JICNA 2020 Supplement(1.1) POSTER PRESENTATIONS BRAIN TUMORS/ONCOLOGY 1. Neuropsychiatric symptoms in an adolescent:Dig deeper? Khan Mahjabeen (Saint Louis, MO, United States) Tanios Aline OBJECTIVE: We report a case of an adolescent who presented with a cluster of vague behavioral symptoms, later diagnosed with an intra-ventricular tumor causing obstructive hydrocephalus. METHODS: A 17 year old female presented with a three month history of mood changes, weight loss, near syncope episodes and urinary incontinence. She had fatigue, anorexia, depressed mood, anhedonia, decreased sociability and insomnia. Patient identified breakup with her boyfriend as a trigger. She also reported intermittent headaches and vomiting. Exam was notable for flat affect, staring spells, increased distractibility, slow thought processing and responsiveness, generalized hyperreflexia, bilateral Babinski’s sign with hand tremors. RESULTS: Although, symptoms were pan positive for Major Depressive(POSTERS) Disorder with severe features, unusual findings of urinary incontinence, frequent falls, headaches and vomiting could not be explained by a mood disorder alone. Neurological signs also raised concerns for intracranial pathology. Brain MRI revealed a heterogeneous enhancing lobular mass arising from the septum pellucidum resulting in obstructive hydrocephalus. She underwent emergent resection of the tumor, which on histopathology, was identified as a Sub-ependymal Giant Cell Astrocytoma (SEGA) and tumor cytogenetics showed TSC2 mutation. She had no clinical diagnosis of Tuberous Sclerosis. CONCLUSIONS: Major Depressive Disorder is highly prevalent among adolescents in the US. Interpersonal dysfunction is a commonly identified trigger. Psychiatric symptoms are a rare presentation of brain tumors and vice versa. Pediatricians and/or psychiatrists may encounter such patients. With atypical symptoms,ABSTRACTS a thorough exam and high index of suspicion is important for a timely diagnosis. This is a clinical conundrum with a classic neuropsychiatric interface. KEYWORDS: Brain Tumors/Oncology, Rare Diseases, Genetics 2. Careful approach to acquired facial nerve palsies in infants: two cases of symptomatic disease Chandler Erika (Louisville, KY, United States) Barton Chris, Puri Vinay OBJECTIVE: Acquired facial nerve palsies in children are commonly encountered. Up to 50% are of unknown causes, often attributed to post-infectious syndromes. In rare cases, peripheral facialACCEPTED palsies may be secondary to underlying infections, tumors, trauma, or even leukemia. In infants, differentiating these may be difficult. We present two cases of infants with symptomatic facial nerve palsies. METHODS: A detailed chart review and literature search. RESULTS: We present two infants with new onset full facial nerve palsies. Patient one presented one day after falling from a 3 foot height and having persistent isolated facial Proceedings of the 16TH INTERNATIONAL CHILD NEUROLOGY VIRTUAL CONGRESS October 2020 JICNA 2020 Supplement(1.1) weakness over 2 days. CT head was obtained due to trauma and showed opacification of bilateral mastoids in the setting of bilateral otitis media, and mastoiditis was suspected. CBC showed a WBC count of >250k, prompting urgent leukapheresis. She was ultimately diagnosed with T-cell ALL with CNS involvement. Patient two presented with right sided head tilt, right sided full facial weakness and truncal ataxia. MRI brain showed a tumor of the internal auditory canal extending into the right cerebellopontine angle. Lumbar puncture with negative cytology, solid tumor panel negative. Electroneurography showed involvement of cranial nerve VII and VIII with chronic involvement, suggesting a schwannoma. CONCLUSIONS: In children, facial nerve palsies are often attributed to post-infectious inflammation. However, in infants with no clear history of recent infection or trauma, alternative differentials should be considered. MRI brain with gadolinium and a CBC should be considered in individuals when indicated by history, examination or a lack of response to treatment. KEYWORDS: Brain Tumors/Oncology 3. Trametinib for pediatric plexiform neurofibroma and recurrent low-grade glioma Sato Aimee (Seattle, WA, United States) Millard Nathan, Oztek Murat Alp, Perez Francisco, Vitanza Nicholas, Leary Sarah OBJECTIVE: Based on early clinical efficacy data, Seattle Children’s(POSTERS) Hospital established a standard clinical practice for MEK inhibitor therapy for children with plexiform neurofibroma (pNF) or recurrent low-grade glioma (LGG). We sought to describe the clinical experience and response to treatment for these children. METHODS: Data were collected under an IRB-approved retrospective chart review. Trametinib was prescribed off-label at 