Regional cerebral blood flow, clinical manifestations, and age in children with moyamoya disease

In children with Moyamoya disease, transient ischemic attacks often occur during hyperventilation, and the frequency of attacks usually decreases with advancing age. To elucidate the mechanism of the attacks, the regional cerebral blood flow was measured during rest and/or hyperventilation in children aged 3-16 with Moyamoya disease. Regional cerebral blood flow during rest was significantly higher in younger children with Moyamoya disease, and it progressively decreased with advancing age through childhood. During hyperventilation, regional cerebral blood flow decreased in all the children, although blood flow in younger children was still higher than that in the older children. Nevertheless, transient ischemic attacks were more readily precipitated by hyperventilation in the younger than in the older children. Cerebral metabolic demand is much higher in the first decade of life than in later decades. Therefore, it seems likely that even a moderate reduction in cerebral blood flow can cause metabolic impairment in young children. Such high cerebral metabolic demand may play an important role in the frequent occurrence of transient ischemic attacks in young children with Moyamoya disease.     

Cerebral blood flow and metabolism of hyperperfusion after cerebral revascularization in patients with moyamoya disease

In moyamoya disease (MMD), surgical revascularization may be complicated with postoperative hyperperfusion. We analyzed cerebral perfusion and metabolism using positron emission tomography (PET) or single-photon emission computed tomography (SPECT) before and after bypass surgery on 42 sides of 34 adult patients with MMD. In seven cases (16.7%) with symptomatic hyperperfusion, diagnosed by qualitative ¹²³I-iodoamphetamine (IMP) SPECT, a subsequent PET study during postoperative subacute stages revealed significantly increased cerebral blood flow (CBF) from 34.1±8.2 to 74.3±12.8 mL/100 g per minute (P<0.01), a persistent increase in cerebral blood volume (CBV) from 5.77±1.67 to 7.01±1.44 mL/100 g and a significant decrease in oxygen extraction fraction (OEF) from 0.61±0.09 to 0.40±0.08 (P<0.01). Mean absolute CBF values during symptomatic hyperperfusion were more than the normal control +2 standard deviations, the predefined criteria of PET. Interestingly, two patients with markedly increased cerebral metabolic rate of oxygen (CMRO₂) at hyperperfusion were complicated with postoperative seizure. Among preoperative PET parameters, increased OEF was the only significant risk factor for symptomatic hyperperfusion (P<0.05). This study revealed that symptomatic hyperperfusion in MMD is characterized by temporary increases in CBF >100% over preoperative values caused by prolonged recovery of increased CBV.     

Hemorrhage predisposing to cerebral infarction in children with moyamoya disease

Two children with a new diagnosis of hemorrhagic type moyamoya disease experienced cerebral infarction after intraventricular hemorrhage. The patients developed ischemia 15 and 2 days after the initial diagnosis of hemorrhage. No provocative factor such as hypoperfusion was identified, but both patients exhibited signs of increased intracranial pressure on computed tomographic scan before infarction. Increased intracranial pressure in the setting of hemorrhage may be a risk factor for ischemic complications in patients with moyamoya disease. The optimal acute management of these patients requires further study.     

Cerebral blood flow in moyamoya disease

Regional cerebral blood flow in forty cases of moyamoya disease was investigated by intravenous 133Xe injection method. Twenty-one cases were children and other nineteen were adults. No or only slight neurological deficit were found at the CBF studies. CBF was calculated by initial slope index. For investigation of the relation between hemispheric blood flow and age, the regression curve was calculated and that with highest correlation was chosen. In normal group, the relationship between hemispheric CBF and age was correlated to following equation: y = 146.5-58.4 log x (r = -0.903). In contrast, in moyamoya disease, it was correlated to following equation: log y = 2.04-0.23 log x (r = -0.730). It can be said that CBF of the whole brain in moyamoya disease is below normal. The distribution of the rCBF was characteristic in moyamoya disease. There are low CBF values in the frontal and temporal lobes and relatively high values in the occipital lobes as compared with normal CBF distribution. These results are thought to indicate the importance of blood circulation to the brain from the vertebro-basilar arterial system. Moreover a comparison of these CBF results with the six stages of basal moyamoya seen angiographically was investigated in child cases. As the stage of moyamoya disease progressed, the hemispheric CBF decreased gradually and the distribution of blood flow gradually changed from a predominance of flow to the frontal lobes to a predominance of flow to the occipital lobes.     

