Longitudinal assessments in continuing specialty certification and lifelong learning.

Longitudinal assessment (LA) involves the regular, spaced delivery of a limited number of questions on practice relevant content on a computer or mobile internet platform. Depending on the platform, participants may indicate relevance of the content to their practice and confidence in their answer prior to receiving immediate feedback (including critiques) on each question. Individual dashboards may be included to assist participants in tracking progress and identifying areas of strength and weaknesss across a content blueprint. This paper provides an overview of the theoretical underpinnings underlying LA programs, briefly describes current uses of LA in medicine and suggests areas for evaluating the role of LA in continuing medical specialty certification and continuing professional development.

Moyamoya syndrome associated with neurofibromatosis Type 1: perioperative and long-term outcome after surgical revascularization.

OBJECT: Children with neurofibromatosis Type 1 (NF1) can present with progressive arteriopathy of the branches of the internal carotid artery consistent with moyamoya syndrome. Clinical symptoms, radiographic evidence of ischemia, and the potential for disease progression may necessitate surgical revascularization to minimize the risk of stroke and progressive neurological deficits. This study aims to evaluate the presentation and surgical outcomes of these patients by reviewing clinical, radiographic, and angiographic data. METHODS: A retrospective review was conducted of clinical and radiographic records of all children with NF1 who were diagnosed with moyamoya syndrome and underwent surgical revascularization between January 1988 and April 2012 at Boston Children's Hospital. RESULTS: During this period, 39 patients (27 female and 12 male, ages 0.2-19.3 years) had both NF1 and moyamoya syndrome, of whom 32 underwent surgical revascularization with pial synangiosis. Of the 32 patients treated by surgical revascularization, 21 (66%) manifested ischemic symptoms and 18 (56%) had radiographic evidence of prior stroke at the time of moyamoya diagnosis. In total, 25 of 32 patients developed neurological symptoms prior to surgical intervention. Only 1 patient presented with hemorrhage. The average age at first surgery was 8.1 years (range 0.5-15.6 years). Perioperative complications in the first 7 days included stroke (n = 2), transient ischemic attack (n = 1), and infection (n = 1). Twenty-two patients had more than 6 months of follow-up, with an average clinical and radiographic postoperative follow-up period of 80.2 months (range 9.4-257.1 months). Of those patients with long-term follow-up, 21 (95%) of 22 demonstrated stable or improved neurological status despite radiographic evidence of moyamoya progression in 48% of patients. CONCLUSIONS: Children with NF1-associated moyamoya syndrome are often diagnosed prior to development of fixed neurological deficits as a consequence of imaging studies obtained for other manifestations of NF1. The clinical, radiographic, and angiographic features in this population are comparable to primary moyamoya disease, with the exception of patients treated with cranial irradiation, who may be at greater risk for both stroke as well as perioperative complications. Despite radiographic evidence of progressive stenosis in 48% of patients, nearly all demonstrated stable or improved neurological status after surgical revascularization. Surgical revascularization for children with NF1 appears safe and is protective against further ischemic and neurological damage, with a 27-fold reduction in stroke rate.

Calvarial defects and skeletal dysplasia in patients with neurofibromatosis Type 1.

OBJECT: Skull defects, including sphenoid dysplasia and calvarial defects, are rare but distinct findings in patients with neurofibromatosis Type 1 (NF1). The underlying pathophysiology is unclear. The goal of this study was to identify the clinical characteristics and natural history of skull defects in patients with NF1. METHODS: An electronic search engine of medical records was used to identify patients with NF1 and bony skull anomalies. All clinical, radiographic, pathology, and operative reports were reviewed. The relationship between bony anomalies and significant clinical associations was evaluated. This study received institutional review board approval. RESULTS: Twenty-one patients were identified. The mean age at NF1 diagnosis was 4.2 years. The mean age at skull defect diagnosis was 8.8 years (9.7 years in the sphenoid wing dysplasia group and 11.9 years in the calvarial defect group). Sphenoid dysplasia was associated with a plexiform neurofibroma or dural ectasia in 73.3% and 80.0% of cases, respectively. Calvarial defects were associated with a plexiform neurofibroma or dural ectasia in 66.7% and 33.3% of patients, respectively. An absence of either an associated neurofibroma or ectasia was not noted in any patient with sphenoid wing dysplasia or 25.0% of those with calvarial defects. In 6 patients, both types of skull defects presented simultaneously. Serial imaging studies were obtained for a mean follow-up time of 7.5 years (range 0.4-20.0 years). Of these patients with serial imaging, radiographic progression was found in 60% of cases of calvarial defects and 56% of cases of sphenoid wing dysplasia. Two patients underwent surgical repair of a skull defect, and both required repeat procedures. CONCLUSIONS: The majority of skull defects in patients with NF1 were associated with an adjacent structural lesion, such as a plexiform neurofibroma or dural ectasia. This findings from this cohort also support the concept of progression in defect size in more than half of the patients. Potential mechanisms by which these secondary lesions contribute to pathogenesis of the bony defect may include changes in the bony microenvironment. A better understanding of the pathophysiology of skull defects will help guide detection, improve treatment and outcome, and may contribute to the understanding of the pathogenesis of bony lesions in NF1.

