The medical history, EEG recordings, and developmental milestones of 19 children with speech and language dysfunction, and focal epileptiform activity were analyzed for prognostic risk factors in a study at University of Gothenburg, Sweden. Three patterns of language development were observed at follow-up: 1) late start and continued slow development (possible Landau-Kleffner syndrome (LKS) or epileptic language disorder (ELD); 2) late start and deterioration/regression (probable LKS); and 3) normal start and later regression/deterioration (definite LKS). Seizures (complex partial, generalized tonic-clonic, absence, perioral, and eye-lid myoclonic) occurred in 15 patients but were rare. Age at onset was 2-9 years. Response to AEDs (carbamazepine, etc) was poor, whereas corticosteroids were effective in 8 of 9 cases. Six (32%) had a family history of seizures. All but one had normal CT or MRI. SPECT showed hypoperfusion in left temporal region. Family history was positive for speech and language delay or reading and writing disability. Early general development was normal in 14 (74%). Early language development was late in 13 (68%), and normal in 6; later deterioration occurred in 9 (47%). EEG spike/spike-and-wave activity was temporal in 12 (63%) and parietal, frontal or central location in 7. CSWS (continuous spike and wave during slow wave sleep) was found in 7 (37%), and 7 had excess epileptiform activity during sleep. At age 9-25 years at follow-up, EEG was normal in 10 and showed epileptiform activity in 9. Cognitive ability was average in 7, and variably impaired in 12. Long-term speech and language function is unfavorable in 50% of participants and not more favorable in any one of the three LKS patterns (possible, probable, and definite). In addition to language dysfunction, patients with LKS at follow-up have auditory dysfunction, oral-motor dysfunction, stuttering, and cognitive dysfunction. Persisting epileptiform activity and a family history of seizures are risk factors for a poor prognosis. Further study of antiepileptic treatment is recommended. [1]

COMMENT. Three patterns of language development are found in children with sleep-activated epileptiform activity and language disorder (Landau-Kleffner syndrome or epileptic language disorder). Long-term prognosis is unfavorable in 50%, and risk factors for a poor outcome include persistent epileptiform activity and a family history of seizures.

Functional connectivity, language impairment, and localization-related epilepsy. Activation maps and functional connectivity networks were studied by fMRI in 34 adults (mean age 40 years) with cryptogenic localization related epilepsy and language impairment and compared to 20 healthy controls. Activation maps did not differ between patients and controls, but patients with epilepsy had significantly lower functional connectivity in left frontal temporal networks during text reading and on the word-fluency test. Impaired language performance in epilepsy patients is associated with loss of functional connectivity in cognitive language networks. [2]