The imaging findings of migraine with visual aura in a CADASIL patient.

Head MRI images of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) patients during migraine attacks are rare.

Detecting a Novel NOTCH3 Variant in Patients with Suspected CADASIL: A Single Center Study.

Introduction: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common form of familial cerebral small vessel disease in adults and is caused by NOTCH3 variants. Clinical manifestations of CADASIL include recurrent ischemic strokes, dementia, migraine or migraineous headaches, epileptic seizures, and psychiatric disorders. The clinical-radiological phenotype of the disease is also highly variable. In this study, we investigated the variability of clinical, radiological, and genetic data in patients analyzed for NOTCH3 variant in our clinic. Methods: We performed clinical and neuropsychological examination, cerebral magnetic resonance imaging (MRI) and Doppler sonography of cerebral arteries in all patients. Next-generation sequencing test was used for detect variants in NOTCH3 gene from all CADASIL patients. Results: By using the next-generation sequencing method, heterozygous c.380C>T pathogenic variant was detected in the 4th exon of the NOTCH3 gene in 3 patients. This is a previously unreported novel variant and resulted in the replacement of the amino acid Proline at 127th position with Leucine. Discussion and Conclusion: The discovery of this novel pathogenic variant region may contribute to the expansion of the clinical and genetic spectrum of diseases associated with NOTCH3, leading to further research and treatment options for this disease in the future.

Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy (CADASIL) Syndrome: A Case Report and Review of Literature.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant genetic disorder of the small arteries that causes ischemic vascular events, subcortical dementia, behavioral changes, and migraine-like headaches. It is caused by a mutation in the NOTCH3 gene; this disease was first described in 1955 by van Bogaert. We present a 29-year-old woman who presented to the neurology department. She has no history of chronic degenerative diseases. She has been complaining of migraine-like headaches for the past six months. She has cognitive impairment with arithmetic and executive function deficits on neurological examination. Blood biometry and blood chemistry are within normal parameters in her laboratory studies. A viral panel and immunological profile were also performed and were not reactive. A lumbar puncture was performed, and the composition of the cerebrospinal fluid was within normal limits. An MRI was performed, which showed bilateral and symmetric white matter hyperintensities consistent with CADASIL syndrome. There is no specific treatment. Management of these patients is based on symptom control. Neurological sequelae have an important impact on the quality of life and mortality of these patients. For this reason, pharmacological preventive therapies have been sought with controversial evidence.

A multicenter, single-arm, phase II clinical trial of adrenomedullin in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

Background: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), the most common form of hereditary cerebral small vessel disease (SVD), currently lacks disease-modifying treatments. Adrenomedullin (AM), a vasoactive peptide with angiogenic, vasodilatory, anti-inflammatory, and anti-oxidative properties, shows potential effects on the neuro-glial-vascular unit. Objective: The AdrenoMedullin for CADASIL (AMCAD) study aims to assess the efficacy and safety of AM in patients with CADASIL. Sample size: Overall, 60 patients will be recruited. Methods: The AMCAD is a multicenter, investigator-initiated, single-arm phase II trial. Patients with a confirmed CADASIL diagnosis, based on NOTCH3 genetic testing, will receive an 8-h AM treatment (15 ng/kg/min) for 14 days following a baseline assessment (from day 1 to day 14). Follow-up evaluations will be performed on days 15, 28, 90, and 180. Study outcomes: The primary endpoint is the cerebral blood flow change rate in the frontal cortex, evaluated using arterial spin labeling magnetic resonance imaging, from baseline to day 28. Summary statistics, 95% confidence intervals, and a one-sample t-test will be used for analysis. Conclusion: The AMCAD study aims to represent the therapeutic potential of AM in patients with CADASIL, addressing an unmet medical need in this challenging condition. Clinical Trial Registration: jRCT 2,051,210,117 (https://jrct.niph.go.jp/en-latest-detail/jRCT2051210117).

Decreased retinal vascular density is associated with cognitive impairment in CADASIL: an optical coherence tomography angiography study.

