[Cerebral arterial air embolism: the effect of hyperbaric oxygen therapy]. / Cerebrale arteriële luchtembolie.

BACKGROUND: Iatrogenic gas embolism is the presence of gas in vascular structures. Feared are those in coronary or cerebral arteries. These can result in cerebral or myocardial infarction. CASE DESCRIPTION: A 79-year-old female underwent CT-guided biopsy of the lung. Minutes later she developed neurological symptoms. After administration of oxygen her symptoms initially improved, but later worsened. Based on her symptoms air embolism was suspected. She recovered fully after treatment with hyperbaric oxygen. CONCLUSION: Air embolism is a potentially life-threatening complication of surgical, radiological or vascular interventions. Early recognition can lead to prompt treatment and better prognosis. If air embolism is suspected the patient should be treated according to ABCDE principles and oxygen should be administered. In case of neurological or circulatory symptoms a hospital that could provide hyperbaric oxygen therapy should be contacted as soon as possible.

Low-dose angiotensin II supplementation restores flow-induced dilation mechanisms in cerebral arteries of Sprague-Dawley rats on a high salt diet.

OBJECTIVE: Salt-induced suppression of angiotensin II contributes to impaired endothelium-dependent vascular reactivity. The present study investigated the effect of chronic low-dose angiotensin II (ANG II) supplementation on the mechanisms of flow-induced dilation (FID) and oxidative stress at the cellular and molecular level in middle cerebral arteries (MCA) of male Sprague-Dawley rats fed high salt diet. METHODS: Rats (10 weeks old) were randomly assigned to a low salt diet group (0.4% NaCl in rat chow); high salt diet group (7 days 4% NaCl in rat chow) or HS+ANG II group [7 days high salt diet with 3 days ANG II administration via osmotic minipumps (100 ng/kg per min on days 4-7)]. FID was determined in absence/presence of the NOS inhibitor L-NAME, the non-selective cyclooxygenase (COX-1,2) inhibitor indomethacin, a selective inhibitor of CYP450 epoxygenase activity (MS-PPOH) and the superoxide dismutase mimetic TEMPOL. Gene expression of antioxidative enzymes, and of genes and proteins involved in FID mechanisms were determined by RT-qPCR and western blot. Vascular nitric oxide and superoxide/reactive oxygen species levels were assessed by direct fluorescence. Serum systemic oxidative stress parameters were measured by spectrophotometry. RESULTS: Chronic low-dose ANG II supplementation in high salt fed rats restored FID of MCAs, which was nitric oxide, prostanoid and epoxyeicosatrienoic acid dependent. ANG II changed the protein/gene expression of COXs, HIF-1α and VEGF and significantly increased GPx4 and EC-SOD antioxidative enzyme expression, decreased systemic oxidative stress, decreased superoxide/ROS levels and increased nitric oxide bioavailability in the vascular wall. CONCLUSION: Physiological levels of circulating ANG II are crucial to maintain the HIF-1α dependent mechanisms of FID and vascular oxidative balance without affecting mean arterial pressure.

Influence of nimodipine combined with ulinastatin on neurological function and inflammatory reaction in patients with cerebral vasospasm after subarachnoid hemorrhage.

OBJECTIVE: This study aimed to discuss the influence of nimodipine+ulinastatin on the neurological function and inflammatory reaction in patients with cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH). METHODS: Overall, 90 patients with CVS after SAH who were admitted to our hospital were enrolled in this study and randomly divided into research and control groups (n = 45 for both groups). On the basis of conventional therapy, patients in the control group were injected with ulinastatin and those in the research group were injected with ulinastatin+nimodipine through an intravenous drip for 7 days with the others the same as those of the control group. RESULTS: Blood flow velocity in all cerebral arteries was lower in the research group than in the control group after treatment (P < 0.05). Calcitonin gene-related peptide and nitric oxide levels were higher in the research group than in the control group after treatment (P < 0.05). Endothelin levels were lower in the research group than in the control group (P < 0.05). The total effective rate was higher in the research group than in the control group (P < 0.05). Glasgow Coma Scale scores were higher in the research group than in the control group (P < 0.05). CONCLUSION: The drug combination of nimodipine and ulinastatin improved blood flow and neurological function in patients with CVS after SAH and enhanced the therapeutic efficacy; the underlying mechanism may be associated with the regulation of vascular endothelial dilatation function and the inhibition of relevant inflammatory factors' expression.

