Intracranial Arterial Tortuosity in Marfan Syndrome and Loeys-Dietz Syndrome: Tortuosity Index Evaluation Is Useful in the Differential Diagnosis

Neurological abnormalities in individuals with Marfan syndrome: results from a genetically confirmed Italian cohort

BACKGROUND AND AIMS

Neurological abnormalities have been frequently reported in individuals with Marfan Syndrome (MFS). However, available data relies solely on retrospective studies predating current diagnostic criteria.

METHODS

Cross-sectional study comprehensively investigating neurological abnormalities within a prospective cohort of adults (≥ 18 years) with genetically confirmed MFS referred to an Italian hub center for heritable connective tissue diseases (Jan. 1st - Nov. 15th, 2021).

RESULTS

We included a total of 38 individuals (53% female). The commonest neurological symptom was migraine (58%), usually without aura (73%). Neuropsychological testing was generally unremarkable, whilst anxiety and depression were highly prevalent within our cohort (42% and 34%, respectively). The most frequent brain parenchymal abnormality was the presence of cortico-subcortical hypointense spots on brain MRI T2* Gradient-Echo sequences (39%), which were found only in patients with a prior history of aortic surgery. Migraineurs had a higher frequency of brain vessels tortuosity vs. individuals without migraine (73% vs. 31%; p = 0.027) and showed higher average and maximum tortuosity indexes in both anterior and posterior circulation brain vessels (all p < 0.05). At univariate regression analysis, the presence of brain vessels tortuosity was significantly associated with a higher risk of migraine (OR 5.87, CI 95% 1.42-24.11; p = 0.014).

CONCLUSIONS

Our study confirms that neurological abnormalities are frequent in individuals with MFS. While migraine appears to be associated with brain vessels tortuosity, brain parenchymal abnormalities are typical of individuals with a prior history of aortic surgery. Larger prospective studies are needed to understand the relationship between parenchymal abnormalities and long-term cognitive outcomes.

Quantitative measurement of dural ectasia: associations with clinical and genetic characteristics in Marfan syndrome

PURPOSE

Dural ectasia (DE) may significantly impact Marfan syndrome (MFS) patients' quality of life due to chronic lower back pain, postural headache and urinary disorders. We aimed to evaluate the association of quantitative measurements of DE, and their evolution over time, with demographic, clinical and genetic characteristics in a cohort of MFS patients.

METHODS

We retrospectively included 88 consecutive patients (39% females, mean age 37.1 ± 14.2 years) with genetically confirmed MFS who underwent at least one MRI or CT examination of the lumbosacral spine. Vertebral scalloping (VS) and dural sac ratio (DSR) were calculated from L3 to S3. Likely pathogenic or pathogenic FBN1 variants were categorized as either protein-truncating or in-frame. The latter were further classified according to their impact on the cysteine content of fibrillin-1.

RESULTS

Higher values of the systemic score (revised Ghent criteria) were associated with greater DSR at lumbar (p < 0.001) and sacral (p = 0.021) levels. Patients with protein-truncating variants exhibited a greater annual increase in lumbar (p = 0.039) and sacral (p = 0.048) DSR. Mutations affecting fibrillin-1 cysteine content were linked to higher VS (p = 0.009) and DSR (p = 0.038) at S1, along with a faster increase in VS (p = 0.032) and DSR (p = 0.001) in the lumbar region.

CONCLUSION

Our study shed further light on the relationship between genotype, dural pathology, and the overall clinical spectrum of MFS. The identification of protein-truncating variants and those impacting cysteine content may therefore suggest closer patient monitoring, in order to address potential complications associated with DE.

Successful surgical management of a superior cerebellar artery aneurysm in a patient with Marfan syndrome: illustrative case

BACKGROUND

Marfan syndrome, a connective tissue disorder, poses unique challenges in neurosurgery, given the fragility of vascular structures. Superior cerebellar artery (SCA) aneurysms in patients with the syndrome are rare and present distinct surgical difficulties, necessitating innovative approaches.

OBSERVATIONS

A 29-year-old male with Marfan syndrome presented with a subarachnoid hemorrhage from a ruptured SCA aneurysm. Given the lack of a defined aneurysm neck and the small diameter of the SCA, standard clipping and endovascular therapies were unsuitable. A microsurgical approach using microsutures was successfully employed, effectively managing the aneurysm while preserving the parent artery.

