Reversible Cerebral Angiopathy after Viral Infection in a Pediatric Patient with Genetic Variant of RNF213.

Ring finger protein (RNF) 213 is known as a susceptibility gene for moyamoya disease (MMD), which is characterized by bilateral carotid folk stenosis. Cerebral angiopathy after viral infection has been known to present angiographical appearance resembling MMD, however its pathogenesis and genetic background are not well known. We report a case of reversible cerebral angiopathy after viral infection in a pediatric patient with genetic variant of RNF213 mutation. The patient had developed a severe headache after hand, foot, and mouth disease. Magnetic resonance imaging and magnetic resonance angiography (MRA) performed 2-3 weeks after disease onset revealed bilateral carotid folk stenosis and an old cerebral infarction in the left putamen. The patient's headache spontaneously resolved and the follow-up MRA showed a complete spontaneous resolution of the arterial stenosis after 9 months. We were able to determine genetic predisposition to angiopathy by identifying the RNF213 c.14576G>A (rs112735431, p.R4859K) mutation. Based on the present case, we hypothesize that an RNF213 variant might play an important role for the onset of postviral cerebral angiopathy.

Heritability of Cerebral Blood Flow and the Correlation to Schizophrenia Spectrum Disorders: A Pseudo-continuous Arterial Spin Labeling Twin Study.

Whether aberrant cerebral blood flow (CBF) in schizophrenia is affected by genetic influences, and consequently a potential marker for genetic susceptibility, is unknown. Our aims were to determine the heritability of CBF in thalamic, frontal, and striatal areas, and to ascertain if associations with disease were under genetic influence. Monozygotic (MZ) twin pairs concordant (n = 2) or discordant (n = 20) for schizophrenia spectrum disorders (ICD-10 F2x.x), matched on sex and age with dizygotic (DZ; n = 20) and healthy control pairs (MZ: n = 27; DZ: n = 18; total: n = 181 individuals), were recruited via the National Danish Twin Register. CBF in thalamus, frontal lobes, and putamen was measured with pseudo-continuous arterial spin labeling on a 3 T magnetic resonance scanner. Twin statistics were performed with structural equation modeling. CBF in the frontal lobes was heritable (h2 = 0.44, 95% CI [0.22-0.60]) but not correlated to disease. CBF correlated to schizophrenia spectrum disorders in the left thalamus (r = 0.17, [0.03-0.31]; P = 0.02), as well as in the left putamen (r = 0.19, [0.05-0.32]; P = 0.007) and the right putamen (r = 0.18, [0.03-0.32]; P = 0.02). When restricting the sample to schizophrenia (F20.x) only, shared genetic influences between CBF in the left putamen and schizophrenia liability (phenotypic correlation = 0.44, [0.28-0.58], P < 0.001) were found. Our results provide heritability estimates of CBF in the frontal lobes, and we find CBF in thalamus and putamen to be altered in schizophrenia spectrum disorders. Furthermore, shared genetic factors influence schizophrenia liability and striatal perfusion. Specifically, higher perfusion in the left putamen may constitute a marker of genetic susceptibility for schizophrenia.

Regional reduction in cortical blood flow among cognitively impaired adults with relapsing-remitting multiple sclerosis patients.

PURPOSE: Detection of cortical abnormalities in relapsing-remitting multiple sclerosis (RRMS) remains elusive. Structural magnetic resonance imaging (MRI) measures of cortical integrity are limited, although functional techniques such as pseudo-continuous arterial spin labeling (pCASL) show promise as a surrogate marker of disease severity. We sought to determine the utility of pCASL to assess cortical cerebral blood flow (CBF) in RRMS patients with (RRMS-I) and without (RRMS-NI) cognitive impairment. METHODS: A total of 19 age-matched healthy controls and 39 RRMS patients were prospectively recruited. Cognition was assessed using the Minimal Assessment of Cognitive Function in Multiple Sclerosis (MACFIMS) battery. Cortical CBF was compared between groups using a mass univariate voxel-based morphometric analysis accounting for demographic and structural variable covariates. RESULTS: Cognitive impairment was present in 51.3% of patients. Significant CBF reduction was present in the RRMS-I compared to other groups in left frontal and right superior frontal cortex. Compared to healthy controls, RRMS-I displayed reduced CBF in the frontal, limbic, parietal and temporal cortex, and putamen/thalamus. RRMS-I demonstrated reduced left superior frontal lobe cortical CBF compared to RRMS-NI. No significant cortical CBF differences were present between healthy controls and RRMS-NI. CONCLUSION: Significant cortical CBF reduction occurs in RRMS-I compared to healthy controls and RRMS-NI in anatomically significant regions after controlling for structural and demographic differences.

