ro-16-0154 and Carotid-Stenosis

The purpose of the present study was to determine whether preoperative cerebral blood flow (CBF) or cortical central benzodiazepine receptor binding potential as measured by brain perfusion or (123)I-iomazenil (IMZ) single-photon emission computed tomography (SPECT) imaging, respectively, can predict cognitive improvement after uncomplicated carotid endarterectomy (CEA).. Neuropsychological testing was performed preoperatively and after 1 month postoperatively in 140 patients who underwent CEA for unilateral internal carotid artery (ICA) stenosis (≥ 70%). Brain perfusion SPECT using N-isopropyl-p-[(123)I]-iodoamphetamine and IMZ SPECT was also performed before surgery. SPECT data were analyzed using a 3-dimensional stereotaxic region-of-interest template.. Fourteen patients (10%) showed improved cognitive function postoperatively. Logistic regression analysis demonstrated that, among the variables tested, low relative CBF in the cerebral hemisphere ipsilateral to surgery was significantly associated with postoperative cognitive improvement (95% confidence interval: 0.623-0.868; P = 0.0003). The combination of reduced relative CBF and moderately reduced relative uptake of IMZ identified development of postoperative cognitive improvement with 100.0% sensitivity, 84.9% specificity, a positive predictive value of 42.4%, and a negative predictive value of 100%. Further, in a subgroup of patients with reduced relative CBF and moderately reduced relative uptake of IMZ, the difference between these 2 values was significantly greater in patients with postoperative cognitive improvement than in those without (P < 0.0001).. The combination of preoperative CBF and cortical central benzodiazepine receptor binding potential as determined by SPECT can predict cognitive improvement after CEA.

Topics: Adult; Aged; Carotid Stenosis; Cerebrovascular Circulation; Cognition; Combined Modality Therapy; Endarterectomy, Carotid; Female; Flumazenil; Humans; Iodine Radioisotopes; Male; Middle Aged; Postoperative Care; Preoperative Care; Stereotaxic Techniques; Tomography, Emission-Computed, Single-Photon

Oxygen extraction fraction (OEF) is a key predictor of stroke recurrence in patients with symptomatic major cerebral arterial occlusive disease. The purpose of the present study was to compare central benzodiazepine receptor binding potential (BRBP) and cerebral blood flow (CBF) images on SPECT with OEF images on PET in patients with chronic unilateral middle cerebral artery (MCA) or internal carotid artery (ICA) occlusive disease.. OEF, CBF, and BRBP were assessed using (15)O PET and N-isopropyl-p-(123)I-iodoamphetamine and (123)I-iomazenil SPECT, respectively, in 20 healthy subjects and in 34 patients with unilateral MCA or ICA occlusive disease. All images were transformed into the standard brain size and shape by linear and nonlinear transformation using statistical parametric mapping for anatomic standardization. A region of interest (ROI) was automatically placed according to the arterial supply using a 3-dimensional stereotactic ROI template, and the ratio of the value in the affected side to that in the contralateral side was calculated in each image.. Among patients with occlusive disease, a significant positive correlation was observed between PET OEF and SPECT BRBP/CBF ratios in 3 cerebral cortical regions (r = 0.851, P < 0.0001, for anterior cerebral artery [ACA] ROI; r = 0.807, P < 0.0001, for MCA ROI; and r = 0.774, P < 0.0001, for posterior cerebral artery [PCA] ROI), but there were no correlations between these 2 parameters in the basal ganglia or the cerebellum. When an abnormally elevated PET OEF ratio was defined as a value greater than the mean + 2 SDs obtained in healthy subjects, sensitivity and specificity were, respectively, 100% and 96% for the ACA ROI, 100% and 89% for the MCA ROI, and 100% and 93% for the PCA ROI for the SPECT BRBP/CBF ratio for detecting an abnormally elevated PET OEF ratio.. BRBP/CBF images on SPECT correlate with OEF images on PET in a specific clinical setting-that is, in the cerebral cortex of patients with chronic unilateral MCA or ICA occlusive disease.

Topics: Adult; Aged; Arterial Occlusive Diseases; Basal Ganglia; Carotid Stenosis; Cerebellum; Cerebral Cortex; Cerebrovascular Circulation; Female; Flumazenil; Humans; Image Processing, Computer-Assisted; Infarction, Middle Cerebral Artery; Intracranial Arterial Diseases; Iofetamine; Magnetic Resonance Imaging; Male; Middle Aged; Oxygen Consumption; Oxygen Radioisotopes; Positron-Emission Tomography; Radiopharmaceuticals; Receptors, GABA-A; Tomography, Emission-Computed, Single-Photon

Topics: Biological Transport; Carotid Stenosis; Cerebral Cortex; Cerebral Revascularization; Cognition; Flumazenil; Humans; Male; Middle Aged; Oxygen; Tomography, Emission-Computed, Single-Photon