PURPOSE: This study aimed to assess alterations in retinal vascular density in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) patients using optical coherence tomography angiography (OCTA) and investigate their association with MRI and cognitive features. METHODS: Twenty-five patients with CADASIL and forty healthy controls were evaluated by Cirrus HD-OCT 5000 with AngioPlex OCTA to determine changes in macular retinal vasculature. Retinal vasculature parameters between two groups were compared. The MRI lesion burden and neuropsychological scales were also examined in patients. The association between OCTA parameters and MRI/cognitive features was evaluated using partial Spearman rank correlation. RESULTS: The vessel density and perfusion density of whole image in macular region (vessel density: t = - 2.834, p = 0.005; perfusion density: t = - 2.691, p = 0.007) were significantly decreased in patients with CADASIL. Moreover, vessel density of whole image in macular region was negatively associated with Fazekas scores (ρ = - 0.457; p = 0.025) and the number of lacunar infractions (ρ = - 0.425, p = 0.038) after adjustment for age. Decreased macular vessel density and perfusion density of whole image were also associated with MoCA scores (vessel density: ρ = 0.542, p = 0.006; perfusion density: ρ = 0.478, p = 0.018) and other domain-specific neuropsychological tests (p < 0.05) after adjustment for age. CONCLUSION: Decreased retinal vascular density was associated with increased MRI lesion burden and cognitive impairment in patients with CADASIL. Our findings suggest that the degree of retinal vascular involvement, as demonstrated by OCTA, may be consistent with the severity of MRI lesions and the degree of cognitive impairment in patients.

Border-Zone Cerebral Infarcts Associated with COVID-19 in CADASIL: A Report of 3 Cases and Literature Review.

INTRODUCTION: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common inherited cerebral small vessel disease and is a cause of early onset ischemic lacunar stroke. COVID-19 infection may lead, in addition to acute respiratory syndrome, to vascular complications including stroke. Herein, we report three CADASIL patients presenting with cerebral border-zone infarcts concomitant to COVID-19 infection and summarize similar cases previously published in literature. METHODS: Clinical and radiological features of the 3 patients were collected and described. A narrative review of literature was performed in PubMed and Google Scholar by the end of 2022 using the "CADASIL" AND "COVID-19" AND "stroke" terms. RESULTS: In our 3 patients, aged 40-58 years, stroke symptoms occurred one to 11 days after the first COVID-19 manifestations. Pulmonary symptoms were mild or absent. One patient presented with hemodynamic failure presumably related to acute cardiomyopathy. Brain magnetic resonance imaging revealed in all cases, ischemic lesions within border-zone areas in both cerebral hemispheres, lesions in the genu of the corpus callosum or in the medium cerebellar peduncles in two cases. The watershed pattern of ischemic lesions was detected in two cases despite any blood pressure drop or severe respiratory dysfunction. Seven CADASIL patients presenting with acute brain infarcts (multiple in 4/7) in context of SARS-CoV-2 infection were identified in literature, despite no fall in blood pressure except for one of them. CONCLUSION: Our observations, in line with previous reports, further suggest that COVID-19 infection may alter blood flow autoregulation in the deepest cerebral white matter in CADASIL patients. The thrombocytopathy and endotheliopathy developing during COVID-19 infection may participate to the underlying vascular processes.

Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy (CADASIL): A Diagnosis to Consider in Atypical Stroke Presentations.

CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is a hereditary cerebral arteriopathy caused by a neurogenic locus notch homolog protein 3 (NOTCH3) gene mutation. This article describes the case of a man in his early 40s who experienced sudden onset temporary left-sided weakness and facial numbness that resolved in two hours, along with residual weakness in the upper and lower limbs. There was a family history of CADASIL with both his mother and brother having experienced strokes. Clinical investigations on admission were unremarkable including a young stroke screen and computed tomography (CT) of the brain. On CT angiography, there was no evidence of significant carotid artery stenosis. Subsequent cerebral magnetic resonance imaging (MRI) revealed an acute infarction in the right corona radiata extending into the right basal ganglia, with the fluid-attenuated inversion recovery (FLAIR) images revealing considerable bilateral symmetrical white matter hyperintensity in the frontal, parietal, and anterior temporal lobes. Based on his clinical presentation, strong family history, and brain MRI findings, a diagnosis of CADASIL was suspected. He received antiplatelet medication for an acute stroke and later underwent genetic testing, which revealed the presence of a NOTCH3 gene mutation.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy: Atypical clinical presentation with isolated frontotemporal dementia.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary syndrome caused by heterozygous mutations in the NOTCH3 gene that manifests in adulthood and is characterized by recurrent transient ischemic attacks and strokes, migraine-like headaches, psychiatric disturbance, and progressive dementia. The current study reports an interesting case of CADASIL in a Saudi patient with a heterozygous mutation in exon 18 of the NOTCH3 gene presenting only with cognitive decline without migraine or stroke. The diagnosis was suspected mainly because of the typical brain magnetic resonance imaging (MRI) features that led to performing genetic testing to confirm the diagnosis. This illustrates the importance of brain MRI in the diagnosis of CADASIL. Increased awareness of neurologists and neuroradiologists about the typical MRI features of CADASIL is of paramount importance to reach the diagnosis in a timely manner. Awareness of the atypical presentations of CADASIL will lead to identifying more CADASIL cases.

Inflammatory Optic Neuropathy as a Presenting Feature of Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy.

Background: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is commonly associated with early-onset stroke, migraine and vascular dementia. However, optic nerve involvement has been previously recognised. Results: We report a case of a 21-year-old female presenting with right inferior temporal scotoma, dyschromatopsia, relative pupillary afferent defect and bilateral disk oedema in the fundoscopic examination. Visual evoked potential latencies were bilaterally increased, suggesting optic neuropathy. Cerebrospinal fluid (CSF) evaluation showed 11 leukocytes, .45 mg/dL proteins, elevated IgG (4.55 mg/dL) and 2 oligoclonal bands (OCB) restricted to the CSF. ESR was 17 mm/h and CRP 5 mg/dL. Anti-Aquaporin4 anti-MOG antibodies were negative. The MRI showed right optic nerve hyperintensity, enhancing after the administration of contrast product, and multiple FLAIR focal lesions present throughout the white matter, with a noticeable confluence in the anterior temporal horns. She improved after IV high-dose methylprednisolone. Because the lesions of the white matter were highly atypical for an inflammatory disease and highly suggestive of CADASIL genetic testing was requested. A heterozygous pathogenic variant c994C>T p (Arg332Cys) in the exon 6 of the NOTCH3 gene, compatible with the diagnosis of CADASIL was found. Conclusions: This case highlights isolated optic nerve involvement as a presenting feature of CADASIL, possibly reflecting an inflammatory process associated with this hereditary vasculopathy.

Status epilepticus no convulsivo como manifestación inicial en una familia con arteriopatía autosómica dominante cerebral con infartos subcorticales y leucoencefalopatía (CADASIL) / Non-convulsive status epilepticus as the initial manifestation in a family with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)

La arteriopatía autosómica dominante cerebral con infartos subcorticales y leucoencefalopatía es una enfermedad autosómica dominante de pequeños vasos causada por mutaciones del gen NOTCH3. Típicamente se presenta con migraña, eventos isquémicos cerebrales recurrentes y trastornos cognitivos. Las crisis epilépticas son inusuales como manifestación inicial, pero aún más infrecuente es su presentación como status epilepticus no convulsivo1. Se presenta una serie familiar de 3 casos con esta arteriopatía, entre los cuales 2 de ellos tuvieron status epilepticus como manifestación de la enfermedad. (AU)

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant small-vessel disease caused by mutations of the NOTCH3 gene. It typically presents with migraine, recurrent brain ischaemia, and cognitive disorders. Seizures rarely present as the initial manifestation, with non-convulsive status epilepticus being even less frequent. We present a series of 3 related patients with this arteriopathy, 2 of whom presented status epilepticus as a manifestation of the disease. (AU)

