Differences In rCBF Research Articles

Diets Varying in Carbohydrate Content Differentially Alter Brain Activity in Homeostatic and Reward Regions in Adults.

Obesity has one of the highest refractory rates of all chronic diseases, in part because weight loss induced by calorie restriction, the first-line treatment for obesity, elicits biological adaptations that promote weight regain. Although acute feeding trials suggest a role for macronutrient composition in modifying brain activity related to hunger and satiety, relevance of these findings to weight-loss maintenance has not been studied. We investigated effects of weight-loss maintenance diets varying in macronutrient content on regional cerebral blood flow (rCBF) in brain regions involved in hunger and reward. In conjunction with a randomized controlled feeding trial, we investigated the effects of weight-loss maintenance diets varying in carbohydrate content [high, 60% of total energy: n=20; 6 men/14 women; mean age: 32.5 y; mean BMI (in kg/m 2): 27.4; moderate, 40% of total energy: n=22; 10 men/12 women; mean age: 32.5 y; mean BMI: 29.0; low, 20% of total energy: n=28; 12 men/16 women; mean age: 33.2 y; mean BMI: 27.7] on rCBF in brain regions involved in hunger and reward preprandial and 4 h postprandial after 14-20 wk on the diets. The primary outcome was rCBF in the nucleus accumbens (NAcc) at 4 h postprandial; the secondary outcome was preprandial rCBF in the hypothalamus. Consistent with a priori hypothesis, at 4 h postprandial, NAcc rCBF was 43% higher in adults assigned to the high- compared with low-carbohydrate diet {P[family-wise error (FWE)-corrected]<0.05}. Preprandial hypothalamus rCBF was 41% higher on high-carbohydrate diet [P(FWE-corrected)<0.001]. Exploratory analyses revealed that elevated rCBF on high-carbohydrate diet was not specific to prandial state: preprandial NAcc rCBF [P(FWE-corrected)<0.001] and 4 h postprandial rCBF in hypothalamus [P(FWE-corrected)<0.001]. Insulin secretion predicted differential postprandial activation of the NAcc by diet. We report significant differences in rCBF in adults assigned to diets varying in carbohydrate content for several months, which appear to be partially associated with insulin secretion. These findings suggest that chronic intake of a high-carbohydrate diet may affect brain reward and homeostatic activity in ways that could impede weight-loss maintenance. This trial was registered at clinicaltrials.gov as NCT02300857.

Abstract P534: Relationship Between rCBF and Pial Collateral Recruitment in Experimental Acute Ischemic Stroke

Purpose: The purpose of this study was to assess the relationship between relative cerebral blood flow (rCBF) by MRI and leptomeningeal collateral recruitment in an experimental acute ischemic stroke model. Methods: This study was approved by the local IACUC. Eight mongrel canines (20-30kg) underwent endovascular middle cerebral artery occlusion (MCAO). Anesthetics were chosen not to interfere with cerebrovascular reactivity. Physiologic parameters were maintained within normal ranges. Pial collateral recruitment was angiographically assessed using a previously published 11-point scale. After the MCAO, subjects underwent DSC and DTI MRI (3T Achieva, Philips Healthcare, Best, Netherlands) in order to derive rCBF and infarct volume by diffusion restriction on mean diffusivity maps. DSC images were imported into Visage software (Visage Imaging; Richmond Australia). The region of interest was drawn on the penumbra and infarct core and corresponding contralateral side. Infarct volume was calculated by using a quantitative voxel-wise threshold by setting a threshold of 1.5 SD relative to normal values based on an ROI drawn to cover the entire contralateral normal hemisphere exclusive of the ventricles. Results: The pial collateral recruitment was strongly correlated with the rCBF on the penumbral region (r 2 = 0.7823, P-value= 0.003), and with the infarct volume measured two hours following occlusion (r 2 = 0.933376, P value= 0.00009.). There was a poor correlation between the pial collateral recruitment and the rCBF ratio on the core region (R 2 =0.4447, p-value= 0.07.) Conclusion: Preliminary data from this study suggests rCBF from the penumbral regions in experimental MCAO has a closer association with pial collateral recruitment relative to rCBF in the core infarct zone. This information has the potential to affect the interpretation of angiographic studies in acute ischemic stroke and underscores the importance of assessing regional differences in rCBF.

Adoption of computerized tomography perfusion imaging in the diagnosis of acute cerebral infarct under optimized deconvolution algorithm.

