Aims
We set out to identify neurobiological factors which may explain some of the observed individual variability in post-surgical cognitive outcomes in children who have undergone resective surgery to treat temporal lobe epilepsy.
Method
This retrospective study included 81 patients with medication-resistant temporal lobe epilepsy and 20 aged-matched healthy participants. Pre- and post-surgical hippocampal volumes and surgical resection volumes were obtained and studied for their association with neuropsychological variables.
Results
In our cohort of paediatric temporal lobe epilepsy patients, we observed a variable degree of pre-surgical hippocampal atrophy. Atrophy extent was associated with age at epilepsy onset.
Following surgery, we showed a decline in verbal function and verbal memory, regardless of lesion laterality. Children with higher pre-operative scores were most vulnerable to post-operative decline in performance across all cognitive domains.
In patients with left hemisphere lesions, extent of surgical resection was the only significant predictor of post-surgical verbal memory function.
Conclusions
Paediatric temporal lobe epilepsy is associated with impairments to general cognitive function and variable degree of hippocampal atrophy.
Resective surgery can result in small cognitive declines at short follow up intervals (around 1 year).
Our results are indicative that pre-operative verbal memory ability is supported by functional brain tissue in the ipsilesional hemisphere.
Surgical methods which allow preservation of healthy hippocampal and cortical tissue are best employed if verbal memory outcomes are to be prioritised in paediatric epilepsy of left temporal lobe origin.