Brain function in psychiatric disorders. I. Regional cerebral blood flow in medicated schizophrenics

We measured regional cerebral blood flow during resting baseline and the performance of verbal and spatial tasks in 15 medicated schizophrenics and 25 matched controls. Patients did not differ from controls in resting flows but showed different blood-flow changes during task performance. Controls replicated earlier findings in normal subjects: flow increased during task performance, and the hemispheric increase was greater in the left for the verbal and in the right for the spatial task. In contrast, patients showed no flow asymmetry for the verbal task and greater left hemispheric increase for the spatial task. The latter finding is consistent with the hypothesis that schizophrenia is associated with left hemispheric overactivation for spatial tasks. In addition, schizophrenic women had unusual flow changes in that their highest flow increase was for the verbal task.     

Brain function in psychiatric disorders. III. Regional cerebral blood flow in unmedicated schizophrenics

Regional cerebral blood flow (rCBF) was measured during resting baseline and the performance of a verbal and a spatial task in 19 unmedicated schizophrenics and 19 matched controls. Abnormalities in rCBF were evident in schizophrenics both for resting and activated measures. Resting flows were higher in the left hemisphere for schizophrenics, supporting the hypothesis of left hemispheric overactivation. This effect was stronger in the more severely disturbed patients. The pattern of rCBF changes during activation with the verbal and spatial tasks was also different in schizophrenics. Laterality of flow changes further supported the hypothesis of left hemispheric overactivation. Furthermore, whereas normals had greater increase in flow for the spatial than the verbal task, schizophrenics showed the reverse pattern. This effect also was more pronounced in the severely disturbed patients. Comparison with an earlier sample of medicated schizophrenics suggested that neuroleptics restore symmetry of resting flows before they produce symptomatic relief. Medication did not affect the abnormalities in pattern of rCBF changes during activation with cognitive tasks.     

Regional cerebral blood flow in schizophrenic disorders

Regional cerebral blood flow was measured using a 133Xe inhalation technique in 16 schizophrenic patients and 20 healthy volunteers. The bilateral frontal blood flows in the patient groups were significantly lower than in the control group. In addition, the patient group having auditory hallucination showed a significantly increased blood flow predominantly in the left temporal region. On the other hand, the patient group without auditory hallucination showed a slightly increased flow in the right temporal region. These findings indicate that there are a hypofrontal activity and also a hypertemporoparietal activity in schizophrenics.     

Tomographic measurements of regional cerebral blood flow in progressive supranuclear palsy and Parkinson's disease

Intellectual changes observed in progressive supranuclear palsy (PSP) are sometimes seen with lesser intensity in Parkinson's disease (PD). Cognitive impairment of PSP has been attributed to a frontal lobe dysfunction explaining the frontal cortex hypometabolism detected by PET. To establish whether this frontal hypometabolism is more pronounced in PSP than in PD, we compared frontal and temporo-parietal cerebral blood flow (CBF) indexes studied by SPECT using Tc99m HmPAO in 18 PSP, 18 PD and 8 control subjects. For each patient neuropsychological performances were also assessed. A significant left frontal hypoperfusion was observed in PSP (mean index value: 0.78 ± 0.03, p < 0.01) and PD (0.78 ± 0.04, p < 0.05) as compared to controls (0.84 ± 0.03), whereas there was no difference between PSP and PD. No correlation was discovered between neuropsychological performances and frontal cortical index changes. This frontal uptake reduction of Tc99m HmPAO in PSP and PD could result from a disconnection phenomenon secondary to subcortical lesions. In both groups mean frontal indexes showed only a left frontal hypoperfusion suggesting that subcortical structures might be asymmetrically involved in early stages of the diseases. The lack of difference for indexe values between PSP and PD might be explained by the difference between the mean disease duration: 4.3 years for the PSP and 7.8 years for the PD. It might also suggest that frontal CBF reduction exists in the same proportions in PD and PSP, but at a later stage in the former case.     

Comparison of regional cerebral blood flow in patients with eating disorders

We used single photon emission computed tomography (SPECT) with Tc-99m-HMPAO to examine the characteristics of regional cerebral blood flow (rCBF) in five patients with bulimia nervosa (BN), eight patients with anorexia nervosa (AN), and in nine healthy controls. The SPECT examinations were performed before and attar food intake stimulus, and the values of the corrected ratio (R) for rCBF in 10 cerebral cortical regions before (R_before) and after eating (R_after) were calculated. The asymmetry indices (AI) of the R values for the left and right side of each cortical region and the percent change from R_before to R_after (%change) were computed. In comparison with the other two groups, BN patients showed significantly higher R_before values in the bilateral inferior frontal and left temporal regions. The AN patients showed significantly lower R_before values in the left parietal region than the control group. There were no significant differences in R_after values among the three groups. The %change values in the AN group showed the greatest increase in 9 out of the 10 regions. In contrast to the positive values obtained from the 10 regions observed in the AN group, 5 out of the 10 regions in the BN group showed negative values. Among the three groups, significant differences in %change were observed on both sides of the inferior frontal, temporal, parietal, and occipital regions. These findings indicate that differences in cerebral function of BN and AN patients can be characterized through SPECT imaging.     