Smith-Lemli-Opitz syndrome: phenotype, natural history, and epidemiology.

Smith-Lemli-Opitz syndrome (SLOS) is a congenital multiple anomaly/intellectual disability syndrome caused by a deficiency of cholesterol synthesis resulting from a deficiency of 7-dehydrocholesterol (7DHC) reductase encoded by DHCR7. SLOS is inherited in an autosomal recessive pattern. It is characterized by prenatal and postnatal growth retardation, microcephaly, a variable degree of intellectual disability that encompasses normal intelligence to severe intellectual deficiency, and multiple major and minor malformations. External malformations include distinctive facial features, cleft palate, postaxial polydactyly, 2-3 syndactyly of the toes, and underdeveloped external genitalia in males, while internal anomalies may affect every organ system. The clinical spectrum is wide, and rare individuals have been described with normal development and only minor malformations. The clinical diagnosis of SLOS is confirmed by demonstrating an abnormally elevated concentration of the cholesterol precursor, 7DHC, in serum or other tissues, or by the presence of two DHCR7 mutations. The enzymatic deficiency results in decreased cholesterol and increased 7DHC levels, both during embryonic development and after birth. The malformations found in SLOS may result from decreased cholesterol, increased 7DHC or a combination of these two factors. This review discusses the physical and behavioral phenotype of SLOS, the diagnostic approaches, the natural history from the prenatal period to adulthood, and current understanding of the pathophysiology of SLOS.

Deletions of NRXN1 (neurexin-1) predispose to a wide spectrum of developmental disorders.

Research has implicated mutations in the gene for neurexin-1 (NRXN1) in a variety of conditions including autism, schizophrenia, and nicotine dependence. To our knowledge, there have been no published reports describing the breadth of the phenotype associated with mutations in NRXN1. We present a medical record review of subjects with deletions involving exonic sequences of NRXN1. We ascertained cases from 3,540 individuals referred clinically for comparative genomic hybridization testing from March 2007 to January 2009. Twelve subjects were identified with exonic deletions. The phenotype of individuals with NRXN1 deletion is variable and includes autism spectrum disorders, mental retardation, language delays, and hypotonia. There was a statistically significant increase in NRXN1 deletion in our clinical sample compared to control populations described in the literature (P = 8.9 x 10(-7)). Three additional subjects with NRXN1 deletions and autism were identified through the Homozygosity Mapping Collaborative for Autism, and this deletion segregated with the phenotype. Our study indicates that deletions of NRXN1 predispose to a wide spectrum of developmental disorders.

Clinicopathologic study of glioblastoma in children with neurofibromatosis type 1.

BACKGROUND: Neurofibromatosis type 1 (NF1) is characterized by low-grade tumors of the central and peripheral nervous system. There is also an increased risk of developing malignant tumors. Glioblastoma is an uncommon, malignant tumor of children that is even less frequently observed in children with NF1. PROCEDURE: We performed a retrospective review of patients with NF1 and glioblastoma to determine specific clinical and pathologic indicators of overall prognosis. RESULTS: Five patients were identified from the CHB/DFCI database for whom pathologic and imaging studies were available. All pathologic specimens demonstrated vascular proliferation and necrosis. All samples stained positively for p53. Chromogenic in situ hybridization (CISH) for epidermal growth factor receptor (EGFR) copy numbers was increased, PTEN copy numbers were normal and the promoter of the O(6)-methylguanine-DNA methyltransferase (MGMT) gene was unmethylated in the one patient evaluated. In the same time period, there were 56 patients without NF1 diagnosed with glioblastoma who were treated at our institution. Although the small sample size precludes formal statistical analysis, the 2-year survival of patients with NF1 is 60% with median overall survival of 9.25 years compared to non-NF1 patients with a 2-year survival of 25% and median overall survival 1.08 years. CONCLUSIONS: This study provides preliminary evidence that children with NF1 may be at risk for glioblastoma, but that these patients have an increased survival compared to children without NF1. Additional molecular studies will be required to determine if the pathogenesis of these tumors differs from glioblastoma in children without NF1.

