Conflict of Interest A patent application for the use of GABAB receptor as a diagnostic test has been filed by Dr. Dalmau. The rest of the authors have no conflicts of interest.
Perfusion 123IMP-SPECT shows reversible abnormalities in GABAB receptor antibody associated encephalitis with normal MRI
Version of Record online: 31 JUL 2012
©2011 The Authors. Brain and Behavior published by Blackwell Publishing Ltd.
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Brain and Behavior
Volume 1, Issue 2, pages 70–72, November 2011
How to Cite
Ohta, K., Seki, M., Dalmau, J. and Shinohara, Y. (2011), Perfusion 123IMP-SPECT shows reversible abnormalities in GABAB receptor antibody associated encephalitis with normal MRI. Brain and Behavior, 1: 70–72. doi: 10.1002/brb3.14
- Issue online: 31 JUL 2012
- Version of Record online: 31 JUL 2012
- Received: 29 March 2011; Revised: 14 July 2011; Accepted: 27 July 2011
- limbic encephalitis;
- cerebral perfusion;
- cerebral cortex
A new subtype of autoimmune encephalitis associated with antibodies against GABAB receptor was recently identified. Although immune-mediated functional abnormalities are suggested for the pathogenesis, functional brain imaging such as perfusion SPECT has not been documented. A 62-year-old woman with anti-GABAB receptor associated encephalitis underwent 123I-IMP SPECT in the beginning and after methylprednisolone pulse therapy. Three-dimensional stereotactic surface projection analysis was used to evaluate the cortical distribution of perfusion abnormality. The patient presented with clinical features of subacute limbic encephalitis. Antibodies to GABAB receptor were identified in her serum and cerebrospinal fluid (CSF), but no tumor was detected. Despite normal magnetic resonance imaging (MRI) findings, the first SPECT revealed hypoperfusion of the frontal, parietal and medial temporal lobes, as well as thalamus, and cerebellum. These areas are known to contain high levels of GABAB receptors. In contrast, the SPECT revealed hyperperfusion in the motor strip and left temporal lobe, which are areas related to some of the patient's symptoms, including seizures, orolingual dyskinesia, and Wernicke aphasia. After treatment with pulses of methylprednisolone, the neuropsychiatric symptoms resolved and the SPECT findings showed substantial improvement in most of these regions. In conclusion, the findings suggest that immunotherapy improved the cortical dysfunction mediated by GABAB receptor antibodies.