Brain-derived neurotrophic factor gene Val66Met polymorphism modulates reversible cerebral vasoconstriction syndromes

Reversible cerebral vasoconstriction syndrome: A review of pathogenesis, clinical presentation, and treatment

Reversible segmental narrowing of the intracranial arteries has been described since several decades in numerous clinical settings, using variable nosology. Twenty-one years ago, we tentatively proposed the unifying concept that these entities, based on similar clinical-imaging features, represented a single cerebrovascular syndrome. This "reversible cerebral vasoconstriction syndrome" or RCVS has now come of age. A new International Classification of Diseases code, (ICD-10, I67.841) has been established, enabling larger-scale studies. The RCVS2 scoring system provides high accuracy in confirming RCVS diagnosis and excluding mimics such as primary angiitis of the central nervous system. Several groups have characterized its clinical-imaging features. RCVS predominantly affects women. Recurrent worst-ever (thunderclap) headaches are typical at onset. While initial brain imaging is often normal, approximately one-third to half develop complications such as convexity subarachnoid hemorrhages, lobar hemorrhages, ischemic strokes located in arterial "watershed" territories and reversible edema, alone or in combination. Vasoconstriction evolves over hours to days, first affecting distal and then the more proximal arteries. An overlap between RCVS and primary thunderclap headache, posterior reversible encephalopathy syndrome, Takotsubo cardiomyopathy, transient global amnesia, and other conditions has been recognized. The pathophysiology remains largely unknown. Management is mostly symptomatic: headache relief with analgesics and oral calcium-channel blockers, removal of vasoconstrictive factors, and avoidance of glucocorticoids that can significantly worsen outcome. Intra-arterial vasodilator infusions provide variable success. Overall, 90-95% of admitted patients achieve complete or major resolution of symptoms and clinical deficits within days to weeks. Recurrence is exceptional, although 5% can later develop isolated thunderclap headaches with or without mild cerebral vasoconstriction.

RCVS: by clinicians for clinicians-a narrative review

BACKGROUND/OBJECTIVE

Reversible cerebral vasoconstriction syndrome may be underdiagnosed. It can be accompanied by various complications, mainly intracerebral hemorrhage and ischemic stroke. The clinical presentation of this condition varies according to its localization. The aims of this review are to raise awareness of the disease, especially in the presence of corresponding risk factors; to connect its precipitating factors, pathophysiology, and complications; and to compare various differential diagnoses of vasoconstriction.

METHODS

A review of the literature in PubMed/MEDLINE and Google Scholar was conducted from May 1997 until May 2022.

RESULTS

Reversible cerebral vasoconstriction syndrome, which is a clinical-radiological syndrome, is mainly characterized by the occurrence of thunderclap headache and widespread vasoconstriction. The most common precipitating factors are the use of vasoactive substances and postpartum status. The pathophysiology is currently assumed to include two mechanisms: sympathetic overactivity and endothelial dysfunction. From these mechanisms, it is possible to derive potential complications as well as the most important differential diagnoses: posterior reversible encephalopathy syndrome, convexity subarachnoid hemorrhage, ischemic and hemorrhagic stroke, and primary angiitis of the central nervous system.

CONCLUSION

In general, the outcome of reversible cerebral vasoconstriction syndrome is very good. Vasospasm as well as thunderclap headache attacks can be fully reversible, and > 90% of patients are functionally independent at discharge.

Pathophysiology of reversible cerebral vasoconstriction syndrome

Reversible cerebral vasoconstriction syndrome (RCVS) is a complex neurovascular disorder being recognized during the past two decades. It is characterized by multiple abrupt severe headaches and widespread cerebral vasoconstrictions, with potential complications such as ischemic stroke, convexity subarachnoid hemorrhage, intracerebral hemorrhage and posterior reversible encephalopathy syndrome. The clinical features, imaging findings, and dynamic disease course have been delineated. However, the pathophysiology of RCVS remains elusive. Recent studies have had substantial progress in elucidating its pathogenesis. It is now believed that dysfunction of cerebral vascular tone and impairment of blood–brain barrier may play key roles in the pathophysiology of RCVS, which explains some of the clinical and radiological manifestations of RCVS. Some other potentially important elements include genetic predisposition, sympathetic overactivity, endothelial dysfunction, and oxidative stress, although the detailed molecular mechanisms are yet to be identified. In this review, we will summarize what have been revealed in the literature and elaborate how these factors could contribute to the pathophysiology of RCVS.

Structural and Functional Characteristics of Cerebral Arteries as an Explanation for Clinical Syndromes Limited to the Brain

Vascular disease affects many different arterial beds throughout the body. Yet the brain is susceptible to several vascular disorders that either are not found in other parts of the body or when found are much less likely to cause clinical syndromes in other organs. This specific vulnerability of the brain may be explained by structural and functional differences between the vessels of the brain and those of vessels in other parts of the body. In this review, we focus on how cerebrovascular anatomy and physiology may make the brain and its vessels more susceptible to unique vascular pathologies. To highlight these differences, we use our knowledge of five diseases and syndromes that most commonly manifest in the intracranial vasculature. For each, we identify characteristics of the intracranial arteries that make them susceptible to these diseases, while noting areas of uncertainty requiring further research.