Pilot study of a novel computerized task to assess spatial learning in children and adolescents with neurofibromatosis type 1.

Difficulties with visual-spatial learning are frequently observed and often considered to be the hallmark of neurocognitive impairment in neurofibromatosis type 1. The computerized Arena Maze is a virtual environment task that has been developed as a human paradigm to the Morris Water Maze, which is used to evaluate spatial learning in animal models. The authors evaluated this task as a measure of spatial learning in children with neurofibromatosis type 1 compared with their unaffected siblings. Affected children were able to learn the task and navigate the virtual environment; however, they performed more poorly on standard measures of spatial learning and spatial working memory than their siblings. The group with neurofibromatosis type 1 demonstrated decreased proficiency in earlier target trials and had more difficulty in remembering target location. This study demonstrates the potential utility of a novel virtual task to assess spatial learning deficits in children with neurofibromatosis type 1.

Mutations in the gene encoding the calcium-permeable ion channel TRPV4 produce spondylometaphyseal dysplasia, Kozlowski type and metatropic dysplasia.

The spondylometaphyseal dysplasias (SMDs) are a group of short-stature disorders distinguished by abnormalities in the vertebrae and the metaphyses of the tubular bones. SMD Kozlowski type (SMDK) is a well-defined autosomal-dominant SMD characterized by significant scoliosis and mild metaphyseal abnormalities in the pelvis. The vertebrae exhibit platyspondyly and overfaced pedicles similar to autosomal-dominant brachyolmia, which can result from heterozygosity for activating mutations in the gene encoding TRPV4, a calcium-permeable ion channel. Mutation analysis in six out of six patients with SMDK demonstrated heterozygosity for missense mutations in TRPV4, and one mutation, predicting a R594H substitution, was recurrent in four patients. Similar to autosomal-dominant brachyolmia, the mutations altered basal calcium channel activity in vitro. Metatropic dysplasia is another SMD that has been proposed to have both clinical and genetic heterogeneity. Patients with the nonlethal form of metatropic dysplasia present with a progressive scoliosis, widespread metaphyseal involvement of the appendicular skeleton, and carpal ossification delay. Because of some similar radiographic features between SMDK and metatropic dysplasia, TRPV4 was tested as a disease gene for nonlethal metatropic dysplasia. In two sporadic cases, heterozygosity for de novo missense mutations in TRPV4 was found. The findings demonstrate that mutations in TRPV4 produce a phenotypic spectrum of skeletal dysplasias from the mild autosomal-dominant brachyolmia to SMDK to autosomal-dominant metatropic dysplasia, suggesting that these disorders should be grouped into a new bone dysplasia family.

Brainstem lesions in neurofibromatosis type 1.

OBJECTIVE: The presence of multiple, nonenhancing areas of hyperintensity without mass effect are well recognized on magnetic resonance imaging scans in children with neurofibromatosis type 1 (NF1). Focal regions of brainstem enlargement with or without contrast enhancement are considerably less frequent; the neuroimaging characteristics and natural history of these lesions in patients with NF1 are poorly understood. The objective of this study was to define the clinical and radiographic course of brainstem lesions in children with NF1. METHODS: We retrospectively reviewed the neuroimaging studies of all patients with NF1 between 2000 and 2006 to determine the prevalence of brainstem lesions. Clinical features, previous treatments, and neuroimaging studies of the brainstem lesions were evaluated. RESULTS: A total of 125 patients underwent neuroimaging studies; of these, 23 patients (18.4%) showed evidence of brainstem mass lesions and had follow-up magnetic resonance imaging scans available for review. Eight patients in this cohort received additional treatment with surgery, radiation, or chemotherapy. Of these, two patients underwent surgery for lesions distant from the brainstem, and six patients underwent treatment that included the brainstem and were thought to potentially affect the natural history or progression of the brainstem abnormality. With a median follow-up period of 67 months for untreated patients (17 out of 23) and 102 months for patients who received therapy (six out of 23), only one previously untreated patient experienced radiographic and clinical progression. All patients but one remain alive. CONCLUSION: We conclude that brainstem lesions in NF1 are prevalent and behave in a biologically indolent nature; most do not require therapeutic intervention.