Reversible Cerebral Vasoconstriction Syndrome Following Exposure to Oleoresin Capsicum "Pepper Spray".

OBJECTIVES: To report a case associating the use of Oleoresin Capsicum Pepper Spray (OCPS) during law enforcement training with development of Reversible Cerebral Vasoconstriction Syndrome (RCVS). MATERIALS AND METHODS: RCVS is radiographically characterized by multifocal smooth narrowing of cerebral arteries heralded by clinical manifestations of recurrent thunderclap headaches. 70% of cases with RCVS have a clear precipitating factor and agents commonly implicated were cannabis, selective serotonin reuptake inhibitors, nasal decongestants, cocaine, postpartum state, eclampsia and strenuous physical/sexual activity.1 RESULTS: 24-year-old female police officer with no past medical history who presented with thunderclap headaches after exposure to pepper spray to her face during work training. Neurological examination was unremarkable. CT angiogram (CTA) of the head and neck and subsequent conventional angiogram revealed multifocal mild arterial narrowing of bilateral middle cerebral arteries (MCA), bilateral posterior cerebral arteries (PCA) and left anterior cerebral artery (ACA) concerning for RCVS. Eight weeks later, she had a repeat MRA head and neck demonstrating complete resolution of the previously noted narrowing of her cerebral arteries. CONCLUSIONS: OCPS is widely used in law enforcement training as well as by general population as a self- defense tool. It is generally assumed to be safe, although the consequences of its use can never be predicted with certainty.2 As our case highlights, use of OCPS may be associated with development of RCVS and awareness needs to be raised regarding this rare but serious complication.

Cerebral arterial air embolism after endobronchial electrocautery: a case report and review of the literature.

BACKGROUND: Endobronchial electrocautery is a common and safe therapeutic endoscopic treatment for malignant airway obstruction. Cerebral arterial air embolism (CAAE) is a rare but potentially fatal complication of endobronchial electrocautery. CASE PRESENTATION: We present the first case of cerebral arterial air embolism after endobronchial electrocautery. A 56-year-old male with a pulmonary tumour in the right upper lobe received repeated endobronchial electrocautery. During the procedure, he experienced unresponsiveness, hypoxemia and bradycardia, and he developed tetraplegia. Brain computed tomography showed several cerebral arterial air emboli with low-density spots in the right frontal lobe. He received hyperbaric oxygen therapy with almost full recovery, except for residual left-sided weakness. CONCLUSIONS: General physicians should realize that CAAE may be a possible complication of endobronchial electrocautery. Several measures, including avoiding positive pressure, lowering ventilatory pressures if possible, avoiding advancing the bronchoscope to occlude the bronchus and using the non-contact technique, should be used to prevent this devastating complication.

COVID-19 Associated Reversible Cerebral Vasoconstriction Syndrome Successfully Treated with Nimodipine and Aspirin.

There have been limited cases linking SARS-CoV-2 infection with the development of reversible cerebral vasoconstriction syndrome (RCVS). We hereby report a rare case of RCVS in the setting of mild SARS-CoV-2 respiratory infection successfully treated with nimodipine and aspirin. SARS-CoV-2 attacks the ACE2-receptors, which are expressed in various body organs including the lungs, kidneys, and blood vessels. Vasoconstriction can result from down-regulation of the ACE2-receptors that can lead to sympathetic hypertonia of the cerebral blood vessel walls and/or over-activation of the renin-angiotensin axis.