LESSONS

This case underscores the efficacy of the microsuture technique in complex neurosurgical scenarios, particularly in patients with connective tissue disorders such as Marfan syndrome. The adaptability of surgical strategies, as demonstrated in this case, is crucial for achieving successful outcomes in patients with unique anatomical challenges.

Arterial tortuosity in pediatric Loeys-Dietz syndrome patients

Loeys-Dietz syndrome (LDS) is an autosomal connective tissue disorder commonly presenting with hypertelorism, bifid uvula, aortic aneurysms, and arterial tortuosity. The aim of the present study was to investigate differences in tortuosity index (TI) between genotypes of LDS, possible progression over time and its use as an adjunctive prognostic tool alongside aortic dimensions to aid timely surgical planning in pediatric patients. A retrospective observational study of pediatric LDS patients referred to our center (November 2012-February 2021) was conducted. Using magnetic resonance angiography (MRA) with 3D maximum intensity projection volume-rendered angiogram, arterial TI was measured. Twenty three patients had genetically confirmed LDS with at least one head and neck MRA and 19 had no less than one follow-up MRA available. All patients presented arterial tortuosity. Patients with TGFBR2 variants had greater values of TI compared to patients with TGFB2 variants (p = 0.041). For patients who did not undergo surgery (n = 18), z-scores at the level of the sinus of Valsalva showed a significant correlation with vertebral TI (rs  = 0.547). There was one death during follow-up. This study demonstrates that patients with LDS and TGFBR2 variants have greater values of TI than patients with TGFB2 variants and that greatest values of TI are associated with increased aortic root z-scores. Furthermore, as TI decreases over time, less frequent neuroimaging follow-up can be considered. Nevertheless, additional studies are needed to better define more accurate risk stratification and long-term surveillance in these patients.

Vertebral artery dissection caused by atlantoaxial dislocation in a patient with Marfan syndrome

A small number of case reports have documented a link between atlantoaxial dislocation (AAD) and vertebral artery dissection (VAD), but this association has never been described in patients with hereditary connective tissue disorders. We present a case of an 18-year-old female patient, diagnosed with Marfan syndrome since the age of one, who underwent brain MRA for intracranial aneurysm screening revealing tortuosity of the internal carotid and vertebral arteries as well as atlantoaxial dislocation. Since the patient was asymptomatic, a wait-and-see approach was chosen, but a follow-up MRA after 18 months showed the appearance of a dissecting pseudoaneurysm of the V3 segment of the left vertebral artery. Despite the patient being still asymptomatic, it was decided to proceed with C1-C2 stabilization to prevent further vascular complications. Follow-up imaging showed realignment of the atlantoaxial joint and reduction of the dissecting pseudoaneurysm of the left vertebral artery. In our patient, screening MRA has led to the discovery of asymptomatic arterial and skeletal abnormalities which, if left untreated, might have led to severe cerebrovascular complications. Therefore, AAD correction or close monitoring with MRA should be provided to MFS patients with this craniovertebral junction anomaly, even if asymptomatic.

Carotid Dolichoarteriopathy (Elongation) of the Carotid Arteries in Patients with Ischemic Stroke Anamnesis

Carotid artery elongation (ECA) is widespread in the asymptomatic population and among people with a history of ischemic stroke (IS). There are different points of view on the ways these changes contribute to brain ischemic damage pathogenesis. Materials and Methods: From 2019 to 2021, we included 1171 people who had suffered from IS less than one year before the investigation in the study, 404 (34.5%) women aged 27 to 95 years (64 ± 13 years) and 767 men (21-90; 60 ± 11 years). All patients involved in the study underwent multimodal radiological investigation in addition to assessments of their clinical and neurological data. Results: In this study, we were unable to detect a relationship between ECA localization and acute ischemic lesions. The frequency of ECA detection in patients with IS was the same as that in carotid and vertebral-basilar arterial systems. The prevalence of ECA was the same in patients with different IS subtypes (TOAST). There was no association between the localization of ECA and ischemic lesions; moreover, there were no differences in the IS frequency between anterior and posterior circulation. There were statistically significant decreases in linear peak systolic and end diastolic velocities in the internal carotid and vertebral arteries, as well as in the intracranial arteries in patients with ECA.

