Regional Cerebral Blood Flow Abnormalities Research Articles

Cerebral perfusion alterations in patients with trigeminal neuralgia as measured by pseudo-continuous arterial spin labeling.

Accumulating evidence suggests that trigeminal neuralgia (TN) causes structural and functional alterations in the brain. However, only a few studies have focused on cerebral blood flow (CBF) changes in patients with TN. This study aimed to explore whether altered cerebral perfusion patterns exist in patients with TN and investigate the relationship between abnormal regional CBF (rCBF) and clinical characteristics of TN. This study included 28 patients with TN and 30 age- and sex-matched healthy controls (HCs) who underwent perfusion functional MRI (fMRI) of the brain using pseudo-continuous arterial spin labeling (pCASL) in the resting state. The regions of significantly altered CBF in patients with TN were detected using group comparison analyses. Then, the relationships between the clinical characteristics and abnormal rCBF were further investigated. Compared to the control group, patients with TN exhibited increased rCBF, primarily in the thalamus, middle frontal gyrus (MFG), and left insula. Furthermore, the CBF values of the thalamus were negatively correlated with the pain intensity of TN and positively correlated with pain duration in patients with TN. Primary alterations in rCBF in patients with TN occurred in different brain regions related to pain, which are involved in cognitive-affective interaction, pain perception, and pain modulation. These results indicate that non-invasive resting cerebral perfusion imaging may contribute complementary information to further understanding the neuropathological mechanism underlying TN.

Single Photon Emission Computed Tomography (SPECT) as a Tool for Diagnosis and Treatment Analysis of Mood Disorders

Background: The misdiagnosis rate for mood disorders is high. Psychiatric literature is in much need of a more objective and quantitative tool for the investigation of mood disorders. Although SPECT has been previously used in research for the understanding of the neuroscience behind depressive and bipolar disorders, it is a tool that remains underutilized in clinical settings.
 Aims: To study the effectiveness of SPECT as a tool for diagnosis and treatment analysis of mood disorders.
 Discussion: SPECT provides a significant insight into the neurochemistry of the brain during normal and abnormal functioning. The involvement of regional cerebral blood flow(rCBF) and serotonin transport (SERT) abnormalities as markers of mood disorders are theories that receive backing from single photon emission computed tomography (SPECT).
 Conclusion: This neuroimaging technique may be used a tool for differential diagnosis between mood disorders. Moreover, SPECT may be utilized to evaluate the effectiveness of treatment being provided to patients with mood disorders. Additional research to improve sensitivity and specificity of SPECT may encourage its further usage in clinical settings. The future of SPECT as a tool for diagnosis and treatment analysis of mood disorders looks promising.

Assessment of normalized cerebral blood flow and its connectivity with migraines without aura during interictal periods by arterial spin labeling

BackgroundMigraine constitutes a global health burden, and its pathophysiology is not well-understood; research evaluating cerebral perfusion and altered blood flow between brain areas using non-invasive imaging techniques, such as arterial spin labeling, have been scarce. This study aimed to assess cerebral blood flow (CBF) and its connectivity of migraine.MethodsThis study enrolled 40 patients with episodic migraine without aura (MwoA), as well as 42 healthy patients as control (HC). Two groups of normalized CBF and CBF connectivity were compared, and the relationship between CBF variation and clinical scale assessment was further evaluated.ResultsIn comparison to HC subjects, MwoA patients exhibited higher CBF in the right middle frontal orbital gyrus (ORBmid.R) and the right middle frontal gyrus, while that in Vermis_6 declined. The increased CBF of ORBmid.R was positively correlated with both the Visual Light Sensitivity Questionnaire-8 (VLSQ-8) and the monthly attack frequency score. In MwoA, significantly decreased CBF connectivity was detected between ORBmid.R and the left superior frontal gyrus, the right putamen, the right caudate, as well as the right angular gyrus. In addition, increased CBF connectivity was observed between the left calcarine cortex and ORBmid.R.ConclusionsOur results indicate that migraine patients exhibit abnormalities in regional CBF and feature CBF connection defects at the resting state. The affected areas involve information perception, information integration, and emotional, pain and visual processing. Our findings might provide important clues for the pathophysiology of migraine.

