Semiquantitative regional cerebral blood flow evaluation using 123I-IMP SPECT in a case showing transient ischemic attack caused by putaminal hemorrhage

Volume of infarction and blood flow in cerebral embolism

The value of measuring asymmetry of cerebral perfusion semiquantitatively by single-photon emission computed tomography (SPECT) correlated with measuring the volume of infarction on computed tomography (CT) was evaluated in cerebral embolism. Eighteen patients with acute cerebral embolism (mean age: sixty-nine years) were evaluated. Ten were diagnosed as having middle cerebral artery (MCA) occlusion, 3 as having MCA branch occlusion, and 4 as having unilateral and 1 as having bilateral internal carotid occlusion. The infarct volume was measured, summing up the area of infarction on CT, at 8.5 days, mean time after onset. Outcomes of the patients were classified into three groups: good, fair, or dead, judged by the consequences one month after onset. Regional cerebral blood flow (rCBF) was measured in 9 of 10 surviving patients at one month, mean time after onset, by 123[iodine N-isopropyl-p-iodoamphetamine (IMP) SPECT. Semiquantitative rCBF index of asymmetry (AI) was evaluated from four regions of brain cortex. Eleven patients with < 300 mL infarct and 7 with > or = 300 mL infarct showed a significant difference of outcome with infarct volumes (P < 0.01). The mean AI value in patients with < 150 mL infarct was 31% while it was 52% with > or = 150 mL infarct (P < 0.039). There were significant linear correlations between mean AI values and the volumes of infarction or infarct/brain volume ratios (P < 0.034 or P < 0.018). The significant correlations of the AI values with the volumes of infarction suggest that the measured asymmetry of perfusion evaluated by SPECT could reflect the ultimate tissue damage and residual intact brain volume after cerebral embolism.

Cerebellar diaschisis in pontine infarctions: a report of five cases

We evaluate regional cerebral and cerebellar perfusion to prove the occurrence and follow the persistence of crossed cerebellar diaschisis in infratentorial pontine infarction. Six consecutive patients exhibiting mild hemiparetic symptoms or a heavy feeling in the head (mean age 65 years; four women, two men) and diagnosed as having pontine infarction by magnetic resonance imaging were subjected to evaluation. Lesions due to infarction were located at the upper basis pontis in five patients and the upper tegmentum pontis in one, and medially at the paramedian portion in four and laterally in two. Regional cerebral and cerebellar perfusion was evaluated semiquantitatively by iodine-123 N-isopropyl-p-iodoamphetamine (IMP) single-photon emission tomography (SPET); this was done during the acute stage in five cases (mean time after onset: 0.7 months) and during the chronic stage in three (mean time after onset: 14.8 months). Four patients had two examinations during their clinical courses. For semiquantitative evaluation of perfusion, an asymmetry index was calculated for each region of interest, set symmetrically in regions of the cerebral cortex and cerebellum in both hemispheres. Significant asymmetry (P < 0.01) in cerebellar perfusion, which was reduced in the contralateral (n = 4) or ipsilateral (n = 1) cerebellar hemisphere, was demonstrated semiquantitatively in four cases during the acute stage and in one during the chronic stage, as compared with normal controls (n = 5, mean age 61 years). This asymmetry continued to the chronic stage (6.5 and 33.0 months) in two cases, while no patient showed any significant asymmetries in cerebral perfusion in any region of interest in either SPET study.(ABSTRACT TRUNCATED AT 250 WORDS)

Cortical blood flow and cognition after extracranial-intracranial bypass in a patient with severe carotid occlusive lesions. A three-year follow-up study

The long-term effect of extra-intracranial arterial bypass on cerebral circulation was examined. Cortical blood flow and cognitive ability were evaluated pre- and up to 3 years post-bypass in a 58-years-old man with severe carotid occlusive lesions, who presented with 3 transient cerebral ischaemic attacks which resulted in mental deterioration over 3 years. Regional cerebral blood flow (rCBF) was evaluated pre- and up to 33 months post-bypass by 123Iodine N-isopropyl-p-iodoamphetamine (IMP) single-photon emission CT (SPECT). Mental abilities were evaluated before and up to 33 months after surgery by the Hasegawa's dementia rating scale (HDRS). Pre-operatively, cerebral angiography showed left carotid siphon occlusion and hypoplastic stenosis of left anterior cerebral artery with collaterals from the anterior communicating artery. CT and MRI showed left temporo-parietal borderzone infarction and an enhanced T 1 lesion by gadolinium-DTPA at left periventriculum. rCBF showed extensive hypoperfusion in left anterior-parieto-temporal-cortex. HDRS scores deteriorated apparently on days 3, 5, which recovered gradually on days 8, 10, 75 after onset of mental deterioration. A bypass was performed 4 months after onset. rCBF showed gradual recovery in the left anterior-parietal cortex up to 33 months after bypass. Semiquantitative rCBF showed gradual decreases of regional asymmetry after the bypass. HDRS scores returned to their maximum up to 37 months after onset. Three-year follow-up shows improved cortical rCBF and cognition after the bypass.