0.025 mg/kg daily for up to two years. Physical exam and labs were monthly for 3 months, then every 3 months. Retinal examination, echocardiogram and ECG were every 3 months. Tumor response was evaluated by MRI every 3 months. RESULTS: 30 patients received trametinib; 17 LGG, 16 PN (3 both); 22 with Neurofibromatosis Type-1 (NF1); 16 female/14 male; median age 11 (range 4.1-22.6). Most common tumor location was optic pathway (n=11) and face/neck (n=10). Most common adverse events (AE) were dermatologic andABSTRACTS gastrointestinal. Ten had dose interruption/reduction, only one discontinued therapy for AE. Six received dermatology specialty care for AE. With median follow-up of 12 months, only 3 patients had progression, one with NF1. One-year EFS was 100% for PN and 88%+7 for LGG. Driver mutations were identified in 9 of 10 tumors tested (5 BRAF fusion, 1 BRAFV600E, 1 FGFR1+NF1, 1 FGFR1+PTPN11, 1 NF1). Central radiology review of response will be presented. CONCLUSIONS: This real-world pediatric cohort supports efficacy and tolerability of MEK inhibitor therapy for short-term control of pNF and LGG with and without NF1. Further studies are warranted to evaluate comparative efficacy, combination therapy and duration of therapy. KEYWORDS: Brain Tumors/Oncology, Genetics 4. AACCEPTED First-Reported Use of Everolimus to Reduce Seizures and Neurodevelopmental Delays in PTEN Tumor Hamartoma Syndrome With Hemimegalencephaly Swarz Jeffrey (Boston, MA, United States) Gaitanis John, Law Jason Proceedings of the 16TH INTERNATIONAL CHILD NEUROLOGY VIRTUAL CONGRESS October 2020 JICNA 2020 Supplement(1.1) OBJECTIVE: To describe the first-reported use of Everolimus for the treatment of seizures and neurodevelopmental delays in a four year old girl with hemimegalencephaly and PTEN Tumor Hamartoma Syndrome (PTHS). METHODS: Patient demographics, history, neurological findings, MRI, neuropsychiatric testing, treatment, and clinical course were reviewed. The literature was reviewed for prior case reports. RESULTS: Our patient with PTHS (confirmed on genetic testing) was treated with the mTOR inhibitor Everolimus. The EXIST 3 studies demonstrated promise for Everolimus in tuberous sclerosis (TSC) for seizure control and neurodevelopmental improvement. The shared pathophysiology of TSC 1 and PTHS, and similar desired clinical goals of improved seizure control and neurodevelopmental outcome, led to the prescription of Everolimus after careful consideration and discussion with her parents. One year after Everolimus initiation our patient showed significant clinical improvements. She experienced improved seizure control (one seizure per year post-treatment versus a pre-Everolimus baseline of one to two per month). She also showed significant advancements in the gross and fine motor domains, cognition, and receptive language. Her expressive language showed less improvement but was likely an underestimate since her communications board was not permitted during standardized testing. CONCLUSIONS: This first-reported use of Everolimus in our patient with hemimegalencephaly and PTHS was associated with decreased seizure(POSTERS) activity and significant global improvement in neurodevelopment. These results are similar to the studied effects of mTOR inhibition in the treatment of TSC and supports growing evidence that a medical, rather than surgical approach, may be considered in similar patients. KEYWORDS: Brain Tumors/Oncology, Epilepsy COGNITIVE/BEHAVIORAL DISORDERS (INCLUDING AUTISM) 5. Amyloid Plaque Proteome in Down Syndrome Garcia Mekka (New York, NY, UnitedABSTRACTS States) Faustin Arline, Askenazi Manor, Ueberheide Beatrix, Pires Geoffrey, Drummond Eleanor, Wisniewski Thomas OBJECTIVE: The aim of the study is to compare Down Syndrome (DS) amyloid plaques and cortex proteome to that of early-onset Alzheimer’s Disease (AD) in hope of finding a novel protein(s) that could elucidate the mechanism of early-onset dementia in DS. METHODS: Protein differences were examined in cases of DS with AD neuropathology (n=5; age= 52.6±8.9yrs), AD (n=5; age=60.6±3.4yrs), and cognitively normal controls (n=5; age=56.2±1.9yrs). Amyloid plaques and non-plaque affected temporal cortex were analyzed using proteomic methods we have previously published (Acta Neuropathologica, 133: 933-954, 2017).ACCEPTED Fluorescent immunohistochemistry (IHC) was used to examine levels of total Aß, pyroglutamate Aß, Aß phosphorylated at serine 8, oligomeric species, and phosphorylated tau. Further studies are being conducted to increase sample size. RESULTS: Proteomic analysis resulted in the quantification of 1650 proteins. Comparison of the plaque proteome in DS and AD revealed similar proteins are present in DS and AD plaques, though a relative abundance of many key proteins