Heart failure and cerebral ischemia

Heart failure patients may have impaired cerebral autoregulation and regional cerebral blood flow abnormalities. Predisposition to thromboembolic complications occur because of dilated chambers and abnormal blood flow, abnormal vessel/chamber lining and abnormal blood particles in heart failure patients. Epidemiological and clinical studies document an increased rate of thromboembolic complications in heart failure. Well known/accepted indications of oral anticoagulation therapy to prevent thromboembolic events are co-existence of atrial fibrillation/flutter, intracardiac thrombi and a history of a thromboembolic event. Other than a co-existence of coronary artery disease and heart failure, antiplatelet agents should not be used in heart failure patients to prevent ischemic stroke. How and who to treat/prevent a thromboembolic event in patients with heart failure and sinus rhythm is a hot topic. Up to date, clinical studies of treatment with oral anticoagulant agents-mainly warfarin and recently rivaroxaban vs antiplatelet agents or placebo could not meet their primary outcome related with morbidity/mortality. In some of these studies, decreased rate of ischemic strokes were offset by increased major hemorrhage.

Cerebral Blood Flow and Its Connectivity Deficits in Mild Traumatic Brain Injury at the Acute Stage

Objective The influence of cognitive impairment after mild traumatic brain injury (mTBI) on cerebral vascular perfusion has been widely concerned, yet the resting-state cerebral blood flow (CBF) connectivity alterations based on arterial spin labeling (ASL) in mild traumatic brain injury (mTBI) remain unclear. This study investigated region CBF and CBF connectivity features in acute mTBI patients, as well as the associations between CBF changes and cognitive impairment. Materials and Methods Forty-five acute mTBI patients and 42 health controls underwent pseudocontinuous arterial spin labeling (pCASL) perfusion magnetic resonance imaging (MRI). The alterations in regional CBF and relationship between the CBF changes and cognitive impairment were detected. The ASL-CBF connectivity of the brain regions with regional CBF significant differences was also compared between two groups. Neuropsychological tests covered seven cognitive domains. Associations between the CBF changes and cognitive impairment were further investigated. Results Compared with the healthy controls, the acute mTBI patients exhibited increased CBF in the bilateral inferior temporal gyrus (ITG) and decreased CBF in the right middle frontal gyrus (MFG), the bilateral superior frontal gyrus (SFG), and the right cerebellum posterior lobe (CPL). In the mTBI patients, significant correlations were identified between the CBF changes and cognitive impairment. Importantly, the acute mTBI patients exhibited CBF disconnections between the right CPL and right fusiform gyrus (FG) as well as bilateral ITG, between the left SFG and left middle occipital gyrus (MOG), and between the right SFG and right FG as well as right parahippocampal gyrus. Conclusion Our results suggest that acute mTBI patients exhibit both regional CBF abnormalities and CBF connectivity deficits, which may underlie the cognitive impairment of the acute mTBI patients.

Altered cerebral blood flow in patients with anti-NMDAR encephalitis.

This study aimed to identify to resting-state cerebral blood flow (CBF) connectivity alterations in patients with anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis. Three-dimensional pseudo-continuous arterial spin labeling (pcASL) imaging was performed to measure the resting-state CBF in 23 patients with anti-NMDAR encephalitis at the peak stage of the disease and 32 healthy subjects. CBF was normalized to reduce variations among subjects. CBF was compared between the groups, and the correlations between the CBF alterations and clinical parameters were assessed. Differences in CBF connectivity in specific brain regions were also compared between groups. Compared with the healthy subjects, the patients with anti-NMDAR encephalitis exhibited increased CBF in the left insula (L_insula), left superior temporallobe (L_STL), L_hippocampus, L_pallidum, bilateral putamen (Bi_putamen), and Bi_caudate, and decreased CBF in the bilateral precuneus (Bi_Pc) and bilateral occipital lobe (Bi_OL) (P < 0.05, FEW corrected). Compared with healthy subjects, the patients with anti-NMDAR encephalitis exhibited increased negative CBF connectivity between the Bi_Pc, Bi_OL and L_TL, L_insula (P < 0.05, FEW corrected). Anti-NMDAR encephalitis patients with behavioral changes exhibited higher CBF in the L_insula and lower CBF in the R_Pc, Bi_calcarine, Bi_cuneus, and Bi_lingual than patients without behavioral changes and health controls. The ROC curve shows changed CBF in the L_insula, and R_Pc, Bi_calcarine, Bi_cuneus, and Bi_lingual served as a predictor of behavioral changes in patients with anti-NMDAR encephalitis. Our results suggest that patients with anti-NMDAR encephalitis may exhibit both regional CBF abnormalities and deficits in CBF connectivity, which may underlie the clinical symptoms of anti-NMDAR encephalitis.