Simultaneous CBF and BOLD mapping of high frequency acupuncture induced brain activity.

This study mapped brain activity elicited by high frequency electroacupuncture by simultaneously using blood oxygenation level dependent (BOLD) and cerebral blood flow (CBF) contrasts. Forty subjects participated in the study, in which twenty ones were imaged during electrical acupoint stimulation (EAS) to the left LI4 acupoint at a maximal intensity without pain, and the others were with a minimal-EAS at a just detectible intensity. Both BOLD and CBF data were acquired simultaneously during alternating blocks of rest and stimulation. The results showed that the minimal-EAS mostly induced the activities in somatosensory region, including those in inferior parietal lobule, SII, insula, and thalamus. On the other hand, EAS activated more including also posterior middle cingulate cortex (pMCC), and deactivated superior temporal gyrus. Moreover, deactivation was found in posterior cingulated cortex (PCC), precuneus from BOLD and in culmen of cerebellum, caudate from CBF. The comparison between EAS and minimal-EAS revealed deactivation in the default mode network in both BOLD and CBF signals, activation in thalamus, insula, and caudal anterior cingulate cortex (ACC) in the CBF signal alone, and deactivation in putamen, rostral ACC and parahippocampal gyrus in the BOLD signal alone. This study provides, for the first time, simultaneous CBF and BOLD responses to high frequency EAS at the LI4 acupoint, revealing concordant and complementary insights into the neural effects of EAS, including modulation of subcortical structures and limbic system.

MDMA (Ecstasy) association with impaired fMRI BOLD thalamic coherence and functional connectivity.

BACKGROUND: MDMA exposure is associated with chronic serotonergic dysfunction in preclinical and clinical studies. A recent functional magnetic resonance imaging (fMRI) comparison of past MDMA users to non-MDMA-using controls revealed increased spatial extent and amplitude of activation in the supplementary motor area during motor tasks (Karageorgiou et al., 2009). Blood oxygenation level dependent (BOLD) data from that study were reanalyzed for intraregional coherence and for inter-regional temporal correlations between time series, as functional connectivity. METHODS: Fourteen MDMA users and ten controls reporting similar non-MDMA abuse performed finger taps during fMRI. Fourteen motor pathway regions plus a pontine raphé region were examined. Coherence was expressed as percent of voxels positively correlated with an intraregional index voxel. Functional connectivity was determined using wavelet correlations. RESULTS: Intraregional thalamic coherence was significantly diminished at low frequencies in MDMA users compared to controls (p=0.009). Inter-regional functional connectivity was significantly weaker for right thalamo - left caudate (p=0.002), right thalamo - left thalamus (p=0.007), right caudate - right postcentral (p=0.007) and right supplementary motor area - right precentral gyrus (p=0.011) region pairs compared to controls. When stratified by lifetime exposure, significant negative associations were observed between cumulative MDMA use and functional connectivity in seven other region-pairs, while only one region-pair showed a positive association. CONCLUSIONS: Reported prior MDMA use was associated with deficits in BOLD intraregional coherence and inter-regional functional connectivity, even among functionally robust pathways involving motor regions. This suggests that MDMA use is associated with long-lasting effects on brain neurophysiology beyond the cognitive domain.

