Neurosarcoidosis: Phenotypes, Approach to Diagnosis and Treatment.

PURPOSE OF REVIEW: The aim of this review is to provide an update of clinical presentation, diagnosis, differential diagnoses, and treatment according to recent evidence. RECENT FINDINGS: Neurosarcoidosis remains a diagnosis of exclusion, with infectious and malignant etiologies recognized as important mimickers. Corticosteroids remain as first-line therapy. In recent years, however, studies have demonstrated the effectiveness of anti-tumor necrosis factor (anti-TNF) therapy in the treatment of neurosarcoidosis, leading to improved outcomes. Neurosarcoidosis is a granulomatous disease with protean manifestations that may affect any part of the central and peripheral nervous system. It has many mimickers, and potentially devastating complications necessitating long-term follow-up. Early initiation of treatment, particularly with anti-TNF therapy, may lead to better outcomes and fewer relapses. There is an unmet need for randomized controlled trials that provide robust data to guide therapy and the long-term management of neurosarcoidosis patients.

Peering Into Peer Review: AJR Neuroradiology Reviewers Discuss Their Approaches to Assessing a Manuscript.

OBJECTIVE. This article provides comments from a small group of highly qualified reviewers of the American Journal of Roentgenology (AJR) regarding their approach to assessing manuscripts. The objective is to educate authors about the issues to which reviewers particularly attend and about errors that will decrease the likelihood of publication. CONCLUSION. By following the advice provided in this article, authors should be able to compose better manuscripts and reviewers should be able to generate better reviews.

Meet in the middle: a technique for resecting nasocranial dermoids-technical note and review of the literature.

INTRODUCTION: Nasal dermoids with intracranial extension are benign lesions that can have life-threatening consequences, as a nasal punctum may serve as a portal of entry for infection into the central nervous system. The surgical management of these lesions can be challenging, as the extracranial and intracranial cysts and sinus tract must be resected to prevent recurrence, and the surgery must be carried out with an acceptable esthetic result. TECHNIQUE: The authors present a technique for the resection of nasocranial dermoids that eliminates the need to remove and replace the frontonasal segment. Working through a small frontal craniotomy enables the surgeon to drill out the sinus tract through the foramen cecum and inferiorly into the nose. This exposure eliminates the need to enter the frontal sinus, if it is present. CONCLUSION: The extracranial punctum and tract are resected from below in a minimally invasive fashion that permits removal of the lesion without a disfiguring scar.

Preschool Language Outcomes following Perinatal Hypoxic-Ischemic Encephalopathy in the Age of Therapeutic Hypothermia.

Early studies following perinatal hypoxic-ischemic encephalopathy (HIE) suggested expressive language deficits and academic difficulties, but there is only limited detailed study of language development in this population since the widespread adoption of therapeutic hypothermia (TH). Expressive and receptive language testing was performed as part of a larger battery with 45 children with a mean age of 26 months following perinatal HIE treated with TH. Overall cohort outcomes as well as the effects of gender, estimated household income, initial pH and base excess, and pattern of injury on neonatal brain MRI were assessed. The cohort overall demonstrated expressive language subscore, visual-reception subscore, and early learning composite scores significantly below test norms, with relative sparing of receptive language subscores. Poorer expressive language manifested as decreased vocabulary size and shorter utterances. Expressive language subscores showed a significant gender effect, and estimated socioeconomic status showed a significant effect on both receptive and expressive language subscores. Initial blood gas markers and modified Sarnat scoring did not show a significant effect on language subscores. Binarized MRI abnormality predicted a significant effect on both receptive and expressive language subscores; the presence of specific cortical/subcortical abnormalities predicted receptive language deficits. Overall, the language development profile of children following HIE in the era of hypothermia shows a relative strength in receptive language. Gender and socioeconomic status predominantly predict expressive language deficits; abnormalities detectable on MRI predominantly predict receptive language deficits.

Stereotactic laser amygdalohippocampotomy for mesial temporal lobe epilepsy.

