Moderator note: The subject of brain inflammation in ME arose in this thread about a Netflix series. The discussion started with the following quote in post #32 from a doctor visiting a patient with ME shown in the film when explaining the word 'encephalomyelitis' in name ME may not be appropriate: There are a subset of patients who did have inflammation in the brain. But the vast majority of people with chronic fatigue don't. The validity of this statement was questioned by @JenB (post #41) and @Jonathan Edwards responded (post #82). His response is copied below. .................................................................................................................... There are a subset of patients who did have inflammation in the brain. But the vast majority of people with chronic fatigue don't. There is cast iron proof @JenB. I wonder who your neuroscientist is? Is he someone also trained in clinical neurology, histopathology, immunology and with extensive clinical experience of looking after people with encephalitis, as in lupus? (Like me.) Neuroscientists have got used to talking of 'neuroinflammation' in the context of everything from Parkinson's to Alzheimer's. This takes the meaning of inflammation completely away from the original meaning as used in the term encephalitis. Inflammation, as in encephalitis, is a process where increased dilatation and permeability of blood vessels leads to increase in flux of fluid and cells followed by tissue restructuring. The term actually means the 'flaming' of the redness due to dilatation. You cannot see that in a brain and dilatation is not necessarily the most important factor so clinical encephalitis is really about the manifestations of increased permeability. Even slight increase in permeability of blood vessels in the brain produces swelling with either impairment of consciousness or abnormal brain function such as severe mood change or loss of sensory or motor capabilities. Lupus encephalitis neatly illustrates all the stages of pathology. Even slight changes with increased water content lead to mood change, drowsiness (not fatigue) and then coma. If there is local change with cellular influx then you get what looks like a stroke. These changes are easy to pick up clinically. There are also now easy to pick up on MRI. In people with ME they are not there. The guy is on cast iron ground. We know for sure that the majority of people with ME do not have encephalitis. They might have some microglial activation but that is not encephalitis. Negative MRIs are not absence of evidence, they are evidence of absence. I understand logic, probability, statistics and causal inference very well, Jen. I am also both a doctor and a scientist. I think you need to make sure you are not mistaking absence of evidence that someone knows what they are taking about for evidence of absence!