Diagnostic utility of array-based comparative genomic hybridization in a clinical setting.

Array-based comparative genomic hybridization is a recently introduced technique for the detection of submicroscopic genomic imbalances (deletions or duplications) across the entire genome. To assess the potential utility of a widely available array-based comparative genomic hybridization platform that targets specific, clinically relevant, loci across the genome for cytogenetic diagnosis in a clinical setting, we reviewed the medical records of all 373 patients at Children's Hospital Boston who had normal chromosomal analysis and were tested with this targeted array-based comparative genomic hybridization over a 1-year period from November 1, 2004 to October 31, 2005. These patients were tested because of a suspicion of chromosomal abnormalities based on their clinical presentation. Thirty-six patients (9.7%) had abnormal array-based comparative genomic hybridization results. Twenty patients (5.4%) had potentially pathogenetic genomic imbalances and 16 patients (4.3%) had copy number variations that are not believed to be pathogenetic. Thirteen of 234 patients (5.6%) with mental retardation/global developmental delay, 10/114 patients (8.8%) with facial dysmorphism, 5/58 patients (8.6%) with multiple congenital anomalies, and 4/35 patients (11.4%) with both facial dysmorphism and multiple congenital anomalies had potentially pathogenetic genomic imbalances. Targeted array-based comparative genomic hybridization is a clinically available test that is useful in the evaluation of patients suspected of having chromosomal disorders. However, it is best used as an adjunct to chromosomal analysis when a clear genetic diagnosis is unavailable.

The spectrum of vascular anomalies in patients with PTEN mutations: implications for diagnosis and management.

BACKGROUND: Mutations in the PTEN gene cause two disorders that predispose to cancer, Bannayan-Riley-Ruvalcaba and Cowden syndromes. Some patients with a PTEN mutation have only macrocephaly and autism, but they may still be at risk for neoplasms. Vascular anomalies occur in patients with a PTEN mutation, but they have not been systematically studied or precisely defined. METHOD: We analysed the clinical and radiological features of the vascular anomalies in 26 patients with PTEN mutations who were either seen or had their medical records reviewed at Children's Hospital Boston. RESULTS: All 23 patients who had their head circumference measured were macrocephalic, and all 13 male patients who were fully examined had penile freckling. Vascular anomalies were found in 14/26 (54%) of patients: 8/14 (57%) had multiple lesions and 11/13 (85%) who had cross-sectional imaging had intramuscular vascular lesions. Radiographic studies showed that 12/14 (86%) were fast-flow vascular anomalies, and angiography typically showed focal segmental dilatation of draining veins. Excessive ectopic fat in the vascular anomalies was present in 11/12 (92%) of patients on CT or MRI. Intracranial developmental venous anomalies (DVAs) were found in 8/9 (89%) of patients who had brain MRI with contrast. CONCLUSIONS: Vascular anomalies in patients with a PTEN mutation are typically multifocal intramuscular combinations of fast-flow channels and ectopic fat. Cerebral DVAs are very common. PTEN mutational analysis should be considered for all macrocephalic patients with fast-flow vascular anomalies or multiple intracranial DVAs.

Identifying Smith-Lemli-Opitz syndrome in conjunction with prenatal screening for Down syndrome.