OBJECTIVE: To evaluate the outcomes 1 year and longer following stereotactic laser amygdalohippocampotomy for mesial temporal lobe epilepsy in a large series of patients treated over a 5-year period since introduction of this novel technique. METHODS: Surgical outcomes of a consecutive series of 58 patients with mesial temporal lobe epilepsy who underwent the surgery at our institution with at least 12 months of follow-up were retrospectively evaluated. A subgroup analysis was performed comparing patients with and without mesial temporal sclerosis. RESULTS: One year following stereotactic laser amygdalohippocampotomy, 53.4% (95% confidence interval [CI] = 40.8-65.7%) of all patients were free of disabling seizures (Engel I). Three of 9 patients became seizure-free following repeat ablation. Subgroup analysis showed that 60.5% (95% CI = 45.6-73.7%) of patients with mesial temporal sclerosis were free of disabling seizures as compared to 33.3% (95% CI = 15.0-58.5%) of patients without mesial temporal sclerosis. Quality of Life in Epilepsy-31 scores significantly improved at the group level, few procedure-related complications were observed, and verbal memory outcome was better than historical open resection data. INTERPRETATION: In an unselected consecutive series of patients, stereotactic laser amygdalohippocampotomy yielded seizure-free rates for patients with mesial temporal lobe epilepsy lower than, but comparable to, the outcomes typically associated with open temporal lobe surgery. Analogous to results from open surgery, patients without mesial temporal sclerosis fared less well. This novel procedure is an effective minimally invasive alternative to resective surgery. In the minority of patients not free of disabling seizures, laser ablation presents no barrier to additional open surgery. Ann Neurol 2018;83:575-587.

Congenital Oral Masses: An Anatomic Approach to Diagnosis.

Although congenital oral masses are rare, they are readily detectable during fetal US screening. Most congenital oral masses are benign, but some may cause mechanical airway obstruction, resulting in poor outcomes at delivery. The radiologist's ability to describe these abnormalities and their physiologic sequelae accurately can have a substantial effect on perinatal treatment. Furthermore, despite being rare, congenital oral lesions encountered at screening and at follow up fetal MRI provide the opportunity to make a specific diagnosis by following a simple anatomic approach. This article describes an anatomic algorithm as the framework for accurate diagnosis of congenital oral lesions. The imaging appearance of the most common congenital oral cavity neoplasms is outlined, including vascular anomalies, epulides, choristomas, congenital lingual thyroid anomalies, lingual hamartomas, and epignathi, and other conditions that mimic these at US. Also reviewed are perinatal management of masses that affect the fetal airway and the imaging features key to optimizing delivery outcomes. Online supplemental material is available for this article. ©RSNA, 2019.

Cerebral Diffusivity Changes in Fetuses with Chiari II Malformation.

OBJECTIVES: Chiari II malformation is a congenital abnormality characterized by a small posterior fossa with downward displacement of the hindbrain into the foramen magnum. Diffusion-weighted imaging (DWI) can be used to quantitatively characterize brain injury and physiological maturation. We aim to evaluate DWI parameters of the infra- and supratentorial brain in fetuses with Chiari II malformation. METHODS: MRI and US studies of 26 fetuses with Chiari II malformation and 15 controls were evaluated for the presence/severity of hydrocephalus, myelomeningocele level, and brain apparent diffusion coefficient (ADC) values. Cerebral flow impedance parameters (resistance and pulsatile indexes, resistance index [RI], and pulsatility index [PI] respectively) from concurrently preformed fetal US were also evaluated. RESULTS: Of the Chiari II group, 16 fetuses had hydrocephalus. There was increasing severity of lateral ventriculomegaly in the high compared to low spinal dysraphism subgroups. There were significant lower ADC values in the frontal (p = 0.01) and temporal lobes (p = 0.05) in Chiari II group compared with normal, regardless of the presence or severity of hydrocephalus. Fetuses with Chiari II showed significantly lower RI and PI values. CONCLUSIONS: Abnormal ADC values indicate supratentorial microstructural changes in fetuses with Chiari II malformation. Further investigation of the role of diffusion imaging metrics in evaluating abnormal brain development, parenchymal damage and efficacy of fetal surgery is needed.

The Child With Macrocephaly: Differential Diagnosis and Neuroimaging Findings.

OBJECTIVE: The purpose of this article is to offer a systematic approach to the imaging of children with macrocephaly and to illustrate key neuroimaging features of common and rare but important disorders. CONCLUSION: Macrocephaly is a common clinical finding in children. Increased volume of one of the intracranial compartments can enlarge the head either prenatally or postnatally while the cranial sutures are open. Imaging plays a central role in establishing a diagnosis and guiding management.

