Meningoceles in the cranium occur when an osseous defect in the skull base allows for the protrusion or herniation of the meninges into the extracranial compartment. Meningoceles vary in severity and may be asymptomatic or complicated by meningitis, brain abscess, pneumocephalus, or cerebrospinal fluid leak. Meningoceles can be congenital, traumatic, iatrogenic (such as in sinus or craniofacial surgery), spontaneous (due to increased intracranial pressure) or idiopathic. The most common sites of meningoceles in the skull base are the cribriform plate, sphenoid sinus, perisellar region, and tegmen tympani or mastoideum. Accurate and timely detection is essential for avoiding complications of meningoceles. Localization of the site of the meningoceles and assessment of their size and composition is accomplished through a variety of imaging techniques, such as with CT or MR myelography. Surgical repair of meningoceles may be accomplished through both open and endoscopic approaches. A 2-year-old male patient with a past medical history of febrile seizures and postinfectious hydrocephalus requiring ventriculoperitoneal shunt placement and multiple shunt revisions initially presented with emesis and lethargy concerning for shunt malfunction. MRI showed a fluid-signal intensity located adjacent to the petrous portion of the right temporal bone, extending caudally to the right upper neck, which raised concern for cerebrospinal fluid (CSF) leak. Lumbar puncture was notable for an elevated CSF opening pressure of 40 cm H2O. CT myelogram confirmed a small (7mm) meningocele protruding through an osseous defect in the right jugular foramen, which completely opacified with intrathecally-injected contrast. Delayed images obtained following two hours further demonstrated subtle contrast enhancement surrounding the right jugular vein in the upper neck, raising concern for a slow CSF leak from the meningocele. Due to elevated CSF opening pressure, shunt malfunction was theorized to be the cause of the patient’s emesis and lethargy. Shunt was revised and patient was subsequently able to be discharged. Repeat follow up imaging demonstrated stabile size of patient’s meningocele. Due to small size, and resolution of patient’s symptoms following shunt revision, patient’s meningocele will be followed with recurrent MR imaging. Read More

Meeting name: SPR 2025 Annual Meeting , 2025

Authors: Kuehne Alexander, Chen Danling, Hwang James, Ehrlich Lauren, Lisse Sean

Keywords: CSF, MRI, Neuroradiology

Grisel syndrome is a rare, acquired, non-traumatic rotatory subluxation of the atlantoaxial joint that typically occurs in the childhood period. It arises from cervical ligamentous laxity and instability following an infectious or inflammatory process in the head and neck, such as from an upper respiratory tract infection or from otolaryngolic surgery. The proposed pathophysiology of the disorder is infective septic emboli spreading from the posterosuperior pharynx to the upper cervical region via the pharyngovertebral vein, which connects the posterior nasopharyngeal veins with the periodontoid plexus. Patients present with neck pain, stiffness, and torticollis. Four types of atlantoaxial subluxation have been described using the Fielding classification system: type 1: rotation of the atlas on the axis without anterior displacement; type 2: atlantoaxial subluxation with 3-5 mm anterior displacement; type 3: atlantoaxial subluxation with greater than 5 mm anterior displacement; and type 4: atlantoaxial subluxation with posterior displacement. Permanent deformation and severe neurologic sequelae may result in the absence of timely intervention. A 11-year-old male patient presented to the hospital with a two-week-history of severe postoperative neck pain, stiffness, headache, jaw pain, trismus, and anorexia after undergoing elective outpatient adenotonsillectomy. Contrast-enhanced CT imaging of the neck demonstrated a 4.0 cm rim-enhancing collection in the right C1-C2 prevertebral space extending into the right atlantoccipitalatlantooccipital and atlantoaxial joints consistent with prevertebral abscess formation. Additional imaging findings included atlantoaxial rotation and anterior subluxation of C1 on C2 up to 9 mm. MR of the cervical spine demonstrated evidence of prevertebral space infection, osteomyelitis of C1 and the C2 odontoid process, and rotatory and anterior atlantoaxial subluxation. Findings met criteria for Fielding type III rotatory atlantoaxial dislocation and Grisel’s syndrome. While the patient initially received conservative treatment with an extended intravenous antibiotics course of intravenous antibiotics and application of a hard collar, follow-up imaging demonstrated worsening infection, increased atlantoaxial subluxation, and central canal stenosis at C1-C2. He consequently underwent neurosurgical decompression and occipital-cervical fusion with full recovery of neurologic function. Read More

