Exercise induced muscle blood flow is decreased in Charcot–Marie–Tooth disease type 1 polyneuropathy: a power Doppler analysis

Background and purpose Intramuscular blood flow increases during physical activity and may be quantified immediately following exercise using power Doppler sonography. Post‐exercise intramuscular blood flow is reduced in patients with muscular dystrophy, associated with disease severity and degenerative changes. It is not known if intramuscular blood flow is reduced in patients with neuropathy, nor if it correlates with muscle strength and structural changes. The aim was to determine whether blood flow is reduced in patients with polyneuropathy due to Charcot–Marie–Tooth disease type 1 (CMT1) and to compare more affected distal to less affected proximal muscles. Methods This was a cross‐sectional study including 21 healthy volunteers and 17 CMT patients. Power Doppler ultrasound was used to quantify post‐exercise intramuscular blood flow in distal (gastrocnemius) and proximal (elbow flexor) muscles. Intramuscular blood flow was compared to muscle echo intensity, muscle strength, disease severity score, patient age and electromyography. Results Polyneuropathy patients showed reduced post‐exercise blood flow in both gastrocnemius and elbow flexors compared to controls. A more prominent reduction was seen in the gastrocnemius (2.51% vs. 10.34%, p