Endothelial TrkB receptor activation controls vascular tone of rat middle cerebral artery

Little is known on the cerebrovascular BDNF (brain-derived neurotrophic factor)/TrkB (tropomyosin related kinase B) pathway. This study investigated the contribution of endogenous endothelial BDNF to the control of vascular tone of rat middle cerebral artery (MCA) and the capacity of exogenous agonist of TrkB receptors to induce their relaxation. Endothelial cells constitutively expressed both BDNF and activated TrkB receptors. Supporting endothelial BDNF as an autocrine regulator of basal myogenic tone, incubation of MCA with the TrkB antagonist cyclotraxin B induced contraction as observed with incubation in the presence of inhibitors of nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF) production. Exposure of MCA with the TrkB agonist LM22A-4 that increased expression of TrkB receptors phosphorylated at tyrosine 816 induced relaxation of preconstricted MCA (EC₅₀ 6.7 × 10^-8 mol/L) as efficiently than acetylcholine (EC₅₀ 5.3 × 10^-8 mol/L). Finally, endothelium removal, exposure to a TrkB antagonist or to inhibitors of NO and EDHF production prevented the relaxant effect of LM22A-4. In conclusion, our study identified endothelial BDNF as a new autocrine regulator of vascular tone of MCA, thus making the endothelial BDNF/TrkB pathway an attractive target for strategies aiming to improve blood supply to the brain.

Posterior Reversible Encephalopathy Syndrome and Reversible Cerebral Vasoconstriction Syndrome as Syndromes of Cerebrovascular Dysregulation

PURPOSE OF REVIEW

This article describes the causes, clinical and imaging features, management, and prognosis of posterior reversible encephalopathy syndrome (PRES) and reversible cerebral vasoconstriction syndrome (RCVS), in which the underlying pathophysiology is related to reversible dysregulation of the cerebral vasculature.

RECENT FINDINGS

PRES and RCVS are descriptive terms, each bringing together conditions with similar clinical-imaging manifestations. Headache, visual symptoms, seizures, and confusion occur in both syndromes. RCVS is usually heralded by recurrent thunderclap headaches, whereas encephalopathy and seizures are typical in PRES. In PRES, brain imaging shows reversible vasogenic edema that is typically symmetric and located in subcortical regions (mostly posterior predominant). In RCVS, brain imaging is often normal; cerebral angiography shows segmental vasoconstriction-vasodilatation affecting the circle of Willis arteries and their branches. Aside from shared clinical features, significant imaging overlap exists. Both PRES and RCVS can be complicated by ischemic and hemorrhagic brain lesions; angiographic abnormalities frequently occur in PRES and vasogenic edematous lesions in RCVS. Common triggers (eg, eclampsia, vasoconstrictive and chemotherapeutic agents) have been identified. Abnormal cerebrovascular tone and endothelial dysfunction may explain both syndromes. Management of these syndromes includes the removal of identified triggers, symptomatic treatment of headache or seizures, and moderate blood pressure control. Both syndromes are self-limited, with clinical recovery occurring within days to weeks. Long-term deficits and mortality are uncommon.

SUMMARY

PRES and RCVS have been well characterized and acknowledged to have significant overlap. Advances in our understanding of pathophysiology and risk factors for poor outcome are expected to optimize the management of these not uncommon syndromes.

Urine metabolomics signatures in reversible cerebral vasoconstriction syndrome

Background

The pathophysiology of reversible cerebral vasoconstriction syndrome is unclear. An unbiased systems-based approach might help to illustrate the metabolite profiling and underlying pathophysiology.

Methods

Urine samples were collected from reversible cerebral vasoconstriction syndrome patients and matched controls recruited in Taipei Veterans General Hospital. 1H-Nuclear magnetic resonance was used to initially explore the metabolic profile, and liquid chromatography tandem mass spectrometry was then used to identify metabolic alterations in reversible cerebral vasoconstriction syndrome. Untargeted metabolite screening was randomly performed on 10 reversible cerebral vasoconstriction syndrome patients and 10 control subjects in the discovery phase. The selected untargeted metabolites were further validated on 47 reversible cerebral vasoconstriction syndrome patients during their ictal stage (with 40 of them having remission samples) and 47 controls in the replication phase.

Results and conclusion

Six metabolites-hippurate, citrate, 1,3,7-trimethyluric acid, ascorbic acid, D-glucurono-6,3-lactone, and D- threo-isocitric acid-with t-test derived p-value < 0.05 and VIP score >1, were identified as potential urine signatures that can well distinguish reversible cerebral vasoconstriction syndrome subjects at ictal stage from controls. Among them, citrate, hippurate, ascorbic acid, and D-glucurono-6,3-lactone were significantly lower, and 1,3,7-trimethyluric acid and D- threo-isocitric acid were higher in reversible cerebral vasoconstriction syndrome patients. Of these, four selected metabolites, citrate, D-glucurono-6,3-lactone, ascorbic acid, and 1,3,7-trimethyluric acid, returned to normal levels in remission. These metabolites are related to pathways associated with free radical scavenging, with the hub molecules being associated with endothelial dysfunction or sympathetic overactivity. Whether these metabolites and their implicated networks play a role in the pathogenesis of reversible cerebral vasoconstriction syndrome remains to be confirmed.

