemetry in a 15-year-old boy with moderate learning difficulties revealed episodes of staring and cessation of activity, followed by sudden stiffening of the body for several seconds, abduction of the arms and a brief vocal utterance ("ugh"). Each episode lasts around 30 seconds, 3-4 times/day despite treatment. The EEG showed generalized 3-4Hz spike-wave discharges during the "absence" period followed immediately by a run of fast polyspikes typical of a tonic seizure, terminating in a run of 1-2 Hz sharp-slow wave complexes. Although tonic-absence seizures have been reported rarely, the clinical sequence appears to be reversed in this patient, with the occurrence of "absence-tonic" attacks. We present video documentation of such attacks and discuss their nosology.[Published with video sequences].