Evidence browser

Pain in adolescent chronic fatigue following Epstein-Barr virus infection.

Brodwall, Elias Myrstad, Pedersen, Maria, Asprusten, Tarjei Tørre et al.·Scandinavian journal of pain·2020

This study looked at pain symptoms in teenagers who developed chronic fatigue after a common virus infection (Epstein-Barr virus). Researchers compared teenagers who had the virus and became fatigued, those who had the virus but did not become fatigued, and healthy teenagers without the virus. They found that the fatigued group reported significantly more pain symptoms and that the amount of pain they experienced was strongly linked to their quality of life.

Pain and SensitizationDiagnostics

Systemic Hyperalgesia in Females with Gulf War Illness, Chronic Fatigue Syndrome and Fibromyalgia.

Surian, Amber A, Baraniuk, James N·Scientific reports·2020

This study measured how sensitive to pain women with ME/CFS, Gulf War Illness, and fibromyalgia are compared to healthy controls. Researchers used a tool called a dolorimeter to apply pressure to 18 specific body points and measured how much pressure it took before women felt pain. Women with these illnesses felt pain at much lower pressure levels than healthy women, showing they have widespread increased pain sensitivity.

OnabotulinumtoxinA Is an Effective Treatment for Chronic Migraine in Patients With Comorbid Fibromyalgia.

Sastre Real, María, Díaz de Terán, Javier·Frontiers in neurology·2020

This study looked at whether a migraine treatment called botulinum toxin (Botox) could help people who have both chronic migraines and fibromyalgia. Researchers found that about two-thirds of patients improved within 3 months, and by 12 months, nearly 70% had at least a 50% reduction in severe headache days. The treatment was generally safe with only mild side effects.

E2 ModerateCohortPEM unclearObservational

Relationship Between Exercise-induced Oxidative Stress Changes and Parasympathetic Activity in Chronic Fatigue Syndrome: An Observational Study in Patients and Healthy Subjects.

Polli, Andrea, Van Oosterwijck, Jessica, Nijs, Jo et al.·Clinical therapeutics·2019

This study looked at whether oxidative stress (cellular damage from normal metabolism) is related to pain in ME/CFS patients, and how it connects to the vagus nerve, which helps control the body's relaxation response. Researchers had ME/CFS patients and healthy people do a mild exercise test and measured their pain, oxidative stress levels, and nerve activity before and after. They found that oxidative stress was linked to pain in ME/CFS patients, but unlike healthy people, ME/CFS patients didn't show improvements in pain or oxidative stress after exercise.

Pain and SensitizationAutonomic Nervous System

The proportion of women with central sensitivity syndrome in gynecology outpatient clinics (GOPDs).

Vij, Monika, Davies, Anthony, Dua, Anu et al.·International urogynecology journal·2019

This study looked at women visiting gynecology clinics whose symptoms didn't match what doctors could see on physical exams or tests. Researchers gave these women a questionnaire about pain sensitivity and related symptoms. They found that 37% of the women screened positive for central sensitization—a condition where the nervous system becomes more sensitive to pain and other sensations. Many of these women also had other conditions like migraine, depression, anxiety, IBS, and ME/CFS.

Musculoskeletal Pain in Individuals With Inflammatory Bowel Disease Reflects Three Distinct Profiles.

Falling, Carrie, Stebbings, Simon, Baxter, George D et al.·The Clinical journal of pain·2019

Most people with inflammatory bowel disease (IBD) experience muscle and joint pain, but the pain works differently in different people. This study found three distinct groups: one with mixed types of pain, one with pain driven by nervous system sensitivity, and one with pain in specific areas that improves when the IBD is under control. The group with nervous system-driven pain had higher rates of depression, anxiety, and chronic fatigue syndrome.

