Cerebral Blood Flow In Patients Research Articles

Influence of hydroxylethyl starch infusions on cerebral blood flow in patients with severe traumatic brain injury

The aim of the study was to evaluate the effects of hydroxylethyl starch (HES) solutions in patients with severe brain injury dependently of cerebral blood flow (CBF) type.

Comparison of SPECT findings and neuropsychological sequelae in carbon monoxide and organophosphate poisoning

Abnormal regional cerebral blood flow in patients with acute carbon monoxide (CO) and organophosphate (OP) poisoning was examined using 99m Tc-hexamethylpropylene amine oxime (HMPAO) brain single photon emission computed tomography (SPECT) in fourteen patients. We evaluated the predictive significance of acute phase brain SPECT findings for long-term neuropsychological sequelae. Changes were found in the frontal, temporal, parietal lobes within the first week after both types of poisoning. The distribution of the hypoperfused cerebral areas as demonstrated by 99m Tc-HMPAO imaging was similar in the two groups during the acute phase. Neuropsychological sequelae developed in five patients poisoned with OP and six with CO. Patients who had SPECT findings heterogeneously or in the temporal or frontal lobes displayed disorientation. Those with fronto-parietal and frontal lobe changes displayed mental confusion. Parkinsonism also was observed in patients with parieto-occipital, parietal and frontal lobe lesions. The distribution of these lesions appears to predict the long term sequelae of these poisonings, though additional studies with larger numbers of patients are needed to confirm the role of SPECT imaging in both OP and CO poisonings.

Regional cerebral blood flow in patients with sickle cell disease: study with single photon emission computed tomography

Neurological complications have been reported in patients with sickle-cell disease (SCD) using positron emission tomography (PET), magnetic resonance imaging (MRI), and computed tomography (CT), but not with single photon emission computed tomography (SPECT). The objective of this study was to investigate brain perfusion in the patients with SCD using SPECT after technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO), was administered and compare the findings with those of demography, physical examination, MRI and hematological profile. The study involved 21 patients (12 males, 9 females, age at study 8-45 years) who were known to be having SCD for a duration of at least 5 years. The patients were not in acute crisis and had normal neurological assessments with no known history of stroke or transient ischemic episode or previous abnormal CT or MRI brain scan, and were right-handed. The brain SPECT was performed after intravenous injection of 740 MBq (20 mCi) 99mTc-HMPAO in adults or an appropriate dose in pediatric patients. The scans were visually interpreted by two nuclear medicine physicians and a decision was reached by consensus. An MRI done 3 months later was interpreted by a radiologist. The demographic data and hematological profile were obtained from the medical records of the patients. Of the 21 patients, 7 (age 11-22 years) had brain perfusion deficit mostly in the frontal lobe either alone or in combination with temporal and/or parietal lobe. The MRI was abnormal in 2 patients. The brain perfusion deficit was not associated with the demographic data of the patients or hematological profiles. The findings show that SPECT was useful in detecting brain perfusion deficit in SCD patients, and such an early detection may be clinically useful in the subsequent follow-up of such patients, since it is known that cerebral perfusion deficit can lead to silent infarct and/or overt stroke, and affect cognitive skills.

Effectiveness of treatment with donepezil hydrochloride and changes in regional cerebral blood flow in patients with Alzheimer's disease

