Regional cerebral blood flow during temporal lobe seizures associated withictal vomiting: An ictal SPECT study in two patients

Purpose: Ictal vomiting represents a rare clinical manifestation during sei zures originating from the temporal lobes of the nondominant hemisphere. Th e precise anatomic structures responsible for generation of ictal vomiting remain to be clarified. Ictal single photon emission computed tomography (S PECT), which allows one to visualize the three-dimensional dynamic changes of regional cerebral blood flow (rCBF) associated with the ongoing epilepti c activity, should be useful to study the brain areas activated during icta l vomiting. Methods: We performed ictal Tc-HMPAO SPECT scans in two patients with mesia l temporal lobe epilepsy (MTLE) whose seizures were characterized by ictal retching and vomiting. MTLE was documented by typical clinical seizure semi ology, interictal and ictal EEG findings, hippocampal atrophy on magnetic r esonance imaging (MRI) scan, and a seizure-free outcome after selective amy dalohippocampectomy. In both patients, seizures originated in the nondomina nt temporal lobe. We obtained accurate anatomic reference of rCBF changes v isible on SPECT by a special coregistration technique of MRI and SPECT. We used ictal SPECT studies in 10 patients with MTLE who had seizures without ictal vomiting as controls. Results: In the two patients with ictal vomiting, we found a significant hy perperfusion of the nondominant temporal lobe (inferior, medial, and latera l superior) and of the occipital region on ictal SPECT. In patients without ictal vomiting, on the contrary, these brain regions never were hyperperfu sed simultaneously. Conclusions: Ictal SPECT provides further evidence that activation of a com plex cortical network, including the medial and lateral superior aspects of the temporal lobe, and maybe the occipital lobes, is responsible for the g eneration of ictal vomiting.