BACKGROUND: Smith-Lemli-Opitz syndrome (SLOS) is a rare hereditary disorder of cholesterol metabolism. We examine the feasibility of identifying SLOS as a part of a routine prenatal screening and evaluate diagnostic testing in maternal urine (or serum), in addition to amniotic fluid. METHODS: Our SLOS risk algorithm utilized three Down syndrome screening markers (estimated 62% detection rate; 0.3% screen-positive rate). Fifteen North American prenatal screening programs implemented this algorithm. RESULTS: SLOS risk was assigned to 1 079 301 pregnancies; 3083 were screen-positive (0.29%). Explanations were found for 1174, including 914 existing fetal deaths. Among the remaining pregnancies, 739 were screen-positive only for SLOS; 1170 were also screen-positive for other fetal disorders. Five of six SLOS pregnancies (83%) were screen-positive. All six had sonographic findings, were biochemically confirmed, and were terminated. Maternal urine steroid measurements were confirmatory in four cases tested. Second-trimester prevalence among Caucasians was 1 in 101 000 (1 in 130 000 overall; no cases in other racial groups). Among 739 pregnancies screen-positive only for SLOS, two cases were identified; another 69 had major fetal abnormalities. CONCLUSIONS: Although SLOS occurred less often than previously reported, many other major abnormalities were detected. Implementing the algorithm as an adjunct to Down syndrome screening may be feasible.

Smith-Lemli-Opitz syndrome in trisomy 13: how does the mix work?

BACKGROUND: Trisomy 13 and Smith-Lemli-Opitz syndrome (SLOS) are both well-recognized multiple congenital anomaly/mental retardation syndromes. CASE: In this report we describe a male newborn with trisomy 13 who also has features of SLOS, such as 2/3 toe syndactyly and a shawl-like scrotum. Biochemical analysis was consistent with SLOS, and limited molecular analysis revealed 1 mutation in the DHCR7 gene. CONCLUSIONS: The challenges in establishing the diagnosis of SLOS in this patient are presented and the unique coexistence of the 2 major malformation syndromes is discussed. Given the overlapping phenotype of the 2 syndromes, our report should encourage further research on cholesterol biosynthesis in patients with trisomy 13.

Fryns syndrome with Hirschsprung disease: support for possible neural crest involvement.

Fryns syndrome is an autosomal recessive multiple congenital anomaly/mental retardation syndrome characterized by coarse face, distal limb hypoplasia, and diaphragmatic anomalies. We describe a newborn girl with Fryns syndrome and Hirschsprung disease, an association that has been reported in five previous cases. These patients support the hypothesis that the neural crest plays a role in the pathogenesis of Fryns syndrome. Clinically asymptomatic or subtle anomalies that are in the spectrum of neural crest maldevelopment should be sought in all patients with Fryns syndrome including stillbirths, neonatal deaths, as well as long-term survivors. We suspect that the clinical observation about Hirschsprung disease and Fryns syndrome may provide insight into its molecular mechanisms and candidate genes.

The biology and management of laryngeal neurofibroma.

OBJECTIVES: To review the presentation of laryngeal neurofibroma, including its association with neurofibromatosis types 1 and 2, and present guidelines for its management. DESIGN: Retrospective study. PATIENTS: Five pediatric patients with laryngeal neurofibroma, 4 girls (80%) and 1 boy (20%), were treated at a tertiary pediatric medical center from 1973 through 2003. Recorded data included age at initial presentation, sex, symptoms, significant medical and family history, preoperative evaluation, location of the tumor, surgical procedure, complications, outcome, and recurrence. RESULTS: The 5 patients presented with stridor and cafe-au-lait spots at or shortly after birth. All patients were diagnosed as having neurofibromatosis type 1 by the established criteria. Studies evaluating the disease processes included plain radiography, computerized tomography, magnetic resonance imaging, barium swallow, and laryngoscopy and bronchoscopy under anesthesia. Pathologic examination of biopsy specimens from all patients showed neurofibromas with plexiform and/or diffuse features. Treatments included tracheotomy (n = 4), carbon dioxide laser excision (n = 4), modified neck dissection (n = 3), partial pharyngectomy (n = 1), supraglottic laryngectomy (n = 1), and endoscopic hemilaryngectomy (n = 1). Three patients were successfully decannulated. Follow-up ranged from 1 to 15 years. One patient was lost to follow-up. No evidence of malignant degeneration was noted. CONCLUSIONS: Neurofibroma of the larynx is a rare condition that should be considered in the differential diagnosis of children with a submucosal laryngeal mass. In our series, all patients had associated neurofibromatosis type 1. Complete surgical excision is the treatment of choice in cases of localized small lesions. To prevent debilitating outcomes due to aggressive surgery, minimally invasive procedures (partial excision via endoscopic approach) may be preferable for larger lesions that infiltrate the surrounding vital structures. Long-term follow up of these patients is essential owing to the possibility of malignant transformation.