The Cerebral Autosomal-Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy (CADASIL) Scale: a screening tool to select patients for NOTCH3 gene analysis

First intravenous thrombolysis for pCys194Arg Notch 3 mutation in a Moroccan CADASIL patient with stroke

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is caused by mutations in the NOTCH3 gene. Clinical manifestations of CADASIL include lacunar infarcts, transient ischemic attacks, dementia, migraine, and psychiatric disorders. Cerebral MRI can show signal abnormalities in the basal ganglia and white matter, especially characteristic when located in the anterior part of the temporal lobe and external capsules. We report CADASIL patient treated with intravenous tenectelase for acute ischemic stroke, and we present a review of literature aimed to report effectiveness and safety of intravenous thrombolysis in CADASIL patients.

Long-Term Treatment with the Calcitonin Gene-Related Peptide Receptor Antagonist Erenumab in CADASIL: Two Case Reports

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic form of cerebral small vessel disease, caused by a mutation in the NOTCH3 gene on chromosome 19. The main clinical features include migraine (often with aura), early onset, recurrent subcortical ischemic strokes, mood disturbances, and cognitive impairment, frequently leading to dementia and disability with a reduction in life expectancy. Cerebral chronic global hypoperfusion, due to impaired cerebrovascular reactivity, seems to play a primary role in CADASIL. Migraine is the most common early feature of the disease, and to date, there are no consensus guidelines for treatment. Given the vasomodulatory influence of many antimigraine drugs, there is concern about their use in this disease. In particular, the calcitonin gene-related peptide (CGRP) system serves as a vasodilatory protective mechanism during cerebral and cardiac ischemia. Blocking this system could exacerbate ischemic events. Herein, we describe two CADASIL patients who were treated with the calcitonin gene-related peptide (CGRP) receptor antagonist erenumab for chronic migraine, reporting a significant reduction in the frequency of attacks and intensity of pain, and an improvement in quality of life without adverse effects.

Headache and NOTCH3 Gene Variants in Patients with CADASIL

Autosomal dominant cerebral arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited vascular disease characterized by recurrent strokes, cognitive impairment, psychiatric symptoms, apathy, and migraine. Approximately 40% of patients with CADASIL experience migraine with aura (MA). In addition to MA, CADASIL patients are described in the literature as having migraine without aura (MO) and other types of headaches. Mutations in the NOTCH3 gene cause CADASIL. This study investigated NOTCH3 genetic variants in CADASIL patients and their potential association with headache types. Genetic tests were performed on 30 patients with CADASIL (20 women aged 43.6 ± 11.5 and 10 men aged 39.6 ± 15.8). PCR-HRM and sequencing methods were used in the genetic study. We described three variants as pathogenic/likely pathogenic (p.Tyr189Cys, p.Arg153Cys, p.Cys144Arg) and two benign variants (p.Ala202=, p.Thr101=) in the NOTCH3 gene and also presented the NOTCH3 gene variant (chr19:15192258 G>T), which has not been previously described in the literature. Patients with pathogenic/likely pathogenic variants had similar headache courses. People with benign variants showed a more diverse clinical picture. It seems that different NOTCH3 variants may contribute to the differential presentation of a CADASIL headache, highlighting the diagnostic and prognostic value of headache characteristics in this disease.

Management of Inherited CNS Small Vessel Diseases: The CADASIL Example: A Scientific Statement From the American Heart Association

Lacunar infarcts and vascular dementia are important phenotypic characteristics of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, the most common inherited cerebral small vessel disease. Individuals with the disease show variability in the nature and onset of symptoms and rates of progression, which are only partially explained by differences in pathogenic mutations in the NOTCH3 gene. Recognizing the disease early in its course and securing a molecular diagnosis are important clinical goals, despite the lack of proven disease-modifying treatments. The purposes of this scientific statement are to review the clinical, genetic, and imaging aspects of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, contrasting it with other inherited small vessel diseases, and to provide key prevention, management, and therapeutic considerations with the intent of reducing practice variability and encouraging production of high-quality evidence to support future treatment recommendations.

NOTCH3 Variants in Patients with Suspected CADASIL

Background

Cerebral autosomal dominant arteriopathy with subcortical infarctions and leukoencephalopathy (CADASIL) is the most common hereditary form of cerebral small vessel disease. It is clinically, radiologically, and genetically heterogeneous and is caused by NOTCH3 mutations.

Methods

In this study, we analyzed NOTCH3 in 368 patients with suspected CADASIL using next-generation sequencing. The significant variants detected were reported along with the clinical and radiological features of the patients.

Results

Heterozygous NOTCH3 changes, mostly missense mutations, were detected in 44 of the 368 patients (~12%).

Conclusions

In this single-center study conducted on a large patient group, 30 different variants were detected, 17 of which were novel. CADASIL, which can result in mortality, has a heterogeneous phenotype among individuals in terms of clinical, demographic, and radiological findings regardless of the NOTCH3 variant.

Genetic Causes of Cerebral Small Vessel Diseases: A Practical Guide for Neurologists

Cerebral small vessel disease (CSVD) includes various entities affecting the brain and, often, systemic small arteries, arterioles, venules, and capillaries. The underlying causes of CSVD are different, and some of them are genetic. Monogenic CSVDs are responsible for 1%-5% of all strokes and for several other disturbances. Despite many genes being involved, the phenotypes of monogenic CSVD partly overlap. Given that the genetic testing for different diseases can be challenging and time-consuming, the practicing neurologist should be adequately informed of the genetic background of CSVD and should be able to select patients to undergo genetic assessment and the genes to be analyzed. The purpose of this review was to summarize clinical, neurologic and non-neurologic, and neuroimaging features of monogenic CSVD and to provide a flowchart to be used in clinical practice to guide neurologists in this field. The proposed flowchart and the relative tables can be applied to 3 different settings, depending on the presentation: (1) ischemic stroke and/or transient ischemic attack, (2) cerebral hemorrhage, and (3) other neurologic, non-neurologic, and/or neuroimaging features of monogenic CSVD, in the absence of stroke syndromes because of infarction or hemorrhage.

Influence of different spectra of NOTCH3 variants on the clinical phenotype of CADASIL - experience from Slovakia

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common hereditary vascular disorder causing ischaemic attacks and strokes in middle-aged adults. Though the clinical spectrum includes some typical symptoms, recognition of the disease, especially at an earlier stage, is very difficult because of the highly variable manifestation and incomplete clinical picture. Characteristic brain MRI findings and the presence of pathogenic variants in the NOTCH3 gene are fundamental for CADASIL diagnosis. In this paper, we provide the first comprehensive report on CADASIL patients from Slovakia. Altogether, we identified 23 different pathogenic variants in 35 unrelated families. In our cohort of patients with clinical suspicion of CADASIL, we found a causal genetic defect and confirmed the diagnosis in 10.2% of cases. We present the case reports with up-to-date unpublished NOTCH3 variants and describe their phenotype-genotype correlation: p.(Cys65Phe), p.(Pro86Leu/Ser502Phe), p.(Arg156*), p.(Cys408Arg), p.(Tyr423Cys), p.(Asp1720His), and p.(Asp1893Thrfs*13). The most frequently described location for pathogenic variants was in exon 4, whereas the most common single variant was p.Arg1076Cys in exon 20. Based on the results of our study, we propose a re-evaluation of the criteria for the selection of patients suitable for NOTCH3 gene analysis. We hereby state that the currently used protocol of a high score requirement is not ideal for assessing molecular analysis, and it will be desirable to be less strict in criteria for genetic testing.

