IACFS/ME Conference – Dr Gudrun Lange “Cognitive Assessment in Patients with and without Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)”

The 2^nd Virtual Scientific Conference for the International Association for Chronic Fatigue Syndrome/ Myalgia Encephalomyelitis was held on the 19^th – 21^st August 2021 (streamed on zoom). The conference promoted unpublished data and included both clinicians and biomedical researchers. 

The talks were grouped into different sections, including the longer 45 minute talks in the Professional Workshops and shorter talks covering topics of infectious diseases, immunology and clinical cases. 

We have chosen a selection of the talks which will hopefully be of interest to you, which are listed We have chosen a selection of the talks which will hopefully be of interest to you, which are listed below. Here we report on our ninth talk in this series with a talk from Dr Gudrun Lange who’s research looks into cognitive function and exercise with her presentation titled “Cognitive Assessment in Patients with and without Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)”. The further talks we will cover are shown below and these will be available in one report by the end of October 2021. 

Due to the format of the conference and the focus on unpublished data, no direct recordings or pictures are available freely as this may jeopardise publication. The full conference programme can be found on the IACFS/ME website here, where recorded presentations may be purchased. 

9. Cognitive Assessment in Patients with and without Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)  

Gudrun Lange, PhD 
New York, NY USA 

Dr Gudrun Lange presented data from the Multi-site Clinical Assessment of ME/CFS (MCAM) study which is sponsored by the Centres for Disease Control and Prevention (CDC). 

The basis of Dr Lange’s research is to look at cognitive function before and after exercise in ME/CFS patients and healthy controls. The study measured cognitive function and exercise capacity to determine the effect of post-exertional malaise (PEM). These effects were measured by a series of online cognitive tests (known as CogState) which assessed processing speed and working memory. 

Dr Lange then summarised the methods of the study which was conducted between 2012 and 2019 in seven USA sites, using patients between 18-62 years old (Unger et al., 2017 describes details of enrolment into the study). Data for this study was collected through cognitive testing (cognitive test battery) using standard neurophysiological tests and CogState test (online test system). The CogState test formed the basis of the results presented by