Fulminant Reversible Cerebral Vasoconstriction Syndrome After Carotid Endarterectomy for Asymptomatic Stenosis

BACKGROUND

Reversible cerebral vasoconstriction syndrome (RCVS) is a rare complication after carotid endarterectomy (CEA). Only a limited number of prior cases of RCVS have been reported after CEA for asymptomatic carotid stenosis.

CASE DESCRIPTION

In this report we present an unusual case of RCVS associated with multifocal intraparenchymal hemorrhage, subarachnoid hemorrhage, subdural hematoma, and ischemic stroke after CEA for asymptomatic carotid stenosis. We review preexisting studies and draw correlations with implications for understanding the mechanisms of RCVS.

CONCLUSIONS

A high index of suspicion should be maintained in post-CEA patients presenting with headaches or focal neurologic deficits, and vigilance with serial vascular imaging may help minimize long-term complications.

The Brain-Derived Neurotrophic Factor (BDNF) gene Val66Met (rs6265) polymorphism and stress among preclinical medical students in Malaysia

OBJECTIVE

This study aimed to determine the allelic and genotypic association of the Val66Met (rs6265) polymorphism in the BDNF gene with stress levels in preclinical medical students of Universiti Sultan Zainal Abidin (UniSZA), Terengganu, Malaysia.

METHODS

In this cross-sectional study, we recruited all 122 preclinical medical students. The validated depression anxiety stress scales-21 (DASS-21) questionnaire was distributed and blood samples were collected from each subject for DNA extraction. Genotyping analysis of the BDNF gene (Val66Met) polymorphism was performed via an optimised polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

A total of 105 subjects agreed to participate in this study. Indian students were found to more likely have the Val/Val genotype, whereas Malay students were more likely to have the Met/Met genotype (p = 0.027). Individuals carrying any one of the three BDNF genotypes (Val/Val, Val/Met and Met/Met) differed significantly from each other in terms of their perception of stress (p = 0.010); students carrying the Val/Val genotype (M = 10.6) perceived significantly lower stress than students carrying the Val/Met (M = 14) and Met/Met (M = 15.1) genotypes.

CONCLUSION

In our study, the Met-allele was associated with higher stress levels. To the best of our knowledge, this is the first study investigating this stress-related gene in medical students. The findings from this study should trigger more investigators to focus on the impact of stress on genetically predisposed medical students.

Seizures in patients with a phaeochromocytoma/paraganglioma (PPGL): A review of clinical cases and postulated pathological mechanisms

The purpose of this work was to expound on the postulated pathological mechanisms through which pheochromocytoma/paraganglioma (PPGL) can cause seizures by conducting a comprehensive review of ten cases and several pathogenic mechanisms. The goal was to enhance awareness amongst doctors and researchers about patients with PPGL presenting with seizures. This would help decrease the risk of misdiagnosis and mismanagement in future clinics. Additionally, this review was written with the purpose to attract more attention to etiological explorations, particularly concerning rare causes of seizures, which is consistent with the idea that League Against Epilepsy (ILAE) has emphasized in the new version of the ILAE position paper published in 2017. It is of great importance to keep in mind the fact that seizures can constitute an atypical presentation of PPGL and to establish early diagnosis and accurate cure for these patients, especially in the presence of paroxysmal hypertension or other suggestive symptoms of PPGL.

Influence of Climate on the Incidence of RCVS - A Retrospective Study From Taiwan

BACKGROUND

Cold weather is reportedly a precipitator of reversible cerebral vasoconstriction syndrome (RCVS) in a few cases. We systematically investigated whether meteorological factors correlate with the occurrence of RCVS.

METHODS

We conducted a retrospective analysis of a cohort of patients diagnosed with RCVS or probable RCVS, based on International Classification of Headache Disorders, third edition (ICHD-3) criteria, in a hospital-based headache center from March 2005 to February 2014. Monthly averages of local weather data measured in Taipei were obtained from the Central Weather Bureau in Taiwan. Primary weather variables were compared with the number of monthly new-onset cases of RCVS.

RESULTS

We recruited 226 patients with established RCVS and 72 patients with probable RCVS during a 108-month study period. Incidence of RCVS was higher in winter than summer months (3.3 persons/month [SD: 2.0] vs 2.1 persons/month [SD: 1.5], P = .013). The monthly incidence of RCVS correlated negatively with mean daily temperature (r = -0.231, P = .016) and average precipitation (r = -0.269, P = .005), but positively with barometric pressure (r = 0.274, P = .004). These 3 correlated meteorological factors together explained about 10% of the variance in RCVS monthly incidence (R²  = 0.095, P = .015).

CONCLUSION

RCVS was found to be more common in winter months and to be associated with weather variables in Taiwan. Further studies are needed to explore the underlying mechanisms of these associations.

Brain-derived neurotrophic factor secreted by the cerebral endothelium: A new actor of brain function?