Neuroimaging Findings of Organic Acidemias and Aminoacidopathies.

Although individual cases of inherited metabolic disorders are rare, overall they account for a substantial number of disorders affecting the central nervous system. Organic acidemias and aminoacidopathies include a variety of inborn errors of metabolism that are caused by defects in the intermediary metabolic pathways of carbohydrates, amino acids, and fatty acid oxidation. These defects can lead to the abnormal accumulation of organic acids and amino acids in multiple organs, including the brain. Early diagnosis is mandatory to initiate therapy and prevent permanent long-term neurologic impairments or death. Neuroimaging findings can be nonspecific, and metabolism- and genetics-based laboratory investigations are needed to confirm the diagnosis. However, neuroimaging has a key role in guiding the diagnostic workup. The findings at conventional and advanced magnetic resonance imaging may suggest the correct diagnosis, help narrow the differential diagnosis, and consequently facilitate early initiation of targeted metabolism- and genetics-based laboratory investigations and treatment. Neuroimaging may be especially helpful for distinguishing organic acidemias and aminoacidopathies from other more common diseases with similar manifestations, such as hypoxic-ischemic injury and neonatal sepsis. Therefore, it is important that radiologists, neuroradiologists, pediatric neuroradiologists, and clinicians are familiar with the neuroimaging findings of organic acidemias and aminoacidopathies. ©RSNA, 2018.

Thalamic and dentate nucleus abnormalities in the brain of children with Gaucher disease.

Gaucher disease (GD) represents the most common lysosomal storage defect. It is classified into three phenotypes: type 1 non-neuronopathic, type 2 acute neuronopathic, and type 3 subacute/chronic neuronopathic. Although children affected by GD may present with a broad spectrum of neurological signs, brain magnetic resonance imaging (MRI) findings are usually normal or non-specific. We report three cases of GD with previously undescribed brain MRI changes mainly affecting the thalami and/or the dentate nuclei. We discuss the possible etiopathogenesis of these abnormalities. Correlation between brain MRI abnormalities, neurological symptoms, and treatment efficacy is still unclear.

Dysplasia and overgrowth: magnetic resonance imaging of pediatric brain abnormalities secondary to alterations in the mechanistic target of rapamycin pathway.

The current classification of malformations of cortical development is based on the type of disrupted embryological process (cell proliferation, migration, or cortical organization/post-migrational development) and the resulting morphological anomalous pattern of findings. An ideal classification would include knowledge of biological pathways. It has recently been demonstrated that alterations affecting the mechanistic target of rapamycin (mTOR) signaling pathway result in diverse abnormalities such as dysplastic megalencephaly, hemimegalencephaly, ganglioglioma, dysplastic cerebellar gangliocytoma, focal cortical dysplasia type IIb, and brain lesions associated with tuberous sclerosis. We review the neuroimaging findings in brain abnormalities related to alterations in the mTOR pathway, following the emerging trend from morphology towards genetics in the classification of malformations of cortical development. This approach improves the understanding of anomalous brain development and allows precise diagnosis and potentially targeted therapies that may regulate mTOR pathway function.

Bottom-of-sulcus focal cortical dysplasia presenting as epilepsia partialis continua multimodality characterization including 7T MRI.

INTRODUCTION: Bottom-of-sulcus focal cortical dysplasias are an under recognized, surgically treatable cause of focal epilepsy. Resection can dramatically reduce the seizure burden for children with refractory epilepsy, or eliminate seizures altogether. MATERIAL AND METHODS: We report the case and present the results of multimodality evaluation of a 15-year-old young man who presented with long-standing partial epilepsy affecting his right leg, which over the years became refractory to therapy. RESULTS: High-resolution 3T MRI images acquired as a dedicated epilepsyprotocol were initially interpreted as unremarkable. On further review by an experienced specialist aware of clinical and electroencephalographic findings, a subtle focal cortical dysplasia was identified at the bottom of a sulcus near the medial aspect of the left precentral gyrus. After confirmation of the extent of the lesion with PET and ultra-high field 7T MRI, the patient underwent cortical mapping and focal resection and remains free of seizures. COCLUSIONS: This case emphasizes the need for a multidisciplinary approach to the evaluation of refractory focal epilepsy in children and highlights the potential role of ultra-high field 7T MRI in identifying the often subtle causative anatomic abnormalities.