Pilot assessment of omega-3 fatty acids and potassium thiocyanate in sickle cell anemia patients with conditional peak systolic cerebral artery blood velocity.

OBJECTIVE: The purpose of this pilot study was to explore the effect of omega-3 fatty acids and potassium thiocyanate on conditional peak systolic cerebral artery blood velocity in children with sickle cell anemia (SCA). METHODS: Transcranial doppler ultrasonography (TCD) was done on 232 SCA children, and 21 found with conditional peak systolic blood velocity (PSV) of 200-249 cm/s in internal carotid, middle or anterior cerebral arteries. These were randomized to receive omega-3 fatty acids and potassium thiocyanate with standard treatment of SCA (test group, N = 14), or standard treatment only (control group, N = 7). After 3 months of treatment, PSV was measured again. RESULTS: Right middle cerebral artery PSV was significantly reduced in the test relative to the control groups (p = 0.04). PSV returned to normal in 79% of the test versus 43% of the control group; and increased to abnormal in one member of the control group, but none of the test group. CONCLUSIONS: The pilot data suggest that in SCA, omega-3 fatty acids and potassium thiocyanate might reduce conditional blood velocity to normal, or prevent progression to abnormal values. A larger, randomized, clinical trial is required to further address the current gap in management of conditional TCD blood velocity.

An unusual artery causing an unusual stroke.

Bilateral thalamic infarctions are uncommon and often lead to more severe and long-lasting symptoms than unilateral thalamic infarctions. This article describes a patient with bilateral thalamic infarction caused by occlusion in the artery of Percheron, an anatomic variant thought to be present in 4% to 12% of the population.

A Paradoxical Vasodilatory Nutraceutical Intervention for Prevention and Attenuation of Migraine-A Hypothetical Review.

Studies suggest that migraine pain has a vascular component. The prevailing dogma is that peripheral vasoconstriction activates baroreceptors in central, large arteries. Dilatation of central vessels stimulates nociceptors and induces cortical spreading depression. Studies investigating nitric oxide (NO) donors support the indicated hypothesis that pain is amplified when acutely administered. In this review, we provide an alternate hypothesis which, if substantiated, may provide therapeutic opportunities for attenuating migraine frequency and severity. We suggest that in migraines, heightened sympathetic tone results in progressive central microvascular constriction. Suboptimal parenchymal blood flow, we suggest, activates nociceptors and triggers headache pain onset. Administration of NO donors could paradoxically promote constriction of the microvasculature as a consequence of larger upstream central artery vasodilatation. Inhibitors of NO production are reported to alleviate migraine pain. We describe how constriction of larger upstream arteries, induced by NO synthesis inhibitors, may result in a compensatory dilatory response of the microvasculature. The restoration of central capillary blood flow may be the primary mechanism for pain relief. Attenuating the propensity for central capillary constriction and promoting a more dilatory phenotype may reduce frequency and severity of migraines. Here, we propose consideration of two dietary nutraceuticals for reducing migraine risk: L-arginine and aged garlic extracts.

Hydrogen gas inhalation improves delayed brain injury by alleviating early brain injury after experimental subarachnoid hemorrhage.

Molecular hydrogen (H2) protect neurons against reactive oxygen species and ameliorates early brain injury (EBI) after subarachnoid hemorrhage (SAH). This study investigated the effect of H2 on delayed brain injury (DBI) using the rat SAH + unilateral common carotid artery occlusion (UCCAO) model with the endovascular perforation method. 1.3% H2 gas (1.3% hydrogen premixed with 30% oxygen and balanced nitrogen) inhalation was performed on days 0 and 1, starting from anesthesia induction and continuing for 2 h on day 0, and starting from anesthesia induction and continuing for 30 min on day 1. EBI was assessed on the basis of brain edema, expression of S100 calcium-binding protein B (S100B), and phosphorylation of C-Jun N-terminal kinase on day 2, and neurological deficits on day 3. Reactive astrogliosis and severity of cerebral vasospasm (CV) were assessed on days 3 and 7. DBI was assessed on the basis of neurological deficits and neuronal cell death on day 7. EBI, reactive astrogliosis, and DBI were ameliorated in the H2 group compared with the control group. CV showed no significant improvement between the control and H2 groups. This study demonstrated that H2 gas inhalation ameliorated DBI by reducing EBI without improving CV in the rat SAH + UCCAO model.

