Further Exploring the Associations Between Sympathetic Activation, Fear of Sleep, and Insomnia Symptoms in Posttraumatic Stress Disorder Further Exploring the Associations Between Sympathetic Activation, Fear of Sleep, and Insomnia Symptoms in Posttraumatic Stress Disorder Download Fear of Sleep May Be a Core Symptom of Sympathetic Activation and the Drive for Vigilance in Posttraumatic Stress Disorder Increased Risk of Benign Paroxysmal Positional Vertigo in Patients With Non-Apnea Sleep Disorders: A Nationwide, Population-Based Cohort Study