Predictive factors of long-term dorsal column dysfunction after intramedullary spinal cord tumor resection: a...

Postoperative dorsal column dysfunction (DCD) has been observed in 43.6%-55.1% of patients who have undergone surgery for intramedullary spinal cord tumors (IMSCTs). There is a paucity of evidence regarding the prognosticators of its occurrence. The objective of the present study was to ascertain the prognostic factors associated with long-term DCD following IMSCT resection, with a particular emphasis on the role of the myelotomy technique and intraoperative neuromonitoring (IONM).

A case-control study was conducted on consecutive patients. Patients were stratified based on the surgical technique used for midline myelotomy: dorsal column (DC) dissection and preservation technique (group A) and midline coagulation and incision technique (group B). Somatosensory evoked potentials (SSEPs) were categorized as either present or absent. The groups were then analyzed with respect to the Short Form Health Survey 36 (SF-36), the McCormick Scale (MMS), Douleur Neuropathique 4 Questions, and a 3-domain numeric rating scale for investigating DCD, named the Dorsal-Columns Questionnaire (DCQ). Univariate analyses were conducted for MMS and DCQ scores, with data regarding demographics; neurological examination; symptoms; surgery, including extent of resection, tumor histology, tumor location, myelotomy, and tumor extension; hemosiderin cap, cleavage plane presence; and IONM taken into consideration. IONM was recorded at three time points during the surgical procedure: baseline intraoperative, worst intraoperative, and final intraoperative.

In total, 37 patients were included. Groups A and B had nonsignificantly different demographic parameters. Group A had superior outcomes in MMS (p = 0.002), SF-36 (p = 0.001), and DCQ (p = 0.031) scores at the last follow-up. Group B experienced a significantly higher incidence of worst intraoperative (p = 0.002) and final intraoperative (p = 0.026) SSEP loss. Univariate analysis documented the following major prognostic factors: myelotomy technique (p = 0.012), capillary hemangioma histology (p = 0.045), and worst intraoperative SSEPs (p = 0.034) for the DCQ; myelotomy technique (p < 0.001), intraoperative (p < 0.001) and final intraoperative (p < 0.001) SSEPs, and follow-up bowel-bladder dysfunction (p = 0.02) for the MMS. Final operative SSEPs were not among DCQ prognosticators (p = 0.213).

The DC dissection and preservation myelotomy technique is associated with lower long-term DCD and intraoperative SSEP loss and better health-related quality of life and disability when compared with the midline coagulation and incision technique. The myelotomy technique and intraoperative SSEP disappearance, even if transient, are major determinants of long-term disability and DCDs.