Orthostatic Intolerance and Autonomic Dysfunction in Youth With Persistent Postconcussion Symptoms: A Head-Upright Tilt Table Study.
To explore head-upright tilt table (HUT) signs of autonomic dysfunction in a cohort of youth with persistent postconcussion symptoms (PCSs) that include light-headedness and to correlate repeat tilt table results with symptom improvements for those patients found to have postural tachycardia syndrome (POTS) on initial testing. Prospective cohort design. Nationwide Children's Hospital, Neurology Clinic. Thirty-four patients (13-18 years of age) with persistent PCSs. All patients underwent at least 1 tilt table test. The PCS Interview (PCS-I) and patient ratings of light-headedness and vertigo were used to measure symptom burden. Patients found to have POTS were asked to repeat tilt table testing when PCSs improved or 3 to 6 months after the initial test if symptoms persisted. Twenty-four of the 34 (70.6%) patients had abnormal tilt table results with patients categorized as normal (n = 10), isolated syncope (n = 10), and POTS (n = 14). Patients with POTS had higher PCS-I scores than normal patients (P < 0.001) and higher ratings of light-headedness than both normal patients (P = 0.015) and syncope patients (P = 0.04). Twelve POTS patients underwent repeat tilt table testing, and 9 of 12 (75%) no longer met POTS diagnostic criteria. All patients with resolution of POTS had corresponding improvements in PCSs, including light-headedness and vertigo. Our study demonstrates a high rate of tilt table abnormalities among youth with persistent PCSs. Several patients with POTS had normalization of tilt table testing when PCSs improved. These findings warrant further research of autonomic dysfunction related to concussion. Our study is the first to prospectively characterize autonomic dysfunction in patients with persistent PCSs using HUT testing and to show that the tilt test abnormalities normalize in some patients as PCSs improve.