Low cerebral levels of brain-derived neurotrophic factor (BDNF), which plays a critical role in many brain functions, have been implicated in neurodegenerative, neurological and psychiatric diseases. Thus, increasing BDNF levels in the brain is considered an attractive possibility for the prevention/treatment of various brain diseases. To date, BDNF-based therapies have largely focused on neurons. However, given the cross-talk between endothelial cells and neurons and recent evidence that BDNF expressed by the cerebral endothelium largely accounts for BDNF levels present in the brain, it is likely that BDNF-based therapies would be most effective if they also targeted the cerebral endothelium. In this review, we summarize the available knowledge about the biology and actions of BDNF derived from endothelial cells of the cerebral microvasculature and we emphasize the remaining gaps and shortcomings.

Intracranial Large Artery Disease of Non-Atherosclerotic Origin: Recent Progress and Clinical Implications

Intracranial large artery disease (ILAD) is the major cause of stroke worldwide. With the application of recently introduced diagnostic techniques, the prevalence of non-atherosclerotic ILAD is expected to increase. Herein, we reviewed recent reports and summarized progress in the diagnosis and clinical impact of differentiation between ILAD of atherosclerotic and non-atherosclerotic origin. Our review of the literature suggests that more careful consideration of non-atherosclerotic causes and the application of appropriate diagnostic techniques in patients with ILAD may not only provide better results in the treatment of patients, but it may also lead to more successful clinical trials for the treatment of intracranial atherosclerosis.

Reversible Cerebral Vasoconstriction Syndrome as an Unusual Complication of a Dural Arteriovenous Fistula treated with Onyx Embolization

BACKGROUND

Reversible cerebral vasoconstriction syndrome (RCVS) is a rare entity with an unknown pathophysiology. RCVS has been reported to occur more frequently in women age 20-50 years. Several causative mechanisms have been postulated involving transient deregulation of cerebral arterial tone, small vessel endothelial dysfunction, biochemical factors, hormonal deregulation, oxidative stress, and genetic predisposition. All these mechanisms and triggers are related to sympathetic overactivation, which eventually produces vasoconstriction. RCVS is distinguished by acute severe recurrent thunderclap headaches with or without other neurologic symptoms. However, the diagnosis can be challenging, requiring a high level of suspicion by the clinician, and RCVS is often underdiagnosed.

CASE DESCRIPTION

We present an unusual case of an 18-year-old female who developed RCVS after embolization of a dural arteriovenous fistula with onyx embolic material. Cerebral angiography was performed and verapamil was administered intra-arterially, resulting in a slight decrease in vasoconstriction with clinical improvement. The patient was maintained on oral verapamil during hospitalization. At a 7-month follow-up, the patient was neurologically stable, and cerebral angiography demonstrated no signs of vasoconstriction.

CONCLUSIONS

Endovascular procedures are a rare trigger for the development of RCVS and may be misdiagnosed. Prompt recognition of symptoms and diagnosis with treatment are necessary to reduce the risk of stroke. The management approach should be based on the premise of discontinuing precipitating drugs and administering calcium channel blocking agents.

Cerebral endothelial dysfunction in reversible cerebral vasoconstriction syndrome: a case-control study

Background

The aim of this study is to investigate cerebral endothelial dysfunction in patients with reversible cerebral vasoconstriction syndrome (RCVS).

Methods

We prospectively recruited patients with RCVS, age-matched controls with episodic migraine, and age-matched healthy controls at Samsung Medical Center from Apr 2015 to Jul 2016. All participants underwent transcranial Doppler evaluation, with a breath-holding maneuver, for the evaluation of bilateral middle cerebral arteries (MCAs), posterior cerebral arteries (PCAs), and the basilar artery (BA). The breath-holding index (BHI) was used to measure cerebral endothelium-dependent vasodilation. Follow-up BHIs were recorded in selected patients with RCVS after 3 months.

Results

A total of 84 subjects were recruited for this study (n = 28 in each group of RCVS, episodic migraine, and healthy control; mean age, 49.8 years). The RCVS group showed lower BHIs in all basal arteries, in comparison to healthy controls (p < 0.001, 0.009 for bilateral MCAs, p < 0.001 and 0.028 for bilateral PCAs, and p = 0.060 for the BA). Compared to migraineurs, RCVS patients had lower BHIs only in the anterior circulation (p = 0.002 and 0.038 for bilateral MCAs; p = 0.069 and 0.247 for bilateral PCAs; p = 0.120 for the BA). Of the 10 patients who had follow-up BHIs at 3 months, 7 showed complete normalization, while three did not.

Conclusions

Cerebral endothelial function is impaired in a widespread distribution in RCVS. Its role in the pathogenesis and clinical outcome of RCVS should be determined in further studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s10194-017-0738-x) contains supplementary material, which is available to authorized users.

Reversible cerebral vasoconstriction syndrome - A narrative revision of the literature

Reversible Cerebral Vasoconstriction Syndrome (RCVS) is a not very well known clinical-imaging entity; it is characterized by thunderclap headache, which mimics an aneurysmal subarachnoid haemorrhage, and a diffuse and segmental constriction of cerebral arteries, that resolves spontaneously within 3 months. The pathophysiology remains unknown. The female gender is the more affected and more than half of cases occur in the puerperium or after exposure to vasoactive substances. Typically, RCVS is self-limited and has a benign course, although it may have more serious complications with permanent neurologic sequelae and death. Treatment is predominantly supportive and directed to the symptoms.