Intravenous thrombolysis in CADASIL: report of two cases and a systematic review

BACKGROUND

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a genetic small vessel disease responsible for recurrent ischemic strokes, often with a progressive course leading to dementia and disability. On MRI, lacunes, microbleeds, and severe white matter alterations are typical features of the disease. In case of acute stroke, because of the bleeding risk associated with the disease and the doubtful efficacy of fibrinolytic treatment in a disease with poor evidence of thrombosis, the efficacy of intravenous thrombolysis remains unproven. Nevertheless, stroke is a frequent occurrence in CADASIL patients, and clinicians not unlikely may face in the emergency room the situation of a CADASIL patient with an acute stroke within the time window for thrombolysis.

OBJECTIVE

We report on two CADASIL patients treated with intravenous alteplase for acute ischemic stroke, and we present a review of literature aimed to report epidemiological data, efficacy and safety of intravenous thrombolysis in CADASIL patients.

METHODS

We performed a systematic review of medical literature published until August 2, 2022. Case reports and series in English language reporting on CADASIL patients and acute stroke were included.

RESULTS

Both patients were treated with intravenous thrombolysis without complications and had a good clinical outcome. The systematic review identified three case reports of CADASIL patients who were treated with intravenous alteplase for acute ischemic stroke; no bleedings complications were described.

CONCLUSIONS

Available data on intravenous thrombolysis in CADASIL patients are scarce but suggest that this treatment can be taken into consideration for these patients.

CADASIL in Greece: Mutational spectrum and clinical characteristics based on a systematic review and pooled analysis of published cases

BACKGROUND

Differences have been noted in the clinical presentation and mutational spectrum of CADASIL among various geographical areas. The aim of the present study was to investigate the mode of clinical presentation and genetic mutations reported in Greece.

METHODS

After a systematic literature search, we performed a pooled analysis of all published CADASIL cases from Greece.

RESULTS

We identified 14 studies that reported data from 14 families comprising 54 patients. Migraine with aura was reported in 39%, ischemic cerebrovascular diseases in 68%, behavioral-psychiatric symptoms in 47% and cognitive decline in 60% of the patients. The mean (±SD) age of onset for migraine with aura, ischemic cerebrovascular diseases, behavioral-psychiatric symptoms and cognitive decline was 26.2 ± 8.7, 49.3 ± 14.6, 47.9 ± 9.4 and 42.9 ± 10.3, respectively; the mean age at disease onset and death was 34.6 ± 12.1 and 60.2 ± 11.2 years. With respect to reported mutations, mutations in exon 4 were the most frequently reported (61.5% of all families), with the R169C mutation being the most common (30.8% of all families and 50% of exon 4 mutations), followed by R182C mutation (15.4% of all families and 25% of exon 4 mutations).

CONCLUSIONS

The clinical presentation of CADASIL in Greece is in accordance with the phenotype encountered in Caucasian populations, but differs from the Asian phenotype, which is characterized by a lower prevalence of migraine and psychiatric symptoms. The genotype of Greek CADASIL pedigrees is similar to that of British pedigrees, exhibiting a high prevalence of exon 4 mutations, but differs from Italian and Asian populations, where mutations in exon 11 are frequently encountered.

A Chinese CADASIL Family with a Novel Mutation on Exon 10 of Notch3 Gene

BACKGROUND

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), which is caused by the Notch3 gene mutation, has its unique clinical and imaging characteristics. Here we present a Chinese family with a novel mutation on exon 10 of Notch3 gene.

METHODS

Clinical and MRI data of the three patients in the family during the 7-year follow-up were collected. The CADASIL Scale Score was calculated to evaluate the disease risk of the three patients at their first admission or clinic visit. Five family members underwent genetic test.

RESULTS

Genetic test confirmed the diagnosis of CADASIL in this family. A novel mutation of p.C533S on exon 10 of Notch3 gene was detected. The CADASIL score of the proband and her sister was both 17 and that of her brother was 14.

CONCLUSIONS

Our report not only expands the mutation spectrum of Notch3 gene in CADASIL, but also shows the distinct heterogeneity of CADASIL patients in the same family with the same mutation.

Brain MRI in Monogenic Cerebral Small Vessel Diseases: A Practical Handbook

:

Monogenic cerebral small vessel diseases are a topic of growing interest, as several genes responsible have been recently described and new sequencing techniques such as Next generation sequencing are available. Brain imaging is a key exam in these diseases. First, since it is often the first exam performed, an MRI is key in selecting patients for genetic testing and for interpreting Next generation sequencing reports. In addition, neuroimaging can be helpful in describing the underlying pathological mechanisms involved in cerebral small vessel disease. With this review, we aim to provide Neurologists and Stroke physicians with an up-to date overview of the current neuroimaging knowledge on monogenic small vessel diseases.

Cerebral Small Vessel Disease

Cerebral small vessel disease (CSVD) represents a cluster of various vascular disorders with different pathological backgrounds. The advanced vasculature net of cerebral vessels, including small arteries, capillaries, arterioles and venules, is usually affected. Processes of oxidation underlie the pathology of CSVD, promoting the degenerative status of the epithelial layer. There are several classifications of cerebral small vessel diseases; some of them include diseases such as Binswanger’s disease, leukoaraiosis, cerebral microbleeds (CMBs) and lacunar strokes. This paper presents the characteristics of CSVD and the impact of the current knowledge of this topic on the diagnosis and treatment of patients.

Imaging-based pregenetic screening for NOTCH3 p.R544C mutation in ischemic stroke in Taiwan

Objective

To develop an easily applicable screening score to guide NOTCH3 p.R544C genetic testing for patients who presented with acute ischemic cerebrovascular events in Taiwan.

Methods

1734 patients who presented with ischemic cerebrovascular events were enrolled from the Formosa Stroke Genetic Consortium stroke registry and were screened for the NOTCH3 p.R544C mutation. Clinical and MRI characteristics of NOTCH3 p.R544C mutation carriers (n = 36) and a subset of noncarriers (n = 673) were tested in a logistic regression model to identify key features associated with the NOTCH3 p.R544C carrier status. Variables and their odds ratios in the regression model were used to develop the R544C screening score to predict positive NOTCH3 p.R544C test results.

Results

We constructed the R544C screening score using five clinical and imaging characteristics, including stroke onset before 50 years of age, the small vessel occlusion subtype, a family history of stroke/TIA in siblings, external capsule involvement, and advanced deep white matter hyperintensity. The area under the ROC curve of the screening score was 0.867 (95% CI = 0.810‐0.924). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were 0.75, 0.88, 0.13, 0.99, and 0.88, respectively, for a cutoff score of 5 points. In addition, the R544C screening score was validated in another cohort composed of 235 stroke patients with comparable performance (area under the ROC curve = 0.957, 95% CI = 0.916‐0.997).

Interpretations

For Taiwanese patients presenting with acute ischemic cerebrovascular events, the R544C screening score is easily applicable and can efficiently select high‐risk patients for NOTCH3 p.R544C mutation test.