The regional pattern of abnormal cerebrovascular reactivity in HIV-infected, virally suppressed women.

The purpose of this study was to assess whole brain and regional patterns of cerebrovascular reactivity (CVR) abnormalities in HIV-infected women using quantitative whole brain arterial spin labeling (ASL). We hypothesized that HIV-infected women would demonstrate decreased regional brain CVR despite viral suppression. This cross-sectional study recruited subjects from the Bay Area Women's Interagency Health Study (WIHS)-a cohort study designed to investigate the progression of HIV disease in women. In addition to conventional noncontrast cerebral MRI sequences, perfusion imaging was performed before and after the administration of intravenous acetazolamide. CVR was measured by comparing quantitative ASL brain perfusion before and after administration of intravenous acetazolamide. In order to validate and corroborate ASL-based whole brain and regional perfusion, phase-contrast (PC) imaging was also performed through the major neck vessels. FLAIR and susceptibility weighted sequences were performed to assess for white matter injury and microbleeds, respectively. Ten HIV-infected women and seven uninfected, age-matched controls were evaluated. Significant group differences were present in whole brain and regional CVR between HIV-infected and uninfected women. These regional differences were significant in the frontal lobe and basal ganglia. CVR measurements were not significantly impacted by the degree of white matter signal abnormality or presence of microbleeds. Despite complete viral suppression, dysfunction of the neurovascular unit persists in the HIV population. Given the lack of association between CVR and traditional imaging markers of small vessel disease, CVR quantification may provide an early biomarker of pre-morbid vascular disease.

Artery of Percheron Infarction: A Short Review.

One uncommon type of ischemic stroke is occlusion of the artery of Percheron (AOP) leading to infarction of the paramedian thalami and mesencephalon. There are several variants of thalamic blood supply, and identifying the potential presence and infarction of an AOP is important in diagnosis and treatment of ischemic strokes affecting the thalami and mesencephalon, especially because of the unusual and variable presentation of these forms of ischemic strokes. This short review includes and discusses the case of a 58-year-old woman with an AOP infarct and indicates the importance of recognizing an AOP infarct early despite its clinical variations in order to treat the stroke in a timely fashion. This short review also includes a discussion of imaging modalities in such cases and clinical differential diagnoses to consider with management strategies.

GM1 Acupoint Injection Improves Mental Retardation in Children with Cerebral Palsy.

To study the clinical effectiveness and mechanism of GM1 acupoint injection therapy on mental retardation for children with cerebral palsy (CP). A total of 90 children with CP were divided into acupoint injection group (group A), subcutaneous injection group (group B), and control group (group C). Another 30 healthy children were set as a healthy control group (group D). The Mental Developmental Index (MDI), Psychomotor Developmental Index (PDI), and hemodynamic parameters in the cerebral arteries were measured before and after treatment. After three treatment courses, the MDI and PDI in groups A, B, and C were increased, and the increase in group A was most obvious (P < 0.05). Peak systolic velocity, mean velocity, and end-diastolic velocity were also elevated in group A, and after three treatment courses, resistance index decreased with a statistical significance (P < 0.05). However, there were no significant changes in groups B and C (P > 0.05). For all groups, neuron-specific enolase levels decreased and total superoxide dismutase increased after treatment. Acupoint injection therapy combined with conventional rehabilitation therapy demonstrated significant effects on cerebral hemodynamic conditions for children with CP.