Abnormal regional cerebral blood flow in systemic lupus erythematosus patients with psychiatric symptoms

OBJECTIVE: Single-photon emission computed tomography (SPECT) studies have demonstrated decreased regional cerebral blood flow (rCBF) in systemic lupus erythematosus (SLE) patients. However, no study has done voxel-based analysis using statistical parametric mapping (SPM) that can evaluate rCBF objectively, and the relationship between rCBF and psychiatric symptoms has not been well investigated. Using L,L-ethyl cysteinate dimer (99mTc ECD) SPECT and SPM, we aimed to clarify the association of rCBF changes with psychiatric symptoms in SLE patients whose magnetic resonance imaging (MRI) showed no morphological abnormalities. METHOD: Twenty SLE patients and 19 healthy volunteers underwent 99mTc ECD SPECT. Data were collected from August 2000 to March 2003. SLE was diagnosed according to American College of Rheumatology criteria, and psychiatric symptoms were diagnosed according to ICD-10 criteria. On the basis of the modified Carbotte, Denburg, and Denburg method, the patients were classified into 3 groups: a group with major psychiatric symptoms (hallucinosis, delusional disorder, and mood disorder), a group with minor psychiatric symptoms (anxiety disorder, dissociative disorder, and emotionally labile disorder), and a group without psychiatric symptoms. Gross organic lesions were ruled out by brain MRI. Group comparisons of rCBF were performed with analysis using SPM99. RESULTS: SLE patients without MRI lesions showed decreased rCBF in the posterior cingulate gyrus and thalamus. The reduction in rCBF was overt in patients with major psychiatric symptoms. CONCLUSION: Our study indicated that SLE patients may have dysfunction in the posterior cingulate gyrus and thalamus and that this may be associated with the severity of psychiatric symptoms.     

Changes in regional cerebral blood flow after body image exposure in eating disorders

Relationships of ‘perceptual distortion’ and ‘cognitive evaluation’ components of body image disturbances to brain activity were investigated. Changes in regional cerebral blood (rCBF) of nine patients with anorexia nervosa restrictive type (AN), 13 patients with bulimia nervosa purging type (BN) and 12 controls following three experiments with single photon emission computed tomography (SPECT) were compared: at rest, following a landscape video presentation (neutral stimulus), and after their filmed body image (positive stimulus) exposure. Body distortion was measured with the Silhouette test and body dissatisfaction with the Body Shape Questionnaire (BSQ). Patients with AN showed a hyperactivation of the left parietal and right superior frontal from neutral to positive stimulus. Patients with BN showed a hyperactivation of the right temporal and right occipital areas. Changes in BSQ responses were associated with changes in the right inferior frontal and right temporal rCBF, whereas changes in body distortion were related to the left parietal. The activation of the right temporal after the own body image exposure might be in accordance with the aversive events' response. Functional abnormalities in AN might be related to the storage of a distorted prototypical image of the body in the left parietal lobe.     

焦虑症伴头晕患者脑血流调节能力的研究

目的 通过研究焦虑症伴头晕患者及单纯头晕患者卧立位脑血流调节变化,明确焦虑症对头晕患者脑血流调节的影响并探讨其作用机制.方法 分别选取焦虑症伴头晕患者及单纯头晕患者各20例,检测两组患者卧立位血压及卧立位脑血流.结果 两组患者卧立位血压变化比较无统计学差异,单纯头晕患者脑血流在立位后2min内可恢复到正常水平,而焦虑症伴头晕患者脑血流不能恢复到正常水平.结论 焦虑症伴头晕患者脑血流调节异常是南焦虑状态引起的,这种脑血流调节异常可能是导致患者头晕症状出现的主要原因.     