Movement initiation-locked activity of the anterior putamen predicts future movement instability in periodic bimanual movement.

In periodic bimanual movements, anti-phase-coordinated patterns often change into in-phase patterns suddenly and involuntarily. Because behavior in the initial period of a sequence of cycles often does not show any obvious errors, it is difficult to predict subsequent movement errors in the later period of the cyclical sequence. Here, we evaluated performance in the later period of the cyclical sequence of bimanual periodic movements using human brain activity measured with functional magnetic resonance imaging as well as using initial movement features. Eighteen subjects performed a 30 s bimanual finger-tapping task. We calculated differences in initiation-locked transient brain activity between antiphase and in-phase tapping conditions. Correlation analysis revealed that the difference in the anterior putamen activity during antiphase compared within-phase tapping conditions was strongly correlated with future instability as measured by the mean absolute deviation of the left-hand intertap interval during antiphase movements relative to in-phase movements (r = 0.81). Among the initial movement features we measured, only the number of taps to establish the antiphase movement pattern exhibited a significant correlation. However, the correlation efficient of 0.60 was not high enough to predict the characteristics of subsequent movement. There was no significant correlation between putamen activity and initial movement features. It is likely that initiating unskilled difficult movements requires increased anterior putamen activity, and this activity increase may facilitate the initiation of movement via the basal ganglia-thalamocortical circuit. Our results suggest that initiation-locked transient activity of the anterior putamen can be used to predict future motor performance.

Cerebral blood flow differences between long-term meditators and non-meditators.

We have studied a number of long-term meditators in previous studies. The purpose of this study was to determine if there are differences in baseline brain function of experienced meditators compared to non-meditators. All subjects were recruited as part of an ongoing study of different meditation practices. We evaluated 12 advanced meditators and 14 non-meditators with cerebral blood flow (CBF) SPECT imaging at rest. Images were analyzed with both region of interest and statistical parametric mapping. The CBF of long-term meditators was significantly higher (p<.05) compared to non-meditators in the prefrontal cortex, parietal cortex, thalamus, putamen, caudate, and midbrain. There was also a significant difference in the thalamic laterality with long-term meditators having greater asymmetry. The observed changes associated with long-term meditation appear in structures that underlie the attention network and also those that relate to emotion and autonomic function.

Positional relationship between recurrent intracerebral hemorrhage/lacunar infarction and previously detected microbleeds.

BACKGROUND AND PURPOSE: Although MBs, ICH, and LI are secondary to cerebral microangiopathy, it remains unclear whether the location of subsequent ICH/LI corresponds to the previous location of MBs. We performed this study to clarify the positional relationship between recurrent ICH/LI and previously detected MBs. MATERIALS AND METHODS: We evaluated patients with recurrent ICH/LI who had MBs, as shown on prior T2*-weighted MR imaging. We assessed retrospectively whether the location of recurrent ICH/LI corresponded to that of the prior MB. Patients with ICH were divided into the deep ICH group and the lobar ICH group, and the positional relationship between hematoma and previously detected MBs was evaluated. RESULTS: A total of 55 patients, including 34 with recurrent ICH and 21 with recurrent LI were evaluated. Although the location of the LI corresponded to prior MBs in only 1 patient (4.8%), the location of ICH corresponded to prior locations of MBs in 21 patients (61.8%) (OR, 32.3; 95% CI, 3.86-270.3; P < .001). Among the patients with ICH, the correspondence ratio was higher in the deep ICH group (19 of 24 patients, 79.2%) than in the lobar ICH group (2 of 10 patients, 20%) (OR, 15.2; 95% CI, 2.42-95.3; P < .002). CONCLUSIONS: The close positional association between recurrent ICH and prior MBs suggests that MBs represent hemorrhage-prone microangiopathy. In addition, different correspondence ratios between the deep ICH group and the lobar ICH group may be attributable to their different pathogenesis.

Acupuncture of LI-4 in anesthetized healthy humans decreases cerebral blood flow in the putamen measured with positron emission tomography.

