ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

2422 studies

2321–2340 of 2,422 studies

E3 PreliminaryCohortPEM not requiredObservational

Postinfectious chronic fatigue syndrome: case history of thirty-five patients in Germany.

Hilgers, A, Krueger, G R, Lembke, U et al.·In vivo (Athens, Greece)·1991

This study followed 35 ME/CFS patients in Germany for up to eight years and found that most experienced severe fatigue, joint and muscle pain, sore throats, and various other symptoms. Researchers found evidence of herpesvirus reactivation in about 73% of patients and Epstein-Barr virus in about 34%, suggesting ongoing viral activity may play a role in the condition. While treatments were tried including immune therapy and antiviral drugs, none consistently worked well, though immune globulin therapy showed the most promise.

Immune System

E3 PreliminaryTrialPEM not requiredRCT

A randomized comparison of two doses of human lymphoblastoid interferon-alpha in hairy cell leukemia. Wellcome HCL Study Group.

Smalley, R V, Anderson, S A, Tuttle, R L et al.·Blood·1991

This study tested two different doses of interferon-alpha (a type of immune protein) in patients with hairy cell leukemia, a blood cancer. Researchers found that the lower dose worked almost as well as the higher dose for improving blood cell counts but caused fewer side effects, including less chronic fatigue. Based on these results, doctors were advised to start patients on the lower dose.

E3 PreliminaryCohortPEM unclearCase-Control

Fibromyalgia and parvovirus infection.

Leventhal, L J, Naides, S J, Freundlich, B·Arthritis and rheumatism·1991

This study describes three patients who developed fibromyalgia (a condition causing widespread pain and fatigue) shortly after having parvovirus B19 infections. Blood tests confirmed the virus was present, and sleep studies showed abnormal sleep patterns in two patients. The researchers suggest that doctors should look more carefully for viral infections in fibromyalgia patients whose symptoms started with flu-like illness.

Immune System

E3 PreliminaryReviewPEM not requiredReview-Narrative

Depression and chronic fatigue in the patient with chronic pain.

Covington, E C·Primary care·1991

This study explores how chronic pain, fatigue, and depression often occur together in patients. The authors suggest that these three conditions share common causes and may influence each other. Treatment works best when doctors address each problem separately using a combination of physical rehabilitation, education, medications, and counseling.

Pain and Sensitization

E3 PreliminaryMechanismPEM not requiredMechanistic

Genomic polymorphism, growth properties, and immunologic variations in human herpesvirus-6 isolates.

Ablashi, D V, Balachandran, N, Josephs, S F et al.·Virology·1991

Researchers studied different versions of human herpesvirus-6 (HHV-6), a virus found in people with various conditions including chronic fatigue syndrome. They found that HHV-6 comes in at least two distinct types—similar to how there are two types of cold sores—and these types behave differently in the lab, infecting different cell types and reacting differently to immune system antibodies.

E3 PreliminaryMechanismPEM not requiredCross-Sectional

Muscle performance, voluntary activation, twitch properties and perceived effort in normal subjects and patients with the chronic fatigue syndrome.

Lloyd, A R, Gandevia, S C, Hales, J P·Brain : a journal of neurology·1991

Researchers tested whether ME/CFS patients have weak muscles or lack motivation during exercise compared to healthy people. They measured muscle strength and effort in both groups while performing repetitive arm exercises for 45 minutes. Both groups showed similar muscle performance and reported similar levels of effort, suggesting that muscle weakness or poor motivation are not the primary causes of fatigue in ME/CFS.

E3 PreliminaryDiagnosticPEM not requiredMethods-Paper

Validation of biologic markers for use in research on chronic fatigue syndrome.

Schulte, P A·Reviews of infectious diseases·1991

This paper explains how scientists should evaluate biological markers—measurable signs in blood, tissue, or other body samples—before using them in ME/CFS research. The authors provide a practical checklist that researchers should follow to make sure these markers are reliable, meaningful, and won't be affected by other factors. This helps ensure that future ME/CFS studies measure things accurately and produce trustworthy results.

E3 PreliminaryReviewPEM not requiredReview-Narrative

The chronic fatigue syndrome.

Shafran, S D·The American journal of medicine·1991

ME/CFS is a serious condition causing extreme fatigue lasting at least 6 months that doctors cannot fully explain. While most patients report getting sick before their fatigue started, researchers have not found proof that any specific infection causes ME/CFS. The condition mainly affects people aged 20-50, with more women than men affected.

