In a newly published review in BMC Medicine , Morris and Maes – two of the most prolific authors of papers on ME/CFS – explore similarities between multiple sclerosis and ME/CFS as regards disease characteristics (phenomenology) and immune or neurological dysfunction. They point out, for example, that in both illnesses patients can suffer severe levels of disabling fatigue, worsening symptoms after exercise, orthostatic intolerance, gastrointestinal problems, and share a range of other clinical characteristics. Their 9,400-word review also tabulates findings from the research literature suggesting similar neuro-immune features – such as increased oxidative stress, immune activation, and brain imaging anomalies.
One strength of the overview – which is certainly food for thought and worth close reading – is that it presents a model integrating immune signalling and metabolic pathways, which could explain the symptomatic similarities. Of course, as the authors say, there are also important differences between the two diagnoses, not least the fact that “inflammation of the central nervous system is clearly more prominent in MS than in ME/CFS”. Nevertheless, a key take-home message is that these demonstrable similarities strongly suggest that ME/CFS belongs on the spectrum of neuro-immune disorders, rather than among the ‘somatic’ or psychological illnesses as is sometimes claimed.