Anterior Cerebral Artery Territory Research Articles

Abstract 295: Impact Of Revascularization Therapy And Decompressive Surgery On Outcomes In Large Hemispheric Infarctions

Introduction/Purpose Large hemispheric infarction (LHI) is a severe form of ischemic stroke that affects the majority or entirety of the middle cerebral artery (MCA) territory, potentially involving the anterior cerebral artery and posterior cerebral artery territories, and is characterized by the development of life‐threatening cerebral edema. Although LHI accounts for a small percentage (≤10%) of acute ischemic strokes, it is associated with high morbidity and mortality rates. More than 50% of LHI patients develop malignant cerebral edema (MCE), leading to rapid neurological deterioration within 2 to 3 days of symptom onset. This study aims to assess the impact of revascularization therapies, including intravenous tissue plasminogen activator (tPA) and mechanical thrombectomy (MT), and decompressive hemicraniectomy (DHC) on functional outcomes in patients with LHI, focusing on the distinction between good (mRS 0‐4) and poor (mRS 5‐6) outcomes. Materials/Methods We retrospectively analyzed 124 patients with LHI treated at our center from November 2015 to March 2023. Patients were categorized into two groups based on their discharge modified Rankin Scale (mRS): good outcome (mRS 0‐4) and poor outcome (mRS 5‐6). Further subgrouping was based on the use of revascularization therapies (intravenous tPA and/or MT) and whether DHC was performed. Data on demographic variables, clinical parameters, and treatment details were collected. Statistical analyses included logistic regression to evaluate associations between revascularization therapies, DHC, and functional outcomes. Results Of the 124 patients with LHI, 48 (38.7%) achieved a good outcome (mRS 0‐4) at discharge, while 76 (61.3%) had a poor outcome (mRS 5‐6). Among those with good outcomes, 22 (45.8%) received intravenous tPA, 19 (39.6%) underwent MT, and 15 (31.3%) underwent DHC. In the poor outcome group, 28 (36.8%) received intravenous tPA, 21 (27.6%) underwent MT, and 23 (30.3%) underwent DHC. Patients who received both intravenous tPA and MT were more likely to have a good outcome (mean mRS 3.6, SD 2.51), whereas those without any revascularization therapy were more likely to have poor outcomes (mean mRS 5.02, SD 1.16). The addition of DHC did not significantly improve outcomes when revascularization therapies were absent. Logistic regression analysis showed no statistically significant association between the use of intravenous tPA, MT, or DHC and achieving a good outcome at discharge. Conclusion In our single‐center study of 124 patients with LHI, neither DHC, intravenous tPA, nor MT alone was significantly associated with achieving good functional outcomes at discharge. While the combination of both intravenous tPA and MT showed a trend toward better outcomes, this was not statistically significant. The findings suggest a complex interplay between revascularization strategies and decompressive surgery in managing LHI, highlighting the need for further research to better understand optimal patient selection and timing for these interventions.

More severe cerebral small vessel disease associated with poor leptomeningeal collaterals in symptomatic intracranial atherosclerotic stenosis.

We investigated the association between cerebral small vessel disease (CSVD) and ipsilateral leptomeningeal collateral (LMC) status in patients with symptomatic intracranial atherosclerotic stenosis (sICAS). In 108 patients with 50-99% symptomatic intracranial internal carotid artery or M1 middle cerebral artery stenosis, 4 CSVD imaging markers (lacunes, cerebral microbleeds, enlarged perivascular spaces [EPVSs], and white matter hyperintensities [WMHs]) were assessed in MRI. Score of 0 or 1 was assigned to each marker and added up as a summary CSVD score (ranging 0-4) to reflect an overall CSVD burden. Ipsilateral LMC status was assessed by determining the laterality of distal vessels in anterior and posterior cerebral artery territories on CT angiography. Moderate-to-severe EPVSs (adjusted odds ratio [aOR] = 4.15; p = 0.031) and WMHs (aOR = 5.90; p = 0.010), and higher summary CSVD score (aOR = 1.66; p = 0.030) were independently associated with poor LMCs. There was significant interaction between stenosis percentage in sICAS and summary CSVD score on poor LMCs (p = 0.022 for interaction), when higher CSVD score was significantly associated with poor LMCs in patients with severe sICAS (aOR = 2.84; p = 0.011) but not in those with moderate sICAS. The findings indicated possibly adverse effect of CSVD on the recruitment or development of LMCs in sICAS patients, especially in patients with severe sICAS.