To minimize the influence of exogenous factors, 13 volunteers were anesthetized with sevoflurane 1 MAC while exposed to manual acupuncture stimulation of LI-4 (Group 1, n = 7) or a placebo point in the space between the third and fourth metacarpals (Group II, n = 6). During anesthesia (baseline) and anesthesia + acupuncture, one H2(15)O scan was performed, respectively. Group I demonstrated a significant decrease in regional cerebral blood flow in the right medial frontal gyrus (20%) and in the left putamen (17%). In Group II regional cerebral blood flow was decreased in the right medial frontal gyrus (22%); in the putamen no significant changes were observed. These data suggest that needle penetration of the skin affects the medial frontal gyrus, whereas acupuncture of LI-4 influences the putamen.

Evaluation of basal ganglia haemodynamic changes with perfusion-weighted magnetic resonance imaging in patients with Parkinson's disease.

PURPOSE: The aim of our study was to assess the regional cerebral blood flow (rCBF) of basal ganglia and thalami in patients with Parkinson's disease (PD) using perfusion-weighted magnetic resonance imaging (PW-MRI). MATERIAL AND METHODS: Twenty subjects affected by idiopathic PD according to the United Kingdom Brain Bank criteria were enrolled in the study. Twenty normal subjects matched for age and gender were included as controls. After 20-day therapy withdrawal, the PD patients underwent PW-MRI. The rCBF was calculated both in patients and in controls. The regions of interest were manually positioned on rCBF maps over the caudate nucleus, the putamen, the external and internal globus pallidus, and over the ventrolateral nucleus of the thalamus. Data were normalised with those obtained from parieto-occipital white matter (POWM). Statistical analysis was performed using a parametric ANOVA test. RESULTS: Patients showed a significant (p<0.01) interhemispheric asymmetry; rCBF values were higher on the more severely affected side. Controls showed no interhemispheric asymmetry. CONCLUSION: Our study suggests that PW-MRI is a valuable tool for assessing haemodynamic changes in PD patients. Haemodynamic change pattern may be useful in the early diagnosis of PD.

Comparison of cerebral blood flow between perfusion computed tomography and xenon-enhanced computed tomography for normal subjects: territorial analysis.

OBJECTIVE: The purpose of this study was to clarify the difference between cerebral blood flow (CBF) by perfusion computed tomography (CT) and that by xenon-enhanced CT (Xe-CT) through simultaneous measurement. METHODS: Xenon-enhanced CT and perfusion CT were continually performed on 7 normal subjects. Ratios of CBF by perfusion CT (P-CBF) to CBF by Xe-CT (Xe-CBF) were measured for 5 arterial territories; 3 were territories of 3 major arteries (the anterior [ACA], middle [MCA], and posterior [PCA] cerebral arteries), and the other 2 were areas of the thalamus and putamen. RESULTS: The ratios were 1.30 +/- 0.10, 1.26 +/- 0.15, 1.61 +/- 0.15, 0.801 +/- 0.087, and 0.798 +/- 0.080 for the ACA, MCA, PCA, thalamus, and putamen, respectively. Although a good correlation was observed between P-CBF and Xe-CBF for each territory, the ratios were significantly different (P < 0.0001) between 3 territory groups (group 1: ACA and MCA, group 2: PCA, and group 3: thalamus and putamen). CONCLUSIONS: The difference in the ratio of P-CBF to Xe-CBF between the 3 territory groups was considered to result principally from the features of P-CBF. To evaluate P-CBF properly, its territorial characteristics should be taken into account.

fMRI reveals two distinct cerebral networks subserving speech motor control.

