Phenotyping of orthostatic intolerance and regulation of cerebral perfusion in ME/CFS

Project description

Orthostatic intolerance (OI) is a condition in which sitting or standing up straight leads to dizziness, palpitations and fainting. OI has several forms, of which the postural tachycardia syndrome (POTS) is one variant. Between 40-90% of ME/CFS patients have OI and experience serious discomfort as a result.

Despite this, little is known about the causes of OI and diagnostics are difficult. OI diagnosis is usually made based on abnormalities in blood pressure or heart rate during posture tests. In about half of the patients with OI complaints, no abnormalities are found with these tests. Recent research shows that patients with OI have reduced blood flow to the brain during posture change (cerebral blood flow). This discovery offers both an important explanation for OI complaints and an opportunity for improved diagnostics.

The goal of this project is to improve diagnostic accuracy and knowledge about OI in ME/CFS. This is done in two sub-studies:

1) Mapping different forms of OI in ME/CFS. For this purpose, a comprehensive analysis of physical (physiological), noticeable (symptomatic) and daily (functional) data from the Dutch ME/CFS Cohort and Biobank (NMCB) is carried out. The aim is to classify different forms of OI into categories and better understand the diagnosis and course of the disease.

2) Investigation with advanced MRI techniques on how a reduced blood supply to the brain may explain OI.

Sub-study 1 uses data from the SNCB cohort. It analyses the reactions to the NASA Lean Test, a method to measure OI. In addition, measurements of symptoms, the autonomis nervous system and cognitive functions are performed. Data from 750 ME/CFS patients are compared with those from 450 healthy controls. In parallel, the researchers analyse data from post-COVID, post-Q fever and post-Lyme patients.

Sub-study 2 imitates orthostatic stress with the help of Lower Body Negative Pressure (LBNP) while patients' brains are scanned via magnetic resonance imaging (MRI). This can determine how reduced blood flow to the brain causes OI symptoms. For this, 50 ME/CFS patients with severe IO complaints are compared to 25 ME/CFS patients without IO complaints and 25 healthy controls.

The expected result are to improve the diagnosis of OI in ME/CFS. MRI scans may serve as a new diagnostic tool to determine abnormalities in the blood supply to the brain. Better objectifying OI in ME/CFS thus provides a foundation for more treatment research and can lead to a better understanding of the disease.

Description adapted from project website: see link above.