Objectives:To explore the significance of the hemodynamic parameters of Computerized Tomography Perfusion Imaging (CTPI) under the deconvolution optimization algorithm for the diagnosis and treatment of patients with acute cerebral infarct (ACI).Methods:A hundred and ten patients with ACI from December 2018 to September 2019 were selected for research, and CTPI was performed before and after Edaravone injection treatment. Then, the CTPI deconvolution algorithm based on the weighted adaptive (WA) total variation (TV) (WA-TV) optimization was constructed, which was compared with tensor total variation (TTV) and Motion-adaptive sparse parity (MASP). Brain Perfusion 4.0 was applied to obtain the relative time to peak (rTTP), the relative transit time of mean (rMTT), relative cerebral blood volume (rCBV), and relative cerebral blood flow (rCBF) of the core infarction area (CIA) and penumbra ischemic (PI).Results:In four parameters of rTTP, rMTT, rCBV, and CBF, the peak signal to noise ratio (PSNR) of the WA-TV algorithm was higher than the MSAP and TTV algorithms, while the Mean Square Error (MSE) and Mean Absolute Error (MAE) were lower than MSAP and TTV algorithms (P<0.05); the parameters of rCBV (71.56±9.87), rCBF (43.17±7.06) of the CIA before treatment were higher than PI (23.66±7.22; 18.37±3.99), rMTT (124.83±9.73) and rTTP (122.57±7.41) were lower than the PI (183.17±10.16); 150.74±9.74) (P<0.05). After treatment, the rCBV and rCBF of PI were higher than before treatment, and rMTT and rTTP were lower than before treatment (P<0.05), and there was no obvious difference in rCBV, rCBF, rMTT, and rTTP before and after treatment in the CIA (P>0.05).Conclusion:Compared with TTV and MASP, the WA-TV algorithm performs better in noise reduction and artifact reduction. The CTPI parameters of rCBV, rCBF, rMTT, and rTTP are all important indications for the diagnosis of PI and ACI.

Differences of cerebral perfusion between subtype of multiple system atrophy with predominant cerebellar ataxia and with predominant parkinsonism

Objective: The abnormally low regional cerebral blood flow (rCBF) in multiple system atrophy (MSA) has been reported in the cerebellum, pons, and the striatum. The aim of the present study was to investigate the difference of rCBF between MSA with predominant cerebellar ataxia (MSA-C) and MSA with predominant parkinsonism (MSA-P).

Altered Regional Cerebral Blood Perfusion in Mild Cognitive Impairment Patients with Dizziness.

Dizziness is a common symptom among the general population, especially in the elderly. Previous studies have reported that dizziness may be associated with various cognitive functions including memory impairment. However, few studies have investigated the neural correlates of dizziness in patients with cognitive impairment. The aim of this study was to examine regional cerebral blood flow (rCBF) in mild cognitive impairment (MCI) patients with or without dizziness using single photon emission computed tomography (SPECT). A total of 50 patients with MCI were recruited. All participants underwent technetium-99m ethyl cysteinate dimer brain SPECT and a neuropsychological battery and completed the Dizziness Handicap Inventory (DHI). Participants were divided into a dizziness group (DHI ≥ 1, n = 18) and a non-dizziness group (DHI = 0, n = 32). Voxel wise differences in rCBF between the groups were estimated. SPECT analysis revealed decreased rCBF in the left superior temporal gyrus, left lateral orbital gyrus, and right middle frontal gyrus in the dizziness group compared with the non-dizziness group (p < 0.005). No significant clusters of increased rCBF were observed in the dizziness group compared with the non-dizziness group. Results of the neuropsychological tests showed a significant difference in Controlled Oral Word Association Test performance between MCI patients with and without dizziness. In conclusion, MCI patients with dizziness showed multifocal frontal and left temporal hypoperfusion compared with patients without dizziness. Our results suggest that hypoperfusion in the frontal and temporal cortices might be reflecting the negative impact of dizziness in MCI patients.

