Dynamic thalamo-cortical perfusion changes in myoclonic-atonic seizures captured by ictal technetium-99m ethyl cysteinate dimer single-photon emission computed tomography: A case report.

A 3-year-old boy with normal development presented with acute cerebellitis at one year and 10 months of age. His truncal ataxia resolved without treatment. He experienced a relapse of truncal ataxia and atonic seizures at 2 years and one month of age. Five months later, he experienced myoclonic atonic seizures. By 3 years of age, the truncal ataxia had become severe, and the frequency of myoclonic atonic seizures increased. Compared to controls, we found higher levels of anti-C-terminal GluN2B and anti-N terminal GluD2 antibodies in the serum, and anti-N terminal GluN2B and anti-C terminal GluD2 antibodies in the cerebrospinal fluid (CSF). A cell-based assay revealed the presence of anti-NMDA-type glutamate receptor antibody in the serum, but absence in the CSF. Ictal EEG of myoclonic atonic seizures showed generalized spike and wave complexes. The patient was diagnosed with myoclonic atonic epilepsy. Adrenocorticotrophic hormone therapy resolved the truncal ataxia and myoclonic atonic seizures, along with the decreased serum anti-C-terminal GluN2B and anti-N-terminal GluD2 antibodies, and CSF anti-N-terminal GluN2B and anti-C-terminal anti-GluD2 antibodies. Our results suggest that the anti-GluN2B and anti-GluD2 antibodies may be associated with myoclonic atonic epileptic seizures and chronic cerebellitis.

BACKGROUNDHepatic encephalopathy (HE) is the most common serious complication after transjugular intrahepatic portosystemic shunts (TIPS) surgery, the pathogenesis of which is not well understood.AIMTo explore the mechanisms of HE after TIPS from a cerebral hemodynamic perspective and provide a theoretical basis for clinical treatment, three-dimensional arterial spin labeling and resting-state functional magnetic resonance imaging were applied in patients with portal hypertension post-TIPS to analyze dynamic changes in cerebral blood flow (CBF) and spontaneous brain activity, respectively.METHODSPatients who meet the inclusion criteria were selected as the case group, and 18 healthy volunteers were assigned as the control group. The differences in amplitude of low-frequency fluctuation (ALFF) and CBF between the case group and the control group before TIPS surgery and the differences in ALFF and CBF between the case group at each detection time point were compared and analyzed, and analyze the correlation between the changes in ALFF and CBF in the case group and the changes in clinical data.RESULTSCompared with the healthy control group, the CBF values of patients with cirrhosis and portal hypertension who were treated with TIPS were reduced in the area centered on the right orbitofrontal gyrus and the left superior temporal gyrus. ALFF scores decreased in the area centered on the left superior temporal gyrus, the left inferior frontal gyrus of the operculum and the right precuneus. Compared with preoperatively, CBF in the TIPS group increased in the area centered on the left fusiform gyrus at 1 month after surgery and the difference in CBF in this area was negatively correlated with the difference in the Child-Pugh liver function score. ALFF values increased in the area centered on the left superior temporal gyrus and the ALFF difference in this area was positively correlated with the portal vein pressure difference. There was no significant difference in CBF 3 months after TIPS in comparison to pre-TIPS. ALFF scores increased in the area centered on the left orbitofrontal gyrus and the left precuneus 3 months after TIPS surgery and the difference in ALFF in the left orbitofrontal gyrus was negatively correlated with the difference in the Digit Symbol Substitution Test score. Compared to 1 month after TIPS surgery, CBF values decreased in the area centered on the right fusiform gyrus and increased in the area centered on the left angular gyrus 3 months after TIPS surgery. The difference in CBF in the right fusiform gyrus was positively correlated with the difference in the Number Connection Test Part A score. ALFF values decreased in the area centered on the right insula and in the cerebellum.CONCLUSIONTIPS surgery has a certain effect on spontaneous brain activity in patients with portal hypertension and cirrhosis for the increase in plasma ammonia as well as postoperative hemodynamic changes increasing CBF and may be factors causing HE. Resting-state functional magnetic resonance imaging is a sensitive diagnostic tool for HE, especially mild HE.

