Reyna De La Garza Karla,  Salinas Puente Estefany,  Mercado Flores Mariana,  Rodríguez Garza Claudia,  Maya Garcia Haziel,  Montemayor Martinez Alberto

Final Pr. ID: Poster #: CR-030

Encephalitis is a rare neurological disease which a viral infection or an autoinmune disorder can cause. Regardless of the etiology, the presentation is widely varied with symptoms stemming from headaches to hallucinations to cardiac dysrhythmias. A diagnosis is most commonly reached through an elimination process, due to the vague nature of the symptoms.
The purpose of this case is to showcase a patient in which the classical imaging findings of an autoimmune encephailits were absent, in favor of an atypical presentation.
A 19-year-old female began with an episode of auditory hallucinations accompanied by a headache, all resolved without treatment. A week later she developed irrational fear as well as nausea and seizures. Visual hallucinations followed, with an altered state of consciousness, memory loss, and a fever of over 100°F. She was admitted into emergency care, where a head CT scan was performed, which revealed a generalized and diffuse decrease in density of the white matter, corresponding to cerebral edema. Spinal fluid revealed a high protein count, with normal glucose and white blood cell count. An electroencephalogram resulted in the presence of theta brain waves with the absence of an epileptogenic area, which indicates a disfunctional neurological state. The patient developed respiratory distress requiring intubation and was admitted into the intensive care unit with a new treatment of antiviral medicine, with the new diagnostic suspicion of encephalitis. A contrast-enhanced thoracoabdominal CT was performed, which revealed a right adnexal theratoma, guiding the diagnostic suspicion to an anti-NMDA induced encephalitis, for which a brain contrast-enhanced MRI was performed, with no classical findings present such as hippocampal atrophy and temporal lobe hyperintensity; instead the T2-based sequences showed cystic oval lesions in the frontal, temporal and occipital lobe, as well as diffuse hyperintensity of white matter, susceptibility weighted sequences showed focal round hypointesities corresponding to microhemorrhages distributed through the entirety of the white matter, and the gadolinium-enhanced sequence showed avid enhancement of the cystic lesions. A second spinal fluid test revealed antibodies against NMDA receptors and immunoglobulin treatment was administered with a poor response from the patient who presented heart failure shortly after and died. Read More

Authors:  Reyna De La Garza Karla , Salinas Puente Estefany , Mercado Flores Mariana , Rodríguez Garza Claudia , Maya Garcia Haziel , Montemayor Martinez Alberto

Keywords:  encephalitis, autoimmune, neuroradiology

Gagnon Marie-helene,  Parikh Ashish,  Taylor Susan,  Derenoncourt Paul-robert,  Ponisio Maria,  Khanna Geetika

Final Pr. ID: Poster #: EDU-050

Germ cell tumors of childhood are most often gonadal in origin. Extragonadal germ cell tumors are located characteristically in the midline arising intracranially, in the mediastinum, pelvis or retroperitoneum. These tumors are generally easily diagnosed due to typical sites of origin and characteristic imaging findings.

However, germ cell tumors can be associated with unusual clinical syndromes or imaging features that can perplex the clinician/radiologist.

We will review and illustrate atypical imaging/clinical manifestations and complications of germ cell tumors in childhood, based on our experience at two large children’s hospitals.

These atypical findings include:
Atypical metastatic disease: a) Burned out tumor – Testicular primary not typically evident with viable metastatic disease in retroperitoneal lymph nodes distant viscera, b) Growing teratoma syndrome (increasing size of tumor/pseudoprogression despite appropriate therapy), c) gliomatosis peritonei (maturation into glial tissue during therapy with pseudoprogression on FDG-PET), d) ossified pulmonary metastasis mimicking granulomas

Antibody mediated paraneoplastic syndromes: a) anti–N-methyl-D-aspartate (NMDA)– receptor antibody–mediated encephalitis associated with ovarian teratomas, b) anti-Ma2 antibody-mediated encephalitis associated with testicular germ cell tumors
Endocrine manifestations: a) Precocious puberty/gynecomastia due to hormonal (hCG) production, b) hyperthyroidism (TSH stimulation and struma ovarii)

