- Last Updated: 05 December 2015 05 December 2015
Marcie and Mark Zinn—EEG/LORETA (low-resolution brain electromagnetic tomography) studies suggesting cortical pathology in ME/CFS
They looked at 50 patients and 50 controls, using a standard EEG. Peak frequency is associated with cognitive function. The CFS patients showed reduced PAFs over 58% of the cortex, This was significant, and suggests brain pathology. They then looked at the effects of fatigue, and this predicted the PAFs well. The implications are that there are interruptions in goal-directed behaviour. This leads to mental status changes (cognitive problems) affecting alertness and attention, memory and temporal organisation of behaviour. These findings could help confirm the diagnosis, monitor disease progression and monitor treatment response.
They then determined whether LORETA can be applied to the understanding of cognitive impairment in CFS, and to examine the underlying neurological underpinning of CFS. CFS patients had widespread delta sources mainly in the left frontal lobes. Axial slices showed depth and abnormalities.
The implications mean disruptions in transmission of information. This includes: destabilisation of ascending arousal system mechanisms, inhibition of faster brain rhythms—thus more basic generalised functional processing takes place, deficits in language production and syntax, pathophysiological CNS conditions: grey/white matter lesions etc. There are also lower beta-2 sources in CFS, primary motor deficits, sensory ataxia and pain sensation disturbances. Speech deficits occur as a result of abnormalities around Broca's area. There may be behavioural effects such as apathy. All this is a possible indicator of limbic encephalomyelitis.
The implications are that there is central fatigue and brain fog with no psychiatric comorbidity. In summary there is hypoactivation in CFS and LORETA shows this link.