0701 Spontaneous Long-Term Resolution of Daytime Sleepiness in Adults Diagnosed with Narcolepsy Type 2: A Case Series

Abstract Introduction Narcolepsy Type 2 (NT2) is traditionally considered a chronic lifelong disorder characterized primarily by excessive daytime sleepiness (EDS). However, long-term evolution of symptoms in NT2 remains poorly understood. We present three cases of patients diagnosed with NT2 in early adulthood who experienced complete resolution of EDS approximately 15 years after diagnosis. Methods A retrospective chart review was conducted of three patients diagnosed with NT2 in their 30s following overnight polysomnography and multiple sleep latency testing. Demographic information, clinical presentation, psychiatric history, treatment course, and long-term outcomes were reviewed. Current clinical status was confirmed at follow-up sleep clinic visits. Results All three patients were diagnosed with NT2 approximately 15 years prior and initially presented with significant daytime sleepiness impacting daily functioning. At the time of diagnosis, each patient also exhibited symptoms of depression and was receiving treatment with antidepressant medications. Over time, all three demonstrated gradual and eventually complete resolution of daytime sleepiness without ongoing pharmacologic treatment for NT2. At most recent follow-up, none required stimulant therapy, and all were functioning without daytime impairment. The improvement in symptoms correlated with stabilization of mood over time. Conclusion This case series suggests that symptoms of NT2, particularly excessive daytime sleepiness, may spontaneously resolve over the course of a lifetime in a subset of patients. The coexistence of depressive symptoms at the time of diagnosis raises the possibility that mood disorders and associated fatigue may contribute to the clinical presentation of NT2, potentially leading to diagnostic overlap or misattribution. Longitudinal studies are needed to better characterize the natural history of NT2 and the influence of comorbid psychiatric conditions on long-term outcomes. Support (if any)