Epilepsy surgery can lead to memory loss

NEW YORK (Reuters Health) - Severe epilepsy that can't be controlled with anti-seizure medication may require a brain operation, but in such cases there's apparently a trade-off. Surgery, especially on the left temporal lobe, can results in long-term loss of verbal memory, Dutch researchers report.

Dr. Willem C. J. Alpherts, from the Epilepsy Institute of the Netherlands, in Heemstede, and his associates evaluated long-term outcomes for 85 patients who had undergone brain surgery for epilepsy.

After repeated evaluation with a verbal test, the team found that patients operated on the left side exhibited a decline in acquisition, learning and in consolidation of verbal memories compared with those treated on the right side.

This decline appears to have leveled off after two years, the researchers report in the medical journal Neurology

For example, the average sum of scores on five tests declined from 49.4 prior to surgery, to 46.6 at 6 months, 42.7 at two years, and 42.6 at six years for those operated on the left side. Corresponding scores for those treated on the right side were 49.2, 52.5, 48.6 and 49.1.

The investigators conclude that the problem of memory loss following epilepsy surgery "has to be weighed against the possibility of becoming seizure free."

SOURCE: Neurology, August 22, 2006.