TREX1 p.A129fs and p.Y305C variants in a large multi-ethnic cohort of CADASIL-like unrelated patients.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and retinal vasculopathy with cerebral leukodystrophy and systemic manifestations (RVCL-S) are the most common forms of rare monogenic early-onset cerebral small vessel disease and share clinical, and, to different extents, neuroradiological and neuropathological features. However, whether CADASIL and RVCL-S overlapping phenotype may be explained by shared genetic risk or causative factors such as TREX1 coding variants remains poorly understood. To investigate this intriguing hypothesis, we used exome sequencing to screen TREX1 protein-coding variability in a large multi-ethnic cohort of 180 early-onset independent familial and apparently sporadic CADASIL-like Caucasian patients from the USA, Portugal, Finland, Serbia and Turkey. We report 2 very rare and likely pathogenic TREX1 mutations: a loss of function mutation (p.Ala129fs) clustering in the catalytic domain, in an apparently sporadic 46-year-old patient from the USA and a missense mutation (p.Tyr305Cys) in the well conserved C-terminal region, in a 57-year-old patient with positive family history from Serbia. In concert with recent findings, our study expands the clinical spectrum of diseases associated with TREX1 mutations.

Non-convulsive status epilepticus as the initial manifestation in a family with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant small-vessel disease caused by mutations of the NOTCH3 gene. It typically presents with migraine, recurrent brain ischaemia, and cognitive disorders. Seizures rarely present as the initial manifestation, with non-convulsive status epilepticus being even less frequent. We present a series of 3 related patients with this arteriopathy, 2 of whom presented status epilepticus as a manifestation of the disease.

The relevance of the socio-emotional deficits in cerebral small vessels disease (CSVD): An exploratory study with sporadic CSVD and CADASIL patients.

Background: Cerebral Small Vessels Disease (CSVD) is categorized in different forms, the most common being the sporadic form and a genetic variant - Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL). Amongst the most frequent clinical manifestations are the neuropsychological changes of cognitive, behavioral, and emotional nature, whose features are still under debate. Objective: This exploratory study aimed to compare the neuropsychological profile of a sporadic CSVD sample and a CADASIL sample with an age, education, and gender matched control group, between the ages of 30-65 YO (total sample mean age=51.16; SD=4.31). Methods: 20 patients with sporadic CSVD, 20 patients with CADASIL and 20 matched controls completed a neuropsychological assessment battery. Global cognitive state, processing speed, working memory, attention, executive dysfunction, episodic memory, social cognition, impulsivity, apathy, alexithymia, depression, and anxiety were measured. White matter hyperintensities (WMH) volume were quantified and measured as lesion burden. Results: The cognitive differences found between the clinical groups combined (after confirming no differences between the two clinical groups) and matched controls were restricted to speed processing scores (d = 0.32 95 % CI [.12-.47]). The socio-emotional and behavioral profile revealed significantly higher levels of depression (d = 0.21, 95 % CI [.16-.33]). and anxiety (d = 0.25 95 % CI [.19-.32]) in CADASIL and sporadic CSVD groups, and the same for the alexithymia score (d = 0.533 95 % CI [.32-.65]) were the clinical groups revealed impoverished emotional processing compared to controls. WMH only significantly correlated with the cognitive changes and age. Conclusions: In our study, CADASIL and sporadic cSVD patients combined, present multiple emotional-behavioral symptoms - alexithymia, anxiety, depression, and in a lower extent apathy and impulsivity - suggesting for the presence of emotion dysregulation behaviors, present independently of age and of the presence of cognitive deficits. Despite of the small sample size that could underpower some findings, this exploratory research supported that these symptoms may have a significant impact in disease monitoring, progression, and prognosis, requiring further investigation regarding their neurophysiological substrates.

Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy (CADASIL): A Rare Cause of Transient Ischemic Attack.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is increasingly recognized as an inherited and autosomal dominant arteriopathy of the cerebral vasculature, which is commonly misdiagnosed due to its different modes of presentation. It is characterized by variable manifestations of ischemic episodes, migraine with aura, cognitive deficits, and psychiatric disturbances. CADASIL is caused by a genetic mutation in the NOTCH3 gene, which is present on chromosome 19. The diagnosis of CADASIL can be made by personal and family history, skin biopsy, and magnetic resonance imaging (MRI) of the head showing high-intensity signal lesions, microbleeds, and white matter changes. There are currently no disease-modifying therapies available for CADASIL, and management focuses on reducing risk factors such as diabetes and hypertension and control of symptoms. We present a rare cause of transient ischemic attack (TIA) in a young female who was later diagnosed with CADASIL and aim to highlight rare and inherited causes of TIA and strokes in younger patients.