Regional cerebral blood flow in children with ADHD: changes with age

The aim of this study was to investigate the changes in regional cerebral blood flow (rCBF) with age in patients with attention deficit hyperactivity disorder (ADHD). Twenty-nine drug-naive ADHD subjects (24 boys, 5 girls; age 7-13; mean+/-SD=age 9.2+/-2.1) and 12 subjects with epilepsy (all diagnosed as having complex partial seizure, 6 boys, 6 girls; age 7-14; mean+/-SD=8.5+/-2.1) were included in the study. All cases of ADHD were diagnosed according to DSM-IV criteria. Cerebral blood flow was evaluated with Tc-99m-hexamethylpropyleneamine oxime (Tc99m HMPAO) brain single photon emission tomography (SPECT) during standard resting condition in all of the cases. Asymmetry indices for each region of interest were calculated. Absolute rCBF values were normalized as the absolute rCBF values divided by the whole brain absolute value. The prefrontal lobe asymmetry indices were significantly negatively correlated with age in ADHD cases (r=-0.408, P=0.025), which indicated the increased prefrontal rCBF lateralization from the right to the left side with age. When ADHD cases older than 7 years of age were compared with those with epilepsy, the ADHD cases had lower right prefrontal and frontal rCBF and higher left parietal rCBF. The epilepsy group showed no significant correlations between age and asymmetry indices and showed a different developmental trajectory for prefrontal asymmetry and right prefrontal rCBF values. The results indicated that the left hemisphere dominance in the prefrontal cortex significantly increases with age in ADHD cases.     

Regional cerebral blood flow in pediatric moyamoya disease: age-dependent decline in specific regions

Thirteen pediatric patients (ages 4–13 years) who underwent surgical treatment were examined regarding their rCBF in the preoperative periods. The postoperative rCBF was measured 39 times in these 13 patients. Thirteen healthy normal subjects (ages from 6 to 21 years) were also examined. The rCBF in the operculum and in the frontal, parietal, and occipital lobes was measured with ¹³³Xe inhalation method and single photon emission computed tomography. In the parietal and occipital lobes, the preoperative rCBF had a negative and significant correlation with their ages, but not in the operculum or frontal lobe. However, subsequent to the surgical treatment, the rCBF increased significantly in the patients 5 years old or less, and then post-operative rCBF values had significant negative correlations with age in each region. Received: 10 September 1997     

Regional cerebral blood flow changes associated with emotions in children

Combining a wireless telemetry system and a portable near-infrared instrument, we developed a movable optical spectroscopy system for monitoring cerebral hemodynamic changes. The patient carries a miniaturized near-infrared spectroscopy instrument on the back, and data are sent by a wireless telemetry system to a computer, without restricting patient movement. We used this system to detect hemodynamic changes associated with being startled, anticipation, and pleasant and unpleasant emotions in the bilateral prefrontal cortices of 16 right-handed 4- to 6-year-old preschool children while they were watching a 21-minute video clip consisting of various scenes that elicited emotional responses, interpolated with neutral scenes for comparison. The children were relaxed and cooperative when they were studied. Anticipation was associated with increases in cerebral blood flow in the left prefrontal cortex of the 6-year-old children, and unpleasant emotion was associated with decreases in cerebral blood flow bilaterally compared with neutral emotion, irrespective of age. No hemodynamic changes associated with the startle response were observed. Although this study should be considered preliminary, it is suggested that the emotional response is age-dependent and that the left prefrontal cortex participates in anticipation. Our newly developed system will open a window into brain physiology in children.     

