Correlation between special brain area and blood perfusion in patients with cerebral infarction at convalescent period Feasibility for quantitative determination and estimation of learning and memory function

BACKGROUND： Presently, clinic memory scale is used to evaluate learning memory ability in most studies, and the influence of difference in measurement condition of individuals exists. OBJECTIVE： To study the correlation between regional cerebral blood flow （rCBF） perfusion and learning memory function in special brain regions of patients with cerebral infarction at convalescent period, and to try to find out a method which can quantitatively evaluate learning ability. DESIGN： Case observation, and correlation analysis. SETTINGS： Shandong Institute for Behavioral Medicine; the Affiliated Hospital of Jining Medical College. PARTICIPANTS： Totally 70 patients with cerebral infarction admitted to Department of Neurology, Jining Medical College between January 2004 and December 2005 were involved. The involved patients, 58 male and 12 female, were averaged （52±3） years, and they were all right handed. They all met the diagnosis criteria instituted by the Fourth National Conference on Cerebrovascular Disease, and were confirmed as cerebral infarction by skull CT or MRI. Informed consents of detected items were obtained from all the patients and relatives. METHODS： When the patients were at convalescent period, their learning and memory ability were measured with “ clinic memory scale （set A）”. The 18 patients whose total mark over 100 were regarded as good learning memory function group; The 23 cases whose total mark less than 70 were regarded as poor learning memory function group. RCBF of hippocampus, nucleus amygdalae, temporal cortex and prefrontal lobe of patients between two groups were measured and compared by single photon emission computed tomography （SPECT）. The total scores of the 18 good learning memory patients and 23 poor learning memory patients were taken as dependent variable Y, and their rCBFs of hippocampus, nucleus amygdale, temporal cortex and prefrontal lobe respectively as independent variable X for linear correlation analysis. MAIN OUTCOME MEASURES： Correlation of rCBF in different brain regions and learning memory ability in patients with cerebral infarction. RESULTS： ①The rCBF of hippocampus, nucleus amygdale, temportal cortex and prefrontal cortex of good learning memory function group were significantly higher than those of poor learning memory function group （P 〈 0.05）. ②In the good learning memory function group, rCBF of hippocampus, nucleus amygdale, temportal cortex and prefrontal cortex were significantly positively correlated with memory scale scores （ r = 0.961, 0.926, 0.954, 0.907, P 〈 0.05 ） , and also in the poor learning memory function group （r = 0.979, 0.976, 0.991, 0.953, P 〈 0.05 ） . CONCLUSION： The rCBF of hippocampus, nucleus amygdale, temportal cortex and prefrontal cortex of patients with cerebral infarction are significantly positively correlated with memory scale scores. Predicting learning memory ability of patients by quantitative determination of rCBF provides a quantitative and objective method for evaluating learning memory ability.

EFFECT OF ELECTROACUPUNCTURE ON CEREBRAL BLOOD FLOW, VIP AND ET IN RATS WITH VASCULAR DEMENTIA

Objective: To investigate the relationship between electroacupuncture (EA)-induced improvement of regional cerebral blood flow and the alternations of vasoactive intestinal peptide (VIP) and endothelin (ET) in rats with experimental vascular dementia (VD). Methods: 40 Wistar rats were evenly randomized into sham-operation, model, medication (Nimotone) and EA groups. Vascular dementia model was established by repeated cerebral ischemia-reperfusion which was induced by occlusion and reopen of the bilateral common carotid arteries. EA (2～200 Hz, 2～3 mA) was applied to "Baihui"(GV 20), "Dazhui"(GV 14) and "Zusanli"(ST 36) for 30 min, once daily and continuously for 15 days. The regional cerebral blood flow (rCBF) in parietal lobe and hippocampus was determined with method of hydrogen clearance; a step-down avoidance test was adopted to observe the rats’ behavior change; and plasma VIP and ET contents were assayed by radioimmunoassay. Results: In comparison with sham-operation group, the correct rate of step-down avoidance test, rCBF in parietal lobe and hippocampus and plasma VIP level in VD model group lowered significantly (P<0.01) and plasma ET increased considerably (P<0.01). However, compared with model group, the correct rate of step-down avoidance test, rCBF values and plasma VIP in EA group raised obviously while plasma ET declined significantly. No significant differences were found between EA and medication groups in the 4 indexes. Conclusion: EA can raise rCBF in the parietal lobe and hippocampus, elevate plasma VIP level and reduce plasma ET in rats with VD.

STUDY OF REGIONAL STABILITY OF ECD DISTRIBUTION IN NORMAL BRAIN

Objective To evaluate in vivo stability of ethylenedylbis cysteine diethylester (ECD) brain SPECT. Methods Each of 13 normal volunteers (31. 2 ± 11. 8 years) has 12 dynamic SPECK scans ac-quired in 60min 1h after an injection of 99mTc-ECD using a triple headed gamma camera equipped with ultra high resolution fan beam collimators. Average counts per pixel were measured from frontal, temporal, parie-tal, occipital regions, cerebellum, basal ganglia, thalamus and white matter. Regional ECD clearance rates, regional gray-to-white matter (G/W) ratios and the change of the G/W ratio were calculated. Results The average ECD clearance rate was 4. 2% /h, ranged from 3. 03% /h to 5. 41% /h corresponding to white matter and occipital. There was no significant difference between regional ECD clearance rates. Regional G 7W ratio was between 1.27 to 1.75. The G/W ratio of temporal lobe was lower than the occipital ( P <0.05). The change of regional G/W ratio with time is slow. Conclusion Regional ECD distribution is stable in normal brain. ECD clearance from brain is slow and no significant regional difference.

