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Regional cerebral blood flow (rCBF) was assessed in 40 chronic male schizophrenic patients (20 medicated, 20 unmedicated) and 31 matched normal controls with Dynamic Single-photon Emission Computed Tomography (D-SPECT). Blind analyses of normalized color-coded tomograms revealed significant bifrontal and bitemporal rCBF deficits in the patient group. Frontal flow deficits were most prominent in paranoid patients (n = 21) and right temporal deficits were most prominent in nonparanoid patients (n = 19). These relative regional declines were observed within the context of significantly elevated hemispheric blood flow in schizophrenics compared with controls. Reduced left frontal rCBF was associated with neuropsychological impairment on the Wisconsin Card Sorting Test and Luria-Nebraska Battery. Increased hemispheric CBF was correlated with the presence of positive schizophrenic symptoms. Medication status was unrelated to rCBF. These findings demonstrate that hypofrontality has important implications for cognitive function in some schizophrenic individuals.

A 65-year-old man with well-defined crossed aphasia secondary to right cerebral infarction 10 years previously was studied for current language and cognitive abilities and regional cerebral blood flow (rCBF) during cognitive activation measured by single-photon emission tomography (SPECT). Reversed hemispheric lateralization was demonstrated by qualitative aspects of the patient's constructional deficits, dominant parietal lobe signs, and absence of the neglect syndrome. Language activation procedures during SPECT produced focal increases in rCBF to both frontal lobes with a phoneme detection task and to right temporal and parietal lobes with a math task. The authors stress the complexities of assessing brain/language mechanisms in vivo and demonstrate variabilities in rCBF during language activation dependent on task selection.

Myocardial imaging using technetium 99m stannous pyrophosphate (99mTc-PYP) has been utilized preoperatively and three to five days postoperatively to detect myocardial infarction in 48 patients undergoing aortocoronary bypass grafting, including 7 having valve replacement (5 aortic, 2 mitral) in addition to revascularization. In the total group of patients operated on there were 3 deaths (6%). Preoperatively, 26 patients had unstable angina and 10 had severe left main coronary artery disease. Eleven of the 48 (23%) were women. ECG and enzyme-proved infarctions occurred in 6 of the 48 patients (12%), but the addition of 99mTc-PYP myocardial imaging demonstrated scintigraphic evidence of infarction in 15 patients (31%), including 2 who died in the operating room. The 99mTc-PYP myocardial imaging technique, which has proved safe, simple, and relatively inexpensive in these patients, suggests that the incidence of infarction after coronary bypass operations is somewhat higher than has been previously recognized from just ECG and enzyme changes. This technique also has been of value in helping to exclude myocardial infarction in difficult clinical situations such as postoperative arrhythmias and the postpericardiotomy syndrome.