Altered Cerebrovascular Control in Concussed Patients during Sympathoexcitation

Concussed patients (CP) have abnormal regional cerebral blood flow during a hypercapnic challenge and exaggerated increases in brain blood flow during graded intensity whole body exercise. These findings suggest that CP have altered cerebrovascular control. The cold pressor test (CPT) is a general sympathoexcitatory test that increases blood pressure. To buffer against cerebral hyperperfusion during the CPT, cerebrovascular conductance is reduced in healthy controls (HC). However, it is not known if CP exhibit abnormal cerebrovascular conductance response to the CPT.PurposeWe tested the hypothesis that cerebrovascular conductance during the CPT would be higher in CP when compared to HC subjects.MethodsFive symptomatic CP within 10 days of injury (20±1 years; 3 women) and five HC (22±2 years; 2 women) completed a CPT. During the CPT, one hand was submerged up to the wrist in cold water (~0°C) for 120 seconds. Blood pressure (photoplethysmography), middle cerebral artery blood velocity (MCAv, transcranial Doppler), and end‐tidal carbon dioxide tension (PETCO2, capnography) were continuously measured. Cerebrovascular conductance was calculated as MCAv divided by mean arterial pressure. Baseline data were compared using unpaired t‐tests. Data during the CPT were analyzed every 30 seconds, expressed as change from baseline and compared using mixed model repeated measures ANOVA.ResultsBaseline mean arterial pressure (HC: 81±9 mmHg vs. CP: 97±14 mmHg, P=0.06), MCAv (HC: 59±15 mmHg vs. CP: 54±14 mmHg, P=0.59), PETCO2 (HC: 46±3 mmHg vs. CP: 46±2 mmHg, P=0.97), and cerebrovascular conductance (HC: 0.74±0.23 cm/sec/mmHg vs. CP: 0.56±0.15 cm/sec/mmHg, P=0.17) were not different between groups. Mean arterial pressure increased in HC during the CPT at 60 seconds (11±14 mmHg, P=0.04), 90 seconds (22±12 mmHg, P&lt;0.01), and 120 seconds (23±11mmHg, P&lt;0.01). Mean arterial pressure did not change in CP (P&gt;0.20). There were no differences in mean arterial pressure between groups (P&gt;0.08). MCAv did not change from baseline (HC: −1±5, −2±4, −5±5, −4±8 cm/sec; CP 5±5, 1±8, 0±11, −1±11 cm/sec, at 30, 60, 90, and 120 seconds, respectively, time main effect: P=0.18) or between groups (group main effect: P&gt;0.33) (interaction effect: P=0.77). PETCO2 decreased in HC at 90 seconds (3±2 mmHg, P&lt;0.01) and 120 seconds (4±3 mmHg, P&lt;0.01). PETCO2 did not change in CP (P&gt;0.36). There were no differences in PETCO2 between groups (P&gt;0.11). Cerebrovascular conductance decreased in HC at 60 seconds (0.11±0.14 cm/sec/mmHg, P=0.02), 90 seconds (0.21±0.11 cm/sec/mmHg, P&lt;0.01), and 120 seconds (0.20±0.13 cm/sec/mmHg, P&lt;0.01). Cerebrovascular conductance in CP did not change over time (P&gt;0.53). Cerebrovascular conductance was lower in HC vs. CP at 90 seconds (CP: 0.05±0.07 cm/sec/mmHg, P=0.05) and 120 seconds (CP: 0.06±0.06 cm/sec/mmHg, P=0.07).ConclusionCP show an attenuated decrease in cerebrovascular conductance compared to HC during the CPT. These findings suggest that symptomatic CP have altered cerebrovascular control during sympathoexcitation.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Constructive disturbance and abnormal regional cerebral blood flow distribution in amyotrophic lateral sclerosis with dementia

Constructive disturbance and abnormal regional cerebral blood flow distribution in amyotrophic lateral sclerosis with dementia

Common and dissociable regional cerebral blood flow differences associate with dimensions of psychopathology across categorical diagnoses.