A-098 Regional Cerebral Blood Flow in Adults with Autism

Abstract Objective To identify regional cerebral blood flow (rCBF) differences between individuals with Autism Spectrum Disorder and healthy controls. Method Healthy controls [n = 81, Mage = 41.9, 53.0% female] and persons diagnosed by psychiatric examination with Autism Spectrum Disorder (ASD) [n = 62, Mage = 29.8, 75.8% male] were selected from a deidentified adult clinical outpatient database. Those with comorbid diagnoses were included. Significant differences (alpha = .001) were found for gender [χ(2) = 13.4] and age [t(141) = −4.8] between groups. Multiple ANCOVA controlled for gender and age on outcomes of rCBF across 17 brain regions from Single-Photon Emission Computed Tomography (SPECT) were analyzed. Results Significant rCBF differences were noted in the cerebellum [left:F(1,143) = 9.43, p = .003; right: F(1,143) = 14.2, p &amp;lt; .001] and basal ganglia [left:F(1,143) = 8.2,p = .005; right:F(1,143) = 10.3, p = .002]. Group means comparisons indicated higher perfusion in the cerebellum and lower perfusion in the basal ganglia in the group with ASD. No significant differences were found bilaterally in limbic system, motor sensory strip, vermis, or occipital, parietal, frontal, or temporal lobes. Conclusion Results indicated that individuals diagnosed with ASD have diminished rCBF in the basal ganglia and increased rCBF in the cerebellum. Previous research supports these conclusions, as the basal ganglia is linked with repetitive and/or restricted motor behaviors, and the cerebellum aids in understanding gross motor and coordination in ASD, as well as social interactions, and language and communication. By understanding the underlying mechanisms of ASD, interventions focused on sensory-motor abilities, such as sensory enrichment (Woo and Leon, 2013), can show a decrease in motor behaviors and improve cognition. Future studies should control for potential comorbidities, the severity of ASD, and medication usage.

A voxel-based analysis of cerebral blood flow abnormalities in obsessive-compulsive disorder using pseudo-continuous arterial spin labeling MRI.

To identify abnormalities of regional cerebral blood flow (rCBF) in individuals with obsessive-compulsive disorder (OCD) by conducting a voxel-based analysis of pseudo-continuous arterial spin labeling (pCASL) perfusion images. This prospective study included 23 OCD patients (nine males, 14 females; age 21-62 years; mean ± SD 37.2 ± 10.7 years) diagnosed based on DSM-IV-TR criteria and 64 healthy controls (27 males, 37 females; age 20-64 years; mean ± SD 38.3 ± 12.8 years). Subjects were recruited from October 2011 to August 2017. Imaging was performed on a 3T scanner. Quantitative rCBF maps generated from pCASL images were co-registered and resliced with the three-dimensional T1-weighted images, and then spatially normalized to a brain template and smoothed. We used statistical nonparametric mapping to assess the differences in rCBF and gray matter volume between the OCD and control groups. The significance level was set at the p-value <0.05 with family-wise error rate correction for multiple comparisons. Compared to the control group, there were significant rCBF reductions in the right putamen, right frontal operculum, left midcingulate cortex, and right temporal pole in the OCD group. There were no significant between-group differences in the gray matter volume. The pCASL imaging noninvasively detected physiologically disrupted areas without structural abnormalities in OCD patients. The rCBF reductions observed in these regions in OCD patients could be associated with the pathophysiology of OCD.

Pseudo-continuous arterial spin labeling MRI study of patients with obsessive–compulsive disorder

Arterial spin labeling (ASL) magnetic resonance imaging is a novel technique that can measure regional cerebral blood flow (rCBF). Here we used pseudo-continuous ASL (pCASL) to examine the structural and functional imaging data in patients with obsessive-compulsive disorder (OCD). We estimated the gray matter volume imaging and pCASL imaging data by means of a voxel-by-voxel statistical analysis. We evaluated the differences of rCBF and gray matter volume between the OCD patients and healthy subjects. We detected a significant rCBF reduction in OCD patients in the right posterior cingulate extending to the lingual gyrus, thalamus, and hippocampus, and a significant increase in the left temporal gyrus and left frontal white matter region, compared with healthy subjects. We also observed a significant reduction in gray matter volume of OCD patients in the right hippocampus. We also estimated the correlation between the clinical severity of OCD and the rCBF and gray matter volumes, and found significant negative correlations between the severity of illness and the regional gray matter volume in the bilateral anterior cingulate corti. Our study demonstrated significant changes of rCBF in the cortico-striato-thalamo-cortical pathway around the hippocampus in OCD patients. These findings may help to elucidate the pathogenesis of OCD.

Regional cerebral blood flow at rest in obesity.

Imaging studies have shown brain abnormalities associated with eating behavior (taste perception, food intake, and food reward), neural connectivity, and cognition related to obesity. The aim of this study was to investigate whether obese individuals have changes in regional cerebral blood flow (rCBF) during fasting and rest using single-photon emission computed tomography (SPECT), and whether these differences are associated with body fat and serum levels of leptin, insulin, and glucose. For this purpose, rCBF assessed by ([99]mTc)-ECD-SPECT was compared between 10 obese women (30 ± 5 y of age, body fat: 38 ± 3 kg) and 10 lean women (30 ± 6 y of age, body fat: 17 ± 5 kg) using statistical parametric mapping. Pearson's coefficient and linear regression were used to search for associations among variables. The obese women showed antagonic rCBF in the left frontoparietal region and greater rCBF in areas related to the default mode network and the salience network (P = 0.0001). Positive linear correlations of rCBF, body fat, and the serum levels of glucose and insulin were found, but no associations were detected using linear regression. Obese women showed rCBF differences in areas related to the frontoparietal neural circuit, the default mode network, and the salience network, suggesting loss of cognitive control and a higher perception of physiologic processes, such as hunger. Hyperactivation in these areas might jeopardize the recognition of changes in energy homeostasis.

