Female sex as a risk factor for the growth of asymptomatic unruptured cerebral saccular aneurysms in elderly patients.

OBJECT: The prevalence of patients with asymptomatic unruptured intracranial aneurysms (UIAs) increases with the advancing age of the general population. The goal of the present study was to identify risk factors for the growth of UIAs detected with serial MR angiography (MRA) in patients 70 years of age or older. METHODS: This prospective study enrolled 79 patients (age range 70-84 years) with 98 UIAs. Patients were followed up every 4 months, including an assessment of the aneurysm diameter and morphological changes on MRA, neurological status, and other medical conditions. Aneurysm growth was categorized into two different patterns on the basis of the MRA findings: 1) maximum increase in aneurysm diameter of 2 mm or more; and 2) obvious morphological change, such as the appearance of a bleb. RESULTS: The mean duration of follow-up was 38.5 months (250.2 patient-years). Aneurysm rupture did not occur, but aneurysm growth was observed in 8 aneurysms (8 patients) during the study period. Univariate analysis showed that female sex, patient age ≥ 75 years, and an aneurysm location in the internal carotid artery (ICA) or middle cerebral artery (MCA) were associated with aneurysm growth (p = 0.04, p = 0.04, and p < 0.001, respectively). Multivariate analysis demonstrated that female sex was the only independent predictor of aneurysm growth (p = 0.0313, OR 2.3, 95% CI 1.3-30.2). CONCLUSIONS: Female sex is an independent risk factor for the growth of UIAs in elderly patients. In addition, an age ≥ 75 years and aneurysm location in the ICA or MCA are characteristics that may warrant additional attention during follow-up imaging.

Appetite loss may be induced by lower serum ghrelin and higher serum leptin concentrations in subarachnoid hemorrhage patients.

BACKGROUND: Patients with aneurysmal subarachnoid hemorrhage (SAH) typically develop appetite loss. However, the mechanisms regulating appetite are not understood. Ghrelin and leptin, both of which signal nutritional status and energy storage levels to the hypothalamus, are essential elements of the appetite system. Thus, the goal of this study was to investigate the relationship between appetite and ghrelin and leptin concentrations in patients with SAH. METHODS: Blood plasma or serum profiles and appetite status were measured in 19 patients with SAH who underwent aneurysmal clipping within 48 hours of SAH onset. Appetite status was measured using dietary oral calorie intake. All outcome variables were measured at an early (day 3) and late (day 8) time point after SAH onset (day 0). RESULTS: Of the 19 patients studied, 6 (31.6%) showed lower dietary oral calorie intake at the late time point than at the early time point. In these patients with appetite loss, plasma hemoglobin (P < 0.02), albumin (P < 0.01), glucose (P < 0.01), plasma insulin (P < 0.04), and serum ghrelin (P < 0.03) concentrations were lower at the late time point than at the early time point. Serum leptin was higher at the late time point than at the early time point (P < 0.02). CONCLUSION: In SAH patients, appetite loss may be induced by lower serum ghrelin and higher serum leptin concentrations resulting from high plasma glucose and insulin levels due to a catecholamine surge following SAH.

Adrenomedullin concentration in the cerebrospinal fluid is related to appetite loss and delayed ischemic neurological deficits after subarachnoid hemorrhage.

OBJECTIVE: Adrenomedullin (AM) is secreted into the cerebrospinal fluid (CSF) from the choroid plexus and regulates appetite. Adrenomedullin concentration in the CSF is elevated 7-10 days after the onset of aneurysmal subarachnoid hemorrhage (SAH). The aim of the present study was to determine whether CSF AM concentration is related to appetite and delayed ischemic neurological deficits (DIND) after SAH. METHODS: Adrenomedullin concentration in the CSF, blood plasma profile, and appetite status were measured in 22 patients with SAH who underwent aneurysmal clipping within 48 hours of SAH onset. Appetite status was measured using dietary oral calorie intake and self-reported appetite level. All outcome variables were measured at an early (Day 3) and late (Day 8) time point after SAH onset (Day 0). RESULTS: Dietary oral calorie intake (P = 0·02), self-reported appetite level (P = 0·03), hemoglobin (P = 0·01), albumin (P = 0·03), glucose (P = 0·01), and insulin (P = 0·03) levels were lower at the late time point than at the early time point. Cerebrospinal fluid adrenomedullin concentration was higher at the late time point than at the early time point (P = 0·0007). There was a significant negative correlation between AM concentration and dietary oral calorie intake (r = -0·478, P = 0·024) and self-reported appetite level (r = -0·454, P = 0·033) at the late time point. Six patients (27%) developed DIND. Adrenomedullin concentration at the late time point was significantly higher in patients who developed DIND than in patients who did not (P = 0·02). CONCLUSIONS: Cerebrospinal fluid adrenomedullin concentration 8 days after SAH onset is related to appetite loss and DIND.

