Magnetization transfer ratio is unable to lateralize epileptic foci in patients with temporal lobe epilepsy.

BACKGROUND AND PURPOSE A preliminary report suggested that magnetization transfer ratio (MTR) was useful to lateralize epileptic foci in patients with refractory temporal lobe epilepsy (TLE). We attempted to confirm this finding in a larger group by investigating the relationship between MTR of mesial temporal structures and seizure lateralization in patients with refractory TLE. METHODS We compared the MTR of amygdalae and hippocampi of 10 patients with unilateral TLE to values obtained from 10 healthy control participants. RESULTS Three of 10 patients with TLE had MTR values that were 2 SD below the normal mean; the MTR abnormality was concordant with electroclinical lateralization in only one of the three. CONCLUSION We conclude that MTR measurements of amygdalae and hippocampi are not useful for lateralization of TLE.