M143. REGIONAL CEREBRAL BLOOD FLOW IN INITIALLY ANTIPSYCHOTIC-NAïVE PATIENTS WITH SCHIZOPHRENIA OR PSYCHOSIS: EFFECTS OF PARTIAL D2 RECEPTOR AGONISM AND ASSOCIATION WITH SYMPTOM IMPROVEMENT

BackgroundSchizophrenia is suggested to stem from dysfunction of cortico-striato-thalamo-cortical networks. Supporting this, we have recently found increased glutamate levels in thalamus in antipsychotic-naïve patients with schizophrenia or psychosis. Moreover, higher baseline glutamate levels were related to less improvement of psychotic symptoms after treatment. Other groups have reported that striatal dopaminergic function in patients with psychosis is increased and associated with psychotic symptoms. Regional cerebral blood flow (rCBF) is considered a marker of neuronal activity and can be used to study the cortico-striato-thalamo-cortical networks.Here, we investigated rCBF in a large group of initially antipsychotic-naïve patients with schizophrenia or psychosis before and after treatment and related the findings to changes in psychotic symptoms.MethodsrCBF was acquired in 49 initially antipsychotic-naïve patients and 50 matched healthy controls at baseline, and in 32 patients and 53 healthy controls after 6 weeks with the pseudo-Continuous Arterial Spin Labelling (pCASL) sequence. Patients were treated with a partial dopamine D2 receptor agonist (aripiprazole) as monotherapy (mean dose: 10.6±5.4mg).Primary regions of interest of rCBF were thalamus, limbic- and associative striatum. In explorative analyses, we estimated rCBF in sensorimotor striatum, hippocampus-amygdala, and frontal lobe.Psychopathology was assessed with the positive and negative syndrome scale (PANSS).A linear mixed model was used to test if the change in rCBF was different in patients compared with healthy controls (significant interaction) with adjustment for age, sex, and whole brain rCBF. Post hoc tests evaluated possible group differences at baseline and after 6 weeks.In a general linear model, we investigated associations between baseline rCBF in striatum and thalamus and improvement in psychotic symptoms.ResultsrCBF changed over 6 weeks in all striatal regions (associative striatum: p=0.023; limbic striatum: p=0.004; sensorimotor striatum: p=0.004). Post hoc tests of associative striatum indicated no baseline group differences in rCBF (SCZ/HC: 63.4/65.1 mL/100g/min, p=0.59), however rCBF was higher in patients after 6 weeks (SCZ/HC: 68.8/63.2 mL/100g/min, p=0.049). Post hoc tests of limbic striatum indicated no baseline group differences in rCBF (SCZ/HC: 62.7/65.3 mL/100g/min, p=0.25) and no group differences rCBF after 6 weeks (SCZ/HC: 69.3/63.3 mL/100g/min, p=0.12).Post hoc tests of sensorimotor striatum indicated no baseline group differences in rCBF (SCZ/HC: 72.6/71.2 mL/100g/min, p=0.18), however, rCBF was significantly higher in patients after 6 weeks (SCZ/HC: 80.0/67.2 mL/100g/min, p<0.001).There were no group differences in the rCBF changes in thalamus (p=0.09), hippocampus-amygdala (p=0.24), frontal lobe (p=0.90), and the whole brain (p=0.14).In patients, higher baseline rCBF in limbic striatum was associated with less improvement in PANSS positive symptoms (p=0.025). We found no other associations between rCBF and psychopathy.DiscussionThe findings suggest that treatment with a partial dopamine D2 agonist increases rCBF in associative and sensorimotor striatum in initially antipsychotic-naïve patients and that higher rCBF in limbic striatum at baseline is related to poorer treatment outcome. Future studies should investigate the associations between different neurotransmitters and rCBF in vivo. This could further characterize disturbances in cortico-striato-thalamo-cortical networks in schizophrenia or psychosis as well as the effect of treatment.