Concurrent myeloid sarcoma, atypical teratoid/rhabdoid tumor, and hypereosinophilia in an infant with a germline SMARCB1 mutation.

We report a 1-year-old female child presenting with hypereosinophilia who was found to have concurrent myeloid sarcoma and a central nervous system (CNS) atypical teratoid/rhabdoid tumor (AT/RT). She was later found to have a germline mutation in SMARCB1. Concurrent hematologic malignancy and CNS AT/RT have not previously been described in the context of a SMARCB1 loss-of-function germline mutation.

Novel Contrast-Enhanced Ultrasound Evaluation in Neonatal Hypoxic Ischemic Injury: Clinical Application and Future Directions.

Sensitive, specific, and safe bedside evaluation of brain perfusion is key to the early diagnosis, treatment, and improved survival of neonates with hypoxic ischemic injury. Contrast-enhanced ultrasound (US) imaging is a novel imaging technique in which intravenously injected gas-filled microbubbles generate enhanced US echoes from an acoustic impedance mismatch. This article describes contrast-enhanced US imaging in 2 neonates with hypoxic ischemic injury and future directions on developing quantitative contrast-enhanced US techniques for improved characterization of perfusion abnormalities. The importance of studying the temporal evolution of brain perfusion in neonatal hypoxic ischemic injury is also highlighted.

Imaging of Herpesvirus Infections of the CNS.

OBJECTIVE: Herpesviridae are a family of DNA viruses remarkable for their ability to both promote acute infection and enter a latent phase with potential of reactivation. Herpes infections are ubiquitous throughout the human life span, regardless of the degree of immunocompetence. CONCLUSION: We review the virology and clinical manifestations of each herpesvirus, with emphasis on recent advances in knowledge and characteristic neuroimaging findings important for diagnosis and appropriate clinical management.

Magnetic Resonance Imaging of Temporomandibular Joints of Children.

PURPOSE: To identify magnetic resonance imaging (MRI) findings of temporomandibular joints (TMJs) in healthy children. MATERIALS AND METHODS: This was a retrospective study of children younger than 18 years undergoing MRI of the head for non-autoimmune indications at Children's Healthcare of Atlanta (Atlanta, GA). Patients with congenital or acquired conditions associated with potential TMJ pathology were excluded. Medical records and MRIs were reviewed to document demographic data. Three neuroradiologists independently recorded specific predetermined MRI findings of the TMJ. The outcome variable was the presence or absence of TMJ findings at MRI. Descriptive and bivariate statistics were used to identify associations (significant at P ≤ .05). RESULTS: Eighty-seven patients (54 boys, 33 girls; mean age, 11.2 yr) met the inclusion criteria. Seventy percent of TMJs had condylar enhancement, 64% of joints had glenoid marginal synovial enhancement, 56% had condylar margin synovial enhancement, and 19% had condylar T1 hyperintense signal. There were no joints with condylar erosion, condylar volume loss, or effusion. Findings of normal marrow development were decreased condylar enhancement and greater condylar T1 signal with increased age. CONCLUSION: This study found a greater than 60% prevalence of synovial enhancement in healthy children. In a healthy child, MRI findings of TMJ synovial enhancement should be carefully correlated with a clinical evaluation.

ACR Appropriateness Criteria® Dizziness and Ataxia: 2023 Update.

Diagnostic evaluation of a patient with dizziness or vertigo is complicated by a lack of standardized nomenclature, significant overlap in symptom descriptions, and the subjective nature of the patient's symptoms. Although dizziness is an imprecise term often used by patients to describe a feeling of being off-balance, in many cases dizziness can be subcategorized based on symptomatology as vertigo (false sense of motion or spinning), disequilibrium (imbalance with gait instability), presyncope (nearly fainting or blacking out), or lightheadedness (nonspecific). As such, current diagnostic paradigms focus on timing, triggers, and associated symptoms rather than subjective descriptions of dizziness type. Regardless, these factors complicate the selection of appropriate diagnostic imaging in patients presenting with dizziness or vertigo. This document serves to aid providers in this selection by using a framework of definable clinical variants. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.