The high comorbidity among neuropsychiatric disorders suggests a possible common neurobiological phenotype. Resting-state regional cerebral blood flow (CBF) can be measured noninvasively with MRI and abnormalities in regional CBF are present in many neuropsychiatric disorders. Regional CBF may also provide a useful biological marker across different types of psychopathology. To investigate CBF changes common across psychiatric disorders, we capitalized upon a sample of 1,042 youths (ages 11 to 23 years) who completed cross-sectional imaging as part of the Philadelphia Neurodevelopmental Cohort. CBF during a resting state was quantified on a voxelwise basis using arterial spin labeled perfusion MRI at 3T. A dimensional measure of psychopathology was constructed using a bifactor model of item-level data from a psychiatric screening interview, which delineated four factors (fear, anxious-misery, psychosis, and behavioral symptoms) plus a general factor: overall psychopathology. Overall psychopathology was associated with elevated perfusion in several regions including the right dorsal anterior cingulate cortex (ACC) and left rostral ACC. Furthermore, several clusters were associated with specific dimensions of psychopathology. Psychosis symptoms were related to reduced perfusion in the left frontal operculum and insula, whereas fear symptoms were associated with less perfusion in the right occipital/fusiform gyrus and left subgenual ACC. Follow-up functional connectivity analyses using resting-state fMRI collected in the same participants revealed that overall psychopathology was associated with decreased connectivity between the dorsal ACC and bilateral caudate. Together, the results of this study demonstrate common and dissociable CBF abnormalities across neuropsychiatric disorders in youth.

Aberrant patterns of brain cerebral blood flow in Chinese han first-episode drug-naïve depressive patients with and without a family history of depression.

A positive family history plays a key role in the brain pathology of depression patients and previous research has confirmed that disturbed mood maintenance may be related to abnormal regional cerebral blood flow (rCBF). However, little is known about whether the rCBF is different between depression patients with and without family histories. To address this question, we examined the rCBF in drug-naïve, first-episode depression patients with and without family histories of depression using a 3D pseudo-continuous arterial spin-labelling technique. We found that decreased rCBF was predominantly observed in the patients without family histories, while decreased and increased rCBF co-existed in patients with family histories. The observed brain regions with altered rCBF were associated with affection processing, such as the prefrontal, occipital and insular areas. However the patterns of rCBF alteration observed in the present study were different from those found in previous studies where patients were compared with healthy controls. Our present findings, together with the findings from previous studies have prompted the need of a long-term follow-up study to characterize the brain features of the developmental trajectory of depression and investigate the targets for precise, personalized treatments.

Abnormal Resting-State Functional Connectivity in Patients with Chronic Fatigue Syndrome: Results of Seed and Data-Driven Analyses.

Although altered resting-state functional connectivity (FC) is a characteristic of many chronic pain conditions, it has not yet been evaluated in patients with chronic fatigue. Our objective was to investigate the association between fatigue and altered resting-state FC in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Thirty-six female subjects, 19 ME/CFS and 17 healthy controls, completed a fatigue inventory before undergoing functional magnetic resonance imaging. Two methods, (1) data driven and (2) model based, were used to estimate and compare the intraregional FC between both groups during the resting state (RS). The first approach using independent component analysis was applied to investigate five RS networks: the default mode network, salience network (SN), left frontoparietal networks (LFPN) and right frontoparietal networks, and the sensory motor network (SMN). The second approach used a priori selected seed regions demonstrating abnormal regional cerebral blood flow (rCBF) in ME/CFS patients at rest. In ME/CFS patients, Method-1 identified decreased intrinsic connectivity among regions within the LFPN. Furthermore, the FC of the left anterior midcingulate with the SMN and the connectivity of the left posterior cingulate cortex with the SN were significantly decreased. For Method-2, five distinct clusters within the right parahippocampus and occipital lobes, demonstrating significant rCBF reductions in ME/CFS patients, were used as seeds. The parahippocampal seed and three occipital lobe seeds showed altered FC with other brain regions. The degree of abnormal connectivity correlated with the level of self-reported fatigue. Our results confirm altered RS FC in patients with ME/CFS, which was significantly correlated with the severity of their chronic fatigue.