Cortical spreading depolarizations (CSDs) are self-propagating waves of transient loss of neuronal transmembrane ion gradients, followed by prolonged suppression of neuronal activity (spreading depression). CSDs emerge spontaneously in animal models of traumatic brain injury,1 subarachnoid hemorrhage,2 and in focal ischemia3 where they are associated with infarct growth.4 In humans, CSDs have been demonstrated in traumatic brain injury,5 subarachnoid hemorrhage,6,7 and malignant hemispheric stroke,8 and they are believed to be the brain mechanism underlying migraine aura.9 CSDs are associated with dramatic changes in cerebral blood flow (CBF). During the depolarization phase of CSDs induced in healthy and well-perfused brain tissue in animal models, an early hyperemic response is observed, typically followed by prolonged oligemia after the neuronal repolarization. Despite the initial CBF increase, tissue hypoxia may develop in more distant territories of capillary supply.10,11 Similar CBF changes have been observed in patients with migraine aura.12–14 In the injured brain, CSDs can be accompanied by severe initial CBF reduction instead of a CBF increase during the depolarization phase, termed spreading ischemia.15 When this inverse hemodynamic response is observed, the energy-dependent recovery from CSD is delayed in a characteristic fashion, indicating a severe mismatch between oxygen supply and demand2 and a high risk of tissue damage.16 In rat and cat models of focal ischemia, CSD-related CBF transients range from monophasic, positive CBF responses in peri-ischemic tissue, over biphasic transients in mildly ischemic tissue, to negative CBF transients in more severe ischemia.17–19 During CSD in animal models, capillary flow patterns become severely disturbed.10,20,21 The passage of a CSD causes erythrocytes in some capillaries to reduce their speed, whereas other capillaries reveal 4-fold increases in flow or higher. …

Background: Females typically display higher cerebral blood flow (CBF) than males at global and regional levels. Greater CBF in females may be due to sex or sex hormone influences in the cerebral vasculature, but human studies indicate estrogen is only weakly correlated with CBF; possibly due to complexity of endogenous sex hormones. The present study design was aimed at minimizing sex hormone influence on CBF via gonadal axis hormone suppression (HS), then testing fundamental impact of primary sex hormones on CBF by single-hormone add-back (SHAB; Estradiol only in females and testosterone only in males). We hypothesized that 1) In females CBF would decrease during HS, but SHAB would restore CBF to baseline levels and 2) In males CBF would decrease during HS and SHAB would continue to decrease CBF. Methods: 13 healthy subjects (24±4 years, 8 F) underwent arterial spin labeling MRI to assess global and regional CBF at three different time points: baseline (BL), hormone suppression (HS), and single-hormone add-back (SHAB). Women completed BL MRI scans on menstrual cycle days 1-7. For HS, subjects took an oral gonadotropin-releasing hormone (GnRH) antagonist (Orilissa) and an aromatase inhibitor (Anastrozole; males only) for 5-6 days. For SHAB, subjects continued Orilissa and began taking sex specific hormone of estradiol (females) and testosterone (males,+Anastrozole) for 4-5 days prior to the SHAB MRI scan. CBF in Grey Matter (GM), White Matter (WM), brain stem and cerebellum, subcortical regions, and frontal, temporal, parietal, and occipital lobes were assessed. One-way ANOVA assessed differences between conditions. Results: Females displayed no change in CBF in GM (p=0.87), WM (p=0.44), or any brain lobe (p all >0.44) in between BL, HS, and SHAB. In males CBF was decreased in the occipital lobe from BL to HS (p=0.038) and BL to SHAB (p=0.007). Males displayed a decrease in GM CBF from BL to SHAB (p=0.05), but no change between BL and HS (p=0.21). In males WM decreased from BL to HS (p=0.048) and BL to SHAB (p=0.001), with a trend for lower CBF in SHAB compared to HS (p=0.058). Males exhibited decreased CBF in the parietal lobe from BL to SHAB (p=0.025), but not BL to HS (p=0.13). Males showed a trend for decreased CBF in the frontal lobe (p=0.082), but displayed no change in CBF between conditions for the brainstem and cerebellum (p all > 0.12), subcortical regions, nor temporal lobe. Serum samples are currently being analyzed for sex hormones to verify Orilissa efficacy. Conclusion: In support of our hypothesis, during HS males displayed decreased CBF in WM and occipital lobe. With testosterone restoration, males continued to decrease CBF in GM, WM, and parietal and occipital lobes. In contrast, females did not demonstrate a change in CBF in GM or WM under HS or SHAB. The lack of change in females could be due to a) short duration of the GnRH antagonist b) balanced vascular effect of hormone changes (e.g. loss of estrogen dilation and loss of testosterone/progesterone constriction) or c) sex differences in CBF are due to sex steroid independent mechanisms. Future work will need to sustain HS and/or SHAB for longer durations to better mimic clinical conditions. NIH R01 HL150361 This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that is rare in China. At present, there are no widespread quantitative imaging markers associated with disease severity in MS. Despite several previous studies reporting cerebral blood flow (CBF) changes in MS, no consensus has been reached. In this study, we enrolled 30 Eastern MS patients to investigate CBF changes in different brain regions using the arterial spin labeling technique and their relationship with disease severity. The average CBF in MS patients were higher than those in health controls in various brain regions except cerebellum. The results indicated that MS patients with strongly increased CBF showed worse disease severity, including higher Expanded Disability Status Scale (EDSS) scores and serum neurofilament light chain (sNfL) values than those with mildly increased CBF in the parietal lobes, temporal lobes, basal ganglia, and damaged white matter (DWM). From another perspective, MS patients with worse disease severity (higher EDSS score and sNfL values, longer disease duration) showed increased CBF in parietal lobes, temporal lobes, basal ganglia, normal-appearing white matter (NAWM), and DWM. Correlation analysis showed that there was a strong association among CBF, EDSS score and sNfL. MS patients with strongly increased CBF in various brain regions had more ratio in relapsing phase than patients with mildly increased CBF. And relapsing patients showed significantly higher CBF in some regions (temporal lobes, left basal ganglia, right NAWM) compared to remitting patients. In addition, MS patients with cognitive impairment had higher CBF than those without cognitive impairment in the right parietal lobe and NAWM. However, there were no significant differences in CBF between MS patients with and without other neurologic dysfunctions (e.g., motor impairment, visual disturbance, sensory dysfunction). These findings expand our understanding of CBF in MS and imply that CBF could be a potential quantitative imaging marker associated with disease severity.

