Background Fibromyalgia (FMS) is a primary chronic pain disorder classified in ICD-11 as widespread
pain with multifactorial symptoms including muscle pain, fatigue, sleep disturbances,
and psychological issues. Therapy recommendations typically involve a multimodal and
interdisciplinary approach, including regular graded exercise. However, participation
in active therapies by patients with FMS is often limited due to lower pain thresholds
and strong pain experience. Increasing nociceptive thresholds could improve access
to movement therapy. In passive whole-body hyperthermia (WBHT), the core body temperature
is therapeutically increased using external heat. This controlled rise triggers a
thermal stress response, influencing various mechanisms of the hormonal and immune
systems. This case series aimed to investigate how sensory and nociceptive thresholds,
as well as pain experience (perception) change in patients with fibromyalgia after
passive whole-body hyperthermia, and whether there is also a change in pain experience.
Method This case series includes four female patients with FM between age of 41 and 66.
Quantitative sensory testing (QST) was used to measure sensory and nociceptive thresholds
and four questionnaires such as the Pain Severity Score (parts 2a and 2b), the Widespread
Pain Index, the Pain Severity Scale according to von Korff, and the Pain Description
List were employed to assess their pain experience. The measurements were conducted
one week before and after the intervention with wIRA-WBHT. All outcomes were analyzed
and described descriptively for each individual patient.
Results The results indicate positive changes in pressure pain threshold (PPT) for all four
patients and positive changes in heat pain threshold (HPT) for three of four patients.
Three patients experienced varying degrees of improvement in sensory thresholds, while
one patient showed no improvement. Seven days after the intervention, three of the
four patients demonstrated some positive changes in pain experience.
Conclusion Objective changes in sensory and nociceptive thresholds were demonstrated within
a short time in this case series. However, for subjective changes in pain experience,
additional factors and longer-term evaluations are probably needed. Future studies
with stronger methodological designs and longer follow-up are needed to validate these
promising results and assess the generalizability of passive WBHP effects in patients
with FM.
