THE ANTERIOR AND POSTERIOR SELECTIVE TEMPORAL-LOBE AMOBARBITAL TESTS - ANGIOGRAPHIC, CLINICAL, ELECTROENCEPHALOGRAPHIC, PET, SPECT FINDINGS, AND MEMORY PERFORMANCE

The techniques, results, and problems of three types of selective temp oral lobe (TL) amobarbital procedures (balloon technique with temporar y occlusion of the internal carotid artery distal to the origin of the anterior choroidal artery (acha) [n = 19]; selective anterior cathete rization of the acha [n = 20]; and selective catheterization of the pe duncular P-2-segment of the posterior cerebral artery [n = 5]) are des cribed in a group of 40 patients with medically refractory complex par tial seizures of mesial TL origin. Selective amobarbital tests were ca rried out before surgery to predict the memory deficit after an intend ed selective amygdalohippocam pectomy. The effects of selective anaest hetization of TL were correlated with clinical data, pattern and durat ion of amobarbital induced EEG changes, and performance on verbal and nonverbal memory tasks measured during the test. In 4 patients the eff ect of selective amobarbital injection on regional and global metaboli sm was studied with F-18-FDG-PET, with the PET tracer being injected i ntravenously immediately after amobarbital. More recently in 2 patient s the vascular territory perfused by amobarbital in the acha test was studied with SPECT using (99m) Tc ECD injected immediately prior to th e amobarbital into the acha. Whereas the PET studies showed a rather w idespread and bilateral amobarbital-induced decrease of metabolism, th e SPECT studies confirmed the selective distribution of the tracer in the vascular territory of the acha, i.e., in amygdala and hippocampus. The comparison of selective TL, amobarbital test performance with pos toperative neuropsychological performance showed that the predictive v alue of this test is rather good for the postoperative verbal memory b ut underestimates postoperative nonverbal (''figural'') memory perform ance. (C) 1997 Academic Press.