SPECT abnormalities in Landau-Kleffner syndrome

Five right-handed children with acquired aphasia elipepsy syndrome (Landau- Kleffner, LKS), were investigated with 99(m) TcHMPAO single photon emission computed tomography (SPECT) and the results were correlated with their EEG s and clinical history. The childrens' ages ranged from 2 to 5 years and th e aphasia had been present for 6 to over 12 months. No clinical seizure had ever been onserved in the younger two children and their waking EEGs showe d infrequent central spikes. Both children had areas of low intensity on SP ECT, involving the left temporal lobe in one and the right temporal lobe in the other. which has also been reported in children with congenital dyspha sia who have normal EEGs. The three older children presented with frequent generalized seizures, with the aphasia occurring 3-6 months later. The SPEC T scans in these children were performed either in the ictal state, or when electrographic seizure activity was very frequent on EEG. All three childr en had hyperintense foci on SPECT involving the left posterior temporal reg ion corresponding to Wernickes area. We conclude that LKS may be initially a unilateral seizure disorder of Wernickes area, with EEG discharges in the contralateral hemisphere representing propagation from the unilateral focu s.