Blood Flow Imaging of the Brain: 50 Years Experience

Iodine-123 (123I)-labeled N-isopropyl-p-iodoamphetamine (IMP) has been used as a cerebral blood flow (CBF) tracer for single-photon emission computed tomography (SPECT), and measurements of the CBF response to acetazolamide stress by SPECT with IMP are widely used to assess cerebral vascular reserve. To quantitate CBF by means of SPECT with IMP, an autoradiographic (ARG) method has been developed and is widely used. In the ARG method, CBF is calculated from the brain counts of the SPECT scan with an assumed distribution volume value of IMP (Vd). However, differences between true Vd and assumed Vd results in errors in calculated CBF. In the present study, errors in the CBF response to acetazolamide stress as calculated by the ARG method were investigated. SPECT studies were performed on 12 patients with steno-occlusive lesions of the major cerebral artery. Two studies were performed on separate days. The first study was performed at rest (baseline), and the second during acetazolamide stress. SPECT scans were performed at 40 min (early scan) and 180 min (delayed scan) after intravenous injection of IMP. Although a simulation study showed that errors in calculated changes in CBF in response to acetazolamide stress, which result from differences between the true Vd and the assumed Vd, were larger when the baseline CBF and change in CBF were larger, values calculated by the ARG method with an assumed Vd were in good agreement with those calculated with true Vd obtained from early and delayed scan data. These data indicate that errors in the calculated CBF response to acetazolamide stress as calculated by the ARG method are negligible even at high CBF responses. The ARG method is therefore reliable for measurement of CBF response to acetazolamide stress.

To determine whether the absolute value for the stump pressure might be a useful index of symmetrical cerebral blood flow (CBF), and to examine correlations with the stump pressure ratio (initial mean stump pressure,preocclusion mean arterial pressure), fifty candidates for ICA injury or permanent occlusion were evaluated preoperatively. Each was continuously monitored for mean stump pressure and arterial pressure before, during (for a total of 20 min), and after balloon test occlusion. During the occlusion, CBF was measured by 99m Tc-hexamethyl-propyleneamine oxime (99m Tc-HMPAO) single photon emission computed tomography (SPECT). The stump pressure and the stump pressure ratio were then compared with the results of 99m Tc-HMPAO SPECT. Patients who failed to tolerate even briefperiods ofcarotid occlusion and showed asymmetric decreases in CBF on SPECT were divided into high and moderate risk groups. Those with no significant changes in CBF on the occluded site formed the minimum risk group. Mean stump pressure was over 50 mmHg in 10 of a total of25 patients in the high and moderate risk groups, and below 50 mmHg in 5 of the 25 patients in the minimum risk group. The stump pressure ratio did not exceed 56% in any bu~ two patients in the high and moderate risk groups, and values were at least 60% in all patients of the minimum. risk group. Decrease ofCBF in two moderate risk group cases was localized in the posterior circulation. Difference in symmetrical CBF between the stump pressure ratio vs. the absolute value ofmean stump pressure were statistically significant (p < 0.01, Fisher,s Exact Test). Maintenance ofa stump pressure ratio of60% or more during test occlusion may be a more useful index for a good collateral circulation than any absolute value for mean stump pressure. [Neural Res 1998; 20: 732–736]