M23. ALTERATION OF REGIONAL CEREBRAL BLOOD FLOW MEASURED BY ARTERIAL SPIN LABELING IN PATIENTS WITH TREATMENT-RESISTANT SCHIZOPHRENIA

BackgroundApproximately 30% of patients with schizophrenia do not respond to antipsychotics, which is called treatment-resistant schizophrenia (TRS). A recent systematic review showed decreased regional cerebral blood flow (rCBF) in the cerebral cortex and increased rCBF in the putamen in patients with schizophrenia. However, to date, no study has examined rCBF using arterial spin labeling (ASL) in patients with TRS. Thus, we compared rCBF between patients with TRS and those with non-TRS to investigate neural basis of this condition.MethodsWe acquired whole-brain rCBF measurements using 1.5T magnetic resonance imaging (MRI) with pseudo-continuous ASL in those with TRS and non-TRS. TRS was defined as 1) a Clinical Global Impression Severity (CGI-S) score of ≧ 4 (moderate) and 2) a score of ≧ 4 (moderate) on two Positive and Negative Syndrome Scale (PANSS) positive symptom items after optimal antipsychotic treatment. Non-TRS was defined as 1) a CGI-S score of ≦3, 2) scores of ≦ 3 on all positive symptom items of the PANSS, and 3) no symptomatic relapse during the previous 3 months. Optimal antipsychotic treatment was defined as ≧ 6 consecutive weeks with ≧ 400 mg of chlorpromazine (CPZ) equivalent daily dose antipsychotic treatment. The rCBF maps were subsequently derived from the proton-density-weighted reference images. Group differences in rCBF between the two groups (non-TRS vs. TRS) were tested using two sample t-test with age, gender, and PANSS positive scores as covariates. Multiple comparisons were corrected using familywise error (FWE) method with a significance threshold of P <.05.ResultsA total of 32 participants were included (13 TRS [6 females, age= 41.2±9.8, PANSS=80.3±9.7] and 19 non-TRS [6 females, age= 40.6±11.9, PANSS=58.9±10.0]). rCBF in the cerebellum was increased in the TRS group compared with the non-TRS group. In addition, there are inverse correlation between rCBF in the cerebellum and PANSS positive score in the non-TRS group.DiscussionThese preliminary results suggest that perfusion in the cerebellum may be implicated in the pathophysiology of TRS. This study will continue to enroll participants (our target sample is 30/each group). To identify the abnormal rCBF in patients with TRS will facilitate elucidating the pathophysiology of TRS and pave a way of developing novel treatment of this difficult-to-treat population.

Combined structural and diffusion tensor imaging detection of ischemic injury in moyamoya disease: relation to disease advancement and cerebral hypoperfusion.

The microstructural integrity of gray and white matter is decreased in adult moyamoya disease, suggesting covert ischemic injury as a mechanism of cognitive dysfunction. Establishing a microstructural brain imaging marker is critical for monitoring cognitive outcomes following surgical interventions. The authors of the present study determined the pathophysiological basis of altered microstructural brain injury in relation to advanced arterial occlusion, cerebral hypoperfusion, and cognitive function. The authors examined 58 patients without apparent brain lesions and 30 healthy controls by using structural MRI, as well as diffusion tensor imaging (DTI). Arterial occlusion in each hemisphere was classified as early or advanced stage based on MRA and posterior cerebral artery (PCA) involvement. Regional cerebral blood flow (rCBF) was measured with N-isopropyl-p-[123I]-iodoamphetamine SPECT. Furthermore, cognitive performance was examined using the Wechsler Adult Intelligence Scale, Third Edition and the Trail Making Test (TMT). Both voxel- and region of interest-based analyses were performed for groupwise comparisons, as well as correlation analysis, using parameters such as cognitive test scores; gray matter volume; fractional anisotropy (FA) of association fiber tracts, including the inferior frontooccipital fasciculus (IFOF) and superior longitudinal fasciculus (SLF); PCA involvement; and rCBF. Compared to the early stages, advanced stages of arterial occlusion in the left hemisphere were associated with a lower Performance IQ (p = 0.031), decreased anterior cingulate volumes (p = 0.0001, uncorrected), and lower FA in the IFOF, cingulum, and forceps major (all p < 0.01, all uncorrected). There was no significant difference in rCBF between the early and the advanced stage. In patients with an advanced stage, PCA involvement was correlated with a significantly lower Full Scale IQ (p = 0.036), cingulate volume (p < 0.01, uncorrected), and FA of the left SLF (p = 0.0002, uncorrected) compared to those with an intact PCA. The rCBF was positively correlated with FA of the SLF, IFOF, and forceps major (r > 0.34, p < 0.05). Global gray matter volumes were moderately correlated with TMT part A (r = 0.40, p = 0.003). FA values in the left SLF were moderately associated with processing speed (r = 0.40, p = 0.002). Although hemodynamic compensation may mask cerebral ischemia in advanced stages of adult moyamoya disease, the disease progression is detrimental to gray and white matter microstructure as well as cognition. In particular, additional PCA involvement in advanced disease stages may impair key neural substrates such as the cingulum and SLF. Thus, combined structural MRI and DTI are potentially useful for tracking the neural integrity of key neural substrates associated with cognitive function and detecting subtle anatomical changes associated with persistent ischemia, as well as disease progression.

