P033 Does a large central gyral DVA worsen paresis in a patient with HTLV-1 myelopathy? A case report

<h3>Introduction</h3> Developmental venous anomalies (DVAs) are prevalent congenital vascular malformations of the brain, often incidentally discovered in imaging studies with small veins draining into a larger collecting vein. They can be associated with other conditions such as cavernomas, gliosis or glioblastoma. Symptoms might be caused by associated cerebral edema, gliosis, compression, thrombosis, increased inflow or decreased outflow. On the other hand, HTLV-1 myelopathy is a chronic, progressive demyelinating neurological condition caused in 80% by Human T-cell lymphotropic virus type 1 (HTLV-1). It primarily affects the spinal cord leading to an atrophy and may cause lower limb weakness, possibly proceeding to paraparesis. <h3>Case Description</h3> A female adolescent patient presented with slowly progressive left-side attenuated paraparesis of the lower limbs. MR-imaging and cranial DSA showed a large right-sided DVA with associated gliosis, combining with an atrophy of the thoracal myelon. Diagnosis of HTLV-1 myelopathy was supported by positive HTLV-1 PCR of the cerebrospinal fluid. Conservative management was opted due to the non-operative nature of DVA. <h3>Results</h3> We publish a unique case of HTLV-1-associated myelopathy combined with a large cerebral DVA, which to our knowledge has never been reported. We concluded the left-sided attenuation of the paraparesis most likely being caused by the gliosis detected on cranial MRI in the context of the large DVA. This throws the benign character of DVA into question and necessitates elaborate guidelines emphasizing the need to identify hazardous consequences as well as accompanying conditions. This case underscores the importance of considering unusual neurological associations in clinical practice. <h3>Disclosure of Interest</h3> yes Frederik Boxberg has recieved travel expenses from Medtronic (Dublin, Ireland) and research grant from Acandis (Pforzheim, Germany). Dominik Grieb has recieved travel expenses from Medtronic (Dublin, Ireland) and Stryker (Kalamazoo, Michigan, USA) and speaker hono- raria from Medtronic (Dublin, Ireland). The authors do not have any conflicts of interest related to this abstract. No other authors have any conflicts of interest to disclose.