The Vertebral Artery: A Systematic Review and a Meta-Analysis of the Current Literature

(1) Background. The anatomical variations of the vertebral arteries (VAs) have a significant impact both in neurosurgery and forensic pathology. The purpose of this study was to evaluate the variational anatomy of the vertebral artery. We evaluated anatomical aspects regarding the V1 and V2 segments of the VA: origin, course, tortuosity, hypoplasia, and dominance, and established the prevalence of each variation. (2) Methods. We conducted a systematic search in PubMed and Google Scholar databases, up to December 2022. Sixty-two studies, comprising 32,153 vessels, were included in the current meta-analysis. We used a random-effects model with a DerSimonian-Laird estimator. The confidence intervals were set at 95%. The heterogeneity between studies was assessed using I². The funnel plot and Egger's regression test for plot asymmetry were used for the evaluation of publication bias. Statistical significance was considered at p < 0.05. (3) Results. The most common site for the origin of both VAs was the subclavian artery. The aortic arch origin of the left VA had a prevalence of 4.81%. Other origins of the right VAs were noted: aortic arch (0.1%), right common carotid artery (0.1%), and brachiocephalic trunk (0.5%). Ninety-two percent of the VAs entered the transverse foramen (TF) of the C6 vertebra, followed by C5, C7, C4, and least frequently, C3 (0.1%). Roughly one out of four (25.9%) VAs presented a sort of tortuosity, the transversal one representing the most common variant. Hypoplasia occurred in 7.94% of the vessels. Left VA dominance (36.1%) is more common, compared to right VA dominance (25.3%). (4) Conclusions. The anatomy of the VA is highly irregular, and eventual intraoperative complications may be life-threatening. The prevalence of VA origin from the subclavian artery is 94.1%, 92.0% of the VAs entered the TF at C6, 26.6% were tortuous, and 7.94% were hypoplastic.

Prevalence of unruptured intracranial aneurysms in patients with Marfan syndrome: A cross-sectional study and meta-analysis

INTRODUCTION

Marfan syndrome (MFS) is the most common inherited connective tissue disorder and its association with intracranial aneurysms (ICAs) has been debated for more than two decades. Here, we report the prevalence of ICAs at screening neuroimaging in a population of genetically confirmed MFS patients and present the results of a meta-analysis including our cohort of patients and those of previous studies.

PATIENTS AND METHODS

We enrolled 100 consecutive MFS patients, who underwent screening with brain magnetic resonance angiography at our tertiary center between August 2018 and May 2022. We did a PubMed and Web of Science search to retrieve all studies on the prevalence of ICAs in patients with MFS published before November, 2022.

RESULTS

Of the 100 patients included in this study (94% Caucasians, 40% females, mean age 38.6 ± 14.6 years), three had an ICA. We pooled the current study with five previously published studies, including a total of 465 patients, 43 of which harbored at least one unruptured ICA, leading to an overall ICA prevalence of 8.9% (95% CI 5.8%-13.3%).

DISCUSSION AND CONCLUSION

In our cohort of genetically confirmed MFS patients, the prevalence of ICAs was 3%, which is substantially lower compared to previous studies based on neuroimaging. The high frequency of ICA found in previous studies could be explained by selection bias and lack of genetic testing, which may have led to the inclusion of patients with different connective tissue disorders. Further studies, including several centers and a large number of patients with genetically confirmed MFS, are needed to confirm our results.

The Role of Genetic Testing in Patients with Heritable Thoracic Aortic Diseases

Heritable thoracic aortic disease (HTAD) is a term used to define a large group of disorders characterized by the occurrence of aortic events, mainly represented by aneurysm or dissection. These events generally involve the ascending aorta, although the involvement of other districts of the aorta or peripheral vessels may occur. HTAD can be classified as non-syndromic if the disorder is limited to the aorta, and syndromic when associated with extra-aortic features. About 20-25% of patients with non-syndromic HTAD exhibit a family history of aortic disease. Thus, a careful clinical evaluation of the proband and the first-degree family members is required to differentiate familial and sporadic cases. Genetic testing is essential since it allows confirmation of the etiological diagnosis of HTAD (particularly in patients with a significant family history) and may guide family screening. In addition, genetic diagnosis significantly impacts patients' management since the different conditions significantly differ with respect to natural history and treatment strategies. The prognosis in all HTADs is determined by the progressive dilation of the aorta, potentially leading to acute aortic events, such as dissection or rupture. Moreover, the prognosis varies according to the underlying genetic mutations. This review aims to describe the clinical characteristics and natural history of the most common HTADs, with particular emphasis on the role of genetic testing in risk stratification and management.

