Dopamine D2 receptor status assessed by IBZM SPECT - A sensitive indicator for cerebral hypoxia
- Univ. of Munich (Germany); and others
The striatum is highly sensitive to tissue hypoxia. Thus, it may be suggested that cerebral hypoxia could affect the integrity of the striatal receptor system. Purpose of the current SPECT investigations with IBZM was to evaluate whether hypoxic conditions cause detectable changes in the D2 receptor status. 25 controls and 30 pts with history of cerebral hypoxia (resuscitation after cardiac arrest: n=19, CABG surgery under cardiopulmonary bypass: n=11) were investigated with SPECT 2h p.i. of 185 MBq I-123 IBZM. For semiquant, evaluation transverse slices corrected for attenuation were used to calculate striatal to frontal cortex (S/FC) ratios. In 13/19 pts with cerebral hypoxia due to cardiac arrest IBZM binding was severely reduced after successful resuscitation. 7 died, 5 were in a vegetative state, 1 remained severely disabled. In 6/19 S/FC ratios were normal/mildly reduced, 2 of them had a good outcome, 4 were moderatley disabled. In pts with CABG IBZM binding was preoperatively normal. After hypoxia due to cardiac surgery striatal S/FC ratios decreased slightly, persisting on this level even 6 months after surgery. Neuropsychological/psychiatric testing showed only minor or transient changes in this group of patients. The striatal D2 receptor status seems to be a sensitive indicator for cerebral hypoxia. After hypoxia due to cardiac arrest IBZM results well correlate (in contrast to morphological or SEP findings) with the clinical outcome and thus may serve as early predictor of the individual prognosis. The moderate decline in IBZM binding following CABG surgery suggests mild cerebral hypoxia despite of protective hypothermia. Sensitively indicating cerebral hypoxia changes in the D2 receptor status assessed by IBZM SPECT may serve as a valuable diagnostic tool for testing neuroprotective drugs or modified surgical techniques.
- OSTI ID:
- 441605
- Report Number(s):
- CONF-950603-; ISSN 0161-5505; TRN: 96:002093-0030
- Journal Information:
- Journal of Nuclear Medicine, Vol. 36, Issue Suppl.5; Conference: 42. annual meeting of the Society of Nuclear Medicine, Minneapolis, MN (United States), 12-15 Jun 1995; Other Information: PBD: May 1995
- Country of Publication:
- United States
- Language:
- English
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