11C-flumazenil positron emission tomography demonstrates reduction of both global and local cerebral benzodiazepine receptor binding in a patient with Stiff Person Syndrome.
Stiff Person Syndrome (SPS) is a rare autoimmune disorder associated with antibodies against glutamic acid decarboxylase (GAD-Ab), the key enzyme in gamma-aminobutyric acid synthesis (GABA). In order to investigate the role of cerebral benzodiazepinereceptor binding in SPS, we performed [(11)C]flumazenil (FMZ) positron emission tomography (PET) in a female patient with SPS compared to nine healthy controls. FMZ is a radioligand to the postsynaptic central benzodiazepine receptor which is co-localized with the GABA-A receptor. In the SPS patient, we found a global reduction of cortical FMZ binding. In addition, distinct local clusters of reduced radiotracer binding were observed. These data provide first in vivo evidence for a reduced postsynaptic GABA-A receptor availability which may reflect the loss of GABAergic neuronal inhibition in SPS.
Dept. of Neurology, University of Cologne, Kerpener Str. 62, 50924, Cologne, Germany. norbert.galldiks@uk-koeln.de
Norbert
N
Galldiks
Alexander
A
Thiel
Cathleen
C
Haense
Gereon R
GR
Fink
Rüdiger
R
Hilker
D000368:Aged; D001667:Binding, Competitive; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D002250:Carbon Radioisotopes; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D004292:Dominance, Cerebral / Q000502:physiology; D005260:Female; D005442:Flumazenil; D006801:Humans; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D011963:Receptors, GABA-A / Q000378:metabolism*; D016750:Stiff-Person Syndrome / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology
D002250:Carbon Radioisotopes; D011963:Receptors, GABA-A; D005442:Flumazenil