The utility of measuring the corpus callosal angle (CA) for the diagnosis of idiopathic normal pressure hydrocephalus (INPH) was investigated. Three-dimensional magnetic resonance imaging (MRI) was performed in 34 INPH patients, 34 Alzheimer's disease (AD) patients, and 34 normal control (NC) subjects. Measurement of the CA on the coronal MR images of the posterior commissure perpendicular to the anteroposterior commissure plane was performed for all subjects. The CA of the INPH group (mean +/- SD, 66 +/- 14 degrees) was significantly smaller than those of the AD (104 +/- 15 degrees) and NC (112 +/- 11 degrees) groups. When using the threshold of the mean - 2SD value of the NC group (= 90 degrees), an accuracy of 93%, sensitivity of 97%, and specificity of 88% were observed for discrimination of INPH from AD patients. Measuring the CA helps in differentiating INPH patients from AD and normally aged subjects.
Background and Purpose-Hyperperfusion syndrome is a rare but potentially devastating complication after carotid endarterectomy (CEA). The aim of this study was to investigate whether preoperative measurement of cerebral vasoreactivity (CVR) and intraoperative measurement of internal carotid artery (ICA) flow could identify patients at risk for hyperperfusion after CEA. Methods-For 26 patients with unilateral ICA stenosis Ն70%, cerebral blood flow (CBF) and CVR were investigated before and 1 month after CEA, with resting and acetazolamide-challenge single-photon emission CT. CBF on the first postoperative day was also measured. ICA flow was measured before and after reconstruction by electromagnetic flowmeter during surgery. Results-Ipsilateral CBF on the first postoperative day significantly increased relatively (56.6Ϯ53.2%) as well as absolutely (37.9Ϯ8.8 to 57.7Ϯ18.0 mL/100 g per minute) in the reduced CVR group (CVR Ͻ12%) but not in the normal CVR group (CVR Ն12%) (10.3Ϯ15.5% and 40.6Ϯ7.9 to 43.9Ϯ5.7 mL/100 g per minute, respectively). One month later, this difference almost disappeared. Two patients showed ipsilateral CBF increase of Ն100%. A significant association of intracerebral steal with hyperperfusion (CBF increase Ն100%) on the first postoperative day was also observed. ICA flow increase after reconstruction significantly correlated with CBF increase on the first postoperative day in the reduced CVR group but not in the normal CVR group. The threshold of ICA flow increase for hyperperfusion was estimated to be 330 mL/min in the reduced CVR group. Conclusions-Single-photon emission CT with acetazolamide challenge and ICA flow measurement during surgery could identify patients at risk for hyperperfusion after CEA, in whom careful monitoring and control of blood pressure should be initiated even intraoperatively. (Stroke. 2001;32:1567-1573.)
Excellent results from multiple burr-hole operations for adult moyamoya disease are reported in this study. Ten patients had between one and four burr holes (mean 2.1) drilled in each hemisphere. In four patients new burr holes were added on the opposite side after depression of cerebral blood flow (CBF) was detected by follow-up single-photon emission computerized tomography imaging of the brain with N-isopropyl-p-[123I]iodoamphetamine. The postoperative follow-up period ranged from 6 to 62 months (mean 34.7 months). Beginning at 6 months postsurgery, angiograms disclosed rich neovascularization at 41 of 43 burr holes, first from the middle meningeal artery, then from the superficial temporal artery. Neovascularization did not occur at two burr holes at which there was subdural effusion and local cerebral atrophy, respectively. Progression of stenosis of the major vessels was seen in six patients. Moyamoya vessels were decreased at six sites in four patients. The CBF study revealed that the reactivity to acetazolamide improved in all six patients tested. Transient ischemic attacks disappeared in all six patients presenting with this symptom, and preoperative symptoms improved in both of the patients who presented with cerebral infarction and in both patients with intraventricular hemorrhage. There was no mortality or morbidity, and no new neurological deficits or rebleeding developed during the follow-up period. The authors strongly recommend the multiple burr- hole operation as the surgical treatment of choice for adult moyamoya disease because of its safety and effectiveness.
Voxel-based analysis showed a characteristic pattern of regional CBF reduction with frontal dominant or diffuse cerebral hypoperfusion accompanying severe hypoperfusion around the corpus callosum and Sylvian fissures with artifacts.
Aims: To investigate regional morphologic changes in idiopathic normal pressure hydrocephalus (INPH) based on diagnosis with INPH Guidelines using voxel-based morphometry. Method: Three-dimensional magnetic resonance imaging was performed in 34 INPH patients, who met probable INPH criteria, probable 34 Alzheimer disease patients, and 34 normal control subjects. Results: Statistical parametric mapping was used to conduct voxel-based morphometry analysis of the morphologic data and revealed enlarged ventricles and sylvian fissures and stenotic sulci of high convexity, especially in the precuneus in the INPH group, with decreased gray matter density in the insula, caudate and thalamus. Conclusion: In INPH, morphologic change occurs in the frontoparietal high convexity with ventricular dilatations, dilated sylvian fissures and tight sulci in the medial parietal lobes.
Background and Purpose-Hyperperfusion syndrome is a rare but disastrous complication after carotid endarterectomy (CEA). The aim of this study was to investigate the relationship between preoperative cerebral blood flow (CBF) abnormalities and postoperative hyperperfusion through the use of statistical brain mapping analysis. Methods-For 41 patients with unilateral carotid stenosis Ն70%, CBF and cerebral vasoreactivity (CVR) were investigated with resting and acetazolamide-challenge single photon emission CT before CEA. CBF 1 day after CEA was also measured. Three-dimensional stereotactic surface projection (3D-SSP) analysis of CBF changes was performed by use of a control database of 20 subjects. Results-Patients with reduced CVR (CVR Ͻ10%, nϭ15) were categorized into 2 groups based on the severity of CBF reduction relative to the control database by 3D-SSP analysis without normalization: type I (ipsilateral CBF decrease Ͻ20%, nϭ8) and type II (ipsilateral CBF decrease Ն20%, nϭ7). With thalamic normalization, the patients were also categorized into 2 groups: type A (ipsilateral Z score Յ2, nϭ10) and type B (ipsilateral Z score Ͼ2, nϭ5). Severe CBF reduction (Ն20% or Z score Ͼ2) was significantly associated with postoperative hyperperfusion (CBF increase Ն100%). However, 3D-SSP with thalamic normalization (Z score) demonstrated a higher predictive value (80%) and specificity (91%) for hyperperfusion than 3D-SSP without normalization (percent reduction) (57% and 73%, respectively). No patients with normal CVR (CVR Ն10%, nϭ26) demonstrated postoperative hyperperfusion. Conclusions-Objective evaluation of abnormalities of CBF and CVR with 3D-SSP could identify patients at risk for postoperative hyperperfusion.
A spontaneous dissecting aneurysm of the basilar artery is a rare disorder, usually presenting with ischemia rather than a subarachnoid hemorrhage (SAH). Two cases are described of a dissecting aneurysm of the basilar artery presenting with an SAH. Vertebral angiography revealed a double lumen to the basilar artery. Magnetic resonance (MR) imaging detected the intramural hematoma. One patient was treated conservatively, and the other underwent operative intervention with wrapping of the aneurysm. The usefulness of MR imaging in the diagnosis and the treatment options are discussed.
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