Baseline brain perfusion and brain structure in patients with major depression: a multimodal magnetic resonance imaging study.

Abnormal regional cerebral blood flow (rCBF) and grey matter volume have been frequently reported in patients with major depressive disorder (MDD). However, it is unclear to what extent structural and functional change co-occurs in patients with MDD and whether markers of neural activity, such as rCBF, can be predicted by structural change. Using MRI, we investigated resting-state rCBF and brain structure in patients with MDD and healthy controls between July 2008 and January 2013. We acquired perfusion images obtained with continuous arterial spin labelling, used voxel-based morphometry to assess grey matter volume and integrated biological parametric mapping analyses to investigate the impact of brain atrophy on rCBF. We included 43 patients and 29 controls in our study. Frontotemporal grey matter volume was reduced in patients compared with controls. In patients, rCBF was reduced in the anterior cingulate and bilateral parahippocampal areas and increased in frontoparietal and striatal regions. These abnormalities were confirmed by analyses with brain volume as a covariate. In patients with MDD there were significant negative correlations between the extent of depressive symptoms and bilateral parahippocampal rCBF. We found a positive correlation between depressive symptoms and rCBF for right middle frontal cortical blood flow. Medication use in patients has to be considered as a limitation of our study. Our data suggest that while changes of cerebral blood flow and brain volume co-occur in patients with MDD, structural change is not sufficient to explain altered neural activity in patients at rest. Abnormal brain structure and function in patients with MDD appear to reflect distinct levels of neuropathology.

(236) Resting regional cerebral blood flow abnormalities of fronto-parietal brain areas in patients with chronic fatigue using arterial spin labeling

(236) Resting regional cerebral blood flow abnormalities of fronto-parietal brain areas in patients with chronic fatigue using arterial spin labeling

Altered resting-state cerebral blood flow and its connectivity in schizophrenia

Small sample sizes and large inter-subject variations result in inconsistent findings in resting-state cerebral blood flow (CBF) in schizophrenia. The CBF connectivity alterations in schizophrenia remain unclear. Recently, three-dimensional pseudo-continuous arterial spin labeling (pcASL) imaging was performed to measure the resting-state CBF in 100 schizophrenia patients and 94 healthy comparison subjects. The normalized CBF was used to reduce the inter-subject variations. Both group comparisons in the CBF and correlations between the CBF alterations and clinical parameters were assessed. The CBF connectivity of the brain regions with regional CBF differences was also compared between the groups. Compared with the healthy controls, the schizophrenia patients exhibited increased CBF in the bilateral inferior temporal gyri, thalami and putamen and decreased CBF in the left insula and middle frontal gyrus and the bilateral anterior cingulate cortices and middle occipital gyri. In the schizophrenia patients, significant correlations were identified between the CBF and clinical parameters. Importantly, the schizophrenia patients exhibited CBF disconnections between the left thalamus and right medial superior frontal gyrus and between the left insula and left postcentral gyrus. Our results suggest that schizophrenia patients may exhibit both regional CBF abnormalities and deficits in CBF connectivity, which may underlie the clinical symptoms of schizophrenia.

Changes in regional cerebral blood flow are associated with endothelial dysfunction markers in cocaine-dependent patients under recent abstinence.

