Decreased density of GABA-A receptors in the left sensorimotor cortex in akinetic catatonia: investigation of in vivo benzodiazepine receptor binding
- Georg Northoffa,
- Reiner Steinkeb,
- Christian Czcervenkae,
- Reiner Krausee,
- Sven Ulrichc,
- Peter Danosa,
- Dieter Kropfd,
- HansJürgen Ottob,
- Bernhard Bogertsa
- aDepartment of Psychiatry, bDepartment of Nuclear Medicine, cDepartment of Clinical Pharmacology, dDepartment of Biometrics Otto-von-Guericke University of Magdeburg, Germany, ePsychiatric Clinic, Blankenburg, Germany
- Dr G Northoff, Department of Psychiatry, Otto-von-Guericke, University of Magdeburg, Leipziger Straβe 44, 39120 Magdeburg, Germany. Telephone 0049 391 6714234; fax 0049 391 6715223; emailGeorg.Northoff{at}Medizin.Uni-Magdeburg.de
- Received 7 October 1999
- Revised 5 May 1999
- Accepted 21 May 1999
Abstract
OBJECTIVES Catatonia is a psychomotor syndrome with concomittant akinesia and anxiety which both respond almost immediately to benzodiazepines such as lorazepam. The benzodiazepine receptor distribution was therefore investigated in akinetic catatonia with single photon emission tomography (SPECT) using iodine-123-iomazenil (123 I Iomazenil).
METHODS Ten akinetic catatonic patients, 10 psychiatric controls (similar age, sex, medication, and underlying psychiatric diagnosis but without catatonic syndrome), and 20 healthy controls were investigated with SPECT 2 hours after injection of 123 I Iomazenil. To exclude potential effects of cerebral perfusion (r-CBF) r-CBF was additionally investigated with Tc-99mECD SPECT.
RESULTS Catatonic patients showed significantly lower iomazenil binding and altered right-left relations in the left sensorimotor cortex compared with psychiatric (p<0.001) and healthy (p<0.001) controls. In addition, there was significantly lower r-CBF in the right lower prefrontal and parietal cortex in catatonia whereas in the left sensorimotor cortex no differences in r-CBF between groups were found. Catatonic motor and affective symptoms showed significant correlations (p<0.05) with benzodiazepine binding in the left sensorimotor cortex as well as with right parietal r-CBF.
CONCLUSIONS Reduced iomazenil binding suggests decreased density of GABA-A receptors in the left sensorimotor cortex in akinetic catatonia. In addition to reduced GABA-A receptor density in the left sensorimotor cortex the parietal cortex seems to be involved in pathophysiology of catatonic symptoms. It is concluded that, considering results from correlation analyses, both emotional and motor symptoms in catatonia seem to be closely related to left sensorimotor and right parietal alterations.