The purpose of the present study was to investigate whether resolution of crossed cerebellar hypoperfusion (CCH) and increase in (123)I-iomazenil (IMZ) uptake in the ipsilateral cerebral cortex after carotid endarterectomy (CEA) are associated with postoperative improvement of cognitive function.. Neuropsychological testing was performed preoperatively and after 1 postoperative month in 79 patients undergoing CEA for ipsilateral internal carotid artery stenosis (>or=70%). Brain perfusion single photon emission computed tomography (SPECT) using N-isopropyl-p-(123)I-iodoamphetamine and (123)I-IMZ SPECT were also performed before and after surgery. Data were analyzed using a three-dimensional stereotaxic region of interest template.. Seven patients (9%) showed improvement in postoperative cognitive function. All the 7 patients exhibited both postoperative increase in blood flow in the ipsilateral cerebral cortex and resolution of CCH. Five patients (6%) had a postoperative hemispheric increase in (123)I-IMZ uptake, and cognitive function improved in all of these 5 patients. Analysis by a receiver operating characteristic (ROC) curve was used to estimate the ability to discriminate between patients with and without postoperative cognitive improvement. The area under the ROC curve was significantly greater when analyzing the magnitude of postoperative resolution of CCH (0.991; 95% CI 0.984-1.001) or postoperative hemispheric increase in (123)I-IMZ uptake (0.981; 95% CI 0.972-0.999) when compared with the magnitude of postoperative increase in cerebral blood flow (0.929; 95% CI 0.886-0.971) (p < 0.05).. Resolution of CCH and increase in (123)I-IMZ uptake in the ipsilateral cerebral cortex after CEA is associated with postoperative improvement in cognitive function. These results may indicate that cognitive impairment is related to a state of potentially reversible central benzodiazepine receptor downregulation in the cortex in response to transient ischemic attack or minor stroke.

Topics: Adult; Afferent Pathways; Aged; Carotid Artery, Internal; Carotid Stenosis; Cerebellum; Cerebral Cortex; Cognition Disorders; Dominance, Cerebral; Down-Regulation; Endarterectomy, Carotid; Female; Flumazenil; Humans; Iodine Radioisotopes; Ischemia; Male; Middle Aged; Neuropsychological Tests; Receptors, GABA-A; ROC Curve; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Although cerebral hyperperfusion after carotid endarterectomy (CEA) often impairs cognitive function, MRI does not always demonstrate structural brain damage associated with postoperative cognitive impairment. The purpose of the present study was to determine whether postoperative cortical neural loss, which can be detected by (123)I-iomazenil single-photon emission CT, is associated with cerebral hyperperfusion after CEA and whether it correlates with postoperative cognitive impairment.. In 60 patients undergoing CEA for ipsilateral internal carotid artery stenosis (>70%), cerebral blood flow was measured using N-isopropyl-p-[(123)I]-iodoamphetamine single-photon emission CT before and immediately after CEA and on the third postoperative day. The distribution of benzodiazepine receptor binding potential in the cerebral cortex was assessed using (123)I-iomazenil single-photon emission CT before and 1 month after surgery and was analyzed using 3-dimensional stereotactic surface projection. Neuropsychological testing was also performed preoperatively and at the first postoperative month.. Post-CEA hyperperfusion and postoperative cognitive impairment were observed in 9 patients (15%) and 8 patients (13%), respectively. Post-CEA hyperperfusion was significantly associated with postoperative hemispheric reduction of benzodiazepine receptor binding potential (95% CIs, 2.765 to 148.804; P=0.0031). Post-CEA hyperperfusion (95% CIs, 1.183 to 229.447; P=0.0370) and postoperative hemispheric reduction of benzodiazepine receptor binding potential (95% CIs, 1.003 to 77.381; P=0.0496) were also significantly associated with postoperative cognitive impairment.. Cerebral hyperperfusion after CEA results in postoperative cortical neural loss that correlates with postoperative cognitive impairment.

Topics: Adult; Aged; Analysis of Variance; Carotid Stenosis; Cerebral Cortex; Cerebrovascular Circulation; Cerebrovascular Disorders; Cognition Disorders; Endarterectomy, Carotid; Female; Flumazenil; Humans; Iofetamine; Male; Middle Aged; Neurons; Neuropsychological Tests; Postoperative Complications; Radiopharmaceuticals; Stereotaxic Techniques; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed

A 70-year-old woman who experienced transient left hemiparesis had 90% stenosis of the right internal carotid artery. CT revealed small low-density areas in the subcortical frontal area. Baseline cerebral blood flow was reduced, and vasoreactivity was poor in the right frontoparietal area according to I-123 IMP brain SPECT with acetazolamide. The distribution of I-123 iomazenil was normal on the delayed SPECT image but reduced in the early SPECT image, mimicking baseline cerebral blood flow. The distribution of I-123 iomazenil SPECT on the delayed image reflected the normal binding potential of the benzodiazepine receptor and thus identified viable tissue in an area of severely reduced perfusion. These findings were confirmed by positron emission tomography.

