Patterns of cerebral glucose metabolism in patients with partial seizures

We analyzed local cerebral metabolic rates of glucose (LCMRglu) in 20 regions from 22 patients with complex partial seizures, who were taking neither phenytoin nor phenobarbital and who had normal CTs. Results were compared with data from 19 normal controls. Ten patients had left temporal, eight right temporal, and four bitemporal or generalized EEG discharges. There were no significant differences between patient and control values in any of 20 regions of interest. LCMRglu was depressed at the site of the epileptic focus: L/R ratio was 0.85 ± 0.12 (p < 0.003 compared with control), 0.92 ± 0.08 (p < 0.05), and 0.84 ± 0.1 (p < 0.001), respectively, in mesial, superior, and inferior temporal regions for patients with left temporal foci; 1.7 ± 0.96 (p < 0.04), 1.1 ± 0.1 (NS), and 1.15 ± 0.04 (p < 0.001) for patients with right temporal foci. Patients with left temporal EEG foci had significantly lower values than patients with right temporal foci in left superior frontal and thalamic as well as left temporal regions, while patients with right-sided EEG foci had depressed LCMRglu (compared with patients with left temporal EEG foci) restricted to right mesial temporal lobe. The patients with left temporal foci tended to have longer seizure histories (22.7 ± 5.4 versus 11 ± 5.6 years; p < 0.001). There was an inverse correlation between length of seizure history and mean LCMRglu (r = 0.38; 0.1 > p > 0.05). Our study suggests that LCMRglu is not depressed in regions beyond the epileptic focus when patients are not taking drugs known to decrease cerebral glucose metabolism.