Triptan-induced Reversible Cerebral Vasoconstriction Syndrome: Two Case Reports with a Literature Review

We encountered two patients with sumatriptan-induced reversible cerebral vasoconstriction syndrome (RCVS). The present patients were taking sumatriptan for the first time because they had been tentatively diagnosed with a migraine. On reviewing the literature, we found nine other cases of triptan-induced RCVS, predominantly among women aged 30 to 40 years. RCVS has been precipitated by triptan at the first ever use, after daily use, and even with long-term use at a normal dose. Patients with acute onset of severe headache should be thoroughly evaluated, and triptan should be administered appropriately. If triptan-induced RCVS is suspected, vascular imaging should be repeated after several days.

A possible role for ghrelin, leptin, brain-derived neurotrophic factor and docosahexaenoic acid in reducing the quality of life of coeliac disease patients following a gluten-free diet

PURPOSE

A gluten-free diet (GFD) has been reported to negatively impact the quality of life (QoL) of coeliac disease (CD) patients. The gut-brain axis hormones ghrelin and leptin, with the brain-derived neurotrophic factor (BDNF), may affect QoL of CD patients undergoing GFD. Our aims were to evaluate whether: (a) the circulating concentrations of leptin, ghrelin and BDNF in CD patients were different from those in healthy subjects; (b) GFD might induce changes in their levels; (c) BDNF Val66Met polymorphism variability might affect BDNF levels; and (d) serum BDNF levels were related to dietary docosahexaenoic acid (DHA) as a neurotrophin modulator.

METHODS

Nineteen adult coeliac patients and 21 healthy controls were included. A QoL questionnaire was administered, and serum concentrations of ghrelin, leptin, BDNF and red blood cell membrane DHA levels were determined at the enrolment and after 1 year of GFD. BDNF Val66Met polymorphism was analysed.

RESULTS

Results from the questionnaire indicated a decline in QoL after GFD. Ghrelin and leptin levels were not significantly different between groups. BDNF levels were significantly (p = 0.0213) lower in patients after GFD (22.0 ± 2.4 ng/ml) compared to controls (31.2 ± 2.2 ng/ml) and patients at diagnosis (25.0 ± 2.5 ng/ml). BDNF levels correlated with DHA levels (p = 0.008, r = 0.341) and the questionnaire total score (p = 0.041, r = 0.334).

CONCLUSIONS

Ghrelin and leptin seem to not be associated with changes in QoL of patients undergoing dietetic treatment. In contrast, a link between BDNF reduction and the vulnerability of CD patients to psychological distress could be proposed, with DHA representing a possible intermediate.

Reversible Cerebral Vasoconstriction Syndrome and Posterior Reversible Encephalopathy Syndrome Presenting with Deep Intracerebral Hemorrhage in Young Women

Reversible cerebral vasoconstriction syndrome (RCVS) is a group of syndromes characterized by reversible segmental constriction of cerebral arteries. Posterior reversible encephalopathy syndrome (PRES) is another clinical-radiologic syndrome characterized by reversible, posterior-predominant brain edema. Although the exact causes of these reversible syndromes are poorly understood, these entities may share some common pathophysiologic elements leading to hemorrhagic strokes and rarely, deep intracerebral hemorrhage (ICH). Recent studies have suggested that endothelial dysfunction is a common pathophysiologic factor associated with these syndromes. We report on two young female patients who presented with deep ICH and were later diagnosed as RCVS and PRES. Both patients suffered from vasoconstriction and delayed ischemic stroke. Early detection of distinguishing clinical-radiologic features associated with these reversible syndromes and removing triggers would facilitate successful treatment with no complications.

BDNF Val66Met polymorphism and hippocampal volume in neuropsychiatric disorders: A systematic review and meta-analysis

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is a neurotrophin involved in neurogenesis and synaptic plasticity in the central nervous system, especially in the hippocampus, and has been implicated in the pathophysiology of several neuropsychiatric disorders. Its Val66Met polymorphism (refSNP Cluster Report: rs6265) is a functionally relevant single nucleotide polymorphism affecting the secretion of BDNF and is implicated in differences in hippocampal volumes.

METHODS

This is a systematic meta-analytical review of findings from imaging genetic studies on the impact of the rs6265 SNP on hippocampal volumes in neuropsychiatric patients with major depressive disorder, anxiety, bipolar disorder or schizophrenia.

RESULTS

The overall sample size of 18 independent clinical cohorts comprised 1695 patients. Our results indicated no significant association of left (Hedge's g=0.08, p=0.12), right (g=0.07, p=0.22) or bilateral (g=0.07, p=0.16) hippocampal volumes with BDNF rs6265 in neuropsychiatric patients. There was no evidence for a publication bias or any demographic, clinical, or methodological moderating effects. Both Val/Val homozygotes (g=0.32, p=0.004) and Met-carriers (g=0.20, p=0.004) from the patient sample had significantly smaller hippocampal volumes than the healthy control sample with the same allele. The magnitude of these effects did not differ between the two genotypes.

CONCLUSION

This meta-analysis suggests that there is no association between this BDNF polymorphism and hippocampal volumes. For each BDNF genotype, the hippocampal volumes were significantly lower in neuropsychiatric patients than in healthy controls.

