The effect of spontaneous reperfusion on metabolic function in early human cerebral infarcts

Abstract

Twelve patients were studied within 48 hours of stroke using positron emission tomography to determine cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CMRO2), oxygen extraction fraction, cerebral blood volume, cerebral pH (CpH), and cerebral metabolic rate for glucose (CMRGlc), the last calculated using published normal rate constants (CMRGlc[N]) and those for severe ischemia. In these studies, a cortical region of severe ischemia (I) was outlined, its metabolic and perfusion properties evaluated, and its length measured. The contralateral uninvolved cortical rim (C) in these patients and the cortical rim in 5 older normal patients were used for comparison. The length of region I correlated with the neurological deficit measured independently by a clinical scoring method. The 12 patients fell into two groups: Group I (8 patients), whose CBF in I was 9.3 +/- 2.5 ml/100 gm/min (mean +/- SEM) and was in every patient lower than that in C (33.1 +/- 2.2), and Group 2 (4 patients), whose CBF in I was 42.1 +/- 8.5 ml/100 gm/min and was in every case higher than that in C (28.2 +/- 1.5). In Group I, region I showed a CMRGlc(N)/CMRO2 ratio of 0.22 +/- 0.06 and a CpH of 6.83 +/- 0.06. In Group 2, the same ratio in the region I was 0.58 +/- 0.09 and the CpH was 7.12 +/- 0.05. The CMRGlc (N)/CMRO2 ratio for the contralateral hemisphere was comparable in the two groups. Our data suggest that, within 48 hours of the clinical onset of stroke, the ischemic cortex is already reperfused in one third of patients. Those ischemic regions with persistent hypoperfusion appear acidotic, whereas in the reperfused regions, despite evidence of an increased CMRGlc/CMRO2 ratio, acidosis is not evident. The implications of these findings for therapies proposed in acute human cerebral ischemia are discussed.

Evaluation of the 11CO2 Positron Emission Tomographic Method for Measuring Brain pH. II. Quantitative pH Mapping in Patients with Ischemic Cerebrovascular Diseases

“…Decreased CBF and aci dotic pH were observed in eight stroke cases within 48 h of onset (Hakim et al , 1987), and alkalotic pH with increased eBF and decreased OEF were re ported in subacute cases (10--34 days after onset) (Syrota et aI., 1983(Syrota et aI., , 1985.…”

“…Regions of relative tissue alkalosis were observed in patients with brain tumors (Brooks et aI., 1986), and in patients with stroke 10-19 days after onset (Syrota et aI ., 1983). More recently, regions of tissue acidosis were observed in stroke patients within 48 h of onset (Hakim et al ., 1987). Vol.…”

Arterial Spin Labeling Perfusion Magnetic Resonance Imaging Performed in Acute Perinatal Stroke Reveals Hyperperfusion Associated With Ischemic Injury

“…In nearly one third of adults with AIS of the middle cerebral artery territory, the occlusion clears spontaneously within 24 hours. 29,30 Using positron emission tomography to determine CBF and metabolism, Hakim et al 31 found increased ipsilesional CBF with associated increase in glucose metabolism within 48 hours of stroke onset in one third of patients. In our sample, patients with normal or low perfusion in the infarct tended to have a longer delay between stroke onset and ASL acquisition.…”

19F Imaging of Cerebral Blood Oxygenation in Experimental Middle Cerebral Artery Occlusion: Preliminary Results

“…Unlike the signal as ymmetry in the retia, the collaterals opened during occlusion per sist following clip release, perhaps owing to the presence of an endogenous vasodilator such as aci dosis (Lassen, 1966;Yamaguchi et a!., 1971). These persistent channels are likely to constitute the basis for the postischaemic hyperaemia encountered in experimental and clinical stroke (Sundt and Waltz, 1971;Olsen et a!., 1981;Hakim et a!., 1987).…”