Improvement and impairment in cognitive function after carotid endarterectomy: comparison of objective and subjective assessments.

Objective and subjective assessments of postoperative improvement and impairment in cognition were prospectively compared in patients who underwent carotid endarterectomy (CEA). Each patient underwent subjective cognitive assessment by a neurosurgeon and the patient's next of kin, and neuropsychological testing consisting of five test scores within 7 days before surgery and between 1 and 2 months after surgery. Of 213 patients studied, 24 (11%), 166 (78%), and 23 (11%) patients were defined as having subjectively improved, unchanged, and impaired cognition, respectively, following surgery. In all neuropsychological tests, differences in test scores between the two tests (postoperative test score - preoperative test score) significantly differentiated patients with subjectively improved, unchanged, and impaired cognition after surgery. Receiver operating characteristic analysis showed that the cut-off point for the differences in neuropsychological test scores in detecting subjective improvement and impairment in cognition after surgery was identical to mean +2 standard deviations (SDs) and mean -2 SDs, respectively, of the control value obtained from normal subjects. Of 27 patients with differences in neuropsychological test scores more than the upper cut-off point and 26 patients with differences in neuropsychological test scores less than the lower cut-off point in one or more neuropsychological tests, 24 (89%) and 23 (88%) exhibited subjectively improved and impaired cognition, respectively, after surgery. The present study indicates that neuropsychological test scores reflect the subjective assessment of postoperative change in cognition, and can detect subjective improvement and impairment in cognition after CEA using the optimal cut-off points for the test scores.

Hemorrhagic infarction at 33 days after birth in a healthy full-term neonate.

Intraparenchymal hemorrhage in the full-term neonate rarely occurs more than 2 weeks after birth, and its definitive cause remains unclear. In the present report, a case of a patient with intraparenchymal hemorrhage occurring 33 days after birth is described. Histological examination of the brain tissue obtained during hematoma evacuation through craniotomy showed hemorrhagic infarction. Patent foramen ovale may have been present and this may have led to spontaneous paradoxical cerebral embolism followed by hemorrhagic infarction.

Cognitive function and anxiety before and after surgery for asymptomatic unruptured intracranial aneurysms in elderly patients.

BACKGROUND: The prevalence of patients with asymptomatic unruptured intracranial aneurysms (UIAs) will likely increase as the general population ages. The goal of the present study was to prospectively assess cognitive function and anxiety before and after surgical repair of asymptomatic UIAs in patients ≥ 70 years. METHODS: A total of 28 patients ≥ 70 years with UIAs underwent cognitive testing using the Wechsler Adult Intelligence Scale-Revised, Wechsler Memory Scale (WMS), and the Rey-Osterrieth Complex Figure test (ROCF) 1 month before and 1 month after surgery. All patients also underwent anxiety testing at these time points using the State-Trait Anxiety Inventory. RESULTS: Group-rate analysis demonstrated that the performance intelligence quotient (IQ) and ROCF recall trial scores were significantly increased postoperatively, whereas there were no postoperative differences in verbal IQ, WMS, and ROCF copy trial scores. State anxiety scores were significantly decreased postoperatively, but there was no change in trait anxiety scores. Furthermore, a significant negative correlation was observed between changes in state anxiety scores and preoperative verbal IQ, performance IQ, and WMS. None of the patients developed postoperative cognitive functional impairments as demonstrated by event-rate analysis. CONCLUSIONS: Surgical treatment of UIAs does not impair cognitive function and results in improvement in state anxiety in elderly patients.

Mechanical characteristics and surface elemental composition of a Yasargil titanium aneurysm clip after long-term implantation.

The mechanical properties of titanium-alloy aneurysm clips after long-term implantation in the human cranium are unclear. The characteristics of a Yasargil titanium aneurysm clip were evaluated after long-term implantation for 12 years in a patient with a cerebral aneurysm. The closing forces of the retrieved clip before and after implantation were approximately equal. The bending test showed no differences between the retrieved and control clips. Titanium oxide and calcium were identified on the surface of the retrieved clip, which indicated the formation of corrosion-resistant layers. Titanium-alloy clips retain their mechanical properties in the human cranium for a long time.

