Predictive Value of Thyroid Function and FDS Score in Subacute Combined Degeneration

This study aimed to investigate the impact of thyroid function on the short-term prognosis of patients with SCD and to evaluate the predictive value of the Function Disability Scale (FDS) score combined with thyroid function for poor prognosis.

We conducted a retrospective analysis of clinical data from SCD patients admitted to the First Hospital of Jilin University between January 2021 and December 2022 (n=40). Neurological deficits were assessed using the FDS score at admission and the modified Rankin Scale (mRS) at 3 months post-discharge. Patients were categorized into two groups: normal thyroid function (control) and hypothyroidism (case). General characteristics, clinical features, laboratory results, Functional Disability Scale (FDS) scores, and mRS scores were compared between groups. A mRS score >2 was defined as poor prognosis. Univariate and multivariate logistic regression analyses were performed to identify risk factors for poor prognosis, and receiver operating characteristic (ROC) curve analysis was used to evaluate predictive performance.

Hypothyroidism was associated with lower folic acid levels, higher mean corpuscular hemoglobin concentration (MCHC), and higher mRS scores (P<0.05). Poor prognosis was significantly correlated with a history of gastrointestinal disease, elevated thyroid-stimulating hormone (TSH), reduced folic acid, and higher admission FDS scores (P<0.05). Multivariate analysis identified elevated TSH (OR=2.152, 95% CI: 1.050~4.411, P=0.036) and high FDS scores at admission (OR=5.573, 95% CI: 1.020~30.438, P=0.047) as independent risk factors for poor prognosis (P<0.05). ROC analysis determined optimal cutoff values of 5.265 mIU/L for TSH and 7.5 for FDS score in predicting poor prognosis. The combination of FDS score and TSH levels demonstrated superior predictive accuracy (AUC=0.978, 95% CI:0.937~1.000, P<0.001, sensitivity=100%, specificity=91.3%).

Elevated TSH levels are associated with worse short-term outcomes in SCD. The combination of FDS score and TSH levels enhances prognostic prediction, potentially serving as a valuable clinical tool for risk stratification.

This study is limited by its small sample size, single-center design, and absence of external validation.