Hemimegalencephaly as diferential diagnosis of Rasmussen encephalitis

Case Presentation: AGRB, male, 9 years old, 52kg, previously healthy, born and raised in Pirambu, Bebedouro village, Sergipe.Adtted on 10/09/2022 to the pediatrics sector of the Sergipe Emergency hospital, reporting headache, fever and vomiting for 7 days, with subsequent evolution with pain in the posterior region of the right thigh, in addition to low back pain.Physical examination showed normal breathing and heart rate.Decreased strength in lower limbs, being worse on the left side.No patellar reflex and left Achilles.Normal right reflexes.Strength preserved in upper limbs.Presence of Babinski's sign on the right.No signs of trunk involvement.During the medical evaluation, a magnetic resonance imaging (MRI) of the dorsal column was requested, with findings of multiple foci with heterogeneous gadolinium uptake affecting the central portion and anterior funiculi of the spinal cord from D8 to the medullary cone, with T2 hypersignal in the spinal cord parenchyma adjacent and extending to the D4 level, with mass effect, with partial erasure of the CSF column in correspondence.The vertebral bodies, joints and musculature had normal contours and structures.It was concluded, then, that the examination showed an inflammatory-type lesion with a focus on schistosomiasis with involvement of the spinal cord associated with epidemiological data and clinical suspicion.Collected CSF that showed total proteins in the amount of 128.6 mg/dL, 597 cells/ mm3 (PNM: 14% and LMN: 86%) with positive IFI for schistosomiasis.Treatment with ivermectin 6 mg was started, administering 2 pills every 24 hours for 2 days.After ivermectin, pulse therapy was started with 1g/day of methylprednisolone for 5 days.After pulse therapy, a dose of praziquantel was started and prolonged corticosteroid therapy was maintained with prednisone 1 mg/kg/day for 6 months.Discussion: Schistosomiasis is considered endemic in 19 districts, one of which is the state of Sergipe, and the S. mansoni species, in addition to being the most prevalent, is also the one most associated with myeloradiculopathy.Diagnosis is based on epidemiology, neurological symptoms, microscopic and serological techniques, and magnetic resonance imaging (MRI) evaluation.In addition, it is necessary to rule out other possible diagnoses.Symptomatology corroborates to determine the degree of involvement of the lesion.Final Comments: Schistosomiasis is an important and endemic parasitic.