Immune System

E3 PreliminaryDiagnosticPEM not requiredMethods-Paper

Issues and problems in the conduct of epidemiologic research on chronic fatigue syndrome.

Grufferman, S·Reviews of infectious diseases·1991

This paper discusses how scientists should study ME/CFS using epidemiology—a research method that looks at how diseases spread through populations. The authors outline the main problems researchers face when studying ME/CFS, such as unclear diagnostic criteria and limited understanding of the condition, and suggest practical solutions. They emphasize that case-control studies (comparing people who have ME/CFS with similar people who don't) should be a priority for understanding what causes the illness.

Diagnostics

E3 PreliminaryReviewPEM not requiredReview-Narrative

Human herpesvirus-6 (HHV-6) (short review).

Ablashi, D V, Salahuddin, S Z, Josephs, S F et al.·In vivo (Athens, Greece)·1991

This review examines Human Herpesvirus-6 (HHV-6), a common virus that most people carry. The virus can reactivate in people with certain illnesses, including ME/CFS. The study found that people with ME/CFS sometimes have higher levels of antibodies to HHV-6, suggesting the virus may be active in their bodies.

Immune System

E3 PreliminaryCommentaryPEM not requiredEditorial

Dual infections of the immune system in patients with chronic active Epstein-Barr virus infection mimicking chronic fatigue syndrome.

Purtilo, D T·Canada diseases weekly report = Rapport hebdomadaire des maladies au Canada·1991

This article discusses the importance of distinguishing patients with ME/CFS (the commonly recognized illness) from those who have dual infections or weakened immune systems that only look like ME/CFS. The authors argue that some patients appearing to have ME/CFS may actually have other treatable conditions involving multiple infections, and recommend long-term studies tracking people who develop ME/CFS-like symptoms after documented viral infections.

Immune System

E3 PreliminaryBehavioralPEM not requiredCase-Control

Seasonal affective disorder presenting as chronic fatigue syndrome.

Lam, R W·Canadian journal of psychiatry. Revue canadienne de psychiatrie·1991

This study describes two patients who were diagnosed with chronic fatigue syndrome (CFS) but actually had seasonal affective disorder (SAD)—a type of depression that occurs during certain seasons. Both patients improved significantly when treated with light therapy rather than typical CFS treatments. The study highlights that depression, including seasonal depression, can look very similar to CFS and needs to be carefully ruled out before diagnosing CFS.

E3 PreliminaryReviewPEM unclearReview-Narrative

Clinical spectrum of postviral fatigue syndrome.

Behan, P O, Bakheit, A M·British medical bulletin·1991

This review article examines postviral fatigue syndrome (also called ME/CFS), a condition that develops after viral infections and causes severe tiredness and other symptoms. The authors describe how this syndrome appears both in individual cases and in epidemic clusters worldwide, and explain why doctors historically had difficulty recognizing it until outbreaks occurred.

E3 PreliminaryReviewPEM unclearReview-Narrative

[Chronic fatigue syndrome; psychiatric aspects].

Hawton, K E, Hengeveld, M W·Nederlands tijdschrift voor geneeskunde·1991

This 1991 review article examines the psychiatric aspects of chronic fatigue syndrome (ME/CFS), exploring how mental health factors relate to the condition. The authors discuss the connection between psychiatric symptoms and fatigue, helping to clarify whether psychological issues cause ME/CFS or occur alongside it. This work contributed to early medical understanding of how ME/CFS affects both the body and mind.

E3 PreliminaryReviewPEM not requiredReview-Narrative

Testing of vestibular function: an adjunct in the assessment of chronic fatigue syndrome.

Furman, J M·Reviews of infectious diseases·1991

Many people with ME/CFS experience dizziness and balance problems, but doctors don't fully understand why. This study looked at whether problems with the inner ear (the system that helps control balance) might explain these symptoms. The researchers tested the vestibular system—which controls balance and eye movement—using specialized equipment to see if people with ME/CFS had measurable abnormalities in how this system works.

Autonomic Nervous System

E3 PreliminaryReviewPEM not requiredReview-Narrative

The chronic fatigue syndrome: a reappraisal and unifying hypothesis.