Regional cerebral blood flow in moyamoya disease using 123-I IMP-SPECT--follow up study before and after therapy

The recent development of a new radiopharmaceutical 123 I-isopropyl-p-iodoamphetamine (IMP), which is taken up by the brain from the blood flow, has offered a possibility of constructing scintigraphy maps of regional cerebral blood flow (rCBF) using single photon emission CT. We evaluated the clinical utility of this method in moyamoya disease. Five patients with moyamoya disease, who were examined by IMP-SPECT before and after bypass operations, were selected. On the IMP images before operations, all patients showed focal or global decrease of rCBF. There was a good correlation between the area and degree of rCBF abnormalities and severity of clinical symptoms and stage on angiography. The area of rCBF decrease coincided with the dominant area of rebuild-up phenomena on EEG. On the IMP images just after operations, the rCBF changed for the worse transiently in three patients, and the crossed cerebellar diaschisis appeared in two patients. On the IMP images 3 months after operations, the rCBF increased in company with the improvement of clinical symptoms. The increased rCBF on the point of operation was recognized in two patients with good prognosis. These results suggest that IMP-SPECT is a noninvasive and useful method of assessing the effects of therapy as well as the characteristic hemodynamic abnormalities in moyamoya disease.     

Cerebral blood flow velocities in an infant with moyamoya disease

Moyamoya disease is a progressive cerebrovascular disorder with bilateral occlusion of the basal circulation and development of collateral blood supply. In a 6-month-old female with multifocal ischemic infarctions, transcranial pulsed Doppler sonography revealed extremely high and low cerebral blood flow velocities, dampened waveforms, reversed flow, and musical murmurs. Magnetic resonance angiography revealed different degrees of vascular stenosis and an abnormal collateral network. Moyamoya disease was confirmed by conventional angiography at the age of 10.5 months. Pulsed-wave transcranial Doppler sonography is a noninvasive screening method in infants at risk of moyamoya disease.     

Modulation of cerebral hemodynamics by surgical revascularization in patients with moyamoya disease

The purpose of this study was to evaluate hemodynamic compromise in the patients with moyamoya discase and surgical modulation of the hemodynamics using stable xenon enhanced computed tomographic CBF measurement with the acetazolamide challenge. The study group consisted of 15 preoperative cases and 17 postoperative cases. In the preoperative group, regional resting cerebral blood flow (rCBF) and regional cerebrovascular reserve capacity (rCRC) were reduced. The reduction was more prominent in the anterior circulation than in the posterior circulation. In the postoperative group, rCBF and rCRC were still low in the anterior circulation. Revascularization increased the resting CBF but did not change the CRC. Postoperative CBF did not increase in adults but increased in children. These findings suggest that the misery perfusion state may be present only in the child's brain. Measurement of CBF and CRC is useful to evaluate the hemodynamics of moyamoya disease.     

Hemorrhagic moyamoya disease in children: clinical features and surgical outcome

Objective  

The clinical presentation of moyamoya disease (MMD) typically includes cerebral ischemia in children and intracranial hemorrhage in adults. Because of its rarity, the benefit of surgery in the hemorrhagic type of pediatric MMD has not been clearly established. The purpose of this study was to delineate the clinical features and surgical outcome of hemorrhagic MMD in children.     

Cerebral blood flow findings in moyamoya disease in adults

Three adult patients with moyamoya disease are described. They presented with intracerebral hematoma, cerebral infarction and subarachnoid hemorrhage, respectively. Subarachnoid hemorrhage is rare in moyamoya and is usually the result of aneurysm rupture. No aneurysm was found in our patient. Regional cerebral blood flow (rCBF) and the cerebral perfusion reserve assessed by the acetazolamide test, were significantly reduced in all three patients. The areas with most reduced baseline rCBF and most impaired vasoreactivity did not always correspond to the site of the vascular accident, indicating that these CBF changes were at least in part due to the moyamoya disease and/or its underlying causes, and not solely to the vascular accidents.     

