Clinical characteristics and long-term prognosis of Landau-Kleffner syndrome

Abstract

To investigate the clinical and electroencephalographic (EEG) characteristics, therapeutic response and long-term prognosis of Landau Kleffner syndrome (LKS). The clinical and EEG data of 10 children with LKS were analyzed, and therapeutic response and long-term outcome were followed up. The age of onset was from 2 to 10.5 years of age. All patients had acquired aphasia, characterized by verbal auditory agnosia. All patients had epileptic seizures. Partial motor seizures during sleep occurred in 8 patients, and other seizure type including atypical absence seizure and generalized tonic-clonic seizure were also observed. Psychological and behavioral abnormalities occurred in 9 patients. There were no abnormalities of hearing and neuro-imaging tests in all patients, and family histories were negative. All the patients had EEG abnormalities. Focal spike and waves of temporal lobe were recorded in 9 patients. Electrical status epilepticus during sleep (ESES) was observed on Video-EEG (VEEG) monitoring in 4 patients. Anti-epileptic drugs (AEDs) showed favorable effects on epileptic seizures, but no effects on aphasia. All patients responded to corticosteroid, and got language improved. Eight patients were followed up for long-term outcome. All patients were seizure free, while the level of language development was abnormal in 5 patients. The VEEG follow-up was conducted in 6 patients. Continuous epileptic discharges in slow sleep recurred in 2 patients after the discontinuation of steroid therapy. LKS is one of the childhood epileptic encephalopathy, and acquired aphasia and epileptic seizures are two main clinical characteristics. Aphasia is characterized by verbal auditory agnosia. Psychological and behavioral abnormalities are very common in children with LKS. Focal epileptic discharges were often located in temporal area, and usually generalized, and could be continuous during sleep. AEDs could control seizure but had no effects on aphasia. Early use of full dose corticosteroids could improve the language significantly. Long-term follow up showed that language impairments often remained, but the outcome in terms of EEG and epileptic seizure was good.