Cocaine is a known risk factor for several vascular ischemic events. The underlying mechanisms leading to the complications are not fully understood, although thrombus formation and accelerated atherosclerosis are prominent findings. Evidence of endothelial dysfunction (ED), a key phenomenon in the pathogenesis of atherogenesis, has been demonstrated in cocaine-dependent individuals. Abnormal regional cerebral blood flow (rCBF) is a common finding among chronic cocaine users. The aim of this study was to evaluate whether brain perfusion changes were associated with ED markers in cocaine-dependent individuals. Circulating endothelial cells (CECs), soluble intercellular cell adhesion molecule, and the chemokine regulated on activation normal T cells expressed and secreted were measured in 27 DSM-IV (Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition) cocaine-dependents patients. Regional cerebral blood flow was assessed using single-photon emission computed tomography at baseline (after recent cocaine consumption) and after 4 weeks of strict abstinence under standard benzodiazepine or antipsychotic therapy. We used statistical parametric mapping analysis to evaluate the covariates. Endothelial cell damage/activation markers were significantly higher in cocaine-dependent individuals after recent consumption and were reduced after 1-month abstinence (P < 0.05). Global rCBF exhibited no significant difference between baseline and after abstinence. When regional perfusion was analyzed in association with ED covariates, significant differences were observed in bilateral cortical areas, including the limbic lobes. We demonstrated an association between systemic ED markers and rCBF in cocaine-dependent patients. These findings suggest that vascular injury may play a role in the pathogenesis of abnormal rCBF.

Characteristic distributions of regional cerebral blood flow changes in major depressive disorder patients: A pseudo-continuous arterial spin labeling (pCASL) study

BackgroundMost previous studies that examined regional cerebral blood flow (rCBF) abnormalities in major depressive disorder (MDD) required the injection of radioisotopes into subjects. Here by using magnetic resonance imaging (MRI) with the pseudo-continuous arterial spin labeling (pCASL) method which does not require radioisotopes, we examined rCBF in patients with MDD in comparison with that in patients with schizophrenia and healthy subjects, taking the regional cerebral gray matter volume into account. MethodsSubjects were 27 patients with MDD, 42 with schizophrenia and 43 healthy volunteers who underwent 3-T MRI with pCASL. Obtained pCASL imaging data were subject to the voxel-by-voxel statistical analysis. ResultsThere were significant reductions of rCBF in the right inferior prefrontal cortex and anterior cingulate cortices (ACCs) in the MDD patients compared with the healthy controls. When compared with the schizophrenic patients, the MDD patients showed lower rCBF in the subgenual ACC and higher rCBF in left occipital region. LimitationThe abnormalities of rCBF in MDD were known to reverse during symptom remission. Further study with follow-up period would bring the perception about the treatment response. ConclusionThe rCBF reduction in the subgenual region may be a specific functional abnormality to MDD patients, which may provide a biological marker for MDD. The MRI with pCASL method is a promising tool to detect rCBF abnormalities controlling for gray matter volume in psychiatric disorders.

Altered Cerebral Perfusion in Executive, Affective, and Motor Networks During Adolescent Depression

Although substantial literature has reported regional cerebral blood flow (rCBF) abnormalities in adults with depression, these studies commonly necessitated the injection of radioisotopes into subjects. The recent development of arterial spin labeling (ASL), however, allows noninvasive measurements of rCBF. Currently, no published ASL studies have examined cerebral perfusion in adolescents with depression. Thus, the aim of the present study wasto examine baseline cerebral perfusion in adolescent depression using a newly developedASL technique: pseudocontinuous arterial spin labeling (PCASL). A total of 25 medication-naive adolescents (13-17 years of age) diagnosed with major depressive disorder (MDD) and 26 well-matched control subjects underwent functional magnetic resonance imaging. Baseline rCBF was measured via a novel PCASL method that optimizes tagging efficiency. Voxel-based whole brain analyses revealed significant frontal, limbic, paralimbic, and cingulate hypoperfusion in the group with depression (p< .05, corrected). Hyperperfusion was also observed within the subcallosal cingulate, putamen, and fusiform gyrus (p< .05, corrected). Similarly, region-of-interest analyses revealed amygdalar and insular hypoperfusion in the group with depression, as well as hyperperfusion in the putamen and superior insula (p< .05, corrected). Adolescents with depression and healthy adolescents appear to differ on rCBF in executive, affective, and motor networks. Dysfunction in these regions may contribute to the cognitive, emotional, and psychomotor symptoms commonly present in adolescent depression. These findings point to possible biomarkers foradolescent depression thatcould inform early interventions and treatments, and establishes amethodology forusing PCASL to noninvasively measure rCBF in clinical and healthyadolescent populations.

