Glossary

A glossary of *key* ME-related terms.

B
B cell - B lymphocyte, or a type of white blood cell, which is involved in the immune response by secreting antibodies to ward off infections. In mammals, they are mostly matured in the bone marrow.

Biopsychosocial model (BPS model) - a school of thought, usually based in psychology, which claims illness and disease to be the result of the intermingling of biological, psychological and social causes.

C
Canadian Consensus Criteria (CCC) - a criteria used to diagnose ME/CFS (sic), developed by a group of clinicians in 2003. Often considered the most complex criteria, with the lowest number of patients meeting the criteria. Led to the development of the International Consensus Criteria in 2011.

Chronic Fatigue Syndrome (CFS) - may be more likely to refer to those diagnosed using the Fukuda Criteria or the Oxford definition. Commonly used in the United States as the name of the disease. Viewed by some patients as dismissive and derogatory.

Chronic Fatigue Syndrome Advisory Committee (CFSAC) - (sometimes pronounced SIF-SACK) meets twice per year, covering current topics related to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Meetings usually last for two days and the results are presented to the Secretary of Health and Human Services (HHS).

Cognitive behavioral therapy (CBT) -  A type of psychotherapy geared toward modifying unhealthy thinking, behaviors or illness beliefs. One of the treatment arms used in the controversial PACE Trial.

conversion disorder - formerly known as "hysteria". A mental condition in which neurologic symptoms can not be explained by a medical condition and are believed by some to develop unconsciously. Although symptoms are considered real, conversion disorder is usually thought to be triggered by stress or trauma.

Crash - see "post-exertional malaise"

Cyclophosphamide - a chemotherapy drug which supresses the immune system. According to Haukeland University Hospital website, the CycloME study (part A) is expected to publish results in the first half of 2018. Analysis of the overall study results indicate that there is reason to persue testing of the drug in ME/CFS patients.

E
Energy Envelope Theory

G
Graded Exercise Therapy (GET) - exercise therapy which gradually increases the patient's activity levels. Considered controversial in the treatment or management of ME.

H
HLA complex (human leukocyte antigen) - a gene complex responsible for encoding certain proteins which help the immune system to distinguish the body's own proteins from proteins which are made by foreign invaders like bacteria and viruses.

Heart rate monitor (HRM) - (noun) a device that measures your heart rate / pulse. Typically a chest strap, wrist strap, or mobile phone app. See also Pacing with a heart rate monitor

Heart rate variability (HRV) - a measurement of the specific changes in time (or variability) between successive heart beats. This is related to autonomic and cardiovascular function. See also Pacing with a heart rate monitor

I
ICD - International Classification of Diseases. A system of medical codes created by the World Health Organization (WHO) for diseases and other health related conditions for the purpose of international consistency. The 11th revision, or ICD-11, is due in 2018.

International Consensus Criteria

L
locus - in genetics, the location or position of a specific gene on a chromosome.

M
magnetic levitation device - uses ferrofluid (a liquid which can become magnetized) in a glass capillary tube surrounded by magnets. This creates a density gradient and cells move to their respective densities within the tube. White blood cells in CFS patients have been discovered to be less dense than those of healthy controls, indicating the possible use of the device as an inexpensive diagnostic test. This technology is being developed by Ron Davis's team at Stanford University. See also OMF Funded Diagnostic Technology Development

mass spectrometer - a device which converts molecules to ions, or charged particles. It then uses magnetic and electric fields to sort the ions according to their mass (similar to weight) and charge, and measure their characteristics.

Medically unexplained physical symptoms (MUPS) - symptoms for which a medical cause is not found.

Medically unexplained symptoms (MUS) - see Medically unexplained physical symptoms.

metabolic trap hypothesis - hypothesis proposed by Dr. Robert Phair. Based on preliminary data from the OMF-funded Severely Ill Patient Study (SIPS), which found several genes which may carry mutations in PwME. These mutations may cause enzymes which process important metabolites to slow down and cause a metabolic trap, which could explain some symptoms in ME/CFS.

metabolite - a substance produced by, or involved in metabolism.

metabolomics - the study and analysis of the chemical processes of metabolites within cells, tissues or organisms.

microbiome - the collective of microscopic organisms (including bacteria, viruses and fungi) and their genetic material, which are present in a particular environment, particularly in the human body.

mitochondria - organelles or subunits within a cell. Their primary role is to take in nutrients and produce energy for the cell in the form of ATP (adenosine triphosphate). This process requires oxygen and is called aerobic respiration.

Myalgic Encephalomyelitis

N
NASA 10-minute lean test - variation of a test used by NASA researchers to test for orthostatic intolerance. A simple test which is recommended by the Bateman Horne Center for ME and fibromyalgia patients. Instructions for medical providers. Instructions for patients.

nanoneedle - a nanofabricated device (one nanometer = one millionth of a millimeter) which measures electrical impedance from a drop of blood. The electrical impedance increased in the blood cells of 10 ME/CFS patients when stressed with salt, but not in healthy controls. This device may be able to distinguish ME/CFS patients from healthy controls and is being developed by Ron Davis's team at Standford University. See also OMF Funded Diagnostic Technology Development

O
Orthostatic intolerance (OI) - the development of symptoms when standing upright which are relieved when reclining; may be due to dysautonomia

P
PACE trial - a controversial study which claims that CBT and GET are effective in treating CFS/ME. Its results and methodology are disputed by patients, scientists and peer-reviewed scientific literature.

pacing - the practice of staying within one's 'energy envelope' by interspersing periods of activity with periods of rest. Patients may use pacing with a heart rate monitor as an objective measure of exertion.

payback - see post-exertional malaise

post-exertional malaise (PEM)- (noun) a worsening of ME symptoms due to physical or cognitive exertion

post-exertional neuroimmune exhaustion - see post-exertional malaise

Postural orthostatic tachycardia syndrome (POTS) - a form of orthostatic intolerance where the cardinal symptom is excessive tachycardia due to changing position (e.g. from lying down to sitting up).

PwME Person with Myalgic Encephalomyelitis

S
Seahorse analyzer -- an instrument which measures oxygen consumption rate and extracellular acidification rate in live cells, in real time, producing information regarding important cellular functions such as mitochondrial respiration and glycolysis.

Severely Ill Patient Study -- (SIPS) a study funded by the OMF (Open Medicine Foundation) and led by Dr. Ron Davis and Wenzhong Xiao, PhD. It includes over 1000 tests per patient, including the patients' genome, gene expression, metabolomics, microbiome, and many others. See also ME/CFS Severely Ill Big Data Study for details, a complete list of tests and Spring 2018 update.

SF-36 Short Form (36) Health Survey -- a 36 item patient reported questionnaire, used to determine patient health status and quality of life

somatic -- relating to the physical body. In biology, all the cells of the body, except those which form egg or sperm.

T
T cell -- T lymphocyte, or a type of white blood cell, which is mostly produced or matured in the thymus gland (hence T-cell) and is involved in immune response on a cellular level. See also Dr. Mark Davis Research Update video.

Two-day cardiopulmonary exercise test

V
VO2 Max -- the maximum volume of oxygen that an individual can utilize during increasingly strenuous exercise, such as on a treadmill. See also two-day cardiopulmonary exercise test.