SPET imaging of cerebral perfusion in patients with non-refractory temporal lobe epilepsy

The pattern of regional cerebral blood flow was assessed by single photon emission tomography and (99mTc)HM-PAO in 28 patients with clinical diagnosis of non-refractory cryptogenic temporal lobe epilepsy on chronic treatment with carbamazepine. Each patient underwent a magnetic resonance imaging study of the brain. An EEG was performed concurrently with the assessment of cerebral blood flow. Areas of focal hypoperfusion were observed in 8/28 patients, and a concurrent EEG focus was identified in 10/28 patients. Areas of hypoperfusion and the EEG foci were consistent in 6 of the 10 patients with EEG abnormalities; in 2 patients hypoperfusion and the EEG abnormalities were on opposite sides, though in homologous areas; in 2 patients the perfusion pattern was normal in spite of the EEG abnormalities. The number of clinical seizures and EEG abnormalities was higher for the patients presenting with cerebral hypoperfusion than for those with normal perfusion. It is concluded that the evaluation of cerebral blood flow may provide useful information for both diagnostic and prognostic assessment of these patients.