The objective of this study was to elucidate the relationship between the effects of donepezil hydrochloride (donepezil) and cerebral blood flow, and to evaluate the usefulness of cerebral blood flow imaging in assessing and predicting treatment effectiveness. The subjects were 29 outpatients (12 men and 17 women; age 50-82 years; mean age 69.2 years), who had received a diagnosis of Alzheimer's disease (AD). Efficacy was evaluated before donepezil administration; after 1 month, 3 months, and 6 months of drug administration; and at 1 year after completion of administration using the Japanese version of the Alzheimer's disease assessment scale-cognitive subscale (ADAS-cog), as a measure of cognitive function. The ADAS-cog has been frequently used to evaluate cognitive function in AD patients. Patients whose ADAS-cog scores improved by 3 or more points during the observation period were classified as responders, and those with no improvement were classified as nonresponders. (123)I-IMP was used for single photon emission computed tomography cerebral blood flow scintigraphy. On the basis of ADAS-cog score improvement, 22 of the 29 patients were responders (7 men and 15 women; age 50-82 years; mean age 69.0 years) and seven were nonresponders (5 men and 2 women; age 61-80 years; mean age 70.0 years). The results indicate that a difference in cerebral blood flow responsiveness after 1 month of treatment distinguishes responders from nonresponders. After 1 month, blood flow was significantly decreased in all regions of nonresponders, whereas significant increases in blood flow were seen in the anterior frontal lobe and parietal lobe of responders. At that time point, blood flow in the basal ganglion differed significantly between the two groups, indicating that this difference in responsiveness after 1 month of treatment may distinguish responders from nonresponders. In cognitive function testing, the group that exhibited a complete response showed improvement primarily in parameters reflecting frontal lobe function. Complete responders also showed significantly greater blood flow increases in the basal ganglion and thalamus early during the treatment period. This indicates that the drug responsiveness of the basal ganglion and thalamus affects frontal lobe function and distinguishes complete responders from patients who do not exhibit such a response.

Assessment of alterations in regional cerebral blood flow in patients with hypothyroidism due to Hashimoto’s thyroiditis

The aim of this study was to assess regional cerebral blood flow (rCBF) using detailed semiquantitative analysis of Technetium-99m hexamethylpropyleneamine (HMPAO) brain single-photon emission computerized tomography (SPECT) in patients with hypothyroidism due to autoimmune thyroiditis. Twenty patients (mean age: 42+/-9 yr) and 12 control subjects (mean age: 35.4+/-8.5 yr) were included in this study. The corticocerebellar rCBF ratios were obtained from 52 cerebral areas on 6 transaxial slices. By using control group rCBF ratios, lower reference values (RLV) (average ratio -2 SD) were calculated and the regions below RLV having an rCBF ratio were considered as abnormal decrease (hypoperfused) areas. Significant reduced rCBF rates were measured for 15 (29%) cortical regions for the patient group. The areas in which significant reduced rCBF were demonstrated in the patient group were as follows: a) in the right hemisphere: superior frontal (slice 1 and 2), inferior frontal (slice 1), anterior temporal (slice 1 and 2), precentral gyrus (slice 1 and 2), postcentral gyrus (slice 1 and 2), and parietal cortex; b) in the left hemisphere: superior frontal (slice 1 and 2), inferior frontal (slice 1), caudate nucleus, and parietal cortex. The hypoperfusion was calculated in 154 (14%, 94 right and 60 left) cortical regions out of 1040 regions in the patient group. These findings indicate that the alteration of rCBF in patients with hypothyroidism due to Hashimoto's thyroiditis before T4 therapy can be demonstrated with brain SPECT. Additionally, the degree of rCBF abnormalities could be determined with brain SPECT in patients with hypothyroidism due to Hashimoto's thyroiditis with or without neurologic or psychiatric symptoms.

Cerebral blood flow in patients with diffuse axonal injury – examination of the easy Z‐score imaging system utility

