title: Benzodiazepine receptors and cerebral blood flow in partial epilepsy.
abstract: It was the aim of this study to compare benzodiazepine (Bz) receptor binding and cerebral perfusion in patients with partial epilepsy. Single photon emission tomography (SPET) studies with the flow-marker technetium 99m hexamethylpropylene amine oxine (99mTc-HMPAO) and with the 123I-labelled Bz-receptor ligand Ro 16-0154 (123I-Iomazenil) were performed in 12 patients with partial epilepsy, all with normal magnetic resonance imaging (MRI) and computed tomography (CT) scans. The SPET studies with 123I-Iomazenil were carried out 5 min and 2 h after injection. At 2 h the distribution of activity was very similar to the expected distribution of Bz-receptors in the human brain, known from positron emission tomography (PET) work and post-mortem studies. Early images showed a significantly higher tracer accumulation in the area of the basal ganglia, cerebellum, and naso-pharyngeal space. This finding is caused by non-specific binding and the contribution of the tracer in the blood pool in this phase. Also after 2 h p.i. of 123I-Iomazenil, 9 of the 12 patients showed a focal decrease of of Bz-receptor binding. Ten patients had focal flow abnormalities with 99mTc-HMPAO SPET. In 8 subjects impairment of flow was seen in sites of reduced 123I-Iomazenil uptake. 123I-Iomazenil is suitable for Bz-receptor mapping. In this series of patients, Bz-receptor mapping with SPET seems to offer no advantage over 99mTc-HMPAO in the detection of epileptic foci.
authors.affiliation: Department of Nuclear Medicine, University of Münster, Federal Republic of Germany.
authors.forename: P
authors.initials: P
authors.lastname: Bartenstein
authors.forename: A
authors.initials: A
authors.lastname: Ludolph
authors.forename: O
authors.initials: O
authors.lastname: Schober
authors.forename: G
authors.initials: G
authors.lastname: Lottes
authors.forename: K
authors.initials: K
authors.lastname: Scheidhauer
authors.forename: J
authors.initials: J
authors.lastname: Sciuk
authors.forename: H F
authors.initials: HF
authors.lastname: Beer
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004833:Epilepsy, Temporal Lobe / Q000000981:diagnostic imaging*; D005260:Female; D005442:Flumazenil / Q000031:analogs & derivatives; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D015609:Organotechnetium Compounds; D010091:Oximes; D011963:Receptors, GABA-A / Q000378:metabolism*; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D007457:Iodine Radioisotopes; D015609:Organotechnetium Compounds; D010091:Oximes; D011963:Receptors, GABA-A; D019690:Technetium Tc 99m Exametazime; D005442:Flumazenil; C063038:iomazenil