CADASIL vs. Multiple Sclerosis: Is It Misdiagnosis or Concomitant? A Case Series

Introduction: Cerebral autosomal dominant arteriopathy and subcortical infarct leukoencephalopathy (CADASIL) is the most common form of hereditary stroke caused by a mutation in the NOTCH3 gene located on the short arm of chromosome 19. A small number of published reports describe CADASIL patients who were initially diagnosed as multiple sclerosis. Although it was previously indicated that there was no association between NOTCH3 mutations and multiple sclerosis, the involvement of autoimmune mechanisms among patients with CADASIL has been hypothesized.

Case Presentation: Case 1 is a middle-aged woman with initial diagnoses of multiple sclerosis (MS) and myelitis that continued to progress despite treatment with disease-modifying agents. She had occasional migraines, transient blurred vision, and multiple lacunar infarcts. She continued treatment for about 15 years with no significant alleviation and progressive changes on brain MRI; genetic testing was ordered which showed NOTCH3 mutation, and diagnosis was changed to CADASIL with subsequent revision of treatment course. However, the presence of myelitis in this patient is unusual and may raise the question of a concurrent autoimmune process. Case 2 is a woman presenting with vertigo and paresthesia and diagnosed with MS based on an initial brain MRI showing biventricular white matter hyperintensities; however, she was not started on any disease-modifying agents. Her symptoms were reevaluated by a neurologist, and genetic testing was performed for NOTCH 3. Case 3 is a young woman with a history of migraines who initially presented with numbness and gait ataxia which later progressed to speech difficulty and memory loss. A diagnosis of MS was established which was later changed to CADASIL.

Conclusion: Since CADASIL is a rare disease, it is imperative to raise awareness of its unique clinical condition as well as variation in its clinical presentations. It is crucial that the overlapping symptoms between MS and CADASIL be thoroughly examined to avoid misdiagnosis and treatment complications. The involvement of autoimmune mechanisms in CADASIL and the role of NOTCH3 gene mutations in provoking an autoimmune process should be further investigated.

A Nationwide Survey and Multicenter Registry-Based Database of Cerebral Autosomal Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy in Japan

Objectives

Clinical characteristics of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) include migraine, recurrent stroke, white matter lesions, and vascular dementia. CADASIL is one of the most common hereditary cerebral small vessel diseases. Clinical presentation of CADASIL varies and a racial gap may exist between the Asian and Caucasian populations. This is the first nationwide epidemiological survey which aimed to elucidate the clinical features of CADASIL in Japan. Moreover, the registration database of CADASIL was constructed.

Methods

Subjects included CADASIL patients who visited the hospitals (totally 1,448 hospitals) certified by the Japanese Society of Neurology and/or Japan Stroke Society in 2016. This study consisted of a two-step survey; patients with CADASIL were identified genetically by the first questionnaire, and their clinical features were assessed by the second questionnaire. Selected 6 hospitals registered the data of all CADASIL patients using a Research Electronic Data Capture (REDCap) system for the second questionnaire.

Results

Based on the criteria, 88 patients (50 male and 38 female) with CADASIL were enrolled. The mean age of symptom onset was 49.5 years. Sixteen (18.2%) patients had an elderly onset (>60 years). Thirteen patients (13.6%) had history of migraine with aura and 33 patients (37.5%) had vascular risk factor(s). From among the 86 patients who were examined using magnetic resonance imaging, abnormal deep white matter lesions were detected in 85 patients (98.8%), WMLs extending to anterior temporal pole in 73 patients (84.9%), and cerebral microbleeds in 41 patients (47.7%). Anti-platelet therapy was received by 65 patients (73.9%). Thirty-eight patients (43.2%) underwent treatment with lomerizine hydrochloride. Thirty-four different mutations of NOTCH3 were found in exons 2, 3, 4, 5, 6, 8, 11, 14, and 19. Most of the mutations existed in exon 4 (n = 44, 60.3%). The prevalence rate of CADASIL was 1.20 to 3.58 per 100,000 adults in Japan.

Conclusion

This questionnaire-based study revealed clinical features and treatment status in Japanese CADASIL patient, although it may not be an exhaustive search. We have constructed the REDCap database for these CADASIL patients.

Prevalence and Atypical Clinical Characteristics of NOTCH3 Mutations Among Patients Admitted for Acute Lacunar Infarctions

Objectives: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common hereditary small vessel disease, with reported frequencies of 2-5/100,000 individuals. Recently, it has been reported that some patients with NOTCH3 gene mutations show atypical clinical symptoms of CADASIL. Assuming that CADASIL is underdiagnosed in some cases of lacunar infarction, this study was designed to examine the prevalence of NOTCH3 gene mutations in the patients at highest risk who were admitted for lacunar infarctions.

Methods: From January 2011 to April 2018, 1,094 patients with lacunar infarctions were admitted to our hospital, of whom 31 patients without hypertension but with white matter disease (Fazekas scale 2 or 3) were selected and genetically analyzed for NOTCH3 gene mutations (Phase 1). Furthermore, 54 patients, who were 60 years or younger, were analyzed for NOTCH3 mutations (Phase 2). NOTCH3 exons 2–24, which encode the epidermal growth factor-like repeat domain of the NOTCH3 receptor, were analyzed for mutations by direct sequencing of genomic DNA.

Results: Three patients presented NOTCH3 p.R75P mutations: two in the Phase 1 and one in the Phase 2 cohort. Among patients aged 60 years or younger and those without hypertension but with moderate-to-severe white matter lesions, the carrier frequency of p.R75P was 3.5% (3/85), which was significantly higher than that in the Japanese general population (4.7KJPN) (odds ratio [95% CI] = 58.2 [11.6–292.5]). All three patients with NOTCH3 mutations had family histories of stroke, and the average patient age was 51.3 years. All three patients also showed white matter lesions in the external capsule but not in the temporal pole. The CADASIL and CADASIL scale-J scores of the three patients were 6, 17, 7 (mean, 10.0) and 13, 20, 10 (mean, 14.3), respectively.

Conclusion: Among patients hospitalized for lacunar infarctions, the p.R75P prevalence may be higher than previously estimated. The NOTCH3 p.R75P mutation may be underdiagnosed in patients with early-onset lacunar infarctions due to the atypical clinical and neuroimaging features of CADASIL. Early-onset, presence of family history of stroke, external capsule lesions, and absence of hypertension may help predict underlying NOTCH3 mutations despite no temporal white matter lesions.

Novel dot-blot assay for detection of vascular Notch3 aggregates in patients with CADASIL

To detect vascular Notch3 extracellular domain aggregates in CADASIL, we developed a novel dot-blot assay with both autopsy and biopsy skin samples. We obtained samples from 11 patients with CADASIL and 12 control patients, and we performed dot-blot analyses by using sequential biochemical tissue extractions with three different antibodies against specific regions of the Notch3 extracellular domain. We also analyzed clinical features and vascular accumulations of Notch3 by immunohistochemistry. Via the dot-blot assay with the antibody against the C-terminal region of the Notch3 extracellular domain, we successfully detected Notch3 extracellular domain aggregates in skin tissue homogenates obtained from patients with CADASIL. Our novel method may therefore aid the diagnosis of CADASIL.