Assessment of glomerular filtration rate based on alterations of serum brain-derived neurotrophic factor in type 2 diabetic subjects treated with amlodipine/benazepril or valsartan/hydrochlorothiazide

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is associated with sympathetic activation. However, the effects of BDNF on diabetic nephropathy are unknown. The aim of this study was to assess the estimated glomerular filtration rates (eGFRs) and changes in serum BDNF levels in type 2 diabetic subjects treated with antihypertensive medications.

METHODS

In this randomized, double-blind clinical trial, type 2 diabetic subjects with hypertension were assigned to either the benazepril/amlodipine or valsartan/hydrochlorothiazide treatment groups for a 16-week period. The post hoc analyses were based on increased or decreased serum BDNF levels.

RESULTS

Of the 153 enrolled subjects, the changes in eGFR were significantly and inversely correlated with those in BDNF in the 76 subjects treated with valsartan/hydrochlorothiazide (r = -0.264, P = 0.021) but not in the 77 subjects treated with benazepril/amlodipine (r = -0.025, P = 0.862). The 45 subjects with increased BDNF following valsartan/hydrochlorothiazide treatment exhibited a significantly reduced eGFR (-8.8 ± 14.9 mL/min/1.73 m(2); P < 0.001). Multivariate regression analysis revealed that increased serum BDNF represents an independent factor for reduced eGFR (95% confidence interval between -0.887 and -0.076, P = 0.020).

CONCLUSIONS

Increased serum BDNF is associated with reduced eGFR in type 2 diabetic subjects treated with valsartan/hydrochlorothiazide but not with amlodipine/benazepril.

Reversible Cerebral Vasoconstriction Syndrome, Part 1: Epidemiology, Pathogenesis, and Clinical Course

Reversible cerebral vasoconstriction syndrome is a clinical and radiologic syndrome that represents a common presentation of a diverse group of disorders. The syndrome is characterized by thunderclap headache and reversible vasoconstriction of cerebral arteries, which can either be spontaneous or related to an exogenous trigger. The pathophysiology of reversible cerebral vasoconstriction syndrome is unknown, though alterations in cerebral vascular tone are thought to be a key underlying mechanism. The syndrome typically follows a benign course; however, reversible cerebral vasoconstriction syndrome may result in permanent disability or death in a small minority of patients secondary to complications such as ischemic stroke or intracranial hemorrhage.

Ischaemic strokes with reversible vasoconstriction and without thunderclap headache: a variant of the reversible cerebral vasoconstriction syndrome?

BACKGROUND

Reversible vasoconstriction (RV) may cause ischaemic stroke (IS) in the absence of any other defined stroke aetiology. The three objectives of our study were to evaluate the frequency of RV in a prospective series of young IS patients, to describe the detailed clinical-radiological features in the patients with RV and IS, and to compare these characteristics with those of reversible cerebral vasoconstriction syndrome (RCVS).

METHODS

We identified between October 2005 and December 2010, 159 consecutive young patients (<45 years) hospitalized for an acute IS confirmed by cerebral magnetic resonance imaging. An extensive diagnostic work-up was performed including toxicological urinary screening for cannabis, cocaine and amphetamines, and the usual biological, cardiac and vascular investigations for an IS in the young. We specifically studied patients with IS and RV, which was defined as multifocal intracranial arterial stenoses confirmed by intracranial arterial imaging that resolved within 3-6 months.

RESULTS

Out of 159 patients with IS, 21 (13%, 12 males, 9 females; mean age 32 years) had multifocal cerebral arterial stenoses that were fully reversible at 3-6 months, and no other cause for stroke. IS were located on posterior territory in 71% of cases, and vasoconstriction predominated on posterior cerebral and superior cerebellar arteries. Precipitating factors of IS and RV were the use of cannabis resin (n = 14), nasal decongestants (n = 2) and triptan (n = 1). Most cases (74%) had unusual severe headache, but none had thunderclap headache. None of 21 cases had reversible posterior leukoencephalopathy, cortical subarachnoid or intracerebral haemorrhage.

CONCLUSION

RV was the sole identified cause of IS in 13% of our cohort. These young patients with IS and RV may have a variant of RCVS, related to an increased susceptibility to vasoactive agents in some individuals. RV in our patients differs from the classical characteristics of RCVS by the absence of thunderclap headache, reversible brain oedema and subarachnoid or intracranial haemorrhage. Intracranial arteries should be looked for, by appropriate vascular imaging, in young patients with IS at the acute stage and during the follow-up period.

Reduced circulating endothelial progenitor cells in reversible cerebral vasoconstriction syndrome

BACKGROUND

The pathophysiology of reversible cerebral vasoconstriction syndrome (RCVS) remains elusive. Endothelial dysfunction might play a role, but direct evidence is lacking. This study aimed to explore whether patients with RCVS have a reduced level of circulating circulating endothelial progenitor cells (EPCs) to repair the dysfunctional endothelial vasomotor control.

METHODS

We prospectively recruited 24 patients with RCVS within one month of disease onset and 24 healthy age- and sex-matched controls. Flow cytometry was used to quantify the numbers of circulating EPCs, defined as KDR+CD133+, CD34+CD133+, and CD34+KDR+ double-positive mononuclear cells. The Lindegaard index, an index of vasoconstriction, was calculated by measuring the mean flow velocity of middle cerebral arteries and distal extracranial internal carotid arteries via color-coded sonography on the same day as blood drawing. A Lindegaard index of 2 was chosen as the cutoff value for significant vasoconstriction of middle cerebral arteries based on our previous study.