To evaluate the utility of easy Z-score imaging system (eZIS) in 27 diffuse axonal injury (DAI) cases. Twenty-seven DAI patients were examined with an magnetic resonance imaging (MRI) T2* sequence and with eZIS (seven women, 20 men; age range, 19-35 years; median age: 26.6 years). In this investigation, we excluded patients who exhibited complications such as acute subdural hematoma, acute epidural hematoma, intracerebral hematoma, or brain contusion. We examined the neuropsychological tests and correlated with findings from MRI/eZIS. Furthermore, we evaluated the degree of ventricular enlargement in the bifrontal cerebroventricular index (CVI). Patients were divided into two groups: the enlargement group (bifrontal CVI > 35%, 12 patients) and the non-enlargement group (bifrontal CVI < 35%, 15 patients). All of the patients showed cognitive deficits as observed from the neuropsychological test results. Fifteen out of 27 patients by MRI T1/T2 weighted images and fluid attenuated inversion recovery (FLAIR), 22 out of 27 patients by MRI T2* weighted images and 24 out of 27 patients by eZIS showed abnormal findings. In MRI T2* weighted imaging, the white matter from the frontal lobe, corpus callosum, and brainstem showed abnormal findings. With eZIS, 22 patients (81.5%) showed blood flow degradation in the frontal lobe, and 12 patients (44.4%) in cingulate gyrus. In the enlargement group, Functional Independence Measure, Mini-Mental State Examination, Verbal IQ (VIQ)/Full Scale IQ (FIQ), Trail Making Test-B (TMT-B), and Non-paired of Miyake Paired Test were significantly lower. Amongst 12 patients without ventricular enlargement who had no abnormal findings in MRI T1/T2 weighted images and FLAIR, abnormal findings were detectable in seven patients with MRI T2* weighted imaging and to 10 patients with eZIS. Results of the MRI examination alone cannot fully explain DAI frontal lobe dysfunction. However, addition of the eZIS-assisted analysis derived from the single photon emission computed tomography (SPECT) data enabled us to understand regions where blood flow was decreased, i.e., where neuronal functions conceivably might be reduced.

Comparaison de quatre méthodes d’évaluation des modifications de la perfusion cérébrale en tomoscintigraphie

Introduction We compared four different methods to assess changes in cerebral blood flow in patients with normal pressure hydrocephalus using cerebral ECD SPECT before and after injection of acetazolamide. Material and methods Eleven patients underwent cerebral SPECT before and after injection of 1 g of acetazolamide using a 99mTc-ECD split-dose protocole with a first injection of 370 MBq and a second of 1100 MBq. After reconstruction of volumes with Neurogam ® (Segami) software, we compared visual analysis to semi quantitative analysis provided by Neurogam software, ratios methods and parametric analysis under SPM99 and SPM2. Results Visual analysis is immediate but frequently misleading. The contribution of Neurogam depends on the reader's skill and may be significant for non expert readers. The manual semi-automatic method is tedious and its results depend on the choice of the areas of interest and reference necessary for activity normalization. At last, the automatic method carried out by SPM is reliable for population analysis, but its efficiency for individual analysis remains to be evaluated.

Cerebral blood flow increase in cancer patients by applying cervical spinal cord stimulation

Generally, high-grade gliomas and head and neck tumors have decreased loco-regional blood flow resulting in reduced delivery of chemotherapy and oxygen, as well as an increases in radiation resistance to radiotherapy. The aim of this study was to analyze the effect of cervical spinal cord electrical stimulation (cSCS) on cerebral blood flow in patients with those tumors. We have evaluated 27 cancer patients with 12 with high grade gliomas and 15 with advanced head and neck tumors, who had cSCS devices placed after tumor diagnoses and before the commencement initiating of radio-chemotherapy. They were 12 high grade gliomas and 15 advanced head and neck tumors. Before and after cSCS, cerebral blood flow was assessed bilaterally by transcranial Doppler. During cSCS there was a significant (p<0.001) increase in systolic (mean > 22%) and diastolic (> 29%) blood-flow velocities in both, healthy and tumor middle cerebral arteries. The analyses by subgroup of tumors showed similarly significant outcomes findings. The results suggest that neuro-stimulation spinal cord electrical stimulation can increase cerebral blood flow in cancer patients. The implication is that this technique could be useful in modifying locoregional ischemia in brain tumors thus improving the outcomes of after radio-chemotherapy. Further research is in progress to confirm the advantages of the technique.