Byrne, E·Clinical and experimental neurology·1991

This 1991 review examined ME/CFS from multiple scientific angles—including viral infection, immune system problems, metabolism, and mental health—to understand why this condition develops. The authors proposed that ME/CFS typically results from a combination of factors: personal characteristics before illness (like psychological traits or immune vulnerabilities), a trigger (such as a virus), and how someone's emotions respond to being sick. Rather than having one single cause, ME/CFS appears to exist on a spectrum of different presentations.

E3 PreliminaryReviewPEM not requiredReview-Narrative

Clinical indications and diagnostic techniques of human herpesvirus-6 (HHV-6) infection.

Krueger, G R, Ablashi, D V, Josephs, S F et al.·In vivo (Athens, Greece)·1991

This review examines how doctors can diagnose human herpesvirus-6 (HHV-6) infection and its connection to various illnesses, including a condition called postinfectious chronic fatigue syndrome. HHV-6 is a common virus that most people catch in childhood and then carry dormant in their bodies for life. The authors explain which tests doctors should use to accurately identify active HHV-6 infection and discuss why proper diagnosis matters for treatment.

E3 PreliminaryCohortPEM not requiredCase-Control

Infectious mononucleosis, Epstein-Barr virus, and chronic fatigue syndrome: a prospective case series.

Fark, A R·The Journal of family practice·1991

This study looked at whether Epstein-Barr virus (EBV), the virus that causes infectious mononucleosis (mono), might be the cause of ME/CFS. Researchers found that some people with chronic fatigue had high levels of antibodies (immune markers) against EBV, and some of them had never fully recovered from a previous mono infection. The study suggests a possible link between EBV infection and the development of chronic fatigue, though it doesn't prove the virus directly causes ME/CFS.

Immune System

E3 PreliminaryReviewPEM not requiredReview-Narrative

[Chronic fatigue: myth or reality?].

Comtois, R·L'union medicale du Canada·1991

This 1991 review article addresses a fundamental question: Is chronic fatigue a real medical condition or just a perception? The authors acknowledge that while fatigue is one of the most common health complaints doctors hear, it can be difficult to diagnose and treat because we don't have simple blood tests like we do for cholesterol. The paper discusses how new diagnostic criteria for chronic fatigue syndrome were beginning to help doctors identify and manage this condition more effectively.

Diagnostics

E3 PreliminaryBehavioralPEM not requiredObservational

Cognitive behaviour therapy in chronic fatigue syndrome.

Butler, S, Chalder, T, Ron, M et al.·Journal of neurology, neurosurgery, and psychiatry·1991

This study tested whether cognitive behaviour therapy (CBT)—a type of talk therapy focusing on thoughts and behaviors—could help 50 ME/CFS patients who had been sick for an average of five years. Patients received therapy aimed at identifying unhelpful beliefs about their symptoms and gradually returning to activities. The therapy led to meaningful improvements in fatigue, overall functioning, and mood, though some patients refused treatment.

Interventions

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Postinfectious chronic fatigue syndrome: case history of thirty-five patients in Germany.

A randomized comparison of two doses of human lymphoblastoid interferon-alpha in hairy cell leukemia. Wellcome HCL Study Group.

Fibromyalgia and parvovirus infection.

Depression and chronic fatigue in the patient with chronic pain.

Genomic polymorphism, growth properties, and immunologic variations in human herpesvirus-6 isolates.

Muscle performance, voluntary activation, twitch properties and perceived effort in normal subjects and patients with the chronic fatigue syndrome.

Validation of biologic markers for use in research on chronic fatigue syndrome.

The chronic fatigue syndrome.

Issues and problems in the conduct of epidemiologic research on chronic fatigue syndrome.

Human herpesvirus-6 (HHV-6) (short review).

Dual infections of the immune system in patients with chronic active Epstein-Barr virus infection mimicking chronic fatigue syndrome.

Seasonal affective disorder presenting as chronic fatigue syndrome.

Clinical spectrum of postviral fatigue syndrome.

[Chronic fatigue syndrome; psychiatric aspects].

Testing of vestibular function: an adjunct in the assessment of chronic fatigue syndrome.

The chronic fatigue syndrome: a reappraisal and unifying hypothesis.

Clinical indications and diagnostic techniques of human herpesvirus-6 (HHV-6) infection.

Infectious mononucleosis, Epstein-Barr virus, and chronic fatigue syndrome: a prospective case series.

[Chronic fatigue: myth or reality?].

Cognitive behaviour therapy in chronic fatigue syndrome.

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