SPET scans, using Tc-exametezime, EEG and MRI were evaluated in 25 children with language deficits associated with epilepsy treated at the Royal Hospital for Sick Children, Edinburgh, UK. Seizures, with onset between 0.3 and 12 years (mean, 4 yrs), included atypical absence in 15 and tonic-clonic in 10. All had epileptiform EEGs, with enhanced abnormalities in sleep in 16. MRI was abnormal in 6, including tuberous sclerosis cortical lesions in 1, stroke in 1, cortical dysplasia (1), temporal sclerosis (3). SPET scans were abnormal and hypometabolic in 22, bilateral in 7, and anterior, mainly frontal and temporal, but variable in localization in 15. Aphasia was receptive in 24, expressive in 20, and nominal in 8. The acquired communication disorder, with onset between 1.5 and 12 years (mean, 6 yrs), did not meet strict criteria for Landau-Kleffner syndrome. Clinical and/or EEG seizure activity were responsive to clobazam or nitrazepam in 11 patients, and ACTH, alone or with benzodiazepine, was effective in 19. Benzodiazepine sensitivity testing employed in 21 under EEG control was positive in 18 and negative in 3. An encephalopathy secondary to a persistent epileptic discharge and characterized by regional hypometabolism on SPET scan was thought to underly the onset of acquired aphasia. [1]
COMMENT. Acquired epileptic aphasia in young children may be induced by the epileptic focus, as suggested by Deonna (1991). The Edinburgh SPET- and EEG-monitored study supports this hypothesis, finding evidence for a regional hypometabolic encephalopathy secondary to a persistent epileptic discharge, and advocating treatment and suppression of the EEG epileptiform activity, with or without concomitant clinical seizures. In epileptic aphasia we attempt to treat the EEG as well as any associated clinical seizures. Unfortunately, my success rate in a small number treated in Chicago cannot compare with that reported in the large series from Edinburgh. Benzodiazepines, the “fortnight drugs” (Dr Cynthia Stack’s apt title), frequently lose effectiveness after 2 weeks, and ACTH has a high relapse rate.
Language and motor reorganization following early left hemisphere lesions was investigated using oxygen 15-water PET scans in 9 patients (aged 4-20 years) studied at Wayne State University Medical School, Detroit, MI [2]. All patients had epilepsy and received antiepileptic medication. Regional cerebral blood flow was studied during rest, listening to sentences, repetition of sentences, and finger tapping of the right hand. Differential reorganizational patterns following early left hemisphere lesions found a greater potential for homotopic interhemispheric reorganization in language than in motor domains.