Decompressive Craniectomy for Bilateral Anterior Cerebral Artery Infarction: Case Report and Brief Literature Review

Decompressive craniectomy for “malignant” bilateral anterior cerebral artery infarction (BACAI) has not been reported in the literature. Here we present such a case in relation to its presentation, surgical management, outcome and anatomical basis.Bifronto-temporal decompressive craniectomy was performed on a patient diagnosed with acute infarction in bilateral anterior cerebral artery (ACA) territories and rapidly deteriorating having clinical and radiological signs of tonsillar herniation. Patient sustained several motor disabilities at sixth week following surgery, however, post-operative CT showed reversing of the “conning” with spaced basal cisterns which was compatible with clinical improvement.

The Silent Threat: Unraveling the Rare Catastrophic Complication after Elective Cranioplasty

AbstractAlthough cranioplasty seems to be a simple procedure, fatal complication of development of diffuse severe cerebral edema following cranioplasty although unusual have been reported in a few cases. The mechanism for this occurrence is still speculative. A 38-year-old male patient presented with a history of having undergone left decompressive hemicraniectomy following a road traffic accident with traumatic left intracranial internal carotid artery dissection leading to anterior cerebral artery and middle cerebral artery territory infarct and endovascular embolization of traumatic type 1 left caroticocavernous fistula. The preoperative computed tomography scan of the brain revealed left frontotemperoparietal craniectomy defect with sunken flap and diffuse encephalomalacia with gliosis of the entire left cerebral hemisphere. Immediately following an uneventful cranioplasty surgery with titanium mesh, the patient developed severe hypotension and dilated fixed pupils. Postoperative imaging revealed diffuse severe cerebral edema in bilateral hemispheres with a significant midline shift toward the ipsilateral (left) side, that is, toward the side of cranioplasty. The patient immediately underwent removal of the titanium mesh, and despite all efforts, the patient had a fatal outcome on postoperative day 5. Although this type of fatal complication of diffuse severe cerebral edema is rare in postcranioplasty patients, neurosurgeons must be aware of this complication and close monitoring postprocedure is important, especially in patients with a large craniectomy defect and sunken skin flap.

AC-ASPECTS, ACh-ASPECTS, and H-ASPECTS: new imaging scales to assess territorial and total cerebral hemispheric ischemic injury.

The extent of ischemic injury in acute stroke is assessed in clinical practice using the Acute Stroke Prognosis Early CT Score (ASPECTS) rating system. However, current ASPECTS semi-quantitative topographic scales assess only the middle cerebral artery (MCA) (original ASPECTS) and posterior cerebral (PC-ASPECTS) territories. For treatment decision-making in patients with anterior cerebral artery (ACA) occlusions and internal carotid artery (ICA) occlusions with large ischemic cores, measures of all hemispheric regions are desirable. In this cohort study, anatomic rating systems were developed for the anterior cerebral (AC-ASPECTS, 3 points) and anterior choroidal artery (ACh-ASPECTS, 1 point) territories. In addition, a total supratentorial hemisphere (H-ASPECTS, 16 points) score was calculated as the sum of the MCA ASPECTS (10 regions), supratentorial PC-ASPECTS (2 regions), AC-ASPECTS (3 regions), and ACh-ASPECTS (1 region). Three raters applied these scales to initial and 24 h CT and MR images in consecutive patients with ischemic stroke (IS) due to ICA, M1-MCA, and ACA occlusions. Imaging ratings were obtained for 96 scans in 50 consecutive patients with age 74.8 (±14.0), 60% female, NIHSS 15.5 (9.25-20), and occlusion locations ICA 34%; M1-MCA 58%; and ACA 8%. Treatments included endovascular thrombectomy +/- thrombolysis in 72%, thrombolysis alone in 8%, and hemicraniectomy in 4%. Among experienced clinicians, inter-rater reliability for AC-, ACh-, and H-ASPECTS scores was substantial (kappa values 0.61-0.80). AC-ASPECTS abnormality was present in 14% of patients, and ACh-ASPECTS abnormality in 2%. Among patients with ACA and ICA occlusions, H-ASPECTS scores compared with original ASPECTS scores were more strongly associated with disability level at discharge, ambulatory status at discharge, discharge destination, and combined inpatient mortality and hospice discharge. AC-ASPECTS, ACh-ASPECTS, and H-ASPECTS expand the scope of acute IS imaging scores and increase correlation with functional outcomes. This additional information may enhance prognostication and decision-making, including endovascular thrombectomy and hemicraniectomy.

