Abstract
The recent development of single-photon emitting radiopharmaceuticals has introduced a new era for the investigation of neurological disease. We have performed single photon emission computed tomography (SPECT) with 123I-N-isopropyl-p-iodoamphetamine (IMP) to measure regional cerebral blood flow (rCBF) in epileptic children. A total of twenty-four patients with epilepsy were investigated. 4 patients had primary generalized seizures and 20 patients had partial seizures. In 11 out of 20 patients with partial seizures, SPECT revealed a seizure focus, which correlated well with EEG findings. All of these abnormalities in foci were decreased rCBF findings. The relative values of decreased rCBF in foci showed from 67% to 93% compared with those of contralateral regions. The decreased rCBF findings in epileptic foci tended to be more extensive in the patients with organic and/or intractable epilepsy than functional and/or benign epilepsy (Rolandic discharges and occipital spike-waves). This method may be useful to determine the property of epileptic focus as well as localization.
On the other hand, three patients had abnormal organic lesions on x-ray CT scan. These were mild atrophy in the right hemisphere (HHE syndrome), small low density area in the left temporal lobe (old infarction) and diffuse cortical atrophy (due to hypoxic encephalopathy during neonate). The SPECT findings of these lesions showed a marked reduction of rCBF in the more extended area. This method may be also suitable to evaluate the underlying organic and secondarily involving disorders with epilepsy.
These results suggest that the measurment of rCBF by IMP-SPECT is of clinical use for the precise diagnosis and management of patients with epilepsy.