RESULTS

Patients with RCVS had a reduced number of CD34+KDR+ cells (0.009 ± 0.006% vs. 0.014 ± 0.010%, p = 0.031) but not KDR+CD133+ cells or CD34+CD133+ EPCs, in comparison with controls. The number of CD34+KDR+ cells was inversely correlated with the Lindegaard index (rs = -0.418, p = 0.047). Of note, compared to controls, patients with a Lindegaard index > 2 (n = 13) had a reduced number of CD34+KDR+ cells (0.007 ± 0.005% vs. 0.014 ± 0.010%, p = 0.010), but those with a Lindegaard index ≤ 2 did not.

CONCLUSIONS

Patients with RCVS had reduced circulating CD34+KDR+ EPCs, which were correlated with the severity of vasoconstriction. Endothelial dysfunction might contribute to the pathogenesis of RCVS.

Reversible cerebral vasoconstriction syndrome: updates and new perspectives

Reversible cerebral vasoconstriction syndrome (RCVS) is an important cause of headaches that can lead to other neurological complications, including stroke, if not recognized early. Over the past few years, there has been great progress in the recognition of this entity. However, there is still much to be learned about its pathophysiology and optimal treatment strategies. RCVS occurs mostly in middle-aged adults, and there is a female preponderance with an increased incidence during the postpartum period. A consistent, predominating feature is a sudden-onset, severe headache that is frequently recurrent, usually over the span of a week. Less common presentations include seizures or focal neurological symptoms. Important causative factors include vasoactive medications, as well as illicit drugs like marijuana and cocaine. The current underlying pathophysiology is thought to be a disturbance in cerebrovascular tone leading to vasoconstriction. The diagnosis is based on history, physical examination, and cerebrovascular imaging findings that demonstrate multifocal, segmental areas of vasoconstriction in large- and medium-sized arteries. An important criterion for making the diagnosis is the eventual reversibility of symptoms and imaging findings.

A novel approach to diagnose reversible cerebral vasoconstriction syndrome: a case series

BACKGROUND

Reversible cerebral vasoconstriction syndrome (RCVS) is classically diagnosed based on the presence of severe thunderclap headache, focal neurologic symptoms, and the radiographic findings of reversible diffuse segmental cerebral vasoconstriction. We present a diagnostic test that may assist in the clinical diagnosis and facilitate treatment.

METHODS

From October 1, 2010, to August 1, 2013, we identified consecutive patients who presented with a presumptive diagnosis of RCVS and underwent cerebral diagnostic angiography with intra-arterial (IA) vasodilator therapy. Medical records including clinical presentation, radiographic, and angiographic images were all reviewed.

RESULTS

We identified a total of 7 patients (4 females; age range, 22-56; mean, 45 years) who met our inclusion criteria. Four patients received a combination of milrinone and nicardipine infusion either in the internal carotid arteries or in the left vertebral artery; the remaining patients received IA therapy solely with either nicardipine or milrinone. Five patients had a positive angiographic response, defined as significant improvement or resolution of the blood vessels irregularities. All 5 patients had a definite discharge diagnosis of RCVS. The remaining 2 patients had a negative angiographic response and based on their clinical and radiographic course had a final diagnosis of intracranial atherosclerotic disease.

CONCLUSIONS

Our small case series suggest that IA administration of vasodilators is safe and may aid in distinguishing vasodilator responsive syndromes such as RCVS from other causes. Further study is required with long-term clinical outcome to determine the utility of this diagnostic test.

Reversible cerebral vasoconstriction syndrome following indomethacin

BACKGROUND

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by severe thunderclap headaches and transient segmental cerebral arterial vasoconstriction. Precipitating factors, including the postpartum state and exposure to vasoactive substances are identified in approximately 50% of cases. Non-steroidal anti-inflammatory drugs have rarely been associated with RCVS.

CASE DESCRIPTION

We report a case of a 51-year-old female with RCVS after administration of indomethacin given to relieve pain caused by renal colic. Cerebral imaging showed non-aneurysmal cortical subarachnoid hemorrhage, and formal angiography demonstrated widespread multifocal segmental narrowing of medium-sized cerebral arteries. These changes resolved on repeat angiography at 3 weeks.

DISCUSSION

Indomethacin is a commonly used drug for treatment of certain primary headache disorders. To date, its mechanism of action remains unclear. A well described side effect of indomethacin is headache, which may be secondary to its vasoconstrictive effects. In our case, we postulate indomethacin, either alone or in combination with emotional stress from pain, triggered or exacerbated an underlying predisposition to RCVS.

