Cerebral infarctions with negative CT scans.

Abstract

A selection of 181 stroke patients with a negative scan on computed tomography (CT) was studied. The CT scans were done at least 24 h after ictus. 39 of these cases were excluded because of a cortically located pathological uptake on a concomitant radionuclide scan. The 142 remaining cases were compared with patients who had CT-verified central and cortical infarctions. The CT-negative infarctions showed a profile of risk factors similar to the one in CT-verified central infarctions. It differed markedly, however, from the clinical picture of the cortically located infarctions. Thus, the subjects with a negative CT and isotope scan had a lower percentage of carotid lesions of hemodynamic significance (studied by isotope angiography) and a lower frequency of atrial fibrillation. There was also a much higher percentage of pure motor hemipareses among the CT-negative infarctions. This suggests that a great part of CT- and gamma camera-negative cerebrovascular infarctions may be suspected to be small lacunae, which are beyond the resolution capacity of the CT scan.