Effect of hypocapnia on cerebral oxygen metabolism and blood flow in ischemic cerebrovascular disorders

Effects of hypocapnia on cerebral oxygen consumption (CMRO2) and blood flow (CBF) in cerebral ischemia were studied in 19 patients. The CMRO2 did not change significantly during hypocapnia within the whole group of patients, because 10 out of 19 cases showed a decrease (p less than 0.001) and other 9 showed an increase (p less than 0.01) of CMRO2 during hypocapnia. The first 10 showed higher resting CMRO2 (p less than 0.001) and arteriovenous differences of oxygen content (AVDO2; p less than 0.02) than the other 9. However, the resting CBF and CO2 reactivity to hypocapnia were not different between them, and clinical situations were also similar. A dissociation between flow and metabolism was suggested in the first 10 with rather preserved CMRO2, while reduced metabolic demands were suggested in the other 9. Different responses of CMRO2 to hypocapnia are expected in cerebral ischemia, i.e. in cases with rather preserved CMRO2 it decreases despite an AVDO2 increase, suggesting a capability of CMRO2 to respond to CBF reduction, while it increases in cases with more decreased CMRO2, as the AVDO2 increase exceeds the CBF reduction to maintain the decreased CMRO2 for a further CBF reduction. The vascular CO2 reactivity, therefore, might be maintained to be constant between these patients.     

Relationship between psychiatric symptoms and regional cerebral blood flow in patients with mild Alzheimer's disease

Background: Behavioral and psychological symptoms of dementia (BPSD) are frequently observed in patients with dementia and often cause serious problems. However, the cause of BPSD has not yet been elucidated. Moreover, the precise evaluation of BPSD in mild dementia has not been studied in any great detail. In the present study, we investigated the relationship between psychiatric symptoms and regional cerebral blood flow (rCBF) in patients with mild Alzheimer's disease (AD). Methods: The present study included 47 patients (20 men and 27 women) who were diagnosed with mild AD. Mean patient age was 72.8 ± 8.2 years. Single photon emission computed tomography (SPECT) with ^99mTc‐ethyl cysteinate dimer (^99mTc‐ECD) was performed in all patients. The SPECT data were analyzed using a three‐dimensional stereotactic region of interest template, which evaluated CBF in 24 segments. Psychiatric symptoms were evaluated in patients using the Brief Psychiatric Rating Scale. Each psychiatric symptom was designated as ‘symptom present’ in cases in which the BPRS item score was more than 3. We compared 10 segments of rCBF in symptom‐present patients with those in symptom‐absent patients. Results: Motor retardation was the most common psychiatric symptom (36.2%), followed by depression (19.1%), anxiety (17.0%), emotional withdrawal (17.0%), and somatic concern (14.9%). Alzheimer's disease patients with motor retardation exhibited a tendency towards lower rCBF in seven segments (left callosomarginal, bilateral parietal, bilateral angular, and bilateral temporal). However, no specific tendency was observed in depression, anxiety, and somatic concern. Conclusions: In the present study, we observed a tendency for decreased brain perfusion in patients with motor retardation. Further studies are necessary to confirm that this trend contributes to the appearance of psychiatric symptoms in patients with mild AD.     

Regional cerebral blood flow in children--normal value and regional distribution of cerebral blood flow in childhood

The changes in CBF and rCBF through the entire age range include the rapid period in childhood was reported. Sixteen children between the ages of 1 and 15 and 14 adults were studied. These 30 subjects were either volunteers of out-patients without CT and EEG abnormalities. rCBF was measured by the 133Xe intravenous injection method using Varmet rCBF analyzer. Ther relationship between age and CBF, the correlation coefficient was calculated based on the regression equations and the regression curve with the highest correlation was chosen. For the analysis of rCBF, he mean rCBF values (ISI) of 3 channels corresponding to the frontal, temporal, parietal and occipital lobes were expressed as a percentage of the hemispheric CBF. The hemispheric blood flow (ISI and CBF gray) of children less than 5 years of age was approximately twice that found in adults. This value decreased rapidly with age and in the 10-15 years the blood flow was approximately 1.3-fold that of adults. Thereafter, there was a slow decrease and a negative correlation with age was found. The decrease showed the correlation on the following equations; y = 146.5 - 58.5 log x. (r = -0.903) for ISI and log y = 2.26 - 0.29 log x. (r = -0.881) for CBF gray, which was statistically significant. In contrast, the CBF white showed a slightly higher value in the 1-2 years old children, but thereafter the CBF did not show a notable decreases with age. Through the entire age range, a best fit for the Fw values was found with : y = 18.3 + 37.5/x. (r = 0.798), which was also statistically significant.     

Familial aggregation of psychiatric disorders and the consequences for the psychiatric diagnosis

Schizophrenic and affective disorders, anxiety disorders, and alcoholism show familial aggregation; the impact of familial aggregation on the classification and etiology of psychiatric disorders is discussed. Ideal diagnostic schedules should a) identify conditions with a substantially increased familial risk and b) reach diagnostic homogeneity in multiplex families. A review of the literature shows a) that age at onset, long-term course and comorbidity modify familial risks and should therefore be given more attention in diagnostic schedules and b) that the heterogeneity of disorders in multiplex families draws the validity of currently used diagnostic schedules into question. Against this background the hypothesis of "unitary psychosis" is discussed.