Topics: Acetazolamide; Aged; Angiography, Digital Subtraction; Brain; Carotid Artery, Internal; Carotid Stenosis; Cerebrovascular Circulation; Female; Flumazenil; Humans; Iodine Radioisotopes; Oxygen Consumption; Radiopharmaceuticals; Receptors, GABA-A; Tomography, Emission-Computed; Tomography, Emission-Computed, Single-Photon

We report two patients with occlusive cerebrovascular disease who were examined by means of benzodiazepine receptor SPECT(BZR-SPECT) with 123I-iomazenil (IMZ) before extracranial-intracranial bypass surgery (EC/IC bypass). Preoperative low perfusion areas detected by cerebral blood flow SPECT (CBF-SPECT) were divided into two parts on BZR-SPECT images. In the low perfusion areas where the BZR were preserved, regional cerebral blood flow (rCBF) increased on postoperative CBF-SPECT, but where the BZR were not preserved, rCBF did not increase on postoperative CBF-SPECT. On visual inspection, the SPECT images of postoperative CBF-SPECT appeared similar to those of preoperative BZR-SPECT. For evaluation of the ischemic brain condition itself, instead of the cerebral metabolism, the distribution and activity of cerebral neurons indicated by BZR-SPECT with IMZ might be utilized.

Topics: Aged; Arterial Occlusive Diseases; Brain; Carotid Artery, Internal; Carotid Stenosis; Cerebral Arterial Diseases; Cerebral Infarction; Cerebral Revascularization; Flumazenil; Humans; Iodine Radioisotopes; Male; Middle Aged; Middle Cerebral Artery; Radiopharmaceuticals; Receptors, GABA-A; Tomography, Emission-Computed, Single-Photon; Tomography, X-Ray Computed; Treatment Outcome

We report a case of 61-year old man who was suffering from cerebrovascular disease with right hemiparesis and received I-123 iomazenil (IMZ) SPECT prior to carotid endoarterectomy. Severe stenosis of the right internal carotid artery and occlusion of the left middle cerebral artery (MCA) were revealed by cerebral angiography, and a hypoperfused area in left MCA territory and crossed cerebellar diaschisis (CCD) on I-123 IMP SPECT was demonstrated. In contrast, IMZ SPECT showed symmetric normal distribution. After the carotid endoarterectomy, the hypoperfused area in left MCA territory on IMP SPECT and hemiparesis had improved. It is thought that IMZ SPECT can be a useful tool for the prediction of improvement of cerebral perfusion and the clinical outcome.

Topics: Arterial Occlusive Diseases; Brain; Carotid Artery, Internal; Carotid Stenosis; Cerebral Arterial Diseases; Cerebral Infarction; Cerebrovascular Circulation; Endarterectomy, Carotid; Female; Flumazenil; Functional Laterality; Humans; Iodine Radioisotopes; Male; Middle Aged; Paresis; Radiopharmaceuticals; Tomography, Emission-Computed, Single-Photon; Treatment Outcome

Iodine-123-iomazenil (IMZ) is a SPECT ligand for central-type benzodiazepine receptors, which are located only on neurons. We evaluated the feasibility of using IMZ SPECT for identifying neuronal damage in patients with the chronic phase of thrombotic cerebral ischemia.. We studied 15 patients with angiographically-confirmed unilateral severe occlusive lesions (occlusion or > 70% stenosis) in the carotid system. IMZ SPECT images obtained 180 min after injection of 167-222 MBq IMZ were analyzed. The regional cerebral blood flow and perfusion reserve were evaluated for comparison with IMZ SPECT findings, using the split-dose 123I-iodoamphetamine (IMP) SPECT method, coupled with intravenous injection of 1 g acetazolamide. On both SPECT images, the count ratio of the affected to the nonaffected whole MCA territory (A/NA ratio) and of the contralateral to the ipsilateral cerebellar cortex (C/I ratio) were determined.. The A/NA ratio with IMZ was significantly higher than that with IMP (94.5% +/- 6.2% versus 91.4% +/- 6.6%, p < 0.005), although a significantly positive correlation was found between these two ratios (r = 0.854, p < 0.0001). The C/I ratio with IMP was decreased significantly in 5 patients compared with that in normal subjects, whereas the C/I ratio with IMZ was decreased in only 1 patient. There was no significant correlation between the A/NA ratio with IMZ and the perfusion reserve in the affected MCA territory. In 2 of 5 patients with a decreased A/NA ratio (<90%) with IMZ, decreased blood flow with preserved perfusion reserve and cerebral hemispheric atrophy were observed, which suggested the influence of neuronal loss due to chronic ischemia.. These findings indicate that IMZ SPECT, which provides new information regarding neuronal damage after ischemic insult to the brain, is useful for evaluating thrombotic cerebral ischemia.

Topics: Amphetamines; Brain; Brain Ischemia; Carotid Stenosis; Case-Control Studies; Cerebrovascular Circulation; Cerebrovascular Disorders; Feasibility Studies; Female; Flumazenil; Humans; Iodine Radioisotopes; Iofetamine; Magnetic Resonance Imaging; Male; Middle Aged; Tomography, Emission-Computed, Single-Photon