Meeting name: SPR 2025 Annual Meeting , 2025

Authors: Chen Danling, Kuehne Alexander, Hwang James, Tu Long, Ehrlich Lauren, Lisse Sean

Keywords: Infection, Cervical Spine, Atlantodental

Pallister-Hall syndrome is an exceedingly rare genetic disorder characterized by multiorgan anomalies encompassing hypothalamic hamartoma, postaxial polydactyly, bifid epiglottis, renal malformations and imperforate anus. The syndrome arises from a mutation in the GLI3 gene, which can be inherited in autosomal dominant fashion or occur de novo. A significant manifestation of Pallister-Hall syndrome is the presence of a hypothalamic hamartoma, a benign tumor of the hypothalamus. Although benign, these lesions can cause severe endocrine dysfunction by interfering with the hypothalamic-pituitary axis. Abnormal neural or glial cell migration in the tuber cinereum of the hypothalamus leads to abnormal expansion of the hypothalamus, manifesting in a spectrum of pituitary dysfunction ranging from pituitary displacement to severe pan-hypopituitarism. A well-established feature of the hypothalamic hamartomas associated with Pallister-Hall syndrome is the incidence of gelastic seizures (so-called “laughing” seizures), characterized by episodes of involuntary laughing. A male neonate was born with polydactyly, bifid epiglottis, cryptorchidism, and Hirschsprung’s disease. The patient was additionally found to have right sided vesicouteral reflux requiring extravesical ureteral reimplantation. Genetic analysis revealed a mutation in the GLI3 gene, compatible with Pallister-Hall syndrome. Once diagnosed, the patient underwent contrast-enhanced MR imaging of the brain which demonstrated a large lobulated 2.6 x 2.0 cm suprasellar mass with encroachment posteriorly upon the midbrain and associated superior displacement of the third ventricle. The lesion showed low-grade enhancement following gadolinium contrast administration, displayed no significant abnormality on diffusion-weighted or susceptibility weighted imaging, and was isodense to brain tissue on all sequences. Serial follow-up MRIs demonstrated minimal increase in size of the non-enhancing suprasellar mass. Findings were suggestive of hypothalamic hamartoma, in keeping with the classical presentation of Pallister-Hall syndrome. Read More

Meeting name: SPR 2025 Annual Meeting , 2025

Authors: Chen Danling, Kuehne Alexander, Hwang James, Benyakoub Amine, Ehrlich Lauren, Lisse Sean