Two cases of acute ischemic stroke associated with strut exposure in the cerebral artery lumen after stent-assisted coil embolization

Stent-assisted coil embolization (SAC) is used for complex wide-necked aneurysms but can expose stent struts to the arterial lumen, leading to thrombosis. Herein, we report two cases of delayed thromboembolic stroke post-SAC. Case 1: A 71-year-old woman had an acute ischemic stroke 2 months after Y-stent SAC for a basilar artery aneurysm, and aspirin was prescribed post-procedure. Diffusion-weighted imaging revealed multiple scattered infarcts of various sizes in the posterior circulation. Case 2: A 72-year-old woman experienced an acute ischemic stroke 3 years post-SAC for a right posterior communicating artery aneurysm. The stroke occurred after discontinuation of antiplatelet therapy. Diffusion-weighted imaging revealed scattered acute infarctions in the right middle and anterior cerebral artery territories. These two cases of delayed thromboembolic stroke after SAC might have been due to stent strut exposure in the arterial lumen and concurrent thrombosis.

A Practical Guide to Train the Side-to-side Anastomosis: Tips, Tricks and Technical Nuances

Microanastomosis presents a challenge in neurosurgical procedures, requiring specialized skills. Regular practice outside the operating room is crucial. This study aims to provide a detailed description of the side-to-side anastomosis technique and analyze its advantages in preventing failures compared with other variations. We examined the technique, characteristics, and outcomes of side-to-side bypass procedures for complex aneurysms in the anterior cerebral artery territory at our institution over the past decade. We compared our technique with those described in the literature by other groups. The Far East Neurosurgical Institute (FENI) technique was used in 15 patients, with 17 side-to-side anastomoses performed. The average anastomosis time was 27.5 minutes, with 100% patency in follow-up. Our technique demonstrated safety and effectiveness in treating intracranial aneurysms, yielding satisfactory short- and long-term functionality outcomes. We highlight the importance of maintaining a curvilinear arteriotomy shape, at least 3 times the diameter of the artery, and utilizing an interrupted suturing technique on the anterior wall. This paper presents the first comprehensive description of the side-to-side anastomosis technique, supported with images and videos for training and replicability. Our technique enhances flow dynamics and reduces the risk of acute thrombus formation. Training in simulators and microsurgery practice centers outside the operating room is essential for acquiring and refining microsurgical skills.

The interpositional bypass with a parietal branch of superficial temporal artery graft for symptomatic atherosclerotic anterior cerebral artery stenosis or occlusion.

For nonmoyamoya patients with anterior cerebral artery (ACA) stenosis or occlusion, whether direct revascularization of the ACA territory can prevent stroke is still unclear. The objective of this study was to investigate the efficacy and safety of a parietal branch of superficial temporal artery-interposed superficial temporal artery-to-ACA bypass (PISAB) for preventing stroke in patients with symptomatic atherosclerotic ACA stenosis or occlusion (SAASO). We retrospectively analyzed the data from patients with SAASO who had undergone PISAB in our center between April 2016 and November 2021. The rates of patency, satisfaction (revascularization grades A and B) of bypass, perioperative complications, recurrence of ischemic stroke, changes in bypass flow, and improvements in cerebral blood perfusion were analyzed. A total of 19 SAASO patients were involved in this study. Sixteen out of 19 (84.2%) patients were free from any cerebral ischemic events after surgery. Only 3 patients (15.8%) had recurrent stroke postoperatively. Two (10.5%) surgery-related complications occurred, including hyperperfusion syndrome and minor stroke. No skin ischemic complications occurred. The average follow-up period was 50.6 ± 18.3 months. The flow rate of the bypass was significantly increased half a year after surgery (56.2 ± 8.0 mL/min vs. 44.3 ± 5.3 mL/min, p < 0.001). The ratio of ipsilateral/contralateral mean transit time in the superior frontal gyrus was decreased significantly after bypass (1.08 ± 0.07 vs. 1.23 ± 0.05, p < 0.001) and continued to decrease 6 months after surgery (1.05 ± 0.04 vs. 1.08 ± 0.07, p = 0.002). The patency rate of PISAB was 94.7% (18/19) 2 years after surgery. The satisfaction rate of bypass was 89.5% (17/19). The results of this study indicate that PISAB, as a safe superficial bypass, can effectively reduce the risk of stroke in SAASO patients. More precise conclusions will require randomized control studies.

