起立性調節障害における脳組織の変化、ネットワーク機能障害、および脳血行動態の異常

Tachycardia upon standing implicates a cardiovascular dysreflexia, potentially resulting from impaired autonomic regulation. However, the pathophysiology of POTS remains unclear. Here we evaluated the central nervous system in POTS.

To evaluate brain tissue changes, functional networks (central autonomic network), and cerebral hemodynamic status in patients with postural orthostatic syndrome (POTS) using magnetic resonance imaging and autonomic reflex challenges.

Individuals with POTS and age and sex-matched healthy controls were enrolled. Brain MRI data were collected using a 3.0-Tesla scanner at rest and during functional MRI using three autonomic reflex challenges: passive leg raise (PLR), mental arithmetic (MA), and isometric handgrip reflex (IHR).

38 participants were enrolled (18 POTS and 20 controls). No significant differences emerged in age, sex, or BMI between POTS and controls (P>0.05). POTS patients had higher anxiety and depression symptoms. Although global screening indicators of cognitive function were preserved (MoCA test; POTS vs controls, 28±1 vs. 29±1, P=0.2), executive function was slowed in POTS (Trail-making test-B; POTS vs controls, 44±12 vs 67±34, P=0.008). Brain tissue structural changes (P<0.005) and reduced cerebral blood flow appeared in POTS compared to controls (P<0.005). Further, impaired neural responses were seen in POTS during PLR, MA and IHR (P<0.005), despite preserved peripheral reflex function (P>0.05).

POTS patients show evidence of brain tissue structural changes, impaired central neural responses, and reduced cerebral blood flow in autonomic regulatory sites during cardiovascular reflex testing. These findings indicate that central autonomic control deficits may help explain the cardiovascular dysreflexia in POTS.