(11)C-Flumazenil positron emission tomography demonstrates reduction of both global and local cerebr
June 27th, 2008 | by admin |(11)C-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.
Galldiks N, Thiel A, Haense C, Fink GR, Hilker R.
Dept. of Neurology, University of Cologne, and the Max-Planck Institute for Neurological Research, Germany, norbert.galldiks@uk-koeln.de.