E2 ModerateCohortPEM unclearCross-Sectional

Pain is associated with reduced quality of life and functional status in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Strand, Elin Bolle, Mengshoel, Anne Marit, Sandvik, Leiv et al.·Scandinavian journal of pain·2019

This study compared 87 ME/CFS patients with 94 healthy people to understand how pain affects quality of life. Researchers found that ME/CFS patients experience significantly more pain, anxiety, and depression, and have lower quality of life than healthy controls. Within the ME/CFS group, pain was strongly linked to reduced physical functioning and overall quality of life, suggesting that managing pain could help improve how well patients function daily.

Endometriosis increased the risk of bladder pain syndrome/interstitial cystitis: A population-based study.

Wu, Chia-Chang, Chung, Shiu-Dong, Lin, Herng-Ching·Neurourology and urodynamics·2018

This study found that women with endometriosis (a condition where tissue similar to the uterine lining grows outside the uterus) have a significantly higher risk of developing bladder pain syndrome/interstitial cystitis (BPS/IC), a chronic bladder pain condition. Over a 3-year period, about 4 times as many women with endometriosis developed BPS/IC compared to women without endometriosis. This suggests these two painful conditions may share common underlying mechanisms.

E2 ModerateBehavioralPEM not requiredCross-Sectional

Negative Affectivity, Depression, and Resting Heart Rate Variability (HRV) as Possible Moderators of Endogenous Pain Modulation in Functional Somatic Syndromes.

Van Den Houte, Maaike, Van Oudenhove, Lukas, Van Diest, Ilse et al.·Frontiers in psychology·2018

This study looked at how the body's natural pain-blocking system works in people with fibromyalgia and chronic fatigue syndrome (CFS), and whether mood, depression, or heart rate variability might affect this system. Researchers compared 78 patients with these conditions to 33 healthy people using a test where they applied cold and electrical stimuli to see if pain would decrease. Unfortunately, the main pain-blocking effect the researchers expected to find did not appear in either group, so they could not draw clear conclusions about what affects pain modulation.

Pain and SensitizationAutonomic Nervous System

Physical Examination for Men and Women With Urologic Chronic Pelvic Pain Syndrome: A MAPP (Multidisciplinary Approach to the Study of Chronic Pelvic Pain) Network Study.

Yang, Claire C, Miller, Jane L, Omidpanah, Adam et al.·Urology·2018

This study looked at physical examination findings in people with chronic pelvic pain to see if doctors could identify characteristic patterns. Researchers examined 62 people with pelvic pain and compared them to 42 people with chronic fatigue syndrome and 39 healthy people. They found that people with pelvic pain were much more likely to have tender muscles in the pelvic floor area, and a special extended examination could help identify which specific areas were affected.

E2 ModerateCohortPEM unclearCross-Sectional

Poor self-reported sleep quality and health-related quality of life in patients with chronic fatigue syndrome/myalgic encephalomyelitis.

Castro-Marrero, Jesús, Zaragozá, Maria C, González-Garcia, Sergio et al.·Journal of sleep research·2018

This study looked at sleep problems in 1,455 Spanish ME/CFS patients and found that nearly all of them reported poor sleep quality that wasn't refreshing, even when they slept. The researchers discovered that poor sleep was strongly linked to worse pain, fatigue, anxiety, depression, and lower quality of life overall. Several factors—including pain intensity, mood problems, fibromyalgia, and autonomic nervous system dysfunction—were particularly associated with sleep difficulties.

Pain and SensitizationSleepAutonomic Nervous System

Endogenous Pain Facilitation Rather Than Inhibition Differs Between People with Chronic Fatigue Syndrome, Multiple Sclerosis, and Controls: An Observational Study.

Collin, Simon M, Nijs, Jo, Meeus, Mira et al.·Pain physician·2017

This study tested how people with ME/CFS, people with multiple sclerosis (MS), and healthy people respond to pain. Researchers found that people with ME/CFS have lower pain thresholds and more pain amplification than people with MS, suggesting their nervous systems may process pain differently. These findings suggest that ME/CFS pain may involve a different biological mechanism than MS pain.

