3149 Real-world Australian experience with Ofatumumab in the MSBase registry

Objectives Iatrogenic cerebral amyloid angiopathy (iCAA) is a very rare but emerging cause of stroke.We present a case of possible iCAA secondary to childhood Lyodura use. Methods Case report.Results A 40-year-old female presented to our service with focal seizures.This occurred on a background of being a monozygotic twin with partial trisomy 17, previous lobar intracerebral haemorrhage (ICH) in 2021, and craniosynostosis with repair and ventriculoperitoneal shunt insertion in 1982.Her twin had no history of ICH or childhood neurosurgery.CT brain on admission revealed a new left frontal ICH.A review of a previous MRI brain from 2022 revealed lobar cerebral microhaemorrhages and foci of cortical superficial siderosis, all clustered towards the vertex, and evidence of the previous right paracentral ICH.Case notes from her 1982 childhood neurosurgery were obtained which revealed Lyodura grafting occurring to repair a dural tear, also at the vertex.Lyodura was a commercially available irradiated human dura mater sourced post-mortem, available in Australia between 1972-1987.Use globally has been implicated in iatrogenic Creutzfeldt-Jakob disease and more recently, in iCAA.Thus, in our case, iCAA was suspected, which met the 'possible' criterion on a recently proposed diagnostic criteria.Options to pursue amyloid PET or biopsy to strengthen diagnostic certainty were offered but were declined by the patient's family.Conclusion iCAA is an exceedingly rare but emerging entity.Cases, such as ours, may be caused by historic use of Lyodura.Interrogation of childhood neurosurgical records is important to ensure similar cases are not missed.