Cerebrovascular reactivity in depressed patients without vascular risk factors

Introduction Cerebrovascular reactivity (CVR) seems to be gaining importance as a prognostic factor for stroke risk. CVR reflects the compensatory dilatory capacity of cerebral arterioles to a dilatory stimulus; this mechanism plays an important role in maintaining a constant cerebral blood flow. Evaluating factors that influence CVR will help prevention or early detection of cerebrovascular disease (CVD). In this study we aimed to measure the CVR in vascular-risk free depressed individuals so as to evaluate the effect depression has on CVR and hence its role as a stroke risk factor. Methods Using acetazolamid (ACZ) stimulation, CVR was assessed with a transcranial Doppler ultrasound in 25 non-smoking depressed patients (average age: 48.48 ± 14.40) and in 25 healthy non-smoking controls (average age: 46.76 ± 13.69) by calculating the difference between the maximal mean blood flow velocity at baseline and the maximal mean blood flow velocity after ACZ stimulation. Results Basal Cerebral Blood flow in Patients was 50.6 cm/s (SD: 11.6) versus controls 52.80 cm/s (SD: 12.70) whereas after stimulation maximal blood flow velocity was 72.64 cm/s (SD: 15.75) in patients versus 80.20 cm/s (SD: 18.43) in controls. In an analysis of covariance we found that cerebrovascular reactivity was significantly reduced in the vascular-risk free depressed sample. Age had a significant influence whereas gender did not. Discussion Major Depression appears to decrease cerebrovascular reactivity supporting the idea of increased risk for stroke in depressed patients. The mechanisms leading to this phenomenon and its subtle subgroup differences should be further investigated.

Treatment of post-dialytic orthostatic hypotension with an inflatable abdominal band in hemodialysis patients

The purpose of this study was to ascertain whether abdominal compression with an inflatable abdominal band, a device we developed, improved post-dialytic orthostatic hypotension (OH) in hemodialysis (HD) patients. Twenty-five chronic HD patients with intractable post-dialytic OH were recruited. Post-HD changes in systolic blood pressure (DeltaSBP) in the supine and standing positions were compared in the patients, measured with or without the use of the band. The study showed DeltaSBP after HD without the band was significantly greater than that measured before HD (-36.1+/-18.2 vs -13.1+/-16.8 mm Hg; P<0.0001). DeltaSBP after HD with the band was reduced significantly in comparison to DeltaSBP after HD without the band (-19.4+/-21.2 vs -36.1+/-18.2 mm Hg; P<0.002). Use of the band did not cause an elevation in SBP in the supine position (149.0+/-29.6 vs 155.4+/-25.7 mm Hg); however, it did increase SBP upon standing (129.6+/-27.3 vs 117.2+/-22.6 mm Hg; P<0.05). Eight patients in whom an increase in SBP of 25 mm Hg or more was achieved with the band were classified as responders. Ejection fraction was significantly higher (76.4+/-11.1 vs 61.9+/-13.6%; P<0.02) and atrial natriuretic peptide concentration significantly lower (27.9+/-22.0 vs 68.9+/-47.5 pg/ml; P<0.02) in responders than in non-responders. We conclude that the abdominal band was effective for overcoming post-dialytic OH, without elevating supine SBP in some patients.

Is it possible to predict the long-term response to venlafaxine with the use of biological markers and psychophysiological methods?

Introduction The present study investigated whether it is possible to predict the medium term response to venlafaxine using biological markers and psychophysiological methods. Material Fourteen (14) patients aged 21–60 years suffering from Major Depression according to DSM-IV were included in the study. Methods The SCAN v 2.0 and the IPDE were used to assist clinical diagnosis. Patients were investigated with electrooculogram (EOG), Pattern-Reversal Visual Evoked Potentials (PR-VEPs), Dexamethasone Suppression Test (DST), d-fenfluramine Challenge Test, and brain Single Photon Emission Tomography (SPECT). Venlafaxine 150–225 mg per os daily was administered. The follow-up period was 2 years. Statistical analysis Chi-square test and ANOVA were used for the analysis of data. Results There was a lower left globus pallidus regional cerebral blood flow in patients with better response. On the contrary, chronic patients were closer to normality. Discussion The results of the current study provide preliminary evidence concerning our ability to predict response to venlafaxine and to understand its way of action.

