Blood Flow To The Head Is Reduced In A Patient With Myalgic Encephalomyelitis With Confirmed Post-exertional Malaise

Reduced Cerebral Blood Flow (CBF) may underlie the pathophysiology of Post-Exertional Malaise (PEM) in Myalgic Encephalomyelitis (ME). PURPOSE: A novel in-ear device provided by STAT Health was used to measure blood flow to the head via the external carotid artery as a proxy for CBF. The goal was to determine if there would be measurable differences in Flow during PEM induced by exercise testing (CPET). METHODS: One patient with ME and one control subject underwent 2-day CPET to induce PEM. STAT’s Flow Index was measured supine and during an orthostatic challenge (10 min standing) before CPET on both days. RESULTS: CPET results confirmed PEM in the ME patient, with a 34% reduction in Work at the Anaerobic Threshold (AT). Relative to the Day 1 supine baseline, the ME patient experiencing Day 2 PEM had a large 17% reduction in supine Flow and a 23% reduction during orthostasis (10 min standing). In contrast, the control subject did not demonstrate PEM (1% reduction in Work at AT) and had a small 5% reduction in supine Flow on Day 2 relative to the Day 1 supine baseline. The control subject did not conduct the orthostatic challenge. CONCLUSION: Diminished Blood Flow during PEM may provide an objective mechanism underlying patient symptomatology for ME patients. The STAT device has the potential to serve both as a diagnostic biomarker and as a biofeedback tool for ME patients to better self-manage their symptoms.