BACKGROUND: There are few data on the cerebral organization of motor aspects of speech production and the pathomechanisms of dysarthric deficits subsequent to brain lesions and diseases. The authors used fMRI to further examine the neural basis of speech motor control. METHODS AND RESULTS: In eight healthy volunteers, fMRI was performed during syllable repetitions synchronized to click trains (2 to 6 Hz; vs a passive listening task). Bilateral hemodynamic responses emerged at the level of the mesiofrontal and sensorimotor cortex, putamen/pallidum, thalamus, and cerebellum (two distinct activation spots at either side). In contrast, dorsolateral premotor cortex and anterior insula showed left-sided activation. Calculation of rate/response functions revealed a negative linear relationship between repetition frequency and blood oxygen level-dependent (BOLD) signal change within the striatum, whereas both cerebellar hemispheres exhibited a step-wise increase of activation at approximately 3 Hz. Analysis of the temporal dynamics of the BOLD effect found the various cortical and subcortical brain regions engaged in speech motor control to be organized into two separate networks (medial and dorsolateral premotor cortex, anterior insula, and superior cerebellum vs sensorimotor cortex, basal ganglia, and inferior cerebellum). CONCLUSION: These data provide evidence for two levels of speech motor control bound, most presumably, to motor preparation and execution processes. They also help to explain clinical observations such as an unimpaired or even accelerated speaking rate in Parkinson disease and slowed speech tempo, which does not fall below a rate of 3 Hz, in cerebellar disorders.

Oral methylphenidate challenge selectively decreases putaminal T2 in healthy subjects.

Despite the recent rise in oral methylphenidate (MPH) abuse, few studies have characterized the time course of oral MPH brain effects in human subjects. Accordingly, this study assessed the hemodynamic effects of oral MPH effects in 11 healthy young adults (six women), by measuring brain transverse relaxation times (T2). T2 can be interpreted as a surrogate marker for, and inversely correlated with, steady-state cerebral blood volume (CBV). Data were acquired from the caudate nucleus, putamen, and thalamus, using a 1.5 T MRI scanner at baseline and serially for 2 h following oral MPH administration (0.5 mg/kg). Physiological and subjective measures and plasma MPH levels also were examined. MPH induced a selective T2 decrease (-1.65+/-0.53 ms) in the putamen (F(6,54)=2.68, P<0.03). Heartrate, blood pressure and plasma MPH levels increased significantly after drug administration, as well as subjective ratings of "feeling drug effect". T2 decreases may reflect MPH-induced increases in putaminal blood volume. These data suggest that T2 relaxometry can be used to study the time course of regional cerebral blood volume responses to MPH and perhaps to other stimulant drugs.

Regional cerebral hyperperfusion with ictal dystonic posturing: ictal-interictal SPECT subtraction.

PURPOSE: Ictal-interictal single-photon emission computed tomography (SPECT) subtraction was performed to find brain structures related to ictal dystonic posturing (DP) in patients with temporal lobe epilepsy (TLE). METHODS: Thirty-two patients with mesial TLE who had ictal and interictal SPECTs were included. They were divided into two groups; DP group with ictal dystonia during ictal SPECT (n = 15) and Non-DP group without ictal DP (n = 17). Ictal-interictal SPECT subtraction was performed, and then subtracted SPECT was coregistered with brain spoiled gradient recalled (SPGR) magnetic resonance imaging (MRI). The ictal hyperperfusion on subtracted SPECT was analyzed in basal ganglia, frontal cortex, thalamus, temporal lobe, and insular cortex. RESULTS: The incidences of ictal hyperperfusion on brain regions in DP versus Non-DP groups were 80.0% (12 of 15 patients) versus none (0 of 17), p = 0.001, chi2, in caudate nucleus; 93.3% (14 of 15) versus 47.0% (eight of 17), p = 0.005, in putamen; and 80.0% (12 of 15) versus 41.2% (seven of 17), p = 0.026, in thalamus. No significant difference of ictal hyperperfusion was found in globus pallidus, temporal lobes, insular and frontal cortices between DP and Non-DP groups. DP patients showed an earlier age at seizure onset [8.6 years (DP) vs. 15.7 years (Non-DP) (p = 0.015)] and a longer duration of seizure history [19.0 years (DP) vs. 11.9 years (Non-DP) (p = 0.015)]. CONCLUSIONS: Caudate nucleus, putamen, and thalamus were significantly related to the ictal DP during TLE seizures. Our study showed first an active involvement of the caudate nucleus in the generation of ictal DP.