Clinical and Genetic Aspects of CADASIL

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a hereditary cerebral small vessel disease caused by mutations in NOTCH3, is characterized by recurrent stroke without vascular risk factors, mood disturbances, and dementia. MRI imaging shows cerebral white matter (WM) hyperintensity, particularly in the external capsule and temporal pole. Missense mutations related to a cysteine residue in the 34 EGFr on the NOTCH3 extracellular domain (N3ECD) are a typical mutation of CADASIL. On the other hand, atypical mutations including cysteine sparing mutation, null mutation, homozygous mutation, and other associate genes are also reported. From the viewpoint of gain of function apart from Notch signaling or loss of function of Notch signaling, we review the research article about CADASIL and summarized the pathogenesis of small vessel, stroke, and dementia in this disease.

Heritable and non-heritable uncommon causes of stroke

Despite intensive investigations, about 30% of stroke cases remains of undetermined origin. After exclusion of common causes of stroke, there is a number of rare heritable and non-heritable conditions, which often remain misdiagnosed, that should be additionally considered in the diagnosis of cryptogenic stroke. The identification of these diseases requires a complex work up including detailed clinical evaluation for the detection of systemic symptoms and signs, an adequate neuroimaging assessment and a careful family history collection. The task becomes more complicated by phenotype heterogeneity since stroke could be the primary or unique manifestation of a syndrome or represent just a manifestation (sometimes minor) of a multisystem disorder. The aim of this review paper is to provide clinicians with an update on clinical and neuroradiological features and a set of practical suggestions for the diagnostic work up and management of these uncommon causes of stroke. The identification of these stroke causes is important to avoid inappropriate and expensive diagnostic tests, to establish appropriate management measures, including presymptomatic testing, genetic counseling, and, if available, therapy. Therefore, physicians should become familiar with these diseases to provide future risk assessment and family counseling.

First Report of a pCys194Arg Notch 3 Mutation in a Romanian CADASIL Patient with Transient Ischemic Attacks and Patent Foramen Ovale - Case Report and Brief Review

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary disease caused by mutations in NOTCH3 gene, characterized by accumulation of a toxic protein in the small and medium size arterioles. Clinical manifestations of CADASIL include lacunar infarcts or, less frequently, large artery ischemic strokes, transient ischemic attacks, dementia, migraine and psychiatric disorders. Brain magnetic resonance imaging (MRI) usually shows multiple lacunar infarcts, diffuse leukoencephalopathy and cerebral microbleeds. The authors report the case of a 39-year-old Romanian woman who presented two transient ischemic attacks manifested with aphasia, headache and mild cognitive impairment. Brain MRI showed multiple isolated and confluent bilateral supratentorial hyperintense fluid-attenuated inversion recovery (FLAIR) and apparent diffusion coefficient (ADC) areas involving the subcortical and deep white matter, but also lenticular and caudate regions and normal aspects of the brain arteries on magnetic resonance angiography (MR-angiography). Differential diagnosis with other disorders affecting small cerebral vessels was performed. Transesophageal echocardiography showed presence of patent foramen ovale (PFO), with right-to-left shunt and contrast passage at Valsalva maneuver. Genetic testing revealed a pCys194Arg heterozygous mutation with C580T>C nucleotide's change on exon 4 of NOTCH 3 gene. The authors discuss the association of CADASIL to PFO and mild cognitive impairment as well as ongoing research for a therapeutic strategy.

Association of NOTCH3 Gene Polymorphisms with Ischemic Stroke and its Subtypes: A Meta-Analysis

Background and objectives: NOTCH3 gene variations play a significant role in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). However, the role of NOTCH3 gene polymorphisms in the risk of ischemic stroke, and its subtypes such as atherothrombotic or lacunar strokes, remains unclear. Aims: Hence, we carried out a meta-analysis to examine whether the NOTCH3 rs1043994, rs1044009 and rs3815188 polymorphisms are associated with ischemic stroke and its major subtypes. Materials and Methods: All relevant studies were systematically screened and meta-analyzed using Review Manager (Revman) version 5.3. The strength of the association between NOTCH3 polymorphisms and ischemic stroke risk and its subtypes were measured as odds ratios and 95% confidence intervals, under different genetic models. Results: A total of ten studies were identified, five of which considered NOTCH3 rs1043994 (2077 cases/2147 controls), five of which considered NOTCH3 rs1044009 (2315 cases/3053 controls), and nine of which considered NOTCH3 rs3815188 (2819 cases/2769 controls). These studies were meta-analyzed for their association with ischemic stroke risk. Four studies (874 cases/2002 controls) of the NOTCH3 rs3815188 polymorphism and three studies of the NOTCH3 rs1043994 (643 cases/1552 controls) polymorphism were meta-analyzed for lacunar stroke risk. Three studies (1013 cases/1972 controls) of the NOTCH3 rs3815188 polymorphism were meta-analyzed for atherothrombotic stroke risk. The meta-analysis results showed a lack of association between all of the studied polymorphisms and the risk of ischemic stroke and its major subtypes (i.e., atherothrombotic and lacunar). Conclusions: NOTCH3 polymorphisms are not significantly associated with the risk of ischemic stroke and its subtypes (p < 0.05).

The CADASIL Scale-J, A Modified Scale to Prioritize Access to Genetic Testing for Japanese CADASIL-Suspected Patients

BACKGROUND

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is definitely diagnosed by genetic testing. Such testing involves the analysis of exons 2-24 of NOTCH3, which encode the epidermal growth factor-like repeat domain, where CADASIL mutations are localized. We previously reported clinical diagnostic criteria for screening CADASIL-suspected Japanese patients prior to genetic testing. Because of its high sensitivity but low specificity, most patients need to undergo genetic testing. In this study, we aimed to develop the CADASIL scale-J, a modified scale to prioritize access to genetic testing for CADASIL-suspected Japanese patients.

METHODS

We modified the CADASIL scale reported by Pescini et al based on clinical features of 126 CADASIL patients and 53 NOTCH3-negative CADASIL-like patients diagnosed up until March 2016 (Phase 1). For validation, we recruited 69 consecutive patients for genetic testing of NOTCH3 from April 2016 to March 2017 (Phase 2).

RESULTS

We developed the CADASIL scale-J with a score ranging from 0 to 25 and the cut-off value of 16, using 8 items: hypertension, diabetes, young onset (≤50 years old), pseudobulbar palsy, stroke/TIA, family history, subcortical infarction, and temporal pole lesion. The sensitivity and specificity of the CADASIL scale-J were 78.9% and 85.7%, respectively. In Phase 2, we obtained a positive predictive value of 70.0% and a negative predictive value of 89.2%. In this study, we identified 54 mutations, 7 of which were novel.

CONCLUSIONS

The CADASIL scale-J is helpful to prioritize access to genetic testing for CADASIL-suspected Japanese patients.

Cerebral small vessel disease and systemic arteriopathy in intracranial arterial dolichoectasia patients

OBJECTIVES

To investigate clinical and demographic characteristics of patients with intracranial arterial dolichoectasia (IADE) and describe the possible coexistence of cerebral small vessel disease (SVD) and systemic arteriopathy.

