Association of total thyroidectomy and lateral neck dissection with sleep disturbance and cognitive impairment: a retrospective cross-sectional study

Postoperative sleep rhythm disturbance is closely associated with cognitive decline. This study aimed to investigate the impact of total thyroidectomy combined with lateral neck dissection on postoperative sleep and cognition. A single-center retrospective cross-sectional study was conducted from September 1, 2023 to March 31, 2025. Patients aged 25–65 years with pathologically confirmed thyroid malignancy, scheduled for either Total Thyroidectomy With Central Neck Dissection (TT + CND group) or Total Thyroidectomy With Central and Lateral Neck Dissection (TT + CND+LND group), were enrolled. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality and the modified Telephone Interview for Cognitive Status (TICSM) to evaluate cognitive memory at 6 months, 1 year, and 1.5 years postoperatively. Thyroid function tests were measured preoperatively and at each follow-up time point. Binary logistic regression models were used to assess the association of surgical approach with postoperative sleep disturbance and memory decline. The risk factors for sleep and cognitive dysfunction was analyzed in the TT + CND+LND group. A total of 397 patients were enrolled, with 263 in the TT + CND group and 134 in the TT + CND+LND group. There was no significant differences in baseline demographic and clinical characteristics between the TT + CND group and TT + CND+LND group ( p > 0.05), except for longer surgical duration in the TT + CND+LND group ( p < 0.01). Preoperative thyroid function indices were comparable between groups ( p > 0.05); free thyroxine (FT4) level was statistically different at 1.5 years after the operation ( p = 0.033), but remained within the normal clinical range. In adjusted models, the TT + CND+LND group had a significantly higher risk of postoperative sleep disturbance (OR, 2.81; 95% CI, 1.71–4.64) and memory decline (OR, 2.06; 95% CI, 1.22–3.50) compared with the TT + CND group. In time-stratified analyses of independent patient subgroups, the risk of sleep disturbance in the TT + CND+LND group was highest at 6 months postoperatively (OR, 4.20; 95% CI, 1.62–11.38), and the risk of memory decline was the most significant at 1 year postoperatively (OR, 3.48; 95% CI, 1.37–9.14). At 1.5 years postoperatively, no significant differences were observed in these risks between two groups. In the TT + CND+LND group, female sex (OR, 2.01; 95% CI, 1.02–4.01) and age (OR, 1.03 per 1-year increase; 95% CI, 1.00-1.06) were independent risk factors for postoperative sleep disturbance, while education level, surgical duration, and medical history had no significant effects ( p > 0.05). In this retrospective cross-sectional study, total thyroidectomy combined with lateral neck dissection was significantly associated with an increased risk of postoperative sleep disturbance and cognitive impairment in patients with thyroid cancer. Female sex and older age were identified as risk factors for sleep disturbance in patients undergoing lateral neck dissection. The study protocol was approved by the Institutional Review Board of the First Affiliated Hospital of Nanjing Medical University (approval number: 2025-SR-350). Chinese Clinical Trial Registry: ChiCTR2500111391.