Case report: Three characteristics of tyrosine kinase inhibitor-associated cerebrovascular stenosis. High threshold for infarction, atypical infarct area, and vascular recoverability under the use of ponatinib

While tyrosine kinase inhibitors (TKI)-associated cerebral vascular stenosis (CVS) exhibit distinct mechanisms compared to conventional stroke in basic research, the clinical strategy remains nearly the same other than TKI-switching. We present the case of a 22-year-old female with chronic myeloid leukemia without stroke risk factors, who developed ponatinib-associated CVS. Three potential characteristics of TKI-associated CVS were identified: a heightened threshold for infarction, an atypical infarct area, and vascular recoverability. Specifically, brain computed tomography remained normal despite 20 h of severe hemiplegia. The ischemic distribution was confined in gray matter and the anterior cerebral artery territory on magnetic resonance imaging, despite severe stenosis of the internal carotid artery. Ischemic changes resolved within 10 days and arterial stenosis improved after ponatinib withdrawal. These unique features, distinct from typical stroke, could lead to misdiagnosis as non-organic neurological disorders or other conditions in ponatinib-treated patients.

Moyamoya Syndrome in a Child with Beta-Thalassemia Trait: A Case Report with Review of Literature

Background: The association of moyamoya angiopathy with hematological conditions such as sickle cell anemia and beta-thalassemia major or intermedia is well-known, but moyamoya syndrome (MMS) associated with thalassemia trait is hardly reported. We report such a rare association. Clinical Description: A 7-year-old boy presented with right-sided monoparesis with right-sided focal seizures, along with right-sided upper motor neuron type facial nerve palsy. He had a history of recurrent transient episodes of limb weakness, which were unevaluated. Examination revealed pallor and mild splenomegaly. Management and Outcome: Routine investigations revealed microcytic hypochromic anemia with normal serum iron levels. High-performance liquid chromatography was suggestive of beta-thalassemia trait. Contrast-enhanced computerized tomography of the head showed infarction in the territory of the left anterior cerebral artery (ACA) and middle cerebral artery (MCA). Magnetic resonance angiography revealed significantly attenuated bilateral internal carotid arteries in the supraclinoid region with attenuated bilateral ACA and bilateral MCA along with collateral formation suggestive of moyamoya angiopathy. The final diagnosis of MMS secondary to beta-thalassemia trait was made. The child improved with aspirin and supportive management. Conclusion: MMS can be rarely associated with the beta-thalassemia trait. Such an underlying, unsuspected heterozygous beta-thalassemia (trait) may be diagnosed only after the identification of moyamoya disease following a stroke.