Management of physiological variables in neuroanaesthesia: maintaining homeostasis during intracranial surgery

The recent literature on the perioperative maintenance of cerebral homeostasis was reviewed. Several studies focused on the regulation of cerebral blood flow in patients without intracranial disease; therefore, further studies in neurosurgical patients are needed. High intracranial pressure and brain swelling can be controlled by the choice of anaesthetic agents, and also by optimal positioning of the patient. The use of positive end-expiratory pressure may impair cerebral blood flow, but the effects of positive end-expiratory pressure seem to depend on the respiratory system compliance. The international multicenter study failed to show any benefit from intraoperative hypothermia in patients with subarachnoid hemorrhage; similarly, the results on corticosteroid therapy in head-injured patients are discouraging. Corticosteroid therapy has prompted studies on the control of blood glucose levels. While tight glycemic control has been recommended, it can have untoward effects manifested as cerebral metabolic stress. From the clinical point of view, the recent research has added only little to the knowledge on the management of physiological parameters in neurosurgery. More adequately powered studies focusing in specific problems, and having a meaningful aim relative to outcome, are needed also in neuroanaesthesia.

Noninvasive Measurement of Intracranial Pressure and Cerebral Blood Flow in Patients with Hydrocephalus

Noninvasive Measurement of Intracranial Pressure and Cerebral Blood Flow in Patients with Hydrocephalus

Noninvasive Measurement of Intracranial Pressure and Cerebral Blood Flow in Patients with Hydrocephalus: A Clinical Predictive Tool

Noninvasive Measurement of Intracranial Pressure and Cerebral Blood Flow in Patients with Hydrocephalus: A Clinical Predictive Tool

Transdermal nitroglycerin lowers BP and maintains cerebral blood flow in patients with recent stroke,

Transdermal nitroglycerin lowers BP and maintains cerebral blood flow in patients with recent stroke,

5 Effect of gastric electrical stimulation on cerebral blood flow in patients with gastroparesis

Gastric electrical stimulation (GES) of the stomach is an effective treatment of nausea and vomiting in patients with gastroparesis (Gastroenterology 125: 421–28, 2003). However, the mechanism is unclear, as many patients show resolution of nausea and vomiting yet continue to exhibit delayed gastric emptying. This suggests GES may relieve symptoms by activation of a mechanism involving the central nervous system. The purpose of this study was to determine whether GES produces changes in the brain evidenced by alterations in cerebral blood flow on positron emission tomography (PET). Eight patients (6 females, 2 males) ranging in age from 27 to 68 yr were studied. Each patient had profound gastroparesis and had undergone implantation of a GES device from 6 to 57 mo (mean 25) prior. All patients studied had significant improvement in symptoms of nausea, vomiting, and early satiety after implantation of the GES device. PET scans were performed after an overnight fast and with the GES device in the ON mode. Each patient was then given an IV injection 30–40 mCi O15‐water. After PET image data were obtained the GES device was then turned to the OFF mode for 30 min. The O15‐water injection and PET image scanning was then repeated. Respective PET images obtained with the GES device in the ON and OFF modes were then analyzed and compared. PET images were analyzed using SPM2 (Statistical Parametric Mapping), implemented using Matlab 6.5 Prior to statistical analysis all images were realigned to correct motion movements and spatially normalized into the MNI standard template to remove inter‐subject anatomical variability. Spatially normalized images were smoothed using an isotropic Gaussian kernel with 16 mm FWHM to increase the signal‐to‐noise ratio. Statistical comparisons between ON and OFF scans were performed on a voxel‐by‐voxel basis using paired t statistics. Significant voxels were superimposed on a high resolution MRI template provided by SPM2, thus allowing anatomical identification. Significant increases in blood flow during GES were noted in the middle, superior, and inferior gyri, in the middle occipital and middle temporal gyri, and in the amygdala and parahippocampal gyri (P &lt; 0.05 for each locus, respectively). Likewise, significant decreases in blood flow during GES were noted in the pre and post central gyri, in the anterior cingulate gyri, and in the caudate head and putamen (p &lt; 0.05 for each locus, respectively).Conclusions: 1) GES produces significant alterations in cerebral blood flow in gastroparetic patients; 2) central nervous system mechanisms during GES may be responsible for the relief of nausea and vomiting in these patients.