Longitudinal study of regional cerebral blood flow in elderly patients with idiopathic rapid eye movement sleep behavior disorder

Single photon emission computed tomography (SPECT) studies showed that regional cerebral blood flow (rCBF) abnormalities in idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) are similar to those seen in Parkinson's disease (PD) and dementia with Lewy bodies (DLB). The aim of the present study was to assess the longitudinal rCBF changes in patients with iRBD using repeated SPECT. Nine patients with iRBD (7 men and 2 women; mean age 71.1 ± 3.2 years) underwent baseline and follow-up SPECT studies (a mean interval of 22.8 ± 9.2 months). A decrease in rCBF was found in bilateral parietotemporal and occipital areas at the first and second SPECT. Compared with the first SPECT, the second SPECT showed a decreased rCBF in the medial portions of the parietooccipital lobe with a significant decrease in rCBF of the right posterior cingulate. None of the patients showed any neurological deficits, including extrapyramidal and cerebellar signs, visual hallucinations, and neuropsychological impairments during the study. These findings suggest that longitudinal measurements of rCBF can show the presence of progressing neurodegenerative process in iRBD. Longitudinal SPECT study can be used to monitor the progression of degenerative process in patients with iRBD, even though there were no evolving neurological and neuropsychiatric impairments.

Regional Cerebral Blood Flow Abnormalities Associated With Apathy and Depression in Alzheimer Disease

The aim of this study was to identify brain areas related to apathy or depression in patients with Alzheimer disease (AD). Eighty-one AD patients were enrolled in this prospective study. (99m)Tc-HMPAO single photon emission computed tomography was performed to evaluate regional cerebral blood flow (rCBF). According to the Neuropsychiatric Inventory subscores of apathy and depression, 9 patients were classified as clinically significant (cs) depressed and non-cs-apathetic (D+) groups and 9 were classified as cs-apathetic and non-cs-depressed (A+) groups. In addition, 18 patients were classified as age-matched and Mini-Mental State Examination-matched disease control groups (D-, A-). The significance of rCBF differences between groups and the correlation between rCBF and subscores in 81 AD patients were estimated by SPM (uncorrected P < 0.005) analysis. D+ patients had significantly lower perfusion in the right orbitofrontal and inferior frontal gyri than D- patients, whereas A+ patients had this in the right amygdala, temporal, posterior cingulate, right superior frontal, postcentral, and left superior temporal gyri than A- patients. The negatively correlated areas with depression subscores included the left inferior frontal and the right middle frontal gyri and those with apathy subscores included the right temporal and right medial frontal gyri. We suggest that this finding may indicate that apathy and depression in AD patients involve distinct functional circuits.

Regional Cerebral Blood Flow Abnormalities in Patients With Kawasaki Disease

Kawasaki disease (KD) is an acute febrile disorder of unknown etiology. Brain single-photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) help in detecting regional cerebral blood flow abnormalities and brain damage. The usefulness of SPECT and MRI in patients with KD was evaluated. All 22 patients with KD underwent brain SPECT using Tc-99m-hexamethyl propylene amine oxime from 6 days to 3 years after onset, and 8 patients underwent brain MRI. Of the 22 patients, 4 had neurologic symptoms. Case 1 showed prolonged apnea; case 2, prolonged disturbance of consciousness; and cases 3 and 4 generalized tonic-clonic seizures. Initial brain SPECT showed localized hypoperfusion in 4 and 13 patients with and without neurologic symptoms, respectively. All patients with neurologic symptoms underwent follow-up SPECT; localized hypoperfusion was detected between 1- and 6-month follow-up in 3 of these patients. Six patients without neurologic symptoms underwent follow-up SPECT. Localized hypoperfusion was detected at approximately 1- to 11-month follow-up in 4 of these patients. Diffusion-weighted imaging revealed abnormal high-intensity areas in the corpus callosum in case 1. Case 2 showed a bilateral chronic subdural hematoma with decreased size and ischemic changes, and case 3 showed bilateral hippocampal atrophy and left hippocampal sclerosis. Because the occurrence of localized hypoperfusion is possibly not restricted to only the acute phase in KD, brain SPECT and MRI should also be performed in KD patients with neurologic symptoms.