Alterations of Attention in POTS Depending on Body Position and Hydration
The Postural Tachycardia-Syndrome (POTS) is a form of autonomic dysregulation, typically accompanied by symptoms of orthostatic intolerance (OI). OI is defined by the inability to tolerate the upright position and is improved by lying down. POTS is considered a syndrome that may include a number of several disorders. Symptoms should be persistent for at least 6 months to reach a diagnosis. It is characterized by a sustained heart rate (HR) increment of 30 beats/min or more within 10 min of standing or head-up tilt (HUT) in adults, in the absence of orthostatic hypotension and with the presence of symptoms of OI. In children and adolescents a diagnosis requests a HR increment of at least 40 beats/min. The increment in HR when moving to an upright posture is often a response to a reduction in venous return, causing excessive blood pooling in the lower limbs. The symptoms present in POTS vary greatly. Typical symptoms are lightheadedness, dizziness, blurred vision, mental clouding ("brain fog") or cognitive dysfunction. Other symptoms may present as palpitations or chest pain. Additional symptoms consist of postural headaches, nausea, sleep disturbances, fatigue and gastrointestinal dysfunction. The manifestation of symptoms in POTS varies in severity, frequency and combination, resulting in POTS being a very heterogenous and subjective disorder. Symptoms can be severe and often make simple daily activities difficult to an extent that compromises the patients quality of life. Typically symptoms exacerbate in the mornings, after physical activity, after eating and during menstruation. This study objective is to examine the occurrence, mechanisms and causes of impaired attention in POTS as well as to test the effect of acute water ingestion for attention in POTS. The investigators therefore conduct a study including patients with POTS and healthy volunteers. All participants will receive a dossier of five self-assessment questionnaires after giving informed consent. Clinical examination includes 2 HUT-tests while standing for 15 minutes, conventional measuring of blood pressure, continuous recording of NIRS signals during testing, determination of pupil size, the diameter of the optic nerve and Neuropsychological testing (Test of Attentional Performance, mobility version" (TAP-M), Go/NoGo Test, Divided Attention Test)
Start: September 2017