Cerebral hemodynamics associated with fluid-attenuated inversion recovery hyperintense vessels in patients with extracranial carotid artery stenosis.

Fluid-attenuated inversion recovery hyperintense vessels (FHVs) are linked to sluggish or disordered blood flow. The purpose of this study is to compare FHVs with digital subtraction angiography (DSA) findings and cerebral hemodynamic changes on acetazolamide challenge SPECT and to determine the clinical and imaging metrics associated with FHVs in patients with extracranial carotid artery stenosis (ECAS). The subjects were patients with chronic ECAS who underwent carotid artery stenting in our department between March 2011 and October 2018. Relationships of FHVs with age, sex, medical history, cerebral angiographic findings using DSA, and quantitative values of cerebral blood flow (CBF) were examined. The resting CBF (rCBF) and cerebrovascular reactivity (CVR) in the middle cerebral artery territory were measured quantitatively using SPECT with acetazolamide challenge. We used multivariate logistic regression analysis to identify independent predictors of FHVs. Of 173 patients included, 92 (53.2%) had FHVs. Patients with FHVs had more severe stenosis (P < 0.01) and more leptomeningeal collateral vessels (P < 0.01). FHV-positive cases had significantly reduced CVR compared with FHV-negative cases (P < 0.01), although there was no significant difference in rCBF between FHV-positive and FHV-negative cases. Logistic regression analysis showed that ipsilateral rCBF and ipsilateral CVR were significant predictors for FHVs (P < 0.01). In patients with ECAS, cerebral hemodynamic metrics, especially ipsilateral rCBF and ipsilateral CVR, are associated with the presence of FHVs.

Abstract WP59: Cerebral Blood Flow Increase After Endovascular Thrombectomy on Perfusion Weighted Image is Associated With Hemorrhagic Transformation

Introduction: The role of increased CBF after endovascular thrombectomy in post-ischemic hyperperfusion has not been studied in detail. We aimed to investigate the timing of CBF increases on PWI after thrombectomy in association with hemorrhagic transformation. Methods: We analyzed prospectively collected data in consecutive patients treated with endovascular thrombectomy. Inclusion criteria were: (1) patients with ICA or M1 occlusion, and (2) PWI and GRE obtained within 12 hours and 12-48 hours after thrombectomy. We compared each rCBF with early hemorrhage (within 12 hours after thrombectomy), late hemorrhage (12-48 hour) and non-hemorrhage in basal ganglia (BG) and MCA cortical or subcortical (CS) region. In each PWI dataset, ROIs were placed in two slice levels of the BG and three slice levels of the CS region. Results: Fifty-three patients met inclusion criteria. Early BG hemorrhages were noted in 13 patients, with 4 late BG hemorrhage, 8 early CS hemorrhage and 3 late CS hemorrhage. There were no significant differences on rCBF in PWI within 12 hours after thrombectomy between early hemorrhage, late hemorrhage and non-hemorrhage groups. In contrast, rCBF on 12-48 hours PWI in the BG region was significantly higher in the early BG hemorrhage than non-BG hemorrhage (lower BG slice 1.36 vs 1.01, p&lt;0.001, upper BG slice 1.33 vs 0.96, p&lt;0.001) and rCBF in CS region were significantly higher in early CS hemorrhage than non-CS hemorrhage (lower CS slice 1.55 vs 0.98, p=0.001, middle CS slice 1.31 vs 0.92, p=0.018). There were no significant differences in rCBF on 12-48 hours PWI between the late hemorrhage and non-hemorrhage group. Conclusions: Most intracerebral hemorrhages after thrombectomy were seen within 12 hours after intervention. A rCBF increase in hemorrhage cases was not seen on PWI within 12 hours after thrombectomy. rCBF increases on PWI 12-48 hours after thrombectomy, however, was associated with post-thrombectomy hemorrhage within 12 hours.

