Multiple sclerosis in a child with neurofibromatosis type I - clinical management of a challenging case.

A 13-year-old girl with neurofibromastosis (NF1) was admitted to the Department of Paediatric Haematology, Oncology and Transplantology due to progressive vision loss in September 2018. The patient was diagnosed with optic nerve gliomas and chemotherapy was initiated. During the treatment, the girl experienced muscle weakness in the lower limbs, and uncharacteristic lesions were detected in the spinal cord. Eventually, the girl was diagnosed with MS. The described case is one of the few reports of a child with coexisting NF1 and MS. The coincidence of these diseases is unusual and requires a multidisciplinary approach. Vision impairment in patients suffering from NF1 is typically associated with optic nerve gliomas, although it can be caused by other factors, such as MS, which is proven to have a higher prevalence in the NF1 population. Extensive ophthalmological diagnostics may not be conclusive, thus there is a need for the thorough neurological evaluation of patients with NF1 and visual deficits.