319 A Case Series of Direct Multi-territory Cerebral Revascularizations Using a Three-Vessel Anastomosis

INTRODUCTION: The ability to perform simultaneous, multi-territory cerebral bypass using a single interposition graft has significant utility for the revascularization of multiple cerebral territories that would otherwise require multiple constructs, serial anastomoses, or a combination of direct and indirect approaches. METHODS: Peri-operative data and outcomes were collected retrospectively for patients undergoing multi-territory cerebral revascularization using a three-vessel anastomosis over a 4-year period (2019-2023). RESULTS: Five patients underwent triple vessel bypass (median age 53 years [range 12-73]). Three patients with complex middle cerebral artery (MCA) aneurysms (one ruptured) were treated multi-territory external carotid artery (ECA)-M2-M2 revascularization using a saphenous vein interposition graft, followed by either proximal ligation or partial/complete aneurysm clip trapping. Two patients with predominately bilateral anterior cerebral artery (ACA) territory moyamoya disease were treated with proximal superficial temporal artery (STA)-A3-A3 revascularization using a radial artery or radial artery fascial flow-through free flap (RAFF) graft. Bypass patency was 100% and zero patients experienced surgery-related ischemia. One patient had new strokes from vasospasm after subarachnoid hemorrhage. One patient required a revision surgery for a post-operative hematoma and RAFF debridement that did not affect bypass patency or neurologic outcome. Median Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) scores on discharge were 4 (range 3-5) and 2 (range 0-5), respectively. GOS and mRS scores were stable or improved on follow up in 4/5 patients; one patient died from medical complications of their original stroke. CONCLUSIONS: In experienced hands, three-vessel anastomosis can be a viable option for the safe, simultaneous revascularization of multiple ACA and MCA territories.

Impact of Cerebral Revascularization on Pial Collateral Flow in Patients With Unilateral Moyamoya Disease Using Quantitative Magnetic Resonance Angiography.

Moyamoya disease (MMD) is a chronic steno-occlusive disease of the intracranial circulation that depends on neoangiogenesis of collateral vessels to maintain cerebral perfusion and is primarily managed with cerebral revascularization surgery. A quantitative assessment of preoperative and postoperative collateral flow using quantitative magnetic resonance angiography with noninvasive optimal vessel analysis (NOVA) was used to illustrate the impact of revascularization on cerebral flow distribution. A retrospective review of patients with unilateral MMD who underwent direct, indirect, or combined direct/indirect cerebral revascularization surgery was conducted between 2011 and 2020. Using NOVA, flow was measured at the anterior cerebral artery (ACA), ACA distal to the anterior communicating artery (A2), middle cerebral artery (MCA), posterior cerebral artery (PCA), and PCA distal to the posterior communicating artery (P2). Pial flow (A2 + P2) and collateral flow (ipsilateral [A2 + P2])-(contralateral [A2 + P2]) were measured and compared before and after revascularization surgery. Total hemispheric flow (MCA + A2 + P2) with the addition of the bypass graft flow postoperatively was likewise measured. Thirty-four patients with unilateral MMD underwent cerebral revascularization. Median collateral flow significantly decreased from 68 to 39.5 mL/min ( P = .007) after bypass. Hemispheres with maintained measurable bypass signal on postoperative NOVA demonstrated significant reduction in median collateral flow after bypass ( P = .002). Median total hemispheric flow significantly increased from 227 mL/min to 247 mL/min ( P = .007) after bypass. Only one patient suffered an ipsilateral ischemic stroke, and no patients suffered a hemorrhage during follow-up. NOVA measurements demonstrate a reduction in pial collateral flow and an increase in total hemispheric flow after bypass for MMD, likely representing a decrease in leptomeningeal collateral stress on the distal ACA and PCA territories. Further studies with these measures in larger cohorts may elucidate a role for NOVA in predicting the risk of ischemic and hemorrhagic events in MMD.

Brain volume measured by synthetic magnetic resonance imaging in adult moyamoya disease correlates with cerebral blood flow and brain function

Moyamoya disease (MMD) is characterized by progressive arterial occlusion, causing chronic hemodynamic impairment, which can reduce brain volume. A novel quantitative technique, synthetic magnetic resonance imaging (SyMRI), can evaluate brain volume. This study aimed to investigate whether brain volume measured with SyMRI correlated with cerebral blood flow (CBF) and brain function in adult MMD. In this retrospective study, 18 adult patients with MMD were included. CBF was measured using iodine-123-N-isopropyl-p-iodoamphetamine single photon emission computed tomography. Cerebrovascular reactivity (CVR) to acetazolamide challenge was also evaluated. Brain function was measured using the Wechsler Adult Intelligence Scales (WAIS)-III/IV and the WAIS-R tests. Gray matter (GM), white matter, and myelin-correlated volumes were evaluated in six areas. Resting CBF was positively correlated with GM fractions in the right anterior cerebral arterial and right middle cerebral arterial (MCA) territories. CVR was positively correlated with GM fraction in the right posterior cerebral arterial (PCA) territory. Full-Scale Intelligence Quotient and Verbal Comprehension Index scores were marginally positively correlated with GM fractions in the left PCA territory. Processing Speed Index score was marginally positively correlated with GM fraction in the right MCA territory. The SyMRI-measured territorial GM fraction correlated with CBF and brain function in patients with MMD.

