Interictal brain 99m Tc-HMPAO SPECT study in chronic epilepsy.

We performed interictal brain 99m Tc-HMPAO study in eight cases of chronic epilepsy. SPECT (single photon emission computed tomography) study showed abnormality in seven cases. As compared to computed tomography (CT) scan and electroencephalogram (EEG) which were positive in 25% and 62% cases respectively it showed abnormality in 87%. In two cases where CT scan and EEG both were normal, SPECT showed areas of hypoperfusion. In one case where EEG indicated a bilateral focus, SPECT study showed a clearly defined unilateral focal hypoperfusion defect. Areas of hyperperfusion were not seen in any of our cases. Our results indicate that HMPAO SPECT is more sensitive than CT scan and EEG, in localising an epileptogenic focus in cases of chronic epilepsy.