Abstracts

Language regression (LR), or loss of previously acquired language in children most commonly occurs in in the context of a more global autistic regression. It also occurs in isolation in which case it may be as part of the Landau-Kleffner (Acquired epileptic aphasia) or ESES (electrographic status epilepticus in sleep) syndromes. Whether the EEG abnormalities are a fundamental part of the pathophysiology of LR or an epiphenomena remains controversial.
We reviewed the EEG findings of children with LR who had overnight video EEG monitoring for the evaluation of LR at Montefiore Medical Center between 1991and 2003. In order to be sure that LR had occurred, we restricted the analysis to children who had clearly acquired at least 5 words prior to the regression. Children were eligible whether LR was in isolation or in the context of more global autistic regression. Data were avilable for 159 children of whom 27 were excluded because they had not clearly acquired a 5 word vocabulary prior to LR. The remaining 132 children are included in this report.
Of the 132 children with LR, 92 (70%) had LR in the setting of a more global autistic regression. The remaining 40 (30%) had isolated LR though many also had some behavioral abnormalities. These 40 children included 3 with classic Landau Kleffner syndrome and an additional 9 children with electrical status epilepticus in sleep (ESES). Abnormal EEGs were present in 63 (48%) including 47 (36%) with epileptiform EEG abnormalities and 16 (12%) with nonepileptiform abnormalities. The frequency of EEG abnormalities was higher in children with isolated LR (27/40, 68%) compared with those with LR associated with autism (36/90, 40%) (p = 0.004). This was particularly true of epileptiform abnormalities (24/40, 60% vs 23/90, 26%, p [lt] 0.001). In addition, the nature of the EEG abnormalities was different. ESES was seen in 9 cases with isolated LR but in only 1 case of LR with associated autistic regression (p [lt] 0.001). Bilateral, unilateral and multifocal epileptiform EEG abnormalities were present in both groups with bilateral abnormalities being the most common. Recurrent seizures (including one child with recurrent febrile seizures) were far less common than abnormal EEGs in this population and occurred in 11 (8%) children including 5 (13%) children with isolated LR and 6 (7%) (p = 0.27) children with LR associated with autism.
The frequency and type of EEG abnormalities appear to be different in those with LR only compared to those with LR and autism. In particular, ESES is seen almost exclusively in those with LR only. The differences in the frequency and type of EEG abnormalities may provide further insights into the differences in the underlying pathophysiology of the different types of LR.
[Supported by: Gowers Research Fellowship from the Epilepsy Foundation and a K12 award (NIH K12 RR17667201) to Dr McVicar.]