Prediction of cerebral hyperperfusion after carotid endarterectomy using middle cerebral artery signal intensity in preoperative single-slab 3-dimensional time-of-flight magnetic resonance angiography.

OBJECTIVE: Cerebral hyperperfusion after carotid endarterectomy (CEA) occurs in patients with preoperative impairments in cerebral hemodynamics. Signal intensity of the middle cerebral artery (MCA) on single-slab 3-dimensional time-of-flight magnetic resonance angiography (MRA) can assess hemodynamic impairment in the cerebral hemisphere. The purpose of the present study was to determine whether the signal intensity of the MCA on preoperative MRA could identify patients at risk for cerebral hyperperfusion after CEA. METHODS: The signal intensity of the MCA ipsilateral to CEA on preoperative MRA was graded according to the ability to visualize the MCA in 81 patients with ipsilateral internal carotid artery stenosis (>or=70%). Cerebral blood flow was also quantified using single-photon emission computed tomography before and immediately after CEA and on the third postoperative day. RESULTS: Cerebral hyperperfusion immediately after CEA (cerebral blood flow increase >or=100% compared with preoperative values) was observed in 10 patients. Multivariate analysis revealed that only reduced signal intensity of the MCA was significantly associated with the development of postoperative cerebral hyperperfusion (95% confidence interval, 1.015-1.401; P = 0.0319). When the reduced signal intensity of the MCA on MRA was defined as an impairment in cerebral hemodynamics, MRA grading resulted in 100% sensitivity and 63% specificity, with a 28% positive predictive value and a 100% negative predictive value for the development of post-CEA hyperperfusion. Hyperperfusion syndrome developed on the fourth and sixth postoperative days in 2 of the 10 patients who exhibited hyperperfusion immediately after CEA. CONCLUSION: Signal intensity of the MCA, as assessed by this simple MRA method, may identify patients at risk for post-CEA cerebral hyperperfusion.

Application of fenestrated aneurysm clip for incomplete clamping of the common carotid artery during carotid endarterectomy: technical note.

Complete occlusion of the common carotid artery with blood vessel forceps may be prevented by hard atherosclerotic plaque during carotid endarterectomy. Incomplete clamping can be recognized via insertion of an elastic catheter, connected to a pressure transducer, into the common carotid artery. Application of a straight fenestrated clip parallel to the clamp avoids the plaque and occludes the vessel more distal to the fulcrum of the clamp, achieving complete arterial occlusion without applying excessive closing force on the artery.

Preoperative single-slab 3D time-of-flight magnetic resonance angiography predicts development of new cerebral ischemic events after carotid endarterectomy. Clinical article.

OBJECT: Preoperative impairment of cerebral hemodynamics predicts the development of new cerebral ischemic events after carotid endarterectomy (CEA), including neurological deficits and cerebral ischemic lesions on diffusion weighted MR imaging. Furthermore, the signal intensity of the middle cerebral artery (MCA) on single-slab 3D time-of-flight MR angiography (MRA) can assess hemodynamic impairment in the cerebral hemisphere. The purpose of the present study was to determine whether, on preoperative MR angiography, the signal intensity of the MCA can be used to identify patients at risk for development of cerebral ischemic events after CEA. METHODS: The signal intensity of the MCA ipsilateral to CEA on preoperative MR angiography was graded according to the ability to visualize the MCA in 106 patients with unilateral internal carotid artery stenosis (>or=70%). Diffusion weighted MR imaging was performed within 3 days of and 24 hours after surgery. The presence or absence of new postoperative neurological deficits was also evaluated. RESULTS: Cerebral ischemic events after CEA were observed in 16 patients. Reduced signal intensity of the MCA on preoperative MR angiography was the only significant independent predictor of postoperative cerebral ischemic events. When the reduced MCA signal intensity on preoperative MR angiography was defined as an impairment in cerebral hemodynamics, MR angiography grading resulted in an 88% sensitivity and 63% specificity, with a 30% positive- and a 97% negative-predictive value for the development of postoperative cerebral ischemic events. CONCLUSIONS: Signal intensity of the MCA on preoperative single-slab 3D time-of-flight MR angiography is useful for identifying patients at risk for cerebral ischemic events after CEA.

Comparison of postoperative cognitive function in patients undergoing surgery for ruptured and unruptured intracranial aneurysm.