MATERIAL AND METHODS

From January 2015 to March 2016, all the patients attending an outpatient service for chronic cerebrovascular diseases were screened for suspected IADE. Identified patients underwent a predefined protocol including: brain MR angiography for the diagnosis of IADE; brain MRI with visual rating of SVD features; whole-body CT angiography to assess signs of systemic arteriopathy; and neuropsychological examination.

RESULTS

Among the 251 patients screened, IADE was diagnosed in seven (mean age ± SD 68.8 ± 7.2 years, six males). Hypertension was the most frequent risk factor. All patients had basilar artery dolichoectasia, two also ectasia of a vessel of the anterior circulation. All patients had white matter hyperintensities that were moderate or severe in six, five had at least one lacune, and all had enlarged perivascular spaces. At least one microbleed was detected in six patients. A variable grade of global cortical atrophy was found in six patients. Systemic arterial ectasia was found in all but one patient. Neuropsychological examination showed a multidomain cognitive impairment in five patients.

CONCLUSIONS

Our study confirms the high prevalence of cerebral SVD in IADE. The involvement of the brain-supplying arteries is probably part of a systemic arteriopathy in IADE patients, thus suggesting the usefulness of assessing the whole arterial tree in clinical practice. Cognitive deterioration signs are frequent in these patients.

The role of clinical and neuroimaging features in the diagnosis of CADASIL

BACKGROUND

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common familial cerebral small vessel disease, caused by NOTCH3 gene mutations. The aim of our study was to identify clinical and neuroradiological features which would be useful in identifying which patients presenting with lacunar stroke and TIA are likely to have CADASIL.

METHODS

Patients with lacunar stroke or TIA were included in the present study. For each patient, demographic and clinical data were collected. MRI images were centrally analysed for the presence of lacunar infarcts, microbleeds, temporal lobe involvement, global atrophy and white matter hyperintensities.

RESULTS

128 patients (mean age 56.3 ± 12.4 years) were included. A NOTCH3 mutation was found in 12.5% of them. A family history of stroke, the presence of dementia and external capsule lesions on MRI were the only features significantly associated with the diagnosis of CADASIL. Although thalamic, temporal pole gliosis and severe white matter hyperintensities were less specific for CADASIL diagnosis, the combination of a number of these factors together with familial history for stroke result in a higher positive predictive value and specificity.

CONCLUSIONS

A careful familial history collection and neuroradiological assessment can identify patients in whom NOTCH3 genetic testing has a higher yield.

Recognition of Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) in Two Oligosymptomatic Sisters with Low CADASIL Scale Scores and a Venous Dysplasia: Report of a Novel Greek Family

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) due to mutations of the NOTCH3 gene is the most common cause of inherited cerebral small-vessel disease and one of the genetic causes of migraine with aura. The so-called CADASIL scale has been proposed as a clinical screening tool, and a score of 15 or higher seems useful in identifying patients with high probability of carrying NOTCH3 mutations. We studied a novel Greek family with clinical features compatible with CADASIL. Genetic analysis of NOTCH3 in the 2 living patients revealed the R182C mutation. Both patients had low scores (12 and 14) in the CADASIL scale, probably due to their relatively young age (38 and 37 years, respectively) at which cognitive decline and external capsule involvement have not developed yet. Another unusual feature in the second patient was a venous dysplasia in the parietal lobe. Observations presented here add to the notion that the CADASIL scale, although useful, probably needs a revision, taking into account the patient's age at which the score is calculated.

CADASIL

Cerebral small-vessel disease is a prevalent condition that is strongly associated with ischemic stroke and dementia. The most prevalent inherited cause of cerebral small-vessel disease is CADASIL, cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy, a disorder linked to mutations in NOTCH3. The most common symptoms of CADASIL are small ischemic strokes and/or transient ischemic attacks and cognitive impairment, appearing in middle age, that may progress to frank vascular dementia. However, it is increasingly recognized that individual symptom types, onset, and disease severity span a wide spectrum, even among individuals in the same family. Magnetic resonance imaging in CADASIL reveals severe white-matter hyperintensities, evidence of prior subcortical strokes, and, in some cases, microhemorrhages. Several hundred mutations in NOTCH3 have been described worldwide in CADASIL, and virtually all of these mutations alter the cysteine content of the extracellular NOTCH3 gene product. This molecular genetic signature of CADASIL has led to the hypothesis that structural abnormalities in the vascular smooth-muscle protein NOTCH3 trigger arterial degeneration, vascular protein accumulation, and cerebrovascular failure.

The diagnosis of dementias: a practical tool not to miss rare causes

Dementia represents one of the most diffuse disorders of our Era. Alzheimer's disease is the principle cause of dementia worldwide. Metabolic, infectious, autoimmune, inflammatory, and genetic dementias represent a not negligible number of disorders, with increasing numbers in younger subjects. Due to the heterogeneity of patients and disorders, the diagnosis of dementia is challenging. In the present article, we propose a practical diagnostic approach following the two-step investigation procedure. The first step includes basic blood tests and brain neuroimaging, performed on all patients. After this first-line investigation, it is then possible to rule out metabolic causes of dementia and to identify three main subgroups in dementia: predominant gray matter atrophy, white matter disease, basal ganglia pathologies. The predominant gray matter atrophy subgroup includes neurodegenerative causes of dementia and some lysosomal storage disorders. The white matter subgroup indicates a comprehensive list of vascular dementia causes, mitochondrial diseases, and leukodystrophies. Whereas, the basal ganglia alterations are due to metal accumulation pathologies, such as iron, copper, or calcium. Each category has specific clinical hallmarks, accurately reported in the article, and requires specific second-line investigation. Thus, we indicate the distinct second diagnostic step of each disease. The proposed diagnostic flow-chart follows the clinical reasoning and helps clinicians through the differential diagnosis of dementia.

Pregnancy in CADASIL

OBJECTIVES

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited cerebral small vessel disease caused by NOTCH3 gene mutations. CADASIL women are frequently considered at high risk of systemic vascular events during pregnancy and often prescribed with antithrombotic drugs. This decision is not evidence-based considering the lack of data about pregnancy outcome in CADASIL. We describe our experience on pregnancy in CADASIL patients.

MATERIALS AND METHODS

We reviewed records of 50 CADASIL females followed in our center, and we collected prospective information in six patients for a total of 93 pregnancies.

RESULTS

No woman had the disease onset or suffered from cerebral vascular ischemic events during pregnancy. Sixteen miscarriages (17.2%) were recorded. There were 72 vaginal births, and five cesarean sections. Considering the six patients followed prospectively (for a total of eight pregnancies), data on fetal growth and newborns weight were in line with those from the general population. Considering gestational complications, we recorded mild proteinuria without hypertension in one patient and hyperinsulinemia and pre-eclampsia in another affected by a known nephropathy. Antithrombotic drugs were used in three patients, in one for an unrelated coexisting prothrombotic condition.

CONCLUSIONS

CADASIL does not seem to be associated with an unfavorable outcome of pregnancy either for women and fetuses. Patients and treating physicians should be reassured that pregnancy can be safely initiated in CADASIL, as there is no evidence to support a specific preventive antithrombotic treatment during pregnancy in CADASIL. Larger studies are needed to definitively confirm these conclusions.