Primary Angiitis of the Central Nervous System: An Uncommon Cause of Stroke in the Young.

Primary angiitis of the central nervous system (PACNS) usually presents with symptoms of headache, cognitive impairment, or stroke with a mean age of onset at 50 years. Inflammation of the cerebral vessels can cause narrowing, occlusion, or thrombosis resulting in tissue ischemia and necrosis of the involved vessel territory. Findings can be seen on Magnetic Resonance Imaging (MRI) scans of the brain and serological markers of inflammation are typically within normal limits. The nonspecificity of PACNS presents a challenge for accurate diagnosis and must be differentiated from secondary vasculitis and Reversible Cerebral Vasoconstriction Syndrome (RCVS). Cerebral angiography, even though having low sensitivity and specificity, could sometimes be the only diagnostic tool available.

Retinal arteriolar parameters as a surrogate marker of intracranial vascular pathology.

Introduction: Development of novel diagnostic tools is a top research priority in vascular dementia. A major obstacle is the lack of a simple, non-invasive method to visualize cerebral arteriolar walls in vivo. Retinal arterioles offer a window into the cerebral circulation. Methods: Intensity-based retinal arteriolar visualization in optical coherence tomography (I-bRAVO) was applied to evaluate mean wall thickness (MWT) and wall-to-lumen ratio (WLR) in 250 subjects with sporadic and genetic cerebral small vessel disease (CSVD), non-vascular neurodegenerative diseases (NVND), and healthy controls (HC) in association with imaging and cognitive markers. Results: MWT and WLR were higher in CSVD, associated with severity of vascular white matter lesions, and correlated with magnetic resonance imaging-based intracranial arteriolosclerosis score. WLR correlated with gray and white matter volume and differentiated asymptomatic sporadic CSVD from HC (area under the curve = 0.82). Discussion: I-bRAVO is a rapid, non-invasive tool. MWT and WLR were associated with imaging markers of CSVD and could contribute to early identification of sporadic CSVD.

Evidence of beta amyloid independent small vessel disease in familial Alzheimer's disease.

We studied small vessel disease (SVD) pathology in Familial Alzheimer's disease (FAD) subjects carrying the presenilin 1 (PSEN1) p.Glu280Ala mutation in comparison to those with sporadic Alzheimer's disease (SAD) as a positive control for Alzheimer's pathology and Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) bearing different NOTCH3 mutations, as positive controls for SVD pathology. Upon magnetic resonance imaging (MRI) in life, some FAD showed mild white matter hyperintensities and no further radiologic evidence of SVD. In post-mortem studies, total SVD pathology in cortical areas and basal ganglia was similar in PSEN1 FAD and CADASIL subjects, except for the feature of arteriosclerosis which was higher in CADASIL subjects than in PSEN1 FAD subjects. Further only a few SAD subjects showed a similar degree of SVD pathology as observed in CADASIL. Furthermore, we found significantly enlarged perivascular spaces in vessels devoid of cerebral amyloid angiopathy in FAD compared with SAD and CADASIL subjects. As expected, there was greater fibrinogen-positive perivascular reactivity in CADASIL but similar reactivity in PSEN1 FAD and SAD groups. Fibrinogen immunoreactivity correlated with onset age in the PSEN1 FAD cases, suggesting increased vascular permeability may contribute to cognitive decline. Additionally, we found reduced perivascular expression of PDGFRß AQP4 in microvessels with enlarged PVS in PSEN1 FAD cases. We demonstrate that there is Aß-independent SVD pathology in PSEN1 FAD, that was marginally lower than that in CADASIL subjects although not evident by MRI. These observations suggest presence of covert SVD even in PSEN1, contributing to disease progression. As is the case in SAD, these consequences may be preventable by early recognition and actively controlling vascular disease risk, even in familial forms of dementia.