Alteration of regional cerebral blood flow in patients with chronic pain —Evaluation before and after epidural spinal cord stimulation—

Chronic pain is defined as intractable pain caused by abnormal pain transmission or impairment of the pain control system per se. Alteration of regional cerebral blood flow (rCBF) is known to occur under the presence of pain stimulation. Epidural spinal cord stimulation (SCS) is occasionally effective in relieving the symptom. The aim of the current study is to investigate the alteration of rCBF in baseline condition and to find the association between the rCBF change and the efficacy of SCS in chronic pain. A total of 18 patients underwent Tc-99m-HMPAO SPECT before and after SCS. Analysis with three-dimensional stereo-tactic surface projections (3D-SSP) with stereo-tactic extraction estimation (SEE) software was adopted to evaluate the rCBF. We assessed the extent score of the abnormal region in each segment (rate of the coordinates with a Z-value that exceeds three kinds of threshold value 2.0, 2.5 and 3.0 in all coordinates within a segment). According to the therapeutic response defined by visual analogue scale, we categorized patients into two groups, the good responder (GR) group (n=12) and poor responder (PR) group (n=6). In the analysis, we compared the extent score in the following two conditions. (1) Comparison between the PR group and normal control group under both baseline condition and after SCS. (2) Comparison between the GR group and normal control group under both baseline condition and after SCS. (1) In the PR group, increased rCBF was observed in left thalamus, bilateral precuneus and bilateral cerebellum under the baseline condition. After SCS, the range of these increased rCBF areas localized but remained. Decrease of rCBF was noted in bilateral subcallosal gyrus, superior temporal gyrus (STG) and bilateral anterior cingulate gyrus (ACG). They localized after SCS, but remained. (2) In the GR group, increased rCBF areas were noted in bilateral precuneus and bilateral cerebellum under the baseline condition. After SCS, they localized in bilateral precuneus but those of bilateral cerebellum remained. Decreased rCBF area was noted in bilateral subcallosal gyrus, STG and bilateral ACG under the baseline. After SCS, they localized in bilateral subcallosal gyrus and bilateral STG. In contrast, they enlarged in bilateral ACG. Chronic pain patients demonstrated abnormal rCBF distribution on both baseline and post SCS conditions. Increased rCBF of thalamus and precuneus under both conditions in the PR group and decreased rCBF of ACG under post SCS conditions in the GR group were characteristic patterns. Tc-99m-HMPAO SPECT with 3D-SSP and SEE analysis is likely objective and effective in monitoring and evaluating therapeutic outcome by SCS in chronic pain. In addition, it provides information that is useful in the selection of SCS candidates.