The purpose of this study was to determine changes in regional cerebral blood flow (rCBF) associated with premenstrual syndrome (PMS). Regional CBF was examined using single photon emission computed tomography (SPECT) in seven women who sought treatment for PMS and seven control subjects. Confirmation of PMS was based on the Daily Symptom Report (DSR) of 17 common symptoms associated with PMS. A first SPECT scan was performed near the peak of premenstrual symptoms based on DSR reports from the two previous cycles. A second scan was performed in the postmenstrual period. Prior to scanning each subject had a Hamilton Depression Rating Scale (Ham-D) obtained. Regions of interest were drawn on the images to generate mean counts per pixel, and normalized to the cerebellum. Activity in the frontal, temporal and parieto-occipitai cortices, and the thalami and basal ganglia, were compared between the two scans. Correlations between activity in each region of interest and Ham-D values were also determined. There were marked decreases in rCBF in the temporal lobes on the premenstrual scan compared to the postmenstrual scan in PMS patients. Significant correlations were observed between the change in rCBF in the right and left temporal lobes and the changes in Ham-D scores (r = 0.91, p < 0.01 and r = 0.86, p = 0.01 respectively). No rCBF changes were observed in controls. We conclude that SPECT imaging demonstrates modest decreases in rCBF in the temporal lobes that correlate with the level of depression in subjects with PMS.

Clinical Neurophysiology: EEG–Video Monitoring

Introduction. Following acute organophosphate exposure, morphological changes in certain regions of the brain have been reported to develop within a few hours and involve neuronal degeneration. Single photon emission computed tomography (SPECT) has been used to determine changes in the regional cerebral blood flow and attempts have been made to correlate these changes with long-term neurological sequelae. Purpose of study. The aim of the study was to determine changes in the regional cerebral blood flow by 99mTc-ECD SPECT following acute organophosphate poisoning and to correlate these defects with abnormalities in neurocognitive testing carried out during admission and at 3 months post exposure, in order to determine whether any changes in the cerebral blood flow could help in predicting future development of neurocognitive deficit. Patients and methods. Twenty-eight patients with acute organophosphorous poisoning were included in the study. The inclusion criteria were a history of ingestion or accidental exposure, clinical features of cholinergic crises, and low serum acetylcholinesterase (AChE). Twenty age- and sex-matched patients from a previous study were used as controls for the neurocognitive tests. There were no controls for SPECT. Results. Of the 28 patients studied, 27 had abnormalities in the regional cerebral blood flow on SPECT with men having significantly higher abnormalities than women (p < 0.05). The right side of the brain had more defects than the left, with the occipital lobes being the most commonly involved. Of seven neurocognitive function tests carried out on patients who had regional cerebral blood flow defects during admission, abnormalities were observed in six tests. In 18 of 26 patients who could be tested at 3 months post exposure, improvement was observed in Trail B and Visual retention tests. However, others tests remained significantly abnormal. Conclusion. We conclude that a single episode of clinically significant organophosphate intoxication can lead to persistent residual neurocognitive deficits. Detection of regional cerebral blood flow defects on 99mTc-ECD SPECT can possibly help in predicting long-term deficits in neurocognitive functions in such patients.

A prospective study made 57 measurements of cerebral blood flow (CBF) by Single Photon Emission Computed Tomography (SPECT) in post-traumatic patients. The aim of the investigation was to evaluate CBF in patients after minor craniocerebral trauma (mCCT) to ascertain the clinicotopographic correlation of the CBF changes, and to study SPECT in comparison with computed tomography (CT) findings. In addition, evaluation of the usefulness of SPECT for forensic medicine, assessment of secondary brain injury by SPECT and the predictive value of hypofrontalism were performed. A direct correlation was shown between mCCT and the observed CBF disorders, and between the CBF disorders and clinical symptoms as well as better SPECT sensitivity in comparison with CT. The usefulness of SPECT for forensic medicine purposes was also shown. Secondary brain injuries were disclose and the predictive value of hypofrontalism was confirmed. No correlation between GCS and CBF changes was found.