Vascular pathology of large cerebral arteries in experimental subarachnoid hemorrhage: Vasoconstriction, functional CGRP depletion and maintained CGRP sensitivity.

Subarachnoid hemorrhage (SAH) is associated with increased cerebral artery sensitivity to vasoconstrictors and release of the perivascular sensory vasodilator CGRP. In the current study the constrictive phenotype and the vasodilatory effects of exogenous and endogenous perivascular CGRP were characterized in detail applying myograph technology to cerebral artery segments isolated from experimental SAH and sham-operated rats. Following experimental SAH, cerebral arteries exhibited increased vasoconstriction to endothelin-1, 5-hydroxytryptamine and U46419. In addition, depolarization-induced vasoconstriction (60 mM potassium) was significantly increased, supporting a general SAH-associated vasoconstrictive phenotype. Using exogenous CGRP, we demonstrated that sensitivity of the arteries to CGRP-induced vasodilation was unchanged after SAH. However, vasodilation in response to capsaicin (100 nM), a sensory nerve activator used to release perivascular CGRP, was significantly reduced by SAH (P = 0.0079). Because CGRP-mediated dilation is an important counterbalance to increased arterial contractility, a reduction in CGRP release after SAH would exacerbate the vasospasms that occur after SAH. A similar finding was obtained with artery culture (24 h), an in vitro model of SAH-induced vascular dysfunction. The arterial segments maintained sensitivity to exogenous CGRP but showed reduced capsaicin-induced vasodilation. To test whether a metabolically stable CGRP analogue could be used to supplement the loss of perivascular CGRP release in SAH, SAX was systemically administered in our in vivo SAH model. SAX treatment, however, induced CGRP-desensitization and did not prevent the development of vasoconstriction in cerebral arteries after SAH.

Anterior communicating artery division in the endoscopic endonasal translamina terminalis approach to the third ventricle: an anatomical feasibility study.

BACKGROUND: Endonasal endoscopic approaches (EEA) to the third ventricle are well described but generally use an infrachiasmatic route since the suprachiasmatic translamina terminalis corridor is blocked by the anterior communicating artery (AComA). The bifrontal basal interhemispheric translamina terminalis approach has been facilitated with transection of the AComA. The aim of the study is to describe the anatomical feasibility and limitations of the EEA translamina terminalis approach to the third ventricle augmented with AComA surgical ligation. METHODS: Endoscopic dissections were performed on five cadaveric heads injected with colored latex using rod lens endoscopes attached to a high-definition camera and a digital video recorder system. A stepwise anatomical dissection of the endoscopic endonasal transtuberculum, transplanum, translamina terminalis approach to the third ventricle was performed. Measurements were performed before and after AComA elevation and transection using a millimeter flexible caliper. RESULTS: Multiple comparison statistical analysis revealed a statistically significant difference in vertical exposure between the control condition and after AComA elevation, between the control condition and after AComA division and between the AComA elevation and division (p < 0.05). The mean difference in exposed surgical area was statistically significant between the control and after AComA division and between elevation and AComA division (p < 0.01), whereas it was not statistically significant between the control condition and AComA elevation (NS). CONCLUSION: The anatomical feasibility of clipping and dividing the AComA through an EEA has been demonstrated in all the cadaveric specimens. The approach facilitates exposure of the suprachiasmatic optic recess within the third ventricle that may be a blind spot during an infrachiasmatic approach.

Reversal of cerebrovascular constriction in experimental cerebral malaria by L-arginine.