Abstract TP40: Identification of Domain-Specific Cognitive Phenotypes of Post Stroke Vascular Contributions to Cognitive Impairment and Dementia

Introduction: Vascular contributions to cognitive impairment and dementia (VCID) are variably expressed following stroke. The purpose of this investigation is to identify the domain-specific cognitive phenotypes of VCID in the acute and sub-acute post-stroke interval measured using the Mark VCID battery. Methods: Mark VCID neurocognitive test battery was administered to 33 patients with incident ischemic stroke in the left (n=15), right (n=17), and bilateral (n=1) hemispheres including the anterior and middle cerebral artery territory, and 39 age and sex matched healthy controls (HC). Participants ranged in age from 42 to 88 years (Patient M=65.64 yrs, Control M=64.97 yrs). Patient group consisted of 17 males and 22 females, and the control group had 20 males and 13 females. Mean post stroke interval was 8 weeks (Range: 2.5 to 19 weeks). The test battery assessed: language (naming, fluency), perception (facial recognition, spatial orientation), psychomotor speed (digit symbol substitution), memory (word list, story recall), and attention (trails, number span). Normative test scores were converted to z-scores for assessment of between group differences using independent t-tests. Results: Patients with stroke performed significantly worse (p&lt;0.05) than HCs on measures of language (semantic and phonemic fluency), perception (facial recognition and spatial orientation), and psychomotor speed (symbol digit modalities test) (Figure 1). There were no significant group differences in the scores of memory (Hopkins Verbal Learning, Craft Story) and attention tracking (Oral Trails A, Number Span). Conclusion: Cognitive abnormalities in these acute stoke patients represent impairments in diverse dominant (language) and non-dominant (perceptual/spatial) hemisphere cortical and subcortical (psychomotor speed) abilities. At the group level, the findings suggest a phenotype of VCID in patients with acute middle and anterior cerebral artery ischemic stroke.

Assessment of Collateral Flow in Patients with Carotid Stenosis Using Random Vessel-Encoded Arterial Spin-Labeling: Comparison with Digital Subtraction Angiography.

Collateral circulation plays an important role in steno-occlusive internal carotid artery disease (ICAD) to reduce the risk of stroke. We aimed to investigate the utility of planning-free random vessel-encoded arterial spin-labeling (rVE-ASL) in assessing collateral flows in patients with ICAD. Forty patients with ICAD were prospectively recruited. The presence and extent of collateral flow were assessed and compared between rVE-ASL and DSA by using Contingency (C) and Cramer V (V) coefficients. The differences in flow territory alterations stratified by stenosis ratio and symptoms, respectively, were compared between symptomatic (n = 19) and asymptomatic (n = 21) patients by using the Fisher exact test. Good agreement was observed between rVE-ASL and DSA in assessing collateral flow (C = 0.762, V = 0.833, both P < .001). Patients with ICA stenosis of ≥90% were more likely to have flow alterations (P < .001). Symptomatic patients showed a higher prevalence of flow alterations in the territory of the MCA on the same side of ICAD (63.2%), compared with asymptomatic patients (23.8%, P = .012), while the flow alterations in the territory of anterior cerebral artery did not differ (P = .442). The collateral flow to MCA territory was developed primarily from the contralateral internal carotid artery (70.6%) and vertebrobasilar artery to a lesser extent (47.1%). rVE-ASL provides comparable information with DSA on the assessment of collateral flow. The flow alterations in the MCA territory may be attributed to symptomatic ICAD.