Observation on the effect of acupoint stimulation on regional cerebral blood flow using near-infrared spectroscopy technology

Objective To observe the effect of acupuncture at Kongzui（孔最LU 6）,Sanyinjiao（三阴交 SP 6） and Zusanli（足三里 ST 36） on cerebral blood oxygenation level and explore the relevance between acupuncture and cerebral blood oxygenation level using near-infrared spectroscopy（NIRS）.Methods Quasi-randomized design（random test sequence） was used.In clinical trial ①,placebo acupuncture was applied at Baihui（百会GV 20） of18 adults.In clinical trial ②,54 adults were divided into three groups with 18 each in which acupuncture was applied at LU 6,SP 6 and ST 36 respectively.Before and after acupuncture,verbal fluency test（VFT） was performed and the blood oxygenation level of cerebral cortex was measured using NIRS.Quantized data was processed with JMP10.0.2 software and SPSS software.Results In clinical trial ①,the mean integral values of cerebral blood oxygenation level were 10.8 mMcm·s and 9.2 mMcm·s respectively before and after acupuncture at GV 20 in placebo acupuncture group.There was no significant difference in the cerebral blood oxygenation level after acupuncture.In clinical trial ②,the mean integral values of cerebral blood oxygen level were18.1 mMcm·s and 8.6 mMcm·s respectively before and after acupuncture at LU 6 in[LU 6]acupuncture group,the cerebral blood oxygenation level was significantly decreased after acupuncture（P = 0.001）.The mean integral values of cerebral blood oxygenation level were 16.1 mMcm·s and 17.4 mMcm·s respectively before and after acupuncture at SP 6 in[SP 6]acupuncture group,the cerebral blood oxygenation level was slightly increased after acupuncture,but the increase was not statistically significant.The mean integral values of cerebral blood oxygenation level were 13.8 mMcnvs and 10.1 mMcnvs respectively before and after acupuncture at ST 36 in[ST 36]acupuncture group,the cerebral blood oxygenation level was slightly deceased after acupuncture,but the increase was not statistically significant.Conclusion The cerebral blood oxygenation level of frontal head was decreased by acupuncture at LU 6,the cerebral blood oxygenation level of frontal head was intended to decrease by acupuncture at ST 36.The cerebral blood oxygenation level of frontal head is intended to increase by acupuncture at SP 6.

Regional cerebral blood flow in children with autism spectrum disorders： a quantitative 99mTc-ECD brain SPECT study with statistical parametric mapping evaluation

Background Autism spectrum disorders （ASD）, which include autism, asperger syndrome （AS） and pervasive developmental disorder-not otherwise specified （PDD-NOS）, are devastating neurodevelopmental disorders of childhood resulting in deficits in social interaction, repetitive patterns of behaviors, and restricted interests and activities. Single photon emission computed tomography （SPECT） is a common technique used to measure regional cerebral blood flow （rCBF）. Several studies have measured rCBF in children with ASD using SPECT, however, findings are discordant. In addition, the majority of subjects used in these studies were autistic. In this study, we aimed to investigate changes in rCBF in children with ASD using SPECT.Methods A Technetium-99m-ethyl cysteinate dimmer （99mTc-ECD） brain SPECT study was performed on an ASD group consisting of 23 children （3 girls and 20 boys; mean age （7.2±3.0） years） who were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, 4th edition （DSM-Ⅳ） criteria and an age-matched control group with 8children （1 girl and 7 boys, mean age （5.5±2.4） years）. Image data were evaluated with Statistical Parametric Mapping,5th version （SPM5）. A Student＇s t test for unpaired data was used to compare rCBF and asymmetry in the autism and corresponding control group. The covariance analysis, taking age as covariance, was performed between the ASD and control group.Results There was a significant reduction in rCBF in the bilateral frontal lobe （frontal poles, arcula frontal gyrus） and the bilateral basal ganglia in the autism group, and a reduction in the bilateral frontal, temporal, parietal, legumina nucleus and cerebellum in the AS group compared to the control. In addition, asymmetry of hemispheric hypoperfusion in the ASD group was observed. Inner-group comparison analysis revealed that rCBF decreased significantly in the bilateral frontal lobe （42.7%）, basal nucleus （24.9%） and temporal lobe （22.8%） in the autism group, and in the bilateral cerebellum （22.8%）, basal nucleus （19.3%） and right thalamencephalon （16.6%）in the AS group （P ＜0.05）.Conclusions The decrease in rCBF in ASD is a global event, which involves the bilateral frontal, temporal, limbic system and basal ganglias. Asymmetry of hemispheric hypoperfusion was more obvious in the AS group than the autism group, which indicates a different neurobiological mechanism from that of autism.

