The Impact of Hydrotherapy on Health-Related Quality of Life, Pain and Mobility in Individuals With Mucopolysaccharidosis Type II (Hunter Syndrome): A Pilot Feasibility Study.

Enzyme Replacement Therapy (ERT) is the clinical standard for Mucopolysaccharidosis II (MPSII), yet its limited penetration into poorly vascularised tissues such as bone, cartilage and heart valves leaves participants with significant musculoskeletal morbidity. This small study evaluated the feasibility of hydrotherapy as an adjunct to ERT in addressing these therapeutic gaps and improving Health-Related Quality of Life (HRQoL). Using a crossover design, the study assessed five male participants with MPSII. Key outcomes included HRQoL via the Short Form Health Survey (SF-36), functional mobility by the 6-Minute Walk Test (6MWT) and pain interference through the Brief Pain Inventory (BPI). Data from the SF-36 and BPI showed improvements, including a mean improvement in Physical Functioning, Role Physical and Social Functioning and a mean reduction of 16.2 in pain interference. Analgesic relief over 24 h was 45.8% in the hydrotherapy arm, compared to 18% in the observation arm. Psychological conditions including anxiety, depression and kinesiophobia were also analysed. Participants demonstrated a mean increase of 44.5 m in the 6MWT, suggesting that the 'unloading' effect of water facilitated gait speed and endurance (compared to observation arm: mean difference 55.8 m 95% CI -51.6 to 163.1). Participants achieved a mean strength increase of 6.1 lb. during the hydrotherapy arm without adverse effects, corroborating the safety of aquatic resistance training in fragile populations. Our findings demonstrate the feasibility of hydrotherapy as an adjunct to ERT in participants with MPSII. By managing pain and improving HRQoL, hydrotherapy addresses physical and psychological burdens that ERT alone cannot achieve.