Increased Parenchymal Free Water May Be Decreased by Revascularization Surgery in Patients with Moyamoya Disease

Moyamoya disease (MMD) is a cerebrovascular disease associated with steno-occlusive changes in the arteries of the circle of Willis and with hemodynamic impairment. Previous studies have reported that parenchymal extracellular free water levels may be increased and the number of neurites may be decreased in patients with MMD. The aim of the present study was to investigate the postoperative changes in parenchymal free water and neurites and their relationship with cognitive improvement. Multi-shell diffusion MRI (neurite orientation dispersion and density imaging and free water imaging using a bi-tensor model) was performed in 15 hemispheres of 13 adult patients with MMD (11 female, mean age 37.9 years) who had undergone revascularization surgery as well as age- and sex-matched normal controls. Parameter maps of free water and free-water-eliminated neurites were created, and the regional parameter values were compared among controls, patients before surgery, and patients after surgery. The anterior and middle cerebral artery territories of patients showed higher preoperative free water levels (P ≤ 0.007) and lower postoperative free water levels (P ≤ 0.001) than those of normal controls. The change in the dispersion of the white matter in the anterior cerebral artery territory correlated with cognitive improvement (r = -0.75; P = 0.004). Our study suggests that increased parenchymal free water levels decreased after surgery and that postoperative changes in neurite parameters are related to postoperative cognitive improvement in adult patients with MMD. Diffusion analytical methods separately calculating free water and neurites may be useful for unraveling the pathophysiology of chronic ischemia and the postoperative changes that occur after revascularization surgery in this disease population.

Intellectual function and memory in children with moyamoya disease: relationship between Wechsler Intelligence Scale and Benton Visual Retention Test scores and regional cerebral blood flow.

Intellectual function declines in about 30% of children with moyamoya disease (MMD). Memory function underpins higher order brain function, but the relationship between intellectual function and memory in pediatric MMD patients has not been well studied. This study aimed to investigate correlations between scores on the Wechsler Intelligence Scale for Children (WISC) and the Benton Visual Retention Test (BVRT), a visual memory test that can be administered to children, in children with MMD. Relationships between intellectual function or memory and regional cerebral blood flow (rCBF) have also not been well clarified in pediatric MMD patients. The authors also investigated associations between WISC or BVRT scores and rCBF in various brain regions. WISC and BVRT scores and rCBF were assessed in 17 children with ischemic-onset MMD before revascularization. Single-photon emission CT with 123I-iodoamphetamine was used to measure rCBF. Relationships between WISC and BVRT scores were evaluated using Spearman's correlation coefficient and multivariate linear regression analysis. Cutoff values were identified for BVRT scores. Sensitivity and specificity were calculated to predict full-scale intelligence quotient (FSIQ) > 85 or ≤ 85. Associations between rCBF and WISC or BVRT scores were evaluated using linear regression analysis. BVRT scores were significantly correlated with FSIQ and scores on the Working Memory Index (WMI), Processing Speed Index, and Verbal Comprehension Index (VCI)/Verbal Intelligence Quotient (VIQ) of WISC. Multivariate linear regression revealed that number correct score and number of errors score of BVRT were associated with FSIQ. As cutoff values, a number correct score of 5 and a number of errors score of 8 offered the most reliable predictors of FSIQ > 85 and ≤ 85, respectively. FSIQ correlated positively with rCBF in the right and left hemispheres, right and left ganglia, right and left thalamus, right and left cerebellum, right middle cerebral artery (MCA) territory, pons, and vermis. WMI score was positively associated with rCBF in the right hemisphere, right anterior cerebral artery territory, right MCA territory, right basal ganglia, right and left thalamus, right and left cerebellum, pons, and vermis. BVRT score correlated well with WISC index scores, suggesting that BVRT may be helpful in screening for intellectual impairments in children with MMD. In the MCA territory, basal ganglia, thalamus, cerebellum, pons, and vermis, rCBF associated well with WISC index scores, suggesting that reduced rCBF in relevant brain regions may influence intellectual function.

Hyperdense Vessel Sign in Brain Computed Tomography as an Early Indication of Reversible Cerebral Vasoconstriction Syndrome: A Case Report

We herein report a case of reversible cerebral vasoconstriction syndrome (RCVS) with an unusual presentation of hyperdense blood vessels. A 53-year-old woman developed thunderclap headache. Brain computed tomography (CT) showed hyperdensity of the anterior cerebral artery. Brain magnetic resonance imaging revealed cerebral infarctions in the left anterior cerebral artery (ACA) territory and cerebellum. The left ACA presented with a hyperintense vessel sign, although magnetic resonance angiography (MRA) appeared normal. One week later, stenotic changes were confirmed using MRA. The vasoconstriction disappeared on day 20, and the patient was diagnosed with RCVS. CT-defined hyperdense vessel signs can be observed at an early stage of RCVS, leading to ischemic events.