Regional cerebral blood flow changes in depression after electroconvulsive therapy

A large number of studies have documented regional cerebral blood flow (rCBF) abnormalities in depression. A smaller yet significant number of studies have examined changes in rCBF before and after treatment. The findings, however, have been variable with regard to changes before and after electroconvulsive therapy (ECT). A consecutive series of patients (n=10) with drug-resistant major depressive episode according to DSM-IV with 17-item Hamilton Rating Scale for Depression (HRSD) scores greater than or equal to 14 gave their informed consent and were studied with technetium-99m ethyl cysteinate dimer single-photon emission computed tomography (99mTc-ECD SPECT) before and after a course of ECT. The results were analyzed with statistical parametric mapping version 99. No region showed significant positive correlations between rCBF patterns of changes and HRSD changes, but three clusters emerged as showing significant negative correlations. These regions corresponded with left frontopolar gyrus, left amygdala, globus pallidus and nucleus accumbens, and left superior temporal gyrus. It was speculated that ECT affected both the prefrontal cortex, commonly assumed to be involved in depression, and the amygdala, known to play a central role in the processing of emotional stimuli, through the limbic-cortical-striatal-pallidal-thalamic circuit.     

Regional cerebral blood flow and prognostic evaluation in Alzheimer's disease

The present investigation reports the application of regional cerebral blood flow (rCBF; (133)Xe method) to prognostic purposes in a consecutive series of 76 patients (mean age 68.4 +/- 8.7 years) with probable Alzheimer's disease (AD; NINCDS-ADRDA criteria). The likelihood that rCBF from a posterior temporal-inferior parietal area in each hemisphere at the first visit may predict timing of achievement of three endpoints (i.e. loss of activity of daily living, ADL, incontinence and death due to end-stage AD) was tested by the 'lifereg' procedure of the Statistical Analysis System package. With respect to baseline evaluation, 32 patients lost ADL 20.6 +/- 17.4 months later, 31 developed incontinence 27.1 +/- 19.0 months later, and 16 patients died after 40.9 +/- 23.8 months of follow-up. Baseline rCBF significantly predicted all end-points: the loss of ADL (left hemisphere: p = 0.04; right hemisphere: p = 0.02), incontinence (p = 0.02 in both hemispheres) and death (p = 0.01 in both hemispheres). Statistical significance was maintained for the loss of ADL and incontinence both in a subgroup of mildly demented patients, in whom death was not considered due to the low number of patients who died, and in a multivariate analysis including patient age, age at onset, sex, duration of illness, Mini-Mental State Examination score and presence of extrapyramidal signs and psychotic symptoms at the first visit. This study shows that rCBF measurement in a posterior temporal-inferior parietal area may give prognostic information on timing of evolution of AD, whenever performed during the course of the disease, and may be utilized both in clinical practice and for social planning.     

Autoregulation of cerebral blood flow to changes in arterial pressure in mild Alzheimer's disease

Studies in transgenic mice overexpressing amyloid precursor protein (APP) demonstrate impaired autoregulation of cerebral blood flow (CBF) to changes in arterial pressure and suggest that cerebrovascular dysfunction may be critically important in the development of pathological Alzheimer''s disease (AD). Given the relevance of such a finding for guiding hypertension treatment in the elderly, we assessed autoregulation in individuals with AD. Twenty persons aged 75±6 years with very mild or mild symptomatic AD (Clinical Dementia Rating 0.5 or 1.0) underwent ¹⁵O-positron emission tomography (PET) CBF measurements before and after mean arterial pressure (MAP) was lowered from 107±13 to 92±9 mm Hg with intravenous nicardipine; ¹¹C-PIB-PET imaging and magnetic resonance imaging (MRI) were also obtained. There were no significant differences in mean CBF before and after MAP reduction in the bilateral hemispheres (−0.9±5.2 mL per 100 g per minute, P=0.4, 95% confidence interval (CI)=−3.4 to 1.5), cortical borderzones (−1.9±5.0 mL per 100 g per minute, P=0.10, 95% CI=−4.3 to 0.4), regions of T2W-MRI-defined leukoaraiosis (−0.3±4.4 mL per 100 g per minute, P=0.85, 95% CI=−3.3 to 3.9), or regions of peak ¹¹C-PIB uptake (−2.5±7.7 mL per 100 g per minute, P=0.30, 95% CI=−7.7 to 2.7). The absence of significant change in CBF with a 10 to 15 mm Hg reduction in MAP within the normal autoregulatory range demonstrates that there is neither a generalized nor local defect of autoregulation in AD.