Neck extension during thyroidectomy: effects on early postoperative cognitive function and optic nerve sheath diameter- a randomized controlled trial.

BACKGROUND: During thyroidectomy, patients are commonly positioned with neck extension using a shoulder roll. Excessive extension may impair arterial and venous outflow, compromise cerebral perfusion, and elevate intracranial pressure, potentially leading to postoperative cognitive impairment. This study investigated the effect of shoulder-roll-assisted neck extension on cognitive outcomes and on optic nerve sheath diameter (ONSD). METHODS: After tracheal intubation, patients were randomly assigned to either a shoulder roll group or a control group without a roll. The primary outcome was the Montreal Cognitive Assessment (MoCA) score at 6 h postoperatively. Secondary outcomes included ONSD and the degree of neck extension. RESULTS: Postoperative MoCA scores were significantly lower in the shoulder roll group (20.56 ± 2.71) compared with the control group (23.57 ± 2.37; P < 0.001). ONSD increased over time in both groups (P < 0.001), but repeated-measures analysis showed no significant difference between groups (P = 0.333). Neck extension was greater in the shoulder roll group (126 ± 4.36°) than in the control group (116 ± 3.74°; P < 0.001). CONCLUSIONS: Shoulder roll positioning during thyroidectomy was associated with lower MoCA scores at 6 h, indicating mild postoperative cognitive decline. Although greater neck extension was observed, ONSD values did not significantly differ between groups. TRIAL REGISTRATION: Muğla Sıtkı Koçman University Clinical Research Ethics Committee (approval number T-XII, June 17, 2019). Australian New Zealand Clinical Trials Registry (registration number: ACTRN12619001066178, date of registration: July 31, 2019).