Published article: Baxendale S, Thompson PJ, Duncan JS. Improvements in memory function following anterior temporal lobe resection for epilepsy. Neurology. 2008; volume 71; pages 1319-25.

Faulty memory is one of the most common complaints voiced by people with epilepsy. Memory difficulties results from a combination of factors, including seizures that disrupt memory formation circuits in the brain, negative effects of some seizure medicines on memory and underlying injuries to the brain that can cause both seizures and memory problems. Patients who are thinking of having epilepsy surgery to help their seizures may wonder, will this also help my memory? The usual answer to this question up to now has been no, but a new study from the National Hospital at Queen Square in London suggests that the answer may sometimes be yes: memory can improve

The study was done on 230 patients who had a type of scarring in their temporal lobe called hippocampal sclerosis. This condition can be seen on the preoperative MRI, and is commonly associated with the place of origin in the brain where seizures arise (the so-called seizure focus). The left temporal lobe, which is more usually involved with word and number memory, was involved in 132 patients. The right temporal lobe, which typically mediates picture, map, and face memory, was involved in 105 patients. Postoperatively, 22% of people with right temporal lobe surgery and 9% of people with left temporal lobe surgery showed improvement in memory with their partial temporal lobectomy. Those with shorter durations of epilepsy tended to improve more. Previous experience from several studies have suggested that secondary improvement in memory may result from successful surgery if surgery eliminates or reduces numbers of seizures and therefore allows reduction in seizure medications. Other individuals, however, have a decrease in memory function after epilepsy surgery. A post-surgical memory decrease may recover after a few months, but sometimes the decrease in memory is lasting. Such a decline does not result in loss of specific memories, but rather the ability to retain new memories: basically, a form of absent-mindedness. So now we have a study with a little more optimism, raising the possibility that epilepsy surgery sometimes makes memory better, and not always worse or unchanged.

By Robert Fisher, M.D., Ph.D.