Neuroradiological findings in Alagille syndrome

Evolution of cerebrovascular imaging and associated clinical findings in children with Alagille syndrome

PURPOSE

Alagille syndrome (ALGS) is a multisystem autosomal dominant disorder with highly variable expression. Intracranial arterial and venous anomalies have a reported prevalence of 30-40% and can increase the risk of stroke by 16%. Few reports document the frequency and evolution of cerebrovascular abnormalities (CVAs) in children with ALGS. We aimed to define the spectrum, frequency, and evolution of CVAs in a series of children with ALGS using magnetic resonance angiography (MRA).

METHODS

We conducted a single-center, retrospective study in a large tertiary pediatric hospital. CVAs were grouped into 4 categories: 1) Stenosis or narrowing; 2) Aneurysms and ectasias; 3) Tortuosity; and 4) Vascular anomalies and anatomical variants.

RESULTS

Thirty-two children met the inclusion criteria. The median age at initial diagnosis was 6 (3.8-10.3) years. Thirteen (40%) had follow-up MRI at a mean of 55 (31.5-66) months. Eighteen (56%) had CVAs; the most frequent fell into group 1 (n = 12, 37.5%). CVAs were stable over time, except for one patient with Moyamoya arteriopathy (MMA). One patient developed a transient ischemic attack secondary to an embolic event. Three (9.3%) had microhemorrhages at the initial diagnosis secondary to Tetralogy of Fallot. Another patient had recurrent subdural hematomas of unknown cause.

CONCLUSION

CVAs were stable except in the presence of MMA. Vascular strokes, which are reported in older patients with ALGS, were not a common feature in children under 16 years of age, either at presentation or over the 31.5-66 month follow-up period.

Imaging Review of Pediatric Monogenic CNS Vasculopathy with Genetic Correlation

Monogenic cerebral vasculopathy is a rare but progressively recognizable cause of pediatric cerebral vasculopathy manifesting as early as fetal life. These monogenic cerebral vasculopathies can be silent or manifest variably as fetal or neonatal distress, neurologic deficit, developmental delay, cerebral palsy, seizures, or stroke. The radiologic findings can be nonspecific, but the presence of disease-specific cerebral and extracerebral imaging features can point to a diagnosis and guide genetic testing, allowing targeted treatment. The authors review the existing literature describing the frequently encountered and rare monogenic cerebral vascular disorders affecting young patients and describe the relevant pathogenesis, with an attempt to categorize them based on the defective step in vascular homeostasis and/or signaling pathways and characteristic cerebrovascular imaging findings. The authors also highlight the role of imaging and a dedicated imaging protocol in identification of distinct cerebral and extracerebral findings crucial in the diagnostic algorithm and selection of genetic testing. Early and precise recognition of these entities allows timely intervention, preventing or delaying complications and thereby improving quality of life. It is also imperative to identify the specific pathogenic variant and pattern of inheritance for satisfactory genetic counseling and care of at-risk family members. Last, the authors present an image-based approach to these young-onset monogenic cerebral vasculopathies that is guided by the size and predominant radiologic characteristics of the affected vessel with reasonable overlap. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

A case study on the pitfalls in prenatal ultrasonic detection of butterfly vertebra

Introduction

Butterfly vertebra is a rare congenital anomaly that is observed both in isolation and also as part of syndromic diseases. In prenatal ultrasonic scans the typical shapes of the two halves for butterfly vertebra are wedge-shaped or triangular. In the case we presented, the 3 dimensional computed tomography (3D CT) showed that the shape was unusual and rare. To improve the prenatal ultrasonic discriminability of this rare form of butterfly vertebra we used multi-directional ultrasonic images, corresponding to postpartum 3D CT images.

Case report

A 25-year-old woman was referred to our department for ultrasound screening. The routine fetal back spinal scan yielded findings indicative of an anomaly within the ninth thoracic vertebral body. The affected vertebra was examined by two-dimensional (2D) and three-dimensional (3D) ultrasound while the fetus was prone and supine. The focussed scanning of the fetal spine from the back, anterior and lateral approaches aided us to reach the final prenatal diagnosis of butterfly vertebra with asymmetric halves.The diagnosis of butterfly vertebra was confirmed by the radiologist with 3D CT after the woman chose to terminate the pregnancy due to multiple malformations. In 3D CT, the body of the ninth thoracic vertebra appeared to be two lateral halves of different sizes, and the bigger half was C-shaped. When prenatal ultrasonic images and postnatal CT images were compared, the echoic shape of the affected vertebra scanned from the front right side was very similar to the CT.

Conclusion

Due to the variable sizes and shapes of vertebrae affected in butterfly vertebra, prenatal diagnosis can be difficult using ultrasound. When the presence of fetal vertebral abnormalities is suspected, it is imperative for sonographers to adopt a comprehensive approach that extends beyond the conventional spinal examination performed solely from the dorsal aspect of the fetus. Instead, a thorough assessment should involve scanning the fetus from various angles, including anterior and lateral perspectives, in order to obtain a comprehensive and detailed evaluation of the identified vertebra.

Alagille syndrome: an orphan disease in Colombia and summary of recent advances in treatment and survival - a case report

Alagille syndrome has been described as a multisystemic clinical spectrum caused by an autosomal dominant genetic disorder. Although it is estimated that there is 1 case per 100 000 live births, the prognosis for survival and quality of life for these patients is varied but tends to be negative. In Colombia, this condition is considered an orphan disease with difficult management due to the lack of specialized centers that have all the medical specialties and subspecialties. Some reports state that no more than 30 cases have been published in this country.

Materials and methods

The authors report a case of a male baby who, at 8 days old, he was taken to the general practitioner's outpatient clinic for persistent jaundice. At 3 months of age, he was reviewed by the pediatric gastroenterology department, which requested liver and biliary tract scintigraphy, showing atresia of the biliary tract, hepatomegaly, and the absence of a gallbladder.

Results

Liver transplantation is the definitive solution. However, in low- and middle-income countries, where there are no well-established organ transplantation programs, the prognosis for these patients is presumed to be worse.

Conclusion

Alagille syndrome is a rare disease that requires an accurate and early diagnosis and timely multidisciplinary management to reduce the impact of multisystemic complications. It is necessary to advance in transplant programs in low- and middle-income countries, to provide a solution to cases where there are no other therapeutic alternatives, and to contribute to the quality of life of the affected patient.

Multidisciplinary Management of Alagille Syndrome

Alagille syndrome (ALGS) is an autosomal dominant disorder characterized by involvement of various organ systems. It predominantly affects the liver, skeleton, heart, kidneys, eyes and major blood vessels. With myriads of presentations across different age groups, ALGS is usually suspected in infants presenting with high gamma glutamyl transpeptidase cholestasis and/or congenital heart disease. In children it may present with decompensated cirrhosis, intellectual disability or short stature, and in adults vascular events like stroke or ruptured berry aneurysm are more commonly noted. Liver transplantation (LT) is indicated in children with cholestasis progressing to cirrhosis with decompensation. Other indications for LT include intractable pruritus, recurrent fractures, hepatocellular carcinoma and disfiguring xanthomas. Due to an increased risk of renal impairment noted in ALGS, these patients would require optimized renal sparing immunosuppression in the post-transplant period. As the systemic manifestations of ALGS are protean and a wider spectrum is being increasingly elucidated, a multidisciplinary team needs to be involved in managing these patients. Moreover, many basic-science and clinical questions especially with regard to its presentation and management remain unanswered. The aim of this review is to provide updated insights into the management of the multi-system involvement of ALGS.