Effect of Low Sodium Oxybate (LXB) on Autonomic Symptom Burden in Idiopathic Hypersomnia Patients With Postural Tachycardia Syndrome

The investigators hope to learn if low sodium oxybate (LXB) is an effective treatment for symptoms of idiopathic hypersomnia (IH) and postural tachycardia syndrome (POTS). Previous research has shown that patients with IH also report having symptoms associated with POTS. The researchers have observed that in patients with both IH and POTS, when patients' sleep quality improves, so do their POTS symptoms. The goal of this study is to test this in a controlled way by using LXB as a treatment for both IH and POTS in patients that have been diagnosed with both conditions.