Efficacy of nicergoline treatment in Parkinson’s disease associated with dementia

Parkinson’s disease (PD) has a variable spectrum of cognitive impairment. However, there are no clear evident-based management guidelines for PD with dementia (PDD). Alternative treatments for PDD are therefore required. We conducted this longitudinal study to evaluate the efficacy of nicergoline in treating PDD by analyzing changes in regional cerebral blood flow (rCBF) and neuropsychological tests before and after nicergoline administration. A total of nine PDD patients who received nicergoline therapy (PDD + N) and 14 PD patients who did not receive nicergoline therapy (PDD − N) underwent single photon emission computed tomography (SPECT) and clinical assessments at baseline and 12-month follow-up visits. The PDD + N received nicergoline at 30 mg twice per day. Changes in rCBF were compared between the groups, and correlation analysis was performed to determine possible relationship between rCBF and clinical characteristics. There were no significant differences in rCBF between the two groups at baseline. Although changes in cognitive test scores and the motor severity scale were not significantly different between baseline and the 12-month follow-up within groups, rCBF was lower in both the temporal and inferior frontal restricted areas in the PDD − N group than the PDD + N at the 12-month follow-up visit. In conclusions, nicergoline appears to delay the speed of deterioration of cognitive function in patients with PDD based on our observation of decreased rCBF in the temporal regions and inferior frontal regions of PDD − N patients compared to PDD + N patients after 12-month of nicergoline therapy. Therefore, we cautiously suggest that nicergoline administration in PDD patients may slow progression of cognitive impairment in affected brain regions.

A-08 Aggressive Presentation of Attention Deficit Hyperactivity Disorder: A SPECT Study

Abstract Objective Explore the effects of aggression in adults diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) on regional cerebral blood flow (rCBF). Method Participants were extracted from an archival de-identified SPECT database (n = 889,Mage = 36.73, 60.4% male, 71.6% Caucasian). Two groups were formed based on self-reported aggressive symptoms: low (below 25th percentile; n = 396) and high aggression (above 75th percentile; n = 435). Results Age was used as a covariate. One-way ANCOVA’s were conducted controlling for age (alpha = .01). Significant differences were found between groups in the left (F[1,829] = 5.755, ) and right (F[1,829] = 6.114) limbic regions, left basal ganglia (F[1,829] = 4.006, p = .046), left occipital (F[1,829] = 3.951,p = .047), and right parietal regions (F[1,829] = 4.341,p = .038). Discussion: Results revealed that individuals with ADHD and high aggression failed to have significantly different levels of rCBF in areas of the brain responsible for emotion regulation compared to those with low aggression. This study is the first to explore differences in rCBF in a sample of individuals with ADHD. It was hypothesized that higher activation in the limbic and basal ganglia areas was the process of experiencing highly emotional/distressing feelings and the process of acting upon these emotional experiences. However, SPECT failed to present as a reliable resource for identifying individuals with ADHD that have aggressive and impulsive tendencies in this study. Thus, it is suggested that clinicians use caution when using SPECT as a resource in identifying populations likely to engage in aggressive and highly dangerous acts (i.e., suicide/homicide). Further research is needed in using SPECT to identify ADHD populations which may be likely to engaged in aggressive and highly dangerous acts.

B-37 Examining Self-Reported Depressive Symptoms: A SPECT Exploratory Analysis

Abstract Objective To examine regional cerebral blood flow (rCBF) differences between those with self-reported high and low levels of depressive symptoms. Method Participants were selected from a de-identified archival SPECT database. Depressive symptoms were determined by self-reported factors related to depression which included eight questions rated on a six point Likert scale. Groups were separated into highest and lowest 20% of ratings on this scale. Low reported depressive symptoms group (n = 2453,Mage = 42.85,SD = 18.35,male = 64%,Caucasian = 67%); high reported depressive symptoms group consisted (n = 2673,Mage = 38.52,SD = 13.44,male = 58%,Caucasian = 70%). Differences between groups were assessed across 17 brain regions at baseline. Results One-way ANCOVAs were conducted (p &lt; .001) controlling for age and gender across 17 brain regions. Significant differences were found between groups in the left cerebellum (F[1,5122] = 19.396,p &lt; .001),left frontal(F[1,5122] = 17.870,p &lt; .001),right frontal (F[1,5122] = 22.175,p &lt; .001),left motor sensory(F[1,5122] = 28.974,p &lt; .001),and right motor sensory(F[1,5122] = 31.534,p &lt; .001),such that the low depressive symptoms group exhibited higher rCBF in the left and right frontal and left and right motor sensory,whereas, the high depressive symptoms group exhibited higher rCBF in the left cerebellum. Conclusion Results indicate increased self-reported depressive symptomatology may be associated with decreased frontal lobe. The motor sensory region can result in deficits involving encoding or motor output showing slower motor/sensory processing in those with increased self-reported depressive symptoms. Research has shown increased activity in the cerebellum during sadness which may explain the higher rCBF in the depressed group. These findings demonstrate that neurological differences exist between varying degrees of self-reported depressive symptom severity. As a result, SPECT may be a useful objective measure to monitor and assess self-reported depressive severity throughout the course of treatment.

