Review abstract:

Chronic Fatigue Syndrome (CFS) is distinguished by a persistent malaise and lethargy that physical or mental exertion exacerbates for a period of several days. Sufferers can identify a clear-cut beginning to their condition. In many, it follows a viral infection such as glandular fever. Sufferers also experience cognitive difficulties and, sometimes, autonomic disturbances such as dizziness on standing, gastrointestinal upsets, cardiovascular irregularities and immune system dysfunction.

Does chronic fatigue syndrome have a neurological origin?, by Leighton R Barnden in Australasian Science, Volume 36 Issue 8 (Oct 2015) [only abstract available]

Link to a review article by the same author:

Evidence in chronic fatigue syndrome for severity-dependent upregulation of prefrontal myelination that is independent of anxiety and depression, by Leighton R Barnden et al