I didn't find anywhere this article from 2012 by Cort, so I post an extract : http://phoenixrising.me/research-2/...nic-fatigue-syndrome-by-cort-johnson-aug-2005 begining of the article: Brain metabolic activity in CFS Three studies have examined metabolic functioning in the brain using proton magnetic spectroscopy (MRS) (Chaudhuri et. al. 2003, Tomoda et. al. 2000, Puri et. al. 2002). The levels of three metabolites (N-acetyl aspartate (NAA), choline, creatine) in the brain are examined using this technique. Puri’s study found that CFS patients (a) have significantly higher levels of choline in the occipital region of the brain than do controls and (b) exhibit an abnormal choline gradient between the motor and occipital cortex (Puri et. al. 2002). Chaudhuri’s study found increased choline levels in the basal ganglia (Chaudhuri et. al. 2003). A very small study (n=3) examining adolescents with CFS also found increased choline levels in the basal ganglia as well (Tomoda et. al. 2001). Three studies then, all of them small, but most with highly significant findings (p<.05, p<.001, p<.008) have found increased brain choline levels mostly in the basal ganglia. Normal NAA levels in two studies indicated neuronal mass was not disturbed. The basal ganglia The basal ganglia are large masses of gray matter at the base of the cerebral hemisphere; i.e. they are near the base of the skull where it meets the spinal column. They provide a nexus for interactions combining limbic/motor activities with volition; i.e. they play a key role in internal motivational states. One of the aspects they effect is perception of effort. The limbic system is a collective term that denotes an array of interconnected brain structures (hippocampus, amygdale, fornicate gyrus) at or near the edge (limbus) of the cerebral hemisphere that connect with the hypothalamus. By way of these connections, the limbic system exerts an important influence upon the endocrine and autonomic motor systems and appears to effect motivation and mood. Several endocrine and autonomic nervous system abnormalities have been identified in ME/CFS. Basal ganglia dysfunction often causes problems with something called ‘tasking’. Sequential task processing, for instance, an important process used in initiating and following through complex tasks, is often impaired in people with basal ganglia dysfunction. The ‘reward’ system which provides motivational impulses that in turn stimulate other parts of the brain is also often disrupted. These two abnormalities can increase the effort needed to carry out complex tasks, in particular. A disease called akinesia which is defined as “poverty and slowness in willful movements” can also occur because of basal ganglia disease. It is believed to result from the inability of the brain to respond to environmental cues such as sight, sound and touch. Choline Choline is found in three forms in humans; phosphatidycholine (lecithin), acetylcholine and cytidine diphosphocholine. Most of the choline in the body is found in specialized fat cells called phospholipids that are abundant in the membranes of cells. Choline in used in the synthesis of three components in cell membranes; phospholipids, phosphatidycholine (lecithin) and sphingomyelin. Causes of increased brain choline production Elevated brain choline levels are usually associated with increased cell production (malignant tumors) and/or increased cell membrane turnover due to inflammation or ischemia (low blood flows) (Chaudhuri et. al. 2003).