E2 ModerateBehavioralPEM unclearCross-Sectional

Activity Pacing is Associated With Better and Worse Symptoms for Patients With Long-term Conditions.

Antcliff, Deborah, Campbell, Malcolm, Woby, Steve et al.·The Clinical journal of pain·2017

This study looked at different ways people with chronic fatigue, fibromyalgia, and chronic pain manage their activities day-to-day. Researchers found that some pacing strategies work better than others: spreading activities consistently throughout the day helped, but drastically cutting back activities was linked to feeling worse. The study suggests that how you pace your activities matters—not all pacing strategies are equally helpful.

Prefrontal Structure Varies as a Function of Pain Symptoms in Chronic Fatigue Syndrome.

van der Schaaf, Marieke E, De Lange, Floris P, Schmits, Iris C et al.·Biological psychiatry·2017

This study examined brain structure in 89 women with ME/CFS using brain imaging. Researchers found that the amount of pain a patient experiences—not fatigue—was the strongest predictor of changes in a specific brain region called the dorsolateral prefrontal cortex. People with more pain showed smaller brain volume and lower levels of brain chemicals in this region, even after accounting for fatigue, depression, and physical activity.

E2 ModerateDiagnosticPEM not requiredMethods-Paper

Establishing Clinically Relevant Severity Levels for the Central Sensitization Inventory.

Neblett, Randy, Hartzell, Meredith M, Mayer, Tom G et al.·Pain practice : the official journal of World Institute of Pain·2017

Researchers created and tested a scoring system called the Central Sensitization Inventory (CSI) to help doctors identify when someone's symptoms may be caused by their nervous system being overly sensitive to pain signals. The study divided CSI scores into five levels—from subclinical to extreme—and confirmed that higher scores are associated with having more chronic conditions like fibromyalgia and ME/CFS, as well as higher levels of depression, sleep problems, and disability.

Pain and SensitizationSleep

Specialist treatment of chronic fatigue syndrome/ME: a cohort study among adult patients in England.

Collin, Simon M, Crawley, Esther·BMC health services research·2017

This study looked at how 952 ME/CFS patients fared after receiving treatment at 11 specialist NHS clinics in England. One year after starting treatment, about 27% felt much better, 37% felt a little better, but 20% felt the same or worse. Even 2-5 years later, 85% of patients still had ME/CFS symptoms, showing that this is a long-lasting condition that often continues despite specialist care.

Binocular Vision in Chronic Fatigue Syndrome.

Godts, Daisy, Moorkens, Greta, Mathysen, Danny G P·The American orthoptic journal·2016

This study found that people with ME/CFS have differences in how their eyes work together compared to healthy people. Specifically, ME/CFS patients had weaker ability to focus both eyes on nearby objects, reduced eye convergence (bringing eyes together to focus), and a smaller range of accommodation (adjusting focus from far to near). The researchers suggest that ME/CFS patients may benefit from reading glasses or vision exercises earlier than other people.

Occupational exposure and health problems among Polish denturists: a population-based study in Łódź province.

Garus-Pakowska, Anna, Leśniewska, Agnieszka, Gaszyńska, Ewelina et al.·International dental journal·2016

This study surveyed 103 denturists (dental laboratory workers) in Poland to understand how their work affects their health. The researchers found that over 60% experienced chronic fatigue syndrome and 70% had back pain, along with skin irritation and eye problems. Poor workplace design and stress from work organization were identified as major contributing factors.

Characteristics of hyperacusis in the general population.

Paulin, Johan, Andersson, Linus, Nordin, Steven·Noise & health·2016

This study looked at how common sound sensitivity (hyperacusis) is in the general population and what characteristics people with this condition share. Researchers surveyed thousands of people and found that sound sensitivity often occurs alongside other conditions like ME/CFS, anxiety, depression, and fibromyalgia. People with sound sensitivity tend to avoid loud environments and may seek medical help for their symptoms.