New diagnostic criteria for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukocencephalopathy in Japan

PURPOSE

Definite diagnosis of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukocencephalopathy (CADASIL) is mostly done by identification of NOTCH3 mutations. We aimed to develop criteria for selecting patients suspected for CADASIL to undergo genetic testing.

SUBJECTS AND METHODS

All subjects were Japanese. We recruited CADASIL patients genetically diagnosed up until 2011 (n=37, Group 1) or after 2011 (n=65, Group 2), 67 young stroke patients (≤55 years old), and 53 NOTCH3-negative CADASIL-like patients. The members of Japanese research committee for hereditary cerebral small vessel disease discussed and generated the new criteria to maximize positive rate in Group 1 CADASIL patients, followed by validation of sensitivity and specificity.

RESULTS

In Group 1 CADASIL patients, the ages at onset excluding migraine were distributed widely (37-74 years old) and bimodal (<55 and >55 years old). Frequencies of an autosomal dominant family history and vascular risk factor(s) were 73 and 65%, respectively. From these findings, the panel considered appropriate cut-off values and weighting for each item. In CADASIL Group 1 versus young stroke controls, the sensitivity and specificity of the new criteria were 97.3% and 80.6%, respectively. However, in CADASIL Group 2 versus NOTCH3-negative controls, the sensitivity and specificity were 96.9% and 7.5%, respectively. Forty mutations of NOTCH3 distributed in exons 2-8, 11, 14, 18, 19, and 21 were identified in this study. Ten mutations were unreported ones.

CONCLUSION

We propose the new criteria of high sensitivity, which will help physicians to assess the need for genetic testing.

The First Report of CADASIL in Peru: Olfactory Dysfunction on Initial Presentation

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is a rare, heritable, small vessel vascular disease caused by mutations in the Notch3 gene that is characterized by migraines, subcortical vascular events, cognitive decline, and mood disturbances. However, many CADASIL cases present with unusual symptoms such as status epilepticus, a movement disorder, or sensory dysfunction. This study describes the clinical, genetic, and radiologic characteristics of a Peruvian family with CADASIL in which multiple family members presented with severe olfactory deficits. Seven members of the family have symptoms suggestive of CADASIL, with genetic testing revealing R133C mutations in the two patients who underwent genetic testing. Cognitive testing and olfactory identification testing (Smell Identification Test) were performed in three CADASIL patients revealing total anosmia in two tested patients and severe hyposmia in the other. Olfactory dysfunction has been associated with various neurologic and psychiatric conditions though few studies have linked it with neurovascular disorders such as CADASIL. This first reported case of CADASIL in Peru emphasizes that symptomatic olfactory dysfunction may be an unusual presentation of CADASIL and that olfactory dysfunction is important to evaluate in CADASIL patients.

Inherited and Uncommon Causes of Stroke

PURPOSE OF REVIEW

This article is a practical guide to identifying uncommon causes of stroke and offers guidance for evaluation and management, even when large controlled trials are lacking in these rarer forms of stroke.

RECENT FINDINGS

Fabry disease causes early-onset stroke, particularly of the vertebrobasilar system; enzyme replacement therapy should be considered in affected patients. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), often misdiagnosed as multiple sclerosis, causes migraines, early-onset lacunar strokes, and dementia. Moyamoya disease can cause either ischemic or hemorrhagic stroke; revascularization is recommended in some patients. Cerebral amyloid angiopathy causes both microhemorrhages and macrohemorrhages, resulting in typical stroke symptoms and progressive dementia. Pregnancy raises the risk of both ischemic and hemorrhagic stroke, particularly in women with preeclampsia/eclampsia. Pregnant women are also at risk for posterior reversible encephalopathy syndrome (PRES), reversible cerebral vasoconstriction syndrome, and cerebral venous sinus thrombosis. Experts recommend that pregnant women with acute ischemic stroke not be systematically denied the potential benefits of IV recombinant tissue plasminogen activator.

SUMMARY

Neurologists should become familiar with these uncommon causes of stroke to provide future risk assessment and family counseling and to implement appropriate treatment plans to prevent recurrence.

Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) as a model of small vessel disease: update on clinical, diagnostic, and management aspects

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common and best known monogenic small vessel disease. Here, we review the clinical, neuroimaging, neuropathological, genetic, and therapeutic aspects based on the most relevant articles published between 1994 and 2016 and on the personal experience of the authors, all directly involved in CADASIL research and care. We conclude with some suggestions that may help in the clinical practice and management of these patients.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoancepahlopathy presenting with postpartum psychosis and late-onset stroke

Aim: To describe the unusual presentation of a novel family with cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoancepahlopathy. Presentation of cases: The clinical features of five patients from three successive generations are described. The index patient presented with postpartum psychosis followed by cognitive decline. Brain imaging revealed no temporal pole involvement. Genetic testing was performed by full scan of the entire NOTCH3 gene revealing the R169C mutation. Multiple cardiovascular risk factors and late-onset strokes were present in the family. Conclusion: The combination of atypical psychiatric onset, absence of anterior temporal lesions, presence of cardiovascular risk factors and late-onset stroke may obscure the correct diagnosis for many years and requires a high index of suspicion.

Possible Role of a Missense Mutation of p.P167S on NOTCH3 Gene Associated with Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy

Background

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a single-gene disorder caused by mutations in the NOTCH3 gene, located on chromosome 19p13. NOTCH3 encodes a transmembrane receptor which plays a role in cellular differentiation and cell cycle regulation.

Case Report

A 71-year-old female showing headache and memory impairment, familial history of stroke and having a missense mutation from proline to serine at codon 167 in the exon 4 on NOTCH3 gene. Five family members revealed the same mutation (c.499C>T), who presented migrainous headache and stroke. In this study, we have uncovered a novel NOTCH3 mutation at the nucleotide position 499 (c.499C>T; p.P167S) in a family with CADASIL.

Conclusions

We suggested a missense mutation of proline to serine at codon 167 in exon 4 of the NOTCH3 gene, which resulted in the substitution of cytosine to thymine (c.499C>T) resulting migraine, stroke and vascular cognitive impairment.

The comparisons of phenotype and genotype between CADASIL and CADASIL-like patients and population-specific evaluation of CADASIL scale in China

Background

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common form of hereditary stroke disorder caused by mutations in the NOTCH3 gene. Although CADASIL scale is a widely used tool to screen clinically suspected CADASIL patients, the differential effects of this scale in various populations remain unknown.

Methods

92 CADASIL-like patients and 24 CADASIL patients were selected based on CADASIL scale and gene tests. The clinical, genetic and radiological characteristics were analyzed.

Results

Based on the CADASIL scale, we first screened 116 suspected CADASIL patients, and detected 20 mutations in 24 CADASIL-patients (Specificity: 20.69 %). Surprisingly, we found that transient ischemic attack/stroke, migraine, cognitive decline, psychiatric disturbances and early onset age in CADASIL scale showed no differences between the CADASIL and the CADASIL-like patients (p > 0.05). Instead, recurrent cerebral ischemic events (58.33 %, p = 0.028) and positive family histories (p < 0.05) were more frequently observed in CADASIL patients. Moreover, compared with CADASIL-like patients (21.74 %), CADASIL patients demonstrated higher percentage of temporal pole involvements (58.33 %, p = 0.001), but not the external capsule involvements (66.67 %, p = 0.602), in MRI imaging. Further, we found that vascular risk factors could occur in both CADASIL patients and CADASIL-like patients, and therefore could not be used as the markers to differentiate the two groups in our study (p > 0.05). By performing DSA analysis, we for the first time identified dysplasia of cerebral blood vessels in CADASIL patients, which were detected more frequently in CADASIL patients (41.67 %) in comparison with CADASIL-like patients (8.69 %, p <0.01).