Effect of lamotrigine on cerebral blood flow in patients with idiopathic generalised epilepsy

The purpose of this study was to investigate the effects of the new anti-epileptic drug, lamotrigine, on cerebral blood flow by performing (99m)Tc-ethylcysteinate dimer (ECD) single-photon emission computed tomography (SPECT) before and after medication in patients with drug-naive idiopathic generalised epilepsy. Interictal (99m)Tc-ECD brain SPECT was performed before drug treatment started and then repeated after lamotrigine medication for 4-5 months in 30 patients with generalised epilepsy (M/F=14/16, 19.3+/-3.4 years). Seizure types were generalised tonic-clonic seizure in 23 patients and myoclonic seizures in seven. The mean lamotrigine dose used was 214.1+/-29.1 mg/day. For SPM analysis, all SPECT images were spatially normalised to the standard SPECT template and then smoothed using a 12-mm full-width at half-maximum Gaussian kernel. The paired t test was used to compare pre- and post-lamotrigine SPECT images. SPM analysis of pre- and post-lamotrigine brain SPECT images showed decreased perfusion in bilateral dorsomedial nuclei of thalami, bilateral uncus, right amygdala, left subcallosal gyrus, right superior and inferior frontal gyri, right precentral gyrus, bilateral superior and inferior temporal gyri and brainstem (pons, medulla) after lamotrigine medication at a false discovery rate-corrected p<0.05. No brain region showed increased perfusion after lamotrigine administration. Our study demonstrates for the first time the effect of lamotrigine on interictal cerebral perfusion in drug-naive idiopathic generalised epilepsy patients. In summary, lamotrigine medication was found to reduce perfusion in cortico-thalamo-limbic areas, the orbitofrontal cortex, and brainstem.

Altered Hemodynamics and Regional Cerebral Blood Flow in Patients With Hemodynamically Significant Stenoses

Blood oxygen level-dependent (BOLD) contrast largely depends on changes in cerebral blood flow (CBF). Because cerebrovascular disease may result in altered CBF, we assessed the temporal dynamics and magnitude of the BOLD response in patients with major arterial stenoses. Seven patients with hemodynamically significant stenoses affecting the anterior circulation (primarily left internal carotid and middle cerebral arteries) were compared with 7 neurologically healthy subjects. Continuous arterial spin-labeled perfusion MRI was used to measure resting CBF globally and within various vascular distributions. The BOLD response was acquired during a visually guided bilateral handball squeeze task while motor performance was recorded by a pressure transducer. Baseline CBF was reduced in bilateral middle cerebral artery and left anterior cerebral artery territories in patients. A prolonged BOLD hemodynamic response was observed in patients in bilateral primary motor cortices but not visual cortex. Patients also exhibited a larger early negative BOLD response, or "initial dip," in left primary motor cortex. There were no differences in motor performance between groups, suggesting behavioral differences were not primarily responsible for the characteristics of the BOLD response. An initial deoxygenation followed by a delayed hyperemic BOLD response was observed in patients, although resting flow values were not within an ischemic range. A simple visuomotor BOLD activation paradigm can reflect alterations in the hemodynamic response in patients with hemodynamically significant stenoses.

Comparison of regional cerebral blood flow in patients with anorexia nervosa before and after weight gain

We investigated changes in regional cerebral blood flow (rCBF) before and after weight gain in patients with restrictive anorexia nervosa (AN-R) in comparison with findings in normal subjects. We assessed resting rCBF using single photon emission computed tomography with technetium-99m hexamethylpropylene amine oxime in 12 AN-R patients and 11 controls. Each patient was examined at two time points, at the beginning of treatment and after weight gain (average examination interval = 88 ± 26 days). Control subjects were examined only once. Before treatment, the AN-R group had lower rCBF in the bilateral anterior lobes, including the anterior cingulate cortex (ACC), and in the right parietal lobe, the insula, and the occipital lobes. After weight gain, the patients showed significant increases in the right parietal lobe and decreases in the basal ganglia and cerebellum in accordance with significant improvement in body weight and eating attitudes. However, they showed persistent decreases in the ACC area even after weight gain compared with findings in the controls. A significant positive correlation was observed between body mass index and rCBF in the occipital lobes in the patients. These results suggest that weight gain is associated with a normalization of rCBF in a number of brain areas, but that the low level of rCBF in the ACC at baseline is unaffected by treatment in AN-R.