BACKGROUND: Patients with SAH often experience cognitive decline. Previous studies used normal volunteers, published normal test values, and orthopedic patients as controls to identify factors for postoperative cognitive decline. The present study excluded the effects of surgery by comparing cognitive function after surgical repair in patients with aneurysmal SAH and patients with unruptured intracranial aneurysm. METHODS: This study recruited 117 patients with SAH due to ruptured aneurysm and 39 patients with incidentally found unruptured intracranial aneurysms. The cognitive test battery consisted of the Japanese translation of the WAIS-R, the Japanese translation of the WMS, and the recall trial of the ROCF. Postoperative neuropsychological test scores for the patients with SAH and control subjects were compared using group-rate and event-rate analysis. The relationship between clinical variable and postoperative cognitive decline in the patients with SAH was evaluated by univariate analysis using the Mann-Whitney U test or chi(2) test. RESULTS: Group-rate analysis showed that the WAIS-R and ROCF scores were significantly lower in the SAH group than in the control group. Event-rate analysis demonstrated that the incidence of cognitive decline in the patients with SAH (73 [62.4%] of the 117 patients) was significantly higher than that in the control subjects (12 [30.8%] of 39 patients). The Hunt and Hess grade was significantly higher in patients with postoperative cognitive decline. CONCLUSION: The cognitive function after SAH was significantly correlated with Hunt and Hess grade on admission when using patients with postoperative unruptured intracranial aneurysm as the control group.

Postoperative cortical neural loss associated with cerebral hyperperfusion and cognitive impairment after carotid endarterectomy: 123I-iomazenil SPECT study.

BACKGROUND AND PURPOSE: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: Cerebral hyperperfusion after CEA results in postoperative cortical neural loss that correlates with postoperative cognitive impairment.

Early post-ischemic hyperemia on transcranial cerebral oxygen saturation monitoring in carotid endarterectomy is associated with severity of cerebral ischemic insult during carotid artery clamping.

BACKGROUND AND OBJECTIVE: In animal models, the magnitude of early post-ischemic hyperemia tends to correlate with the duration and intensity of prior ischemic insult. The aim of this study was to determine whether early post-ischemic hyperemia in human brain during carotid endarterectomy (CEA) is associated with the severity of cerebral ischemic insult during clamping of the internal carotid artery (ICA). METHODS: Transcranial cerebral oxygen saturation using near-infrared spectroscopy was monitored intraoperatively in 171 patients undergoing CEA for ipsilateral ICA stenosis (>70%) to assess the intensity of cerebral hemispheric ischemia during ICA clamping and the magnitude of early post-ischemic hyperemia after ICA declamping. RESULTS: Early post-ischemic hyperemia peaked within 3 minutes after ICA declamping and resolved at 20 minutes after ICA declamping. A significant correlation was observed between the magnitude of early post-ischemic hyperemia and the intensity of cerebral ischemia (r=0.697; p<0.0001). Eight patients recovered from anesthesia with a new minor neurological deficit on the side contralateral to the CEA (4.7%). Analysis by receiver operating characteristics (ROC) curve was used to estimate the ability to discriminate between patients with and without post-operative development of new neurological deficits. Area under the ROC curve was significantly greater when analysing the magnitude of early post-ischemic hyperemia (1.00; 95% CI: 0.99-1.00) when compared with the intensity of cerebral ischemia (0.93; 95% CI: 0.89-0.98) (p<0.01). CONCLUSION: Early post-ischemic hyperemia in CEA is correlated with the severity of cerebral ischemic insult during clamping of the ICA.

Preoperative cerebrovascular reactivity to acetazolamide measured by brain perfusion SPECT predicts development of cerebral ischemic lesions caused by microemboli during carotid endarterectomy.