Effects of nicergoline treatment on regional cerebral blood flow in early Alzheimer's disease

AbstractAlzheimer's disease (AD) is associated with reduction of regional cerebral blood flow (rCBF) in various brain regions. Although nicergoline has been used to treat cognitive impairment in various types of dementia, the effect of nicergoline on brain perfusion in AD has not been elucidated. The aim of the study was to examine the effect of nicergoline on rCBF in patients with early AD using technetium‐99m hexamethylpropylene amine oxime single‐photon emission computed tomography (SPECT). For 1.7 years on average, 22 patients with early AD received nicergoline (30 mg twice daily) and acetylcholinesterase inhibitors (AChEI), whereas other 22 patients received AChEI only. All patients underwent assessment of dementia severity and SPECT scans at baseline and follow‐up. We compared baseline rCBF and annual percent change of rCBF between the two groups. There were no significant differences in rCBF between the groups at baseline. Although changes in dementia severity was not statistically different, the annual percent changes of rCBF were higher in the left temporal pole (−0.12 ± 3.95 vs −3.38 ± 3.30, P = 0.002) and middle cingulate gyrus (1.91 ± 3.58 vs −1.34 ± 3.17, P = 0.002) among the nicergoline group. Our study demonstrated that nicergoline treatment combined with AChEI either better preserves or further improves cerebral perfusion in the temporal and cingulate cortices in patients with early AD compared to AChEI treatment alone. These results may indicate potential beneficial effects of nicergoline on brain functions in AD.

Cerebral blood flow and Alzheimer's disease-related biomarkers in cerebrospinal fluid in idiopathic normal pressure hydrocephalus.

Alzheimer's disease (AD) pathology is highly prevalent in patients with idiopathic normal pressure hydrocephalus (iNPH), and the presence of AD pathology may involve regional cerebral blood flow (rCBF). In this study, we examined the relationship between rCBF and AD-related biomarkers in the cerebrospinal fluid of iNPH patients. Patients with iNPH (n = 39) were classified into groups with (iNPH/AD+) (n=15) and without (iNPH/AD-) (n=24) high biomarker probability of AD (i.e. combined low amyloid β 42 and high total tau in the cerebrospinal fluid). rCBF was quantified in 17 regions of interest by N-isopropyl-p-[123 I]iodoamphetamine single-photon emission computed tomography with the autoradiography method. We compared rCBF between the iNPH/AD- and iNPH/AD+ groups at baseline using a t-test and then compared changes in rCBF after shunt surgery between the groups using a paired t-test and two-way repeated measures ANOVA. At baseline, there were no significant differences in rCBF between the groups in most regions apart from the putamen. After shunt surgery, a significant increase in rCBF in the putamen, amygdala, hippocampus, and parahippocampal gyrus was observed in iNPH/AD- patients. In iNPH/AD+ patients, no significant improvement in rCBF was observed in any region. In repeated measures analysis of variance, a significant group × shunt interaction was observed in the parietal lobe, frontal lobe, posterior cingulate cortex, precuneus, lateral temporal lobe, amygdala, hippocampus, parahippocampal gyrus, and putamen. Improvement in rCBF after shunt surgery in iNPH/AD+ patients may be poorer than that in iNPH AD- patients.

Chronic intracranial artery stenosis: Comparison of whole-brain arterial spin labeling with CT perfusion

PurposeTo evaluate the potential clinical value of Arterial spin-labeled (ASL) through comparison with computed tomography perfusion (CTP) in patients with chronic intracranial artery (middle cerebral artery, MCA) stenosis. MethodsTwenty-nine patients (14 female, average ages 62) were included in our study from October 2013 to August 2016. Relative cerebral blood flow (rCBF) in the MCA territory was calculated on both ASL and CTP. Patients were divided into three groups (mild, moderate and severe) based on their degree of MCA stenosis on DSA. The paired t-tests and Bland-Altman plots were used to evaluate the differences of rCBF between ASL and CTP. ResultsThere was a significant difference in rCBF between ASL and CTP for all patients (P < 0.001) and for those with severe MCA stenosis (P < 0.001). For patients with mild or moderate stenosis, there were no significant differences (P = 0.496 and 0.645, respectively). The 95% limits of agreement for all patients and those with severe stenosis were (−0.25, 0.41) and (−0.13, 0.56), respectively. For patients with mild or moderate stenosis, the values were (−0.21, 0.22) and (−0.20, 0.19). ConclusionCompared with CTP, ASL tended to overestimate the perfusion deficit in patients with severe chronic MCA stenosis. However, ASL is noninvasive, repeatable method and can be a promising clinical diagnostic tool to evaluate patients with intracranial stenosis.