Normal pressure hydrocephalus and cerebral blood flow: a PET study of baseline values.

Regional cerebral blood flow (CBF) was studied with O(15)-water positron emission tomography and anatomic region-of-interest analysis on co-registered magnetic resonance in patients with idiopathic (n = 12) and secondary (n = 5) normal pressure hydrocephalus (NPH). Mean CBF was compared with values obtained from healthy volunteers (n = 12) and with clinical parameters. Mean CBF was significantly decreased in the cerebrum and cerebellum of patients with NPH. The regional analysis demonstrated that CBF was reduced in the basal ganglia and the thalamus but not in white matter regions. The results suggest that the role of the basal ganglia and thalamus in NPH may be more prominent than currently appreciated. The implications for theories regarding the pathogenesis of NPH are discussed.

Arm chorea secondary to an unruptured giant aneurysm.

We describe the case of a 20-year-old male who developed right-arm choreic movements secondary to a giant unruptured aneurysm impinging upon the left thalamus, putamen, globus pallidus, cerebral peduncle, midbrain, and subthalamic nucleus. The aneurysm was treated successfully with coils and a supraclinoid balloon. Abnormal movements initially failed to ameliorate, but within a few months, it was possible to discontinue symptomatic haloperidol therapy, with only mild residual abnormal movements.

Impaired functionality of reperfused brain tissue following short transient focal ischemia in rats.

Functional magnetic resonance imaging (fMRI) has been applied to study the consequences of transient focal ischemia on neuronal excitability in the rat brain. The experimental paradigm consisted of measuring the changes in local cerebral blood volume (CBV) induced by systemic infusion of the GABA(A) antagonist bicuculline after occlusion of the middle cerebral artery (MCA) for durations of 5, 15, 30 and 60 min using the intraluminal thread model. fMRI studies were carried out 60 min after successful reperfusion of the ischemic territory. Bicuculline-induced dynamic changes in local CBV were assessed in three brain regions: Parietal cortex, caudate putamen and thalamus. The measured CBV response was negatively correlated with the ischemia duration. Additionally, the three regions showed different vulnerability to the transient MCA occlusion, caudate being the most susceptible followed by parietal cortex and thalamus. The fMRI signals weakly correlated with basal CBF and CBV following reperfusion. Our results indicate that fMRI is a sensitive method to assess functional integrity of the brain. Activation maps allow to quantitatively assess the functionally compromized territory at an early stage following the ischemic event prior to the manifestation of pathomorphological changes.

Effects of anesthesia on functional activation of cerebral blood flow and metabolism.

Functional brain mapping based on changes in local cerebral blood flow (lCBF) or glucose utilization (lCMR(glc)) induced by functional activation is generally carried out in animals under anesthesia, usually alpha-chloralose because of its lesser effects on cardiovascular, respiratory, and reflex functions. Results of studies on the role of nitric oxide (NO) in the mechanism of functional activation of lCBF have differed in unanesthetized and anesthetized animals. NO synthase inhibition markedly attenuates or eliminates the lCBF responses in anesthetized animals but not in unanesthetized animals. The present study examines in conscious rats and rats anesthetized with alpha-chloralose the effects of vibrissal stimulation on lCMR(glc) and lCBF in the whisker-to-barrel cortex pathway and on the effects of NO synthase inhibition with N(G)-nitro-L-arginine methyl ester (L-NAME) on the magnitude of the responses. Anesthesia markedly reduced the lCBF and lCMR(glc) responses in the ventral posteromedial thalamic nucleus and barrel cortex but not in the spinal and principal trigeminal nuclei. L-NAME did not alter the lCBF responses in any of the structures of the pathway in the unanesthetized rats and also not in the trigeminal nuclei of the anesthetized rats. In the thalamus and sensory cortex of the anesthetized rats, where the lCBF responses to stimulation had already been drastically diminished by the anesthesia, L-NAME treatment resulted in loss of statistically significant activation of lCBF by vibrissal stimulation. These results indicate that NO does not mediate functional activation of lCBF under physiological conditions.