Conclusion

Our data suggested that the efficacy of CADASIL scale to diagnose the disease varied with specific populations. Recurrent cerebral ischemic events, temporal pole involvements (but not the external capsule) in MRI imaging and dysplasia of cerebral blood vessels in DSA may be the new potential risk factors of the CADASIL scale suitable for Chinese patients. Gene testing by encephalopathy gene panel is expected to improve the accuracy of CADASIL differential diagnosis and increase the understanding of this disease in the future.

Association of Notch3 single-nucleotide polymorphisms and lacunar infarctions in patients

Cerebrovascular disease is a leading cause of morbidity and mortality worldwide, which is influenced by genetic and environmental factors. The aim of the present study was to examine the association between single-nucleotide polymorphisms (SNPs) in Notch3 exons 3–6 and lacunar infarction by comparing SNPs between control subjects and those with lacunar infarction. A single-center case-control study was conducted to investigate the association between Notch3 SNPs and risk of stroke. A total of 140 patients were included in the study, 30 of whom had no infarction (control) and 110 had lacunar infarction. Lacunar patients were divided into the ‘pure lacunar’ and ‘lacunar + leukoarasis’ groups based on brain imaging. All the patients were of Chinese Han ethnicity, and the male to female ratio was 84:56. Patient clinical histories included hypertension, diabetes mellitus (DM), hyperlipidemia, and heart disease were recorded. The Notch3 sequence was obtained from the National Centser for Biotechnology Information database. Notch3 was amplified by polymerase chain reaction from whole blood samples, and exons 3–6 were sequenced to identify SNPs. The result showed that there was no significant difference in the prevalence of hypertension, DM, hyperlipidemia, and heart disease between the control and lacunar infarction patients. Notabley, the age of the lacunar + leukoarasis patients was significantly higher than that of the control and pure lacunar patients (P<0.05). Eight SNPs were detected at low frequencies, and only rs3815388 and rs1043994 exhibited slightly higher frequencies. A χ² test indicated that Notch3 SNPs, particularly rs1043994, were associated with lacunar infarction (P<0.05). In conclusion, the result of the present study have shown that Notch3 SNPs, particularly rs1043994, are associated with lacunar infarction.

Genotypic and phenotypic spectrum of CADASIL in Japan: the experience at a referral center in Kumamoto University from 1997 to 2014

This study elucidates the genotypic and phenotypic spectrum and histopathological findings related to cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) in Japan. For this single-center retrospective observational study, we enrolled 215 patients who were clinically suspected of having CADASIL and were examined at Kumamoto University from 1997 to 2014, and we diagnosed CADASIL in 70 patients. We found 19 different NOTCH3 mutations in the patients, with the NOTCH3 Arg133Cys mutation being found most frequently. We also found the Arg75Pro mutation, a cysteine-sparing NOTCH3 mutation. CADASIL patients with this Arg75Pro mutation were frequently found throughout Japan, and fewer patients with the Arg75Pro mutation showed MRI hyperintensity in the anterior temporal pole compared with patients with other NOTCH3 mutations. Significantly more CADASIL patients with the NOTCH3 Arg133Cys mutation had hyperintensity in the external capsule compared with CADASIL patients with the other mutations not including the NOTCH3 Arg75Pro mutation. We also showed postmortem pathological findings of the first Japanese CADASIL case with the NOTCH3 Arg133Cys mutation, and histopathological findings of fresh frozen skin biopsy specimens of CADASIL patients. In conclusions, the spectrum of NOTCH3 mutations in Japanese CADASIL patients may be partially explained by founder effects. Genotype-phenotype correlations may exist in CADASIL, which should be considered so as to make an accurate diagnosis of CADASIL in each population. Fresh frozen skin biopsy specimens may aid detection of Notch3 deposits on vascular walls for an improved diagnosis of CADASIL.

The genetic spectrum and the evaluation of CADASIL screening scale in Chinese patients with NOTCH3 mutations

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited small artery disease caused by NOTCH3 gene mutation. Here we report clinical, pathological and genetic profiles of 29 newly-diagnosed CADASIL patients, evaluation of the CADASIL scale in Chinese CADASIL patients, and reanalysis of all reported mainland Chinese patients with identified NOTCH3 gene mutation. We found two novel mutations (p.C134G and p.C291Y) and 13 reported NOTCH3 mutations in the newly-diagnosed group. CADASIL scale score was less than the cutoff score in 19 of 53 Chinese patients with NOTCH3 mutation, generating only a sensitivity of 64.1%. At the time of study, the total number of genetically confirmed CADASIL cases reached 158 from 97 unrelated mainland Chinese families, with 9/97 (9.3%) sporadic patients. The NOTCH3 gene mutation profile showed 43 mutations, with hotspots in exon 4, followed by exon 3. The considerable variability in onset age and CADASIL scale score in patients carrying the same NOTCH3 missense mutation suggested no obvious phenotype-genotype correlation. In conclusion, we report two novel mutations which expand the NOTCH3 mutational spectrum. Exons 4 and 3 are hotspots in mainland Chinese patients with NOTCH3 mutation. The low sensitivity of CADASIL scale in our patients group indicated that the CADASIL scale should be refined according to the clinical characteristics of Chinese CADASIL patients when used in Chinese populations.

Clinical, familial, and neuroimaging features of CADASIL-like patients

OBJECTIVES

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited small vessel disease caused by NOTCH3 mutations. There are no clinical and neuroimaging findings pathognomonic of the disease. The aim of this paper was to provide a description of a group of NOTCH3-negative patients with a phenotype closely resembling that of CADASIL.

MATERIALS AND METHODS

We performed NOTCH3 analysis (exons 2-23) in 117 probands because of a clinician's suspicion of CADASIL. The CADASIL scale, a recently developed tool that allows to better select patients for NOTCH3 analysis, was retrospectively applied to NOTCH3-negative patients; the patient subgroup that scored higher than the screening cutoff for CADASIL was defined as CADASIL-like.

RESULTS

Thirty-four CADASIL-like patients (mean age at onset 57.8 years [52.1-63.4], 50% males) were identified. Compared with 25 patients with CADASIL for clinical, familial, and neuroimaging features, only the following variables were significantly (α level <0.05) different in frequency between patients with CADASIL and CADASIL-like patients: a positive family history for stroke at age ≤ 60 years, more frequent in patients with CADASIL, and hypertension, more frequent in CADASIL-like patients.

CONCLUSIONS

Our experience highlights the growing number of patients presenting with a high suspicion of a cerebral small vessel disease with an autosomal dominant pattern of inheritance and a phenotype closely similar to that of CADASIL but without NOTCH3 mutations. This group remains to be characterized from the genetic point of view. The role of other genes or NOTCH3 alterations on exons other than 2-23 or introns has to be further assessed.