Study of Cerebral Hemispheric Lateralization in Stroke and the Arterial Territories Involved in High-risk Patients

Introduction: According to WHO, Stroke is the 2nd leading cause of death and disability after Ischemic heart disease. Prevalence rate of stroke in India varies from 44.45 to 150 per lakh population. Studies have reported a higher frequency of stroke of the left hemisphere. The artery reported to be the most affected is Left Middle Cerebral artery(MCA) followed by Right Middle Cerebral artery. The aim of this study is to determine the side of cerebral hemisphere most affected by stroke and the arterial territories involved in high-risk patients aged above 35 years presenting to the tertiary healthcare centre, as well as to study the sex predilection of stroke. Materials and Methods: A cross-sectional prospective study of 50 high risk stroke patients with Diabetes Mellitus(DM) and /or Hypertension(HTN) presenting to General medicine OPD of a tertiary healthcare centre were investigated with CT/MRI for the side of the cerebral hemisphere affected and the arterial territories involved. The data was tabulated over the course of three months and statistical analysis was carried out. Results: The left cerebral hemisphere was affected in 50%, right in 40% and bilateral involvement was found in 10% patients. Slight predilection of stroke towards the left was seen, however it was not found to be statistically significant (P-value= 0.249). MCA territory was involved in 66% of the patients, Posterior Cerebral Artery(PCA) territory in 8%, Vertebrobasilar Artery(VB) territory in 8%, Anterior Cerebral Artery(ACA) territory in 6% and MCA+ACA in 4%, MCA+VB in 2% and MCA-PCA watershed in 6% patients. Conclusions: We found a slight predilection of stroke towards the left, which was however, not found to be statistically significant. We also found that Middle Cerebral Artery(MCA) territory is the most commonly involved in stroke.

Long-term prognostic value of [15O]H2O PET imaging in patients suspected for cerebral hemodynamic insufficiency

ObjectivesQuantitative regional cerebral perfusion (rCBF) measurements using [15O]H2O PET with arterial cannulation and acetazolamide (ACZ) challenge have been reserved to identify high-risk patients that are candidates for by-pass operation. We aimed to assess the prognostic value of various parameters in quantitative [15O]H2O PET measurements in patients not subsequently undergoing surgery. MethodsWe identified 32 eligible patients who underwent [15O]H2O brain PET imaging for suspicion of hemodynamic insufficiency between 2009 and 2020. Cerebrovascular events were defined as new ischemic lesions on MRI, stroke, transient ischemic attack, vascular dementia. Follow-up period was 91 months (range: 26-146). rCBF before (rCBFbase) and after (rCBFacz) ACZ challenge and the relative increase (CVR), were examined in the anterior (ACA), middle (MCA), and posterior (PCA) cerebral artery territories of the affected hemisphere, and the most recent MRI scans were scored for infarcts and white matter lesions. ResultsReceiver operating characteristic (ROC) curve analysis showed higher prognostic accuracy for rCBFacz(AUC:0.82) compared to CVR (AUC:0.72) and rCBFbase (AUC:0.77). ROC AUC, optimal thresholds (and corresponding sensitivity/specificity/accuracy) for rCBFacz after ACZ in individual territories were 0.79 and 37.8 mL 100g−1 min−1 (0.81/0.63/0.72) for the ACA, 0.84 and 32 mL 100g−1 min−1 (0.81/0.75/0.78) for the MCA, and 0.70 and 43.9 ml/(mL 100g−1 min−1 (0.81/0.43/0,62) for the PCA. Kaplan Meier survival curve showed longer event-free survival in patients with rCBFacz below cut-off (p=0.007). In multivariate analysis rCBFacz remained a significant predictor when correcting for age. ConclusionQuantitative rCBF measurements after ACZ challenge with [15O]H2O PET provided high prognostic value for future cerebrovascular events.