TY - JOUR T1 - MR ‘scalpel sign’ of spinal arachnoid web JF - Practical Neurology JO - Pract Neurol SP - 235 LP - 236 DO - 10.1136/practneurol-2021-003293 VL - 22 IS - 3 AU - Thomas Morrison AU - Raka Datta AU - Lynette Masters AU - Mike Boggild AU - Stephen Reddel AU - Jeffrey Brennan Y1 - 2022/06/01 UR - http://pn.bmj.com/content/22/3/235.abstract N2 - Spinal arachnoid web is a rare and reversible cause of myelopathy and syringomyelia. Intradural, extramedullary transverse bands exert focal pressure on the spinal cord, disrupt the flow of Cerebrospinal fluid (CSF) in the subarachnoid space and by doing so can lead to the formation of a syrinx. Patients present with myelopathic symptoms including numbness, weakness and gait disturbance. MR imaging can show a characteristic ‘scalpel sign’ on sagittal T2 images. Traditional sequences rarely show the web itself, requiring clinicians to infer its presence.1 2 For patients with progressive symptoms, the only treatment is surgical decompression, generally with good clinical outcomes.3 We describe three patients who presented in the outpatient setting.Patient A: A 65-year-old woman had a 1 year of burning dysaesthetic pain in the trunk and flank and unsteadiness when walking. She was mildly spastic with lower limb hyperreflexia and reduced proprioception … ER -