Vascular dysfunction associated with low nitric oxide (NO) biavailability and low plasma L-arginine levels is observed in both human and experimental cerebral malaria (ECM). In ECM, cerebrovascular constriction results in decreased pial blood flow and hypoxia, and administration of NO donors reverses constriction and increases survival. Supplementation of L-arginine, the substrate for NO synthesis by NO synthases, has been considered as a strategy to improve vascular health and act as adjunctive therapy in human severe malaria. We investigated the effect of L-arginine supplementation on pial vascular tonus of mice with ECM after direct superfusion on the brain surface or systemic delivery. Pial arteriolar diameters of Plasmodium berghei-infected mice with implanted cranial windows were measured using intravital microscopy methods, before and after L-arginine administration. Systemic delivery of L-arginine was performed intravenously, at 10, 50, 100 and 200 mg/kg, as bolus injection or slowly through osmotic pumps, combined or not with artesunate. Direct superfusion of L-arginine (10-7M, 10-5M and 10-3M) on the brain surface of mice with ECM resulted in immediate, consistent and dose-dependent dilation of pial arterioles. ECM mice showed marked cerebrovascular constriction that progressively worsened over a 24 h-period after subcutaneous saline bolus administration. L-arginine administration prevented the worsening in pial constriction at all the doses tested, and at 50 mg/kg and 100 mg/kg it induced temporary reversal of vasoconstriction. Slow, continuous delivery of L-arginine by osmotic pumps, or combined bolus administration of artesunate with L-arginine, also prevented worsening of pial constriction and resulted in improved survival of mice with ECM. L-arginine ameliorates pial vasoconstriction in mice with ECM.

Transarterial Balloon-Assisted Glue Embolization of Pial Arteriovenous Fistulas.

OBJECTIVE: Endovascular disconnection of pial arteriovenous fistulas (AVFs) is challenging. The aim of this study was to evaluate safety and effectiveness of transarterial balloon-assisted glue embolization for treating pial AVFs. METHODS: We retrospectively reviewed medical and imaging records of 8 patients with high-flow pial AVFs treated by transarterial balloon-assisted glue embolization from August 2011 to July 2017. RESULTS: There were 6 male patients and 2 female patients with age range of 1-48 years. Presentation was seizure in 4 patients, headache in 3 patients, and subarachnoid hemorrhage in 1 patient. Seven lesions were located in the supratentorial region. All lesions were single-channel fistulas associated with venous varix. Five lesions had a single feeder, and 3 had multiple feeders. All lesions were obliterated completely in single-session embolization with no procedure-related complications. Two patients experienced symptomatic thrombosis of drainage venous system after embolization. One patient fully recovered on discharge, and another patient fully recovered after 8 months. With a mean clinical follow-up of 12.1 months, all patients were free of pretreatment symptoms. Follow-up angiograms revealed durable occlusion of fistulas. CONCLUSIONS: Transarterial balloon-assisted glue embolization is a feasible and effective option for treatment of high-flow pial AVFs.

A rare case of ruptured aneurysm of the paramedian artery of Percheron.

Introduction The artery of Percheron is a rare anatomic variant supplying bilateral medial thalamic nuclei and a variable portion of the rostral part of midbrain. Case report A 48-year-old female with massive subarachnoid hemorrhage due to a ruptured aneurysm of the paramedian artery of Percheron presented to the emergency room. Because of significant risk of recurrent intracranial hemorrhage, it was decided to proceed with endovascular embolization of the aneurysm. The patient was ultimately sent to a rehabilitation center and her presenting neurologic deficits showed significant improvements in the weeks following endovascular embolization treatment. Discussion The paramedian artery of Percheron is a rare anatomic variant and subarachnoid hemorrhage due to aneurysm of this artery is exceedingly rare. This case underlines the importance of a correct evaluation of cerebral arterial anatomy in order to choose the best endovascular therapeutic approach, reduce complications, and optimize patient outcome.

[Reversible cerebral vasoconstriction syndrome following smoking cessation and treatment with bupropion]. / Sindrome de vasoconstriccion cerebral reversible tras abandono de habito tabaquico y tratamiento con bupropion.

TITLE: Sindrome de vasoconstriccion cerebral reversible tras abandono de habito tabaquico y tratamiento con bupropion.