PURPOSE: The aim of the present study was to determine whether preoperative cerebrovascular reactivity (CVR) to acetazolamide measured by quantitative brain perfusion single-photon emission computed tomography (SPECT) predicts development of cerebral ischemic lesions on postoperative diffusion-weighted magnetic resonance imaging (DWI) that are caused by microemboli during carotid endarterectomy (CEA). MATERIALS AND METHODS: One hundred and fifty patients with ipsilateral internal carotid artery stenosis (>70%) underwent CEA under transcranial Doppler monitoring of microembolic signals (MES) in the ipsilateral middle cerebral artery (MCA). Preoperative CVR to acetazolamide was measured using [(123)I]N-isopropyl-p-iodoamphetamine SPECT, and region of interest (ROI) analysis in the ipsilateral MCA territory was performed using a three-dimensional stereotaxic ROI template. DWI was performed within 3 days before and 24 h after surgery. RESULTS: Twenty-six patients (17.3%) developed new postoperative ischemic lesions on DWI. Logistic regression analysis demonstrated that, among the variables tested, a high number of MES during carotid dissection (95% CIs, 1.179 to 1.486; P < 0.0001) and preoperative reduced CVR to acetazolamide (95% CIs, 0.902 to 0.974; P = 0.0008), which were significantly associated with the development of new postoperative ischemic lesions on DWI. In 47 patients with MES during carotid dissection, the combination of number of MES during carotid dissection and CVR to acetazolamide identified development of new postoperative ischemic lesions on DWI with a positive predictive value of 100% or zero. CONCLUSIONS: Preoperative CVR to acetazolamide measured by quantitative brain perfusion SPECT predicts development of cerebral ischemic lesions on postoperative DWI that are caused by microemboli during CEA.

Mechanical and surface properties of Yasargil Phynox aneurysm clips after long-term implantation in a patient with cerebral aneurysm.

This study evaluated the mechanical properties and the surface elemental composition of Yasargil Phynox aneurysm clips implanted for 10 years in a patient with cerebral aneurysm. Two Yasargil Phynox aneurysm clips implanted 10 years previously to treat a ruptured vertebral artery aneurysm were retrieved when the regrown and ruptured aneurysm was repaired with a new aneurysm clip. Two new Yasargil aneurysm clips were used as controls. Measurements of closing force, bending strength, and the elemental composition of the clip surface were performed. The closing force of the retrieved clips was similar or greater compared to the force before implantation. The bending test showed that the elastic limit and 0.2% proof load of the retrieved clip were higher than those of the unused clip, whereas the ultimate load of the retrieved clip was similar to that of the unused clip. The elemental concentration of Cr oxide on the surface of the retrieved clips was almost the same as that on the unused clips. The present study demonstrated that Yasargil Phynox aneurysm clips retain their mechanical properties and surface elemental composition in vivo for a long time, which indicates that Yasargil aneurysm clips will remain reliable in patients for extended periods.

Intraoperative microemboli and low middle cerebral artery blood flow velocity are additive in predicting development of cerebral ischemic events after carotid endarterectomy.

BACKGROUND AND PURPOSE: Microemboli generated during dissection of the carotid arteries in patients undergoing carotid endarterectomy result in postoperative cerebral ischemic events. The purpose of this study was to determine whether these events correlate with middle cerebral artery blood flow velocity. METHODS: One hundred sixty-three patients with ipsilateral internal carotid artery stenosis (>70%) underwent carotid endarterectomy under transcranial Doppler monitoring of mean blood flow velocity and microembolic signals in the ipsilateral middle cerebral artery. RESULTS: Logistic regression analysis of several variables demonstrated that only middle cerebral artery mean blood flow velocity during carotid dissection was significantly associated with new postoperative neurological deficits in patients with microembolic signals during carotid dissection (95% CI, 1.069 to 1.528; P=0.0072). The combination of low middle cerebral artery mean blood flow velocity (or=10 during carotid dissection resulted in improved specificity and positive predictive value for the development of new postoperative neurological deficits when compared with either criterion used alone. CONCLUSIONS: Intraoperative microemboli and low middle cerebral artery mean blood flow velocity are additive in predicting the development of cerebral ischemic events after carotid endarterectomy.

Magnetic resonance imaging in patients with cerebral hyperperfusion and cognitive impairment after carotid endarterectomy.