CADASIL in central Italy: a retrospective clinical and genetic study in 229 patients

The objective of the study is to detail clinical and NOTCH3 gene mutational spectrum in a large group of Italian CADASIL patients. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a familial cerebral small vessels disease caused by mutations in the NOTCH3 gene on 19p13 usually presenting in young or middle adulthood. Characteristic features include migraine, recurrent lacunar stroke, subcortical dementia, mood disturbances and leukoencephalopathy. The disorder is often overlooked and misdiagnosed. CADASIL prevalence and disease burden is still undetermined. We retrospectively reviewed demographic, clinical, and mutational characteristic of all CADASIL patients diagnosed from January 2002 to December 2012 in three referral centers for neurogenetic and cerebrovascular diseases in central Italy. 229 NOTCH3 positive subjects were identified. Mean age at diagnosis was 57.8 ± 14.7 years, and 48.6 ± 17.1 years at first symptom onset. Most frequent clinical symptoms were ischemic events (59 %) and psychiatric disturbances (48 %). The highest percentage of mutations were found on exons 4 and 19 (20.6 and 17.6 % respectively), the remaining being dispersed over the entire EGF-like region of the NOTCH3 gene. 209 patients resided in a circumscribed geographic area which included three regions of the central Italy, yielding a minimum prevalence of 4.1 per 100.000 adult inhabitants. This is the most extensive study on CADASIL in Italy. Clinical phenotype showed several peculiarities in frequency and presentation of the main disease manifestations. Our study enlarges the number of pathogenic NOTCH3 mutations and due to the heterogeneous mutational spectrum observed suggests that full sequencing of exons 2-24 is mandatory for CADASIL screening in the Italian population.

Inherited leukoencephalopathies with clinical onset in middle and old age

The currently widespread use of neuroimaging has led neurologists to often face the problem of the differential diagnosis of white matter diseases. There are various forms of leukoencephalopathies (vascular, inflammatory and immunomediated, infectious, metabolic, neoplastic) and sometimes white matter lesions are expression of a genetic disease. While many inherited leukoencephalopathies fall in the child neurologist's interest, others may have a delayed or even a typical onset in the middle or old age. This field is rapidly growing and, in the last few years, many new inherited white matter diseases have been described and genetically defined. A non-delayed recognition of middle and old age inherited leukoencephalopathies appears important to avoid unnecessary tests and therapies in the patient and to possibly anticipate the diagnosis in relatives. The aim of this review is to provide a guide to direct the diagnostic process when facing a patient with a suspicion of an inherited form of leukoencephalopathy and with clinical onset in middle or old age. Based on a MEDLINE search from 1990 to 2013, we identified 24 middle and old age onset inherited leukoencephalopathies and reviewed in this relation the most recent findings focusing on their differential diagnosis. We provide summary tables to use as a check list of clinical and neuroimaging findings that are most commonly associated with these forms of leukoencephalopathies. When present, we reported specific characteristics of single diseases. Several genetic diseases may be suspected in patients with middle or old age and white matter abnormalities. In only few instances, pathognomonic clinical or associated neuroimaging features help identifying a specific disease. Therefore, a comprehensive knowledge of the characteristics of these inherited white matter diseases appears important to improve the diagnostic work-up, optimize the choice of genetic tests, increase the number of diagnosed patients, and stimulate the research interest in this field.

Changing clinical patterns and increasing prevalence in CADASIL

OBJECTIVES

CADASIL is a monogenic small vessel vasculopathy causing recurrent stroke. Early descriptions suggested dementia and disability were common from the 5th decade but there is evidence of marked phenotypic variability. We investigated the prevalence and clinical features of CADASIL in the west of Scotland.

METHODS

We undertook a retrospective review of clinical records of patients with confirmed CADASIL identified through a specialist clinic. Patients were divided to examine the effect of date of diagnosis on clinical outcomes and the characteristics at different ages. The location of pedigree members was used to estimate prevalence.

RESULTS

Twenty-one different CADASIL-causing NOTCH3 mutations were identified in 49 pedigrees (61% in exon 4). Disease prevalence in Glasgow was 4.6/100,000 adults. Mutation prevalence was estimated at 10.7/100,000 population. Median age at first stroke in women (57 years) was higher than previous estimates, and stroke age in men was higher in patients diagnosed more recently (pre 2006 46 years, post 2006 56 years, P=0.034). In patients over 58 years of age, 13/34 (38%) were living independently and 17/28 (61%) were mobile without aids when last seen.

CONCLUSIONS

CADASIL prevalence is at least 4.6 per 100,000 adults. Median age of first stroke may be older than previously thought. Clinicians should consider CADASIL in the differential diagnosis even in older patients with stroke.

Hypomorphic NOTCH3 mutation in an Italian family with CADASIL features

The cerebral autosomal dominant arteriopathy with subcortical infarcts and leucoencephalopathy (CADASIL) is because of NOTCH3 mutations affecting the number of cysteine residues. In this view, the role of atypical NOTCH3 mutations is still debated. Therefore, we investigated a family carrying a NOTCH3 nonsense mutation, with dominantly inherited recurrent cerebrovascular disorders. Among 7 family members, 4 received a clinical diagnosis of CADASIL. A heterozygous truncating mutation in exon 3 (c.307C>T, p.Arg103X) was found in the 4 clinically affected subjects and in one 27-year old lady, only complaining of migraine with aura. Magnetic resonance imaging scans found typical signs of small-vessel disease in the 4 affected subjects, supporting the clinical diagnosis. Skin biopsies did not show the typical granular osmiophilic material, but only nonspecific signs of vascular damage, resembling those previously described in Notch3 knockout mice. Interestingly, messenger RNA (mRNA) analysis supports the hypothesis of an atypical NOTCH3 mutation, suggesting a nonsense-mediated mRNA decay. In conclusion, the present study broadens the spectrum of CADASIL mutations, and, therefore, opens new insights about Notch3 signaling.

Clinical and radiological features in CADASIL and NOTCH3-negative patients: a multicenter study from Turkey

BACKGROUND

The diversity of clinical presentation and neuroimaging findings of CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) from different regions of the world has not yet been studied in depth. Here we investigated the variability of clinical, radiological and genetic data of 48 patients analyzed for NOTCH3 mutation in Turkey.

METHODS

Clinical evaluation was made according to a preformed questionnaire. Cranial neuroimaging findings were determined on the basis of T1, T2, FLAIR and proton-density magnetic resonance scans. For genetic analysis, polymerase chain reaction was performed with primers flanking exons 2-6 and 11 of NOTCH3 gene.

RESULTS

Twenty-five patients (52.1%) were diagnosed as CADASIL with NOTCH3 mutation, while 23 patients (47.9%) had no mutation (NOTCH3-negative patients). The mean age and age at stroke onset were lower in male CADASIL patients (p < 0.03). A family history of migraine (p = 0.012), stroke (p < 0.001), recurrent strokes (p = 0.020) and dementia (p = 0.012) was more common in CADASIL patients. Temporal pole involvement was more common in CADASIL patients (p = 0.004).

CONCLUSION

It is of clinical importance to identify the heterogeneity of CADASIL from different countries due to a low correlation of clinical and radiological data with respect to NOTCH3 mutation.