Correlation of hippocampal glucose oxidation capacity and interictal FDG-PET in temporal lobe epilepsy

Epilepsia. 2003 Feb;44(2):193-9. doi: 10.1046/j.1528-1157.2003.38102.x.


Purpose: Interictal [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) demonstrates temporal hypometabolism in the epileptogenic zone of 60-90% of patients with temporal lobe epilepsy. The pathophysiology of this finding is still unknown. Several studies failed to show a correlation between hippocampal FDG-PET hypometabolism and neuronal cell loss. Because FDG is metabolized by hexokinase bound to the outer mitochondrial membrane, we correlated the glucose-oxidation capacity of hippocampal subfields obtained after surgical resection with the corresponding hippocampal presurgical FDG-PET activity.

Methods: In 16 patients with electrophysiologically confirmed temporal lobe epilepsy, we used high-resolution respirometry to determine the basal and maximal glucose-oxidation rates in 400-microm-thick hippocampal subfields obtained after dissection of human hippocampal slices into the CA1 and CA3 pyramidal subfields and the dentate gyrus.

Results: We observed a correlation of the FDG-PET activity with the maximal glucose-oxidation rate of the CA3 pyramidal subfields (rp = 0.7, p = 0.003) but not for the regions CA1 and dentate gyrus. In accordance with previous studies, no correlation of the FDG-PET to the neuronal cell density of CA1, CA3, and dentate gyrus was found.

Conclusions: The interictal hippocampal FDG-PET hypometabolism in patients with temporal lobe epilepsy is correlated to the glucose-oxidation capacity of the CA3 hippocampal subfield as result of impaired oxidative metabolism.

MeSH terms

  • Adolescent
  • Adult
  • Apoptosis / physiology
  • Blood Glucose / metabolism*
  • Energy Metabolism / physiology*
  • Epilepsy, Temporal Lobe / diagnostic imaging*
  • Epilepsy, Temporal Lobe / pathology
  • Epilepsy, Temporal Lobe / surgery
  • Female
  • Fluorodeoxyglucose F18
  • Hexokinase / physiology
  • Hippocampus / diagnostic imaging
  • Hippocampus / pathology
  • Hippocampus / surgery
  • Humans
  • Image Processing, Computer-Assisted
  • Male
  • Middle Aged
  • Oxidation-Reduction
  • Sclerosis / diagnostic imaging
  • Sclerosis / pathology
  • Sclerosis / surgery
  • Tomography, Emission-Computed*


  • Blood Glucose
  • Fluorodeoxyglucose F18
  • Hexokinase