Pecoraro, Nathan C.

Study Design: A retrospective chart review. Objective: The authors aim to investigate the role of clinical and radiographic parameters in patients who underwent posterior cervical surgery, and their association with C5 palsy severity and time to recovery. Background: Postoperative C5 palsy affects 1%–30% of patients undergoing posterior decompression, with or without fusion. Causation and avoidance of this complication remain widely debated. Materials and Methods: A single institution review of patients who underwent posterior cervical spine surgery was focused on using specific Common Procedural Technology codes associated with the patient population of interest. Patients were excluded if they had inadequate pre and postoperative imaging, as well as a history of prior cervical spine surgery, concurrent anterior surgery, intradural pathology, spinal tumor, or spinal trauma. Radiographic measurements of the pre and postoperative images were completed with subsequent intraclass correlation coefficient analysis to confirm the precision of measurements. Results: Out of 105 total patients, 35 (33%) patients developed a C5 palsy. Twenty-four (69%) of those palsies completely resolved, with a median time to recovery of 8 months. Preoperative demographics and radiographic parameters demonstrated heterogeneity among those patients who did and did not have a resolution of palsy. Patients with increased change in C2–C7 lordosis (P = 0.011) after surgery were associated with decreased likelihood of recovery. Patients without a smoking history (P = 0.009) had an increased likelihood of recovering from C5 palsy. Conclusions: The degree of increased lordosis in the treatment of degenerative cervical disease plays a role in the rate of recovery from C5 palsy. This should be considered during preoperative planning in determining the amount of lordosis desired. In addition, patients without a smoking history were associated with a higher rate of recovery. Level of Evidence: Level IV.

OBJECTIVE Advancements in microsurgical technique and technology continue to improve outcomes in patients with skull base tumor. The primary cranial nerve eight monitoring systems used in hearing preservation surgery for vestibular schwannomas (VSs) are direct cranial nerve eight monitoring (DCNEM) and auditory brainstem response (ABR), although current guidelines are unable to definitively recommend one over the other due to limited literature on the topic. Thus, further research is needed to determine the utility of DCNEM and ABR. The authors performed a retrospective cohort study and created an interactive model that compares hearing preservation outcomes based on tumor size in patients receiving ABR+DCNEM and ABR-only monitoring. METHODS Twenty-eight patients received ABR+DCNEM and 72 patients received ABR-only monitoring during VS hearing preservation surgery at a single tertiary academic medical center between January 2008 and November 2022. Inclusion criteria consisted of adult patients with a preoperative American Academy of Otolaryngology–Head and Neck Surgery (AAO-HNS) hearing classification of A or B. Tumor size was measured as the maximal medial to lateral length, including the internal auditory canal component. RESULTS Overall hearing preservation (word recognition score [WRS] > 0%) was achieved in 31 patients with ABR-only monitoring (43.1%) and in 18 patients with ABR+DCNEM (64.3%). Serviceable hearing preservation (AAO-HNS class A or B) was attained in 19 patients with ABR-only monitoring (26.4%) and in 11 patients with ABR+DCNEM (39.3%). There was no difference in overall hearing preservation between the two groups (p = 0.13). Change in tumor size was not associated with the odds of serviceable hearing preservation for the ABR-only group (p = 0.89); however, for ABR+DCNEM, there was some indication of an interaction between tumor size and the association of ABR+DCNEM versus ABR-only monitoring, with the odds of serviceable hearing preservation at p = 0.089. Furthermore, with ABR+DCNEM, every 0.5-cm increase in tumor size was associated with a decreased odds of serviceable hearing preservation on multivariable analysis (p = 0.05). For both overall and serviceable hearing preservation, a worse preoperative AAO-HNS classification was associated with a decreased odds of preservation (OR 0.43, 95% CI 0.19–0.97, p = 0.042; OR 0.17, 95% CI 0.053–0.55, p = 0.0031, respectively). CONCLUSIONS The result of this interactive model study proposes that there may be a higher chance of hearing preservation when using ABR+DCNEM rather than ABR alone for smaller tumors, with that relationship reversing as tumor size increases.