Local complications: a) ovarian torsion (common), b) ruptured teratoma or dermoid cyst (uncommon)

Unusual primary tumors: a) Multifocal primary (e.g. pineal and suprasellar germinoma), b) Currarino triad, c) fetus-in-fetu, d) malignant transformation Read More

Authors:  Gagnon Marie-helene , Parikh Ashish , Taylor Susan , Derenoncourt Paul-robert , Ponisio Maria , Khanna Geetika

Keywords:  growing teratoma, gliomatosis peritonei, NMDA encephalitis

Hedlund Alec,  Stern Sara,  Bohnsack John,  Hedlund Gary

Final Pr. ID: Poster #: EDU-075

To familiarize the pediatric radiologist with the important role that the perforin gene plays in lymphocyte cytotoxicity, to discuss the diversity in clinical presentation, and review the scope of neuroimaging abnormalities that may arise in the setting of a missense perforin genetic defect. The brain MRI findings and relevant clinical information of two remotely related children with the same novel missense mutation in the perforin gene represent the basis of this educational poster.

Perforin is a glycoprotein (encoded by the PRF-1 gene) involved in several human cellular functions, including, immune response and stored mainly in CD8-positive T-cells as well as natural killer (NK) cells. Normally, T-cells and NK cells are responsible for attacking dead cells. In the clinical setting of perforin deficiency, T-cells and NK cells attack the healthy immune system. This arises from a missense mutation of the PRF-1 gene. Links between perforin deficiency and the autoimmune clinical syndrome of hemophagocytic lymphohistiocytosis (HLH), have been reported.

MR imaging abnormalities in patients with perforin gene mutations, are diverse and complex as the defect may occur in the setting of familial hemophagocytic lymphohistiocytosis, primary necrotizing lymphocytic CNS vasculitis or associated with CNS infections such as the Epstein Barr virus.

To date, MRI abnormalities that have been reported include mimics of septic cerebral emboli, confluent white matter abnormalities involving the cerebral hemispheres and cerebellum invoking the consideration of diffuse demyelinating disease, and multifocal infratentorial and supratentorial intraaxial lesions with “necrotic-like” character and marginal enhancement. Multifocal sites of perivascular space pathological enhancement has also been reported. Common to many of these reports is cerebellar involvement.

The imaging differential diagnosis includes atypical infection, histocytic disorders of the CNS, lymphomatous granulomatosis, neurosarcoidosis, and primary CNS lymphoma. Read More

Authors:  Hedlund Alec , Stern Sara , Bohnsack John , Hedlund Gary

Keywords:  Perforin defect, Chronic encephalitis, Necrotizing vasculitis

Uncanin Nedeljko,  Kuzminski Christopher

Final Pr. ID: Poster #: CR-018

Parechovirus is generally asymptomatic in older children and can cause symptoms similar to that of the common cold. However, in infants less than 3 months, infection can be severe with seizures and sepsis-like presentations. Currently, there are no good treatments. Some providers have administered IVIG, but the efficacy is unknown. Most patients will recover with supportive care, however neonates can have long-term consequences. The Parechovirus A3 strain has been more prevalent in circulation over the summer of 2022, such that the Center for Disease Control and Prevention has issued a health alert about the unusually high prevlalence of the A3 strain in neonates and young infants. We present a case of meningoencephalitis with unique imaging findings on MRI with Parechovirus detection in CSF studies. Although few descriptions exist within the radiology literature, our case has MRI imaging characteristics are nearly identical to that of a case series published in the American Journal of Neuroradiology in August 2019. Given the increased prevalence of this virus and radiology findings consistent with the prior publication, the imaging findings on MRI can prove to be vital in assisting with the diagnosis of patients where CSF cannot be obtained. Read More

Authors:  Uncanin Nedeljko , Kuzminski Christopher

Keywords:  encephalitis, meningitis, parechovirus