Association between cerebrovasoreactivity and stroke in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

Background: Impaired cerebrovasoreactivity is thought to play an important role in the pathophysiology of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). We aimed to clarify the association between cerebrovascular reactivity and stroke in patients with CADASIL. Methods: We retrospectively recruited 14 patients with CADASIL, eight of whom had symptomatic stroke. They underwent quantitative single-photon emission computed tomography using an autoradiographic method at rest and after acetazolamide (ACZ) administration. Regional cerebral blood flow (rCBF) in the cerebral cortex, lenticular nucleus, thalamus, and cerebellum was measured. We compared the rCBF parameters between patients with and without stroke. Results: The baseline characteristics and magnetic resonance imaging findings were similar between the two groups, except for a higher frequency of pyramidal tract sign (75% vs. 0%) and a larger number of old lacunes (15.4 ± 8.8 vs. 2.2 ± 1.8) in the patients with stroke. Of the rCBF parameters measured, significantly lower flow (mL/100 g/min) was observed in ACZ-rCBF in the thalamus (35.6 ± 9.4 vs. 51.1 ± 7.6, p = 0.01) and ΔrCBF in the thalamus (10.6 ± 3.7 vs. 21.0 ± 7.9, p = 0.02) in the patients with stroke. Conclusion: Cerebrovasoreactivity in the thalamus was significantly associated with stroke in patients with CADASIL.

Ischemic Stroke in a Patient with Stable CADASIL during COVID-19: A Case Report.

BACKGROUND: SARS-CoV-2 infection has been associated with different neurological conditions such as Guillain-Barré, encephalitis and stroke. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited small-vessel disease characterized by recurrent ischemic stroke, cognitive decline, migraine and mood disturbances. One of the mechanisms involved in CADASIL pathogenesis is endothelial dysfunction, which causes an increased risk of recurrent strokes. Since COVID-19 infection is also associated with coagulopathy and endothelial dysfunction, the risk of ischemic stroke might be even higher in this population. We describe the case of a CADASIL patient who developed an acute ischemic stroke after SARS-CoV-2 infection. In patients with diseases causing endothelial dysregulation, such as CADASIL, the hypercoagulability related to COVID-19 may contribute to the risk of stroke recurrence.

Sex Differences in Cerebral Small Vessel Disease: A Systematic Review and Meta-Analysis.

Background: Cerebral small vessel disease (SVD) is a common cause of stroke, mild cognitive impairment, dementia and physical impairments. Differences in SVD incidence or severity between males and females are unknown. We assessed sex differences in SVD by assessing the male-to-female ratio (M:F) of recruited participants and incidence of SVD, risk factor presence, distribution, and severity of SVD features. Methods: We assessed four recent systematic reviews on SVD and performed a supplementary search of MEDLINE to identify studies reporting M:F ratio in covert, stroke, or cognitive SVD presentations (registered protocol: CRD42020193995). We meta-analyzed differences in sex ratios across time, countries, SVD severity and presentations, age and risk factors for SVD. Results: Amongst 123 relevant studies (n = 36,910 participants) including 53 community-based, 67 hospital-based and three mixed studies published between 1989 and 2020, more males were recruited in hospital-based than in community-based studies [M:F = 1.16 (0.70) vs. M:F = 0.79 (0.35), respectively; p < 0.001]. More males had moderate to severe SVD [M:F = 1.08 (0.81) vs. M:F = 0.82 (0.47) in healthy to mild SVD; p < 0.001], and stroke presentations where M:F was 1.67 (0.53). M:F did not differ for recent (2015-2020) vs. pre-2015 publications, by geographical region, or age. There were insufficient sex-stratified data to explore M:F and risk factors for SVD. Conclusions: Our results highlight differences in male-to-female ratios in SVD severity and amongst those presenting with stroke that have important clinical and translational implications. Future SVD research should report participant demographics, risk factors and outcomes separately for males and females. Systematic Review Registration: [PROSPERO], identifier [CRD42020193995].