Autoimmune thyroid disease in narcolepsy: A case report

While the previous studies have discussed the association of narcolepsy with autoimmune diseases, autoimmune thyroid disease (IATD) has rarely been described in patients with narcolepsy. The association of narcolepsy with thyroid disease is intriguing for speculating the causal or coexisting autoimmune disorder. We report a case of narcolepsy Type 1 with IATD, presenting with excessive daytime sleepiness (EDS), cataplexy attacks, and unexplainable weight gain. Oral modafinil and sodium oxybate were used for treatment and prevention. During the 1-year follow-up, the patient’s EDS and cataplexy attacks improved. However, the patient developed hypothyroidism and was subsequently prescribed with thyroid replacement therapy.