Laser Doppler flowmeter study on regional cerebral blood flow in early stage after standard superficial temporal artery-middle cerebral artery bypass surgery for moyamoya disease

Background Standard superficial temporal artery-middle cerebral artery （STA-MCA） bypass surgery is an effective treatment for moyamoya disease, but recent evidence suggests that postoperative cerebral hyperperfusion can occur. In this study, the trendline of changes in regional cerebral blood flow （rCBF） after surgery were continually monitored near the site of anastomosis in order to investigate both the efficacy of the procedure for improving rCBF and the possible risk of hyperperfusion . Methods Standard STA-MCA bypass surgery was performed on 13 patients, rCBF was measured continually using laser Doppler flowmetry （LDF） until the 5th day after the operation with the LDF probe implanted adjacent to the area of the anastomosis. The trendline of rCBF changes postoperatively was recorded for the analysis performed using SPSS 13.0. Results The baseline LDF value of cortical rCBF was （84.68±14.39） perfusion unit （PU）, which was linear relative to absolute perfusion volume before anastomosis and （88.90±11.26） PU immediately after anastomosis （P 〉0.05）. The value changed significantly from before to after anastomosis （P 〈0.05）; it was （417.72±21.35） PU on the 1st day after surgery, and （358.99±18.01） PU, （323.46±17.38） PU, （261.60±16.38） PU and （375.72±18.45） PU on the following 4 days, respectively. The rCBF decreased gradually from the 2nd day until the 4th postoperative day, but still was at a high level （P 〈0.05）. However, on the 5th postoperative day the rCBF increased again to the second highest level, which was significantly different compared with the baseline value （P 〈0.05）, but not significantly different compared with the values on the other 4 days （P〉0.05）. Conclusions STA-MCA anastomosis improves the cerebral blood supply significantly in the early stage after surgery, however, the risk of symptomatic hyperperfusion may exist, which may possibly occur on the 1st day and 5th day after surgery. A LDF is useful for postoperative monitoring for both the efficacy of bypass and possible risk of neurologic deterioration or bleeding from hyperperfusion.

Apolipoprotein E polymorphisms increase the risk of post-stroke depression

Recent reports have shown that apolipoprotein E （APOE） polymorphisms are involved in neurodegenerative disease. However, it is unclear whether APOE affects post-stroke depression. Accordingly, we hypothesized that APOE polymorphisms modify the risk of post-stroke depression. Here, we performed a hospital-based case-control study （including 76 cerebral infarction cases with post-stroke depression, 88 cerebral infarction cases without post-stroke depression, and 109 controls without any evidence of post-stroke depression or cerebral infarction） to determine possible association between APOE rs429358 and rs7412 polymorphisms and risk of post-stroke depression. Our findings show no difference among the groups with regards genotype distribution of the rs7412 polymorphism. In contrast, APOE genotypes with rs429358-C alleles increased the risk of post-stroke depression. Further, the rs429358 polymorphism was associated with significantly decreased regional cerebral blood flow values in the left temporal lobe of post-stroke depression cases. Additionally, the rs429358 polymorphism was not only associated with depression severity, but with increasing serum levels of total cholesterol. These resuits suggest that the APOE rs429358 polymorphism is associated with increased risk of developing post-stroke depression, and that APOE rs429358-C allele genotypes may be detrimental to recovery of nerve function after stoke. Indeed, these findings provide clinical data for future post-stroke depression gene interventions.

Influences of Age and Length of Education on rCBF-SPECT in Healthy Elderly:Diagnostic Implications for Dementia

Background: Few previous studies have described other than age- and gender related changes in regional cerebral blood flow (rCBF) in healthy elderly. What is the influence of other common clinically relevant variables such as ache, education, MMSE, and smoking history? Purpose: To study rCBF in Swedish healthy elderly by single-photon emission computed tomography (SPECT) and evaluate the influence on rCBF of age, gender, education, MMSE, ache, and smoking with a focus on education in relation to the ‘cognitive reserve’. Methods: Healthy subjects (n = 45, 50 -75 y), sampled from a large longitudinal aging study took part in an extensive examination of health and memory, including cognitive testing and socio-economic survey. After injection of 99 mTc-hexamethylpropylene amine oxime (HMPAO) followed by SPECT the rCBF-SPECT images were analyzed using statistical parametric mapping (SPM). Results: Age-related decreases in uptake were seen in interhemispheric and interlobar regions. There was a positive rCBF correlation with education in the inferior frontal lobe and a higher uptake in the left temporal lobe in an age-gender-matched high education subgroup. Conclusion: The localization of the age related findings except for the medial temporal lobe differs markedly from typical dementia related findings. A reduction close to interhemispheric or interlobar space should always be related to chronological age. Education seems to have an influence on basal brain function at a resting-state condition. Knowledge of normal rCBF variations for variables such as age and education should be considered when making clinical diagnosis. The findings could be interpreted as further support for the theory of cognitive reserve.