Reversible cerebral vasoconstriction syndrome (RCVS) in antiphospholipid antibody syndrome (APLA): the role of centrally acting vasodilators. Case series and review of literature

Reversible cerebral vasoconstriction syndrome (RCVS) is Raynaud's phenomenon of the brain. Changes in neurological function are dependent upon which areas of the brain are deprived of normal blood flow. Antiphospholipid antibody syndrome (APLA) is a common cause of Raynaud's phenomenon that can occur anywhere in the body, including the brain. Management of CNS vasospasm generally involves the use of centrally acting calcium channel blockers, which have been shown to relieve the associated headaches and transient neurological symptoms associated with it. Three patients with APLA and RCVS from our clinics are illustrated. It is demonstrated that the use of centrally acting calcium channel-blocking drugs, such as nimodipine, which prevent and reverse CNS vasospasm, led to clinical improvement in our patients over the course of 5-9 years. All of them had MRIs done at the initiation of therapy and 5-9 years after being on therapy. MRI measures of T2 lesion volumes (LVs) and number were obtained. All three patients had a good response in controlling clinical symptoms related to CNS vasospasm, Raynaud's phenomenon, visual disturbances, confusion, headaches, and hearing loss. There was also a resolution in the MRI findings of these patients. This case series of three patients shows a clinical improvement and decrease in T2 LV and number in patients with APLA and Raynaud's syndrome on centrally acting calcium channel blockers. RCVS is much more common than that currently appreciated. APLA is the common cause of RCVS. Further studies are needed to determine the optimal methods to diagnose RCVS and optimal therapies to treat it.

Reversible cerebral vasoconstriction syndrome: a review of recent research

Reversible cerebral vasoconstriction syndrome (RCVS) is a collective term used for transient noninflammatory, nonatherosclerotic segmental constriction of cerebral arteries. The angiopathies of RCVS have previously been defined by several nomenclatures. Current opinion favors the unification of these pathophysiologically related angiopathies because of their similar angiographic features and clinical course. RCVS typically presents acutely as headache, delirium, seizure, cerebral ischemia, and/or hemorrhage. The angiographic features make RCVS an important mimic of CNS vasculitides. In contrast to CNS vasculitis, RCVS is typically a transient condition with relatively good clinical outcomes. Although a complete understanding of the etiological and pathological features of RCVS has not yet been achieved, alterations in vascular tone lead to the observed arterial changes. In this review, we aim to provide a summary of RCVS and provide insight into current perspectives of the underlying pathophysiological processes, diagnosis, and treatment.

Reversible cerebral vasoconstriction syndrome

Recurrent thunderclap headaches, seizures, strokes, and non-aneurysmal subarachnoid haemorrhage can all reveal reversible cerebral vasoconstriction syndrome. This increasingly recognised syndrome is characterised by severe headaches, with or without other symptoms, and segmental constriction of cerebral arteries that resolves within 3 months. Reversible cerebral vasoconstriction syndrome is supposedly due to a transient disturbance in the control of cerebrovascular tone. More than half the cases occur post partum or after exposure to adrenergic or serotonergic drugs. Manifestations have a uniphasic course, and vary from pure cephalalgic forms to rare catastrophic forms associated with several haemorrhagic and ischaemic strokes, brain oedema, and death. Diagnosis can be hampered by the dynamic nature of clinicoradiological features. Stroke can occur a few days after initial normal imaging, and cerebral vasoconstriction is at a maximum on angiograms 2-3 weeks after clinical onset. The calcium channel blocker nimodipine seems to reduce thunderclap headaches within 48 h of administration, but has no proven effect on haemorrhagic and ischaemic complications.

[Reversible cerebral vasoconstriction syndrome]

The reversible cerebral vasoconstriction syndrome (RCVS) is an under-estimated transient acute cerebrovascular disorder. It has long been mistaken as central nervous system vasculitis whereas it is now believed to result from an acute but prolonged vasospasm of cerebral arteries. This disorder can be precipitated by postpartum or vasoactive drug. However, it occurs spontaneously in a significant number of cases. The characteristic clinico-radiological presentation and disease course of the RCVS has been delineated only recently. Mean age at onset is 40-45 years, with a female predominance. A provocative factor can be identified in 12-60% out of the patients. Clinical presentation is predominantly marked by recurrent thunderclap headaches, but can be complicated with focal neurological deficit or seizures. Brain imaging is normal in most cases, but can reveal hemorrhagic or ischemic complications. Cortical subarachnoid hemorrhage is a suggestive finding. A posterior reversible encephalopathy syndrome (PRES) can be seen occasionally. Cerebral angiography reveals multifocal arterial narrowing with string and bead appearance. Cerebrospinal fluid reveals no or mild abnormalities. The disease resumes spontaneously within several days to weeks, whereas vasoconstriction reverses within 1 to 3 months. This clinico-radiological presentation should be promptly recognized in order to avoid unnecessary investigations and aggressive treatment, and lead to search for a triggering factor. Further studies are required in order to clarify the precipitating role of several drugs, and clinical trials are needed to reduce the occurrence of strokes.

Reversible cerebral vasoconstriction syndrome: current and future perspectives

Reversible cerebral vasoconstriction syndromes (RCVS) are characterized by recurrent acute severe headaches, namely thunderclap headaches, and multifocal segmental vasoconstrictions. Interest has arisen in the definitions, clinical presentations, differential diagnoses, risk factors and complications of RCVS. This article will comprehensively review the milestone monographs and the latest research work addressing these issues. Studies that have focused on the relationship between RCVS and thunderclap headache will be detailed. We will also discuss research on the enigmatic pathophysiology and potential therapeutic approaches. Up-to-date information and challenges, undergoing studies and future research directions will be deeply probed.