OBJECT: Cerebral hyperperfusion after carotid endarterectomy (CEA) impairs cognitive function and is often detected on cerebral blood flow (CBF) imaging. The purpose of the present study is to investigate structural brain damage seen on magnetic resonance (MR) images obtained in patients with cerebral hyperperfusion and cognitive impairment after CEA. METHODS: One hundred and fifty-eight patients with ipsilateral internal carotid artery stenosis (> or = 70%) underwent CEA. Neuropsychological testing was performed preoperatively and at the 1st postoperative month. Cerebral blood flow was measured using single-photon emission computed tomography before, immediately after, and 3 days after surgery. Magnetic resonance imaging was performed before and 1 day after surgery. In patients with post-CEA hyperperfusion (defined as a CBF increase > or = 100% compared with preoperative values) on CBF imaging, MR images were also obtained on the 3rd postoperative day, the day on which hyperperfusion syndrome developed, and 1 month after the operation. RESULTS: The incidence of postoperative cognitive impairment was significantly higher in patients with post-CEA hyperperfusion on CBF imaging (12 [75%] of 16 patients) than in those without (6 [4%] of 142 patients; p < 0.0001). Only 1 of 5 patients with cerebral hyperperfusion syndrome developed reversible brain edema in the cerebral hemisphere ipsilateral to the CEA on MR images obtained on the day hyperperfusion syndrome occurred. However, postoperative cognitive impairment developed in all 5 patients with cerebral hyperperfusion syndrome regardless of the presence or absence of new lesions on MR images. In addition, postoperative cognitive impairment developed in 5 (45%) of 11 patients with asymptomatic cerebral hyperperfusion on CBF imaging despite the absence of new lesions on any postoperative MR images. CONCLUSIONS: Although cerebral hyperperfusion syndrome after CEA sometimes results in reversible brain edema visible on MR imaging, postoperative cerebral hyperperfusion -- even when asymptomatic -- often results in impaired cognitive function without structural brain damage on MR imaging.

Concentration of matrix metalloproteinase-9 in the jugular bulb during carotid endarterectomy correlates with severity of intraoperative cerebral ischemia.

BACKGROUND: Matrix metalloproteinase (MMP)-9 targets major components of the basal lamina of cerebral blood vessels and is a biochemical marker of blood-brain barrier disruption. The goal of this study was to determine whether plasma concentrations of MMP-9 in the jugular bulb during carotid endarterectomy (CEA) correlate with severity of intraoperative cerebral ischemia. METHODS: In 41 patients undergoing CEA for ipsilateral internal carotid artery (ICA) stenosis, plasma samples for measurement of MMP-9 concentration were intraoperatively obtained from a venous catheter inserted into the ipsilateral jugular bulb. Transcranial cerebral oxygen saturation using near-infrared spectroscopy was also monitored intraoperatively to assess the severity of the ischemic insult during ICA clamping. RESULTS: The MMP-9 concentrations were significantly higher after ICA declamping than before ICA clamping (p = 0.0023). A strong linear correlation was observed between the severity of the ischemic insult during carotid clamping and the increase in MMP-9 levels after ICA declamping (r = 0.776; p < 0.0001). At the postoperative neurological assessment, 3 patients showed transient minor neurological deficits. The MMP-9 level in the jugular bulb after ICA declamping was increased in patients with postoperative transient neurological deficits relative to those without. CONCLUSIONS: The concentration of MMP-9 in the jugular bulb during CEA correlates with the severity of intraoperative cerebral ischemia.

Significance of postoperative crossed cerebellar hypoperfusion in patients with cerebral hyperperfusion following carotid endarterectomy: SPECT study.

PURPOSE: Cerebral hyperperfusion after carotid endarterectomy (CEA) results in cerebral hyperperfusion syndrome and cognitive impairment. The goal of the present study was to clarify the clinical significance of postoperative crossed cerebellar hypoperfusion (CCH) in patients with cerebral hyperperfusion after CEA by assessing brain perfusion with single-photon emission computed tomography (SPECT). METHODS: Brain perfusion was quantitatively measured using SPECT and the [(123)I]N-isopropyl-p-iodoamphetamine-autoradiography method before and immediately after CEA and on the third postoperative day in 80 patients with ipsilateral internal carotid artery stenosis (>or=70%). Postoperative CCH was determined by differences between asymmetry of perfusion in bilateral cerebellar hemispheres before and after CEA. Neuropsychological testing was also performed preoperatively and at the first postoperative month. RESULTS: Eleven patients developed cerebral hyperperfusion (cerebral blood flow increase of >or=100% compared with preoperative values) on SPECT imaging performed immediately after CEA. In seven of these patients, CCH was observed on the third postoperative day. All three patients with hyperperfusion syndrome exhibited cerebral hyperperfusion and CCH on the third postoperative day and developed postoperative cognitive impairment. Of the eight patients with asymptomatic hyperperfusion, four exhibited CCH despite resolution of cerebral hyperperfusion on the third postoperative day, and three of these patients experienced postoperative cognitive impairment. In contrast, four patients without postoperative CCH did not experience postoperative cognitive impairment. CONCLUSIONS: The presence of postoperative CCH with concomitant cerebral hyperperfusion reflects the development of hyperperfusion syndrome. Further, the presence of postoperative CCH in patients with cerebral hyperperfusion following CEA suggests development of postoperative cognitive impairment, even when asymptomatic.