Acquired motor speech disorders in childhood epilepsy

Aim: To evaluate a group of children with epilepsy and motor speech regression, with the aim of characterizing their speech disorders, electrographic features, and outcomes. Method: Children referred to a tertiary developmental epilepsy clinic with epilepsy and motor speech regression were identified retrospectively. A clinical history was taken, and longitudinal speech and cognitive data were recorded. Speech samples were scored for severity and speech features. Seizure frequency and epileptiform discharges in the interictal electroencephalogram were analysed. Results: Eighteen children (10 female) were evaluated, including seven with Landau-Kleffner syndrome and six with Rasmussen syndrome. Speech regression occurred at a mean age of 5years (SD=2years 6months), which was concurrent with seizure onset or peak seizure burden in eight children. Speech features included dysarthria (n=13), phonological errors (n=7), and dyspraxia (n=6). Electrographic abnormalities occurred most frequently in the left centrotemporal and right frontal regions. Among children who were followed up, intelligibility of speech was affected in 13 at baseline and seven at follow-up (p=0.03). Expressive language standardized scores increased from a mean (SD) of 50.0 (11.3) to 91.4 (27.8) in children with Landau-Kleffner syndrome (mean change=41.4, 95% confidence interval [CI] 0.04-82.8, p=0.0498) and decreased from 75.2 (15.3) to 59.0 (9.8) in children with Rasmussen syndrome (mean change -16.2, 95% CI -9.0 to -23.4, p=0.002) over the follow-up. Interpretation: Motor speech disorders in epilepsy were severe, multifarious, and often fluctuated with seizure burden. Symptoms typically improved, especially in children with Landau-Kleffner syndrome, but rarely fully resolved.