Acute Progressive Spinal Arachnoid Web Without the Scalpel Sign: A Case Report

Spinal arachnoid web (SAW) is a chronic disorder characterized by thickened arachnoid tissue obstructing the cerebrospinal fluid flow, leading to spinal cord compression and often associated with syringomyelia. We report an uncommon case of a 77-year-old man with SAW who presented with acute progressive neurological deterioration. Spinal cord deformation and displacement identified on initial imaging prompted the use of advanced imaging techniques, such as heavily T2-weighted magnetic resonance imaging (MRI), which facilitated a timely diagnosis and subsequent surgical intervention. Microsurgical web excision with laminectomy was selected as the surgical treatment. Intraoperative findings were consistent with the typical characteristics of SAW, showing no discrepancies with the preoperative diagnosis. After the operation, the patient displayed considerable neurological recovery, including the resolution of spinal cord distortion and normalization visible on MRI. This case underscores the importance of including SAW in the differential diagnosis of acute progressive thoracic myelopathy and highlights the critical role of advanced imaging and early surgical intervention in achieving favorable clinical outcomes.