[Clinical study of cerebral blood flow in unilateral chronic subdural hematoma measured by 99mTc-HMPAO SPECT].

Cerebral blood flow (CBF) measured by 99mTc-HMPAO SPECT before operation was studied in 60 patients with unilateral chronic subdural hematoma. The regional CBF was measured in 26 regions of the fronto-occipital 10 cortices, putamen, thalamus and cerebellar hemisphere on both sides. Sixty cases with unilateral chronic subdural hematoma were classified into four groups on the basis of clinical symptoms: 17 cases with headache (headache group), 34 cases with hemiparesis (hemiparesis group) and 9 cases with consciousness disturbance or dementia (consciousness disturbance group), and into three groups on the basis of the degree of midline brain shift on MRI: 7 cases of mild shift group, 24 cases of moderate shift group and 29 cases of severe shift group. The average CBF in 60 patients in each region indicated that the regional CBF was reduced in frontal, occipital cortices and cerebellum on the non-hematoma side, and in putamen and thalamus on the hematoma side. In the headache group, the regional CBF reduction on the non-hematoma side was found in only frontal and occipital cortices compared with the corresponding regions on the hematoma side. In the hemiparesis group, the regional CBF was reduced in frontal and occipital cortices on the non-hematoma side and in putamen and thalamus on the hematoma side. The part of CBF reduction in both hemispheres was also noted in the hemiparesis group. In the consciousness disturbance group, the CBF reduction was markedly noted in whole brain. The CBF reductions in frontal and occipital cortices on the non-hematoma side and in putamen, thalamus and cerebellum on the hematoma side was not mutually related with the degree of midline brain shift. We concluded that the disturbance of CBF in chronic subdural hematoma was started from frontal and occipital cortices on the non-hematoma side observed in the headache group, and which was extended to putamen and thalamus on the hematoma side and a part of both hemispheres observed in the hemiparesis group. And such disturbance was finally observed as the CBF reductions in whole brain in the consciousness disturbance group.

Xenon contrast-enhanced CT imaging of supratentorial hypoperfusion in patients with brain stem infarction.

BACKGROUND AND PURPOSE: The characteristics of hypoperfusion in the supratentorial region of patients with brain stem infarction are unclear. We investigated the relationships between the presence of hypoperfusion and the location, number, and size of the infarcts with xenon contrast-enhanced CT. METHODS: One hundred five patients with brain stem infarction detected by MR imaging underwent xenon contrast-enhanced CT to measure the regional CBF (rCBF) in the frontal, temporal, parietal, and occipital regions and in the putamen and thalamus. A decrease of more than 10% from the mean rCBF value for normal individuals was considered to indicate hypoperfusion. RESULTS: Thirty-six patients had supratentorial hypoperfusion. The mean rCBF values (measured in mL/100 g/minute) were as follows: frontal region, 36.2 +/- 5.1 (-14.8%, n = 28); parietal region, 42.3 +/- 4.7 (-19.1%, n = 29); temporal region, 41.5 +/- 2.8 (-12.6%, n = 12); and thalamus, 50.1 +/- 3.2 (-19.6%, n = 7). Supratentorial hypoperfusion was associated with pontine infarction in 33 patients (upper pons in 15, middle pons in 18, and lower pons in seven), midbrain infarction in two, and medulla infarction in one. Twenty-three patients had infarcts that were larger than 5 mm, and 11 had infarcts that were 2 to 5 mm. Only two had infarcts that were smaller than 2 mm. Seven patients each had one infarct, 13 each had two, and 16 each had three. CONCLUSION: Supratentorial hypoperfusion was associated with larger infarcts, with more infarcts, and with pontine infarction.