Evaluating cognitive function in patients with differentiated thyroid cancer who experienced short- term hypothyroidism by levothyroxine withdrawal using Montreal Cognitive Assessment-Philippines (MoCA-P) tool

Abstract

Background & Objective: Although there are numerous data studying cognitive dysfunction on hypothyroidism in general, there are limited researches that venture on short-term hypothyroidism. This study aimed to determine the cognitive function of patients with differentiated thyroid cancer (DTC) who experienced short-term hypothyroidism.

Methods: This was a prospective study done in a tertiary hospital in Manila that enrolled 16 DTC patients either for radioactive iodine (RAI) therapy or thyroid cancer monitoring, who were followed at baseline before levothyroxine (LT4) withdrawal, during hypothyroid state and post-LT4 treatment. MoCA-P tool was used to objectively assess cognition while HADS-P tool was used to detect anxiety and depression. Mean scores were calculated for each time point and analyzed using paired T-test.

Results: There was a decrease in the mean MoCA-P score from baseline to hypothyroid state (25.22 to 22.97, p= 0.032) with improvement post-LT4 treatment (22.97 to 24.93, p= 0.004). Older age was associated with decrease in MoCA-P scores (p= 0.04). Total HADS-P scores were nonsignificant. Visuospatial (3.86 to 3.43, p 0.014) and attention (4.86 to 4.36, p value 0.021) domains declined with hypothyroidism, with reversal of visuospatial function post-LT4 treatment.

Conclusion: There is a significant alteration in cognition during short-term hypothyroidism that generally improves with LT4 treatment. It is important to educate patients on specific cognitive domains that can be affected to ensure occupational safety.