Effect of Blood Transfusion on Cerebral Hemodynamics and Vascular Topology Described by Computational Fluid Dynamics in Sickle Cell Disease Patients

The main objective of this study was to demonstrate that computational fluid dynamics (CFD) modeling can be used to study the contribution of covert and overt vascular architecture to the risk for cerebrovascular disease in sickle cell disease (SCD) and to determine the mechanisms of response to therapy such as chronic red blood cell (cRBC) transfusions. We analyzed baseline (screening), pre-randomization and study exit magnetic resonance angiogram (MRA) images from 10 (5 each from the transfusion and observation arms) pediatric sickle SCD participants in the silent cerebral infarct transfusion (SIT) trial using CFD modeling. We reconstructed the intracranial portion of the internal carotid artery and branches and extracted the geometry using 3D Slicer. We cut specific portions of the large intracranial artery to include segments of the internal carotid, middle, anterior, and posterior cerebral arteries such that the vessel segment analyzed extended from the intracranial beginning of the internal carotid artery up to immediately after (~0.25 inches) the middle cerebral artery branching point. Cut models were imported into Ansys 2021R2/2022R1 and laminar and time-dependent flow simulation was performed. Change in time averaged mean velocity, wall shear stress, and vessel tortuosity were compared between the observation and cRBC arms. We did not observe a correlation between time averaged mean velocity (TAMV) and mean transcranial Doppler (TCD) velocity at study entry. There was also no difference in change in time average mean velocity, wall shear stress (WSS), and vessel tortuosity between the observation and cRBC transfusion arms. WSS and TAMV were abnormal for 2 (developed TIA) out of the 3 participants (one participant had silent cerebral infarctions) that developed neurovascular outcomes. CFD approaches allow for the evaluation of vascular topology and hemodynamics in SCD using MRA images. In this proof of principle study, we show that CFD could be a useful tool and we intend to carry out future studies with a larger sample to enable more robust conclusions.

Loeys-Dietz syndrome: Case report and review of the literature

Loeyz-Dietz syndrome (LDS) is a genetic connective tissue disorder characterized by various clinical manifestations, most notably vasculopathies and skeletal abnormalities. The disease is rare, and has multiple overlapping features with other connective tissue disorders. As such, many radiologists remain unfamiliar with the imaging and clinical findings in LDS. Here, we describe the case of a 14-year-old male without previous diagnosis of LDS who presented with aortic root aneurysm and acute type A aortic dissection. Further workup revealed numerous abnormalities, including marked tortuosity of the cervical arterial system, a bifid uvula, hypertelorism, and a superior mesenteric artery aneurysm. Genetic testing ultimately revealed a mutation in Transforming Growth Factor Beta Receptor 1.

Increased intracranial arterial tortuosity is associated with worse cardiovascular outcome in patients with Loeys-Dietz syndrome

The aim of our study was to evaluate the association between intracranial arterial tortuosity and cardiovascular outcome in patients with Loeys-Dietz syndrome (LDS). We performed a retrospective analysis of all patients with genetically confirmed LDS who underwent at least one brain MRA at our institution (n = 32); demographic and clinical features were evaluated in relation to the tortuosity of intracranial arteries as measured by tortuosity index (TI), which was calculated using the formula: [(centerline length) / (straight-line length)-1] × 100. Receiver operating characteristic curve analysis for intracranial TI and the binary end point of aortic surgery showed vertebrobasilar TI (VBTI) to be the best classifier among the examined arterial segments (AUC = 0.822). Patients with higher VBTI showed a greater incidence of aortic surgery (p < 0.001) and underwent more surgical and endovascular procedures (p = 0.006), with a higher rate of operations (p = 0.002). Kaplan-Meier analysis showed a significantly longer surgery-free survival in patients with lower arterial tortuosity (p < 0.001). At multivariate analysis, higher VBTI was associated with an increased risk of surgery (p < 0.001), which was independent of gene mutation and patient age. Increased VBTI is a marker of adverse cardiovascular outcome in patients with LDS, which can be easily measured on brain MRA, and may be useful in the management of this heterogeneous patient population.