Temporal lobe seizures are accompanied by complex behavioral phenomena including loss of consciousness, dystonic movements and neuroendocrine changes. These phenomena may arise from extended neural networks beyond the temporal lobe. To investigate this, we imaged cerebral blood flow (CBF) changes during human temporal lobe seizures with single photon emission computed tomography (SPECT) while performing continuous video/EEG monitoring. We found that temporal lobe seizures associated with loss of consciousness produced CBF increases in the temporal lobe, followed by increases in bilateral midline subcortical structures. These changes were accompanied by marked bilateral CBF decreases in the frontal and parietal association cortex. In contrast, temporal lobe seizures in which consciousness was spared were not accompanied by these widespread CBF changes. The CBF decreases in frontal and parietal association cortex were strongly correlated with increases in midline structures such as the mediodorsal thalamus. These results suggest that impaired consciousness in temporal lobe seizures may result from focal abnormal activity in temporal and subcortical networks linked to widespread impaired function of the association cortex.

BackgroundArterial spin labeling (ASL), a non-invasive magnetic resonance imaging (MRI) technique, has been employed to assess variations in cerebral blood flow (CBF) in adolescents diagnosed with depression. While prior studies have explored CBF abnormalities in depressed adolescents, the specific patterns of CBF changes following pharmacological interventions, particularly with selective serotonin reuptake inhibitors (SSRIs) such as sertraline, remain insufficiently characterized.ObjectiveTo investigate the alterations in CBF induced by an 8-week sertraline treatment in adolescents with depression, and to assess whether baseline CBF can serve as a potential biomarker for predicting treatment response.MethodsA total of 40 adolescents diagnosed with depression and 31 age- and sex-matched healthy controls were enrolled in the study. Among the depressed cohort, 25 participants adhered to the treatment protocol and completed MRI scans. Resting-state functional MRI (rs-fMRI) scans were conducted for all participants, with a subsequent scan for the depression group after 8 weeks of sertraline therapy. Changes in CBF across various brain regions were examined using ASL data. The analysis and processing of ASL data were performed using Statistical Parametric Mapping 12 (SPM12) software and the MATLAB platform. Furthermore, Pearson correlation analysis was employed to examine associations between changes in regional CBF and clinical improvement, as measured by changes in the 17-item Hamilton Depression Rating Scale (HAMD-17) scores.ResultsAt baseline, adolescents with depression exhibited increased CBF in the posterior cuneus and decreased CBF in the middle temporal gyrus (MTG), right middle orbitofrontal gyrus, and the left middle frontal gyrus (MFG), compared to healthy controls. After 8 weeks of sertraline treatment, patients showed increased CBF in the right insula and decreased in the right MTG. Notably, baseline CBF in the left orbitofrontal gyrus was positively correlated with the magnitude of clinical improvement (i.e., reduction in HAMD-17 scores).ConclusionThe findings reveal significant differences in CBF between adolescents with depression and healthy controls. Moreover, alterations in CBF were observed in specific brain regions after an 8-week treatment regimen with sertraline, suggesting that these areas may be pivotal in the therapeutic effects of sertraline for treating adolescent depression. A decrease in HAMD-17 scores in the majority of treated patients underscores the efficacy of sertraline therapy. Notably, the change in HAMD scores from pre- to post-treatment was positively correlated with baseline CBF in the left MFG, indicating the potential of this region as a prognostic indicator.

Objective Chronic fatigue syndrome (CFS) is a complex disorder, with no consensus on therapeutic options. However, Waon therapy has been reported to be an effective treatment. The purpose of this study was to evaluate changes in the cerebral blood flow (CBF) before and after Waon therapy in CFS patients and to investigate the correlation between such changes and the therapeutic efficacy of Waon therapy. Methods Eleven patients (2 men and 9 women, mean age 27 years old) diagnosed with CFS participated in the study. The disease duration was 8-129 months, and the performance status was 5-8 (on a scale of 0-9). All patients underwent CBF scintigraphy using brain single-photon emission computed tomography (SPECT) with technetium-99m ethyl cysteinate dimer (99mTc-ECD) before and after Waon therapy. CBF changes after Waon therapy were evaluated using a statistical analysis of imaging data, which was performed with a statistical parametric mapping software program (SPM5). Results Waon therapy reduced symptoms in all 11 patients. We also observed an increase in the CBF within the prefrontal region, orbitofrontal region, and right temporal lobe. These results indicated that an improvement in clinical symptoms was linked to an increase in the CBF. Conclusion The results indicated abnormalities of the cerebral function in the prefrontal region, orbitofrontal region, and right temporal lobe in CFS patients and that Waon therapy improved the cerebral function and symptoms in CFS patients by increasing the regional CBF. To our knowledge, this is the first report to clarify the CBF changes in CFS patients before and after Waon therapy.