게시판
| 21KS-039 |
Diagnosis of Thoracic Arachnoid Web at Outpatient Pain Clinic: A Case Report
Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine
Introduction
An arachnoid web (AW) is a rare clinical diagnosis which is characterized by thickened arachnoid tissue, forming a web. AW can exert compressional force on the spinal cord, which can in turn cause a variety of symptoms including axial and radicular pain, paresthesia, and weakness in upper and lower extremities. AWs are often diagnosed by the pathognomonic “scalpel sign” on magnetic resonance imaging (MRI) and computed tomography (CT) myelography. In this report, we describe a case of 71-year-old male who was diagnosed with AW in our outpatient pain clinic.
Case
A 71-year-old male initially presented to our pain clinic with progressive mid-upper back pain which had been lasting for 7 months. He denied any weakness or paresthesia in upper and lower extremities, and a particular dermatomal radiculopathy was not clear. Several months of conservative treatment with conventional analgesics had failed to show effect. The patient had also received cervical medial branch blocks and a caudal epidural steroid injection at another institution, but his symptoms did not alleviate. Lumbar and cervical MRI which he had brought from an outside institution showed disc lesions and several levels of foraminal stenosis, but these findings did not correlate well with the areas of his clinical complaint. The patient underwent thoracic spine MRI at our institution, and the pathognomonic “scalpel sign” was discovered at T3-4 level, which was suggestive of an AW. This web was causing an indentation on dorsal part of the thoracic spinal cord and was thought to be the cause of the patient’s mid-upper back pain.
Conclusion
Because AWs can present with a wide variety of clinical manifestations, it is difficult to distinguish them from other more common diagnoses of outpatient pain clinics. Without an accurate diagnosis, AWs are often refractory to conventional non-surgical treatment. According to previous reports, early surgical release of the web usually showed improved outcomes. Therefore, it is important to perform imaging work-up such as T-spine MRI or CT myelography early in the clinical course to correctly diagnose AW.
1. Hirai et al. Clinical Outcomes of Surgical Treatement for Arachnoid Web: A Case Series. Spine Surg Relat Res 2019;3(1):43-38.
2. Dua SG, Jhaveri MD. Scalpel sign of dorsal arachnoid web. Neurol India 2016;64:1092-3
An arachnoid web (AW) is a rare clinical diagnosis which is characterized by thickened arachnoid tissue, forming a web. AW can exert compressional force on the spinal cord, which can in turn cause a variety of symptoms including axial and radicular pain, paresthesia, and weakness in upper and lower extremities. AWs are often diagnosed by the pathognomonic “scalpel sign” on magnetic resonance imaging (MRI) and computed tomography (CT) myelography. In this report, we describe a case of 71-year-old male who was diagnosed with AW in our outpatient pain clinic.
Case
A 71-year-old male initially presented to our pain clinic with progressive mid-upper back pain which had been lasting for 7 months. He denied any weakness or paresthesia in upper and lower extremities, and a particular dermatomal radiculopathy was not clear. Several months of conservative treatment with conventional analgesics had failed to show effect. The patient had also received cervical medial branch blocks and a caudal epidural steroid injection at another institution, but his symptoms did not alleviate. Lumbar and cervical MRI which he had brought from an outside institution showed disc lesions and several levels of foraminal stenosis, but these findings did not correlate well with the areas of his clinical complaint. The patient underwent thoracic spine MRI at our institution, and the pathognomonic “scalpel sign” was discovered at T3-4 level, which was suggestive of an AW. This web was causing an indentation on dorsal part of the thoracic spinal cord and was thought to be the cause of the patient’s mid-upper back pain.
Conclusion
Because AWs can present with a wide variety of clinical manifestations, it is difficult to distinguish them from other more common diagnoses of outpatient pain clinics. Without an accurate diagnosis, AWs are often refractory to conventional non-surgical treatment. According to previous reports, early surgical release of the web usually showed improved outcomes. Therefore, it is important to perform imaging work-up such as T-spine MRI or CT myelography early in the clinical course to correctly diagnose AW.
1. Hirai et al. Clinical Outcomes of Surgical Treatement for Arachnoid Web: A Case Series. Spine Surg Relat Res 2019;3(1):43-38.
2. Dua SG, Jhaveri MD. Scalpel sign of dorsal arachnoid web. Neurol India 2016;64:1092-3