Keywords: Pituitary Abnormalities, Genetics, Genitourinary

Parechovirus infection is a recognized cause of childhood meningoencephalitis with distinctive neuroimaging findings. Human parechovirus (HPeV) is a single-RNA virus from the Picornaviridae viral family transmitted through respiratory or gastrointestinal contact. While the clinical presentation of parechovirus infection usually manifests as mild, self-limiting symptoms, in rare cases, the virus may infect the central nervous system and result in seizures, encephalopathy, and permanent neurologic disability. Pediatric patients younger than two years of age are at greatest risk for central nervous system (CNS) infection. CNS viral infection may be confirmed by lumbar puncture. Typical imaging features of parechovirus encephalitis on brain MR imaging include a diffuse pattern of restricted diffusion involving the subcortical and deep periventricular white matter, predominantly within the frontoparietal region, with additional involvement of the corpus callosum and the bilateral thalami. The differential diagnosis of similar radiologic presentations includes other causes of viral encephalitides (such as rotavirus, chikingunya, and HSV), hypoxic-ischemic encephalopathy, leukodystrophy, and rare genetic metabolic disorders. A two-week-old male patient without significant past medical history presented to the pediatrician with irritability and increased work of breathing. Within a day, the patient developed worsening tachypnea, increased grunting, pallor, lethargy, and exanthem of the chest and neck. The patient presented to the hospital and was intubated for respiratory distress. Continuous electroencephalography recorded during inpatient admission was notable for abnormal ictal burden consistent with status epilepticus. Brain MR imaging was obtained, and demonstrated the characteristic imaging findings of parechovirus infection of diffuse abnormal restricted diffusion throughout the bilateral subcortical and periventricular white matter, corpus callosum, and thalami, with sparing of the cortex. HPeV RNA was positive in PCR assays of cerebrospinal fluid, serum, and stool. Patient received 2 doses of intravenous immunoglobulin. Unfortunately, there is no current further treatment for parechovirus infection and our patient ended up succumbing to the disease. We hope that this case presentation highlights the unique imaging feature characteristics of parechovirus and can help include this rare infection on the differential for pediatric radiologists moving forward. Read More

Meeting name: SPR 2025 Annual Meeting , 2025

Authors: Kuehne Alexander, Chen Danling, Hwang James, Tu Long, Ehrlich Lauren, Lisse Sean

Keywords: Meningitis, Infection, Neuroradiology

Filamin A (FLNA) is a widely expressed X-linked dominant gene that encodes Filamin A, a protein that crosslinks actin filaments and plays a crucial role in the structure of the cell cytoskeleton. With such a broad role, FLNA mutations are especially consequential and can result in cardiovascular malformations, intellectual disability, skeletal dysplasia, and neuronal migration abnormalities. Additionally, recent literature has linked FLNA mutation to pediatric-onset interstitial lung disease. A three-month-old female with a history of atrial septal defect, patent ductus arteriosus, pulmonary valve dysplasia, micrognathia, and recent hospitalization for parainfluenza infection causing respiratory failure presented to the emergency department with worsening hypoxemia and respiratory distress. Initial chest radiograph demonstrated an interval increase in bilateral patchy opacifications suggestive of worsening multifocal infection. The patient was subsequently admitted. The patient’s clinical status failed to improve after multiple days of admission. A non-contrast CT study of the chest revealed multiple regions of air trapping, atelectasis, coarsened interstitial markings, and diffuse septal thickening, differential diagnosis included interstitial lung disease versus congenital alveolar abnormality. Of note, MR imaging of the brain obtained showed diffuse nodularity along the subependymal lining of the lateral ventricles and temporal horns, compatible with gray matter heterotopia. This prompted genetic testing which revealed Filamin A deficiency. Filamin A mutation typically presents radiographically with hyperinflation of the lungs with scattered atelectasis, which can be complicated by concomitant pneumonia. This appearance can mimic pulmonary emphysema and bronchopulmonary dysplasia. Cardiac anomalies are a common manifestation of the mutation; notably, our patient had a history of a dysplastic pulmonary valve, ASD and PDA. CT imaging patterns vary and can present as a combination of cystic and diffuse ground-glass changes, hyperinflation, and emphysema. After extensive consultation, our patient transitioned to palliative care and ultimately passed away at 5 months of age. Maintaining a high index of suspicion for this rare but important entity is crucial to accurately diagnosing this inherited mutation, treating affected patients appropriately, and providing patients and their families with essential information regarding prognosis and inheritance patterns. Read More

Meeting name: SPR 2025 Annual Meeting , 2025

Authors: Hwang James, Chen Danling, Kuehne Alexander, Benyakoub Amine, Tu Long, Lisse Sean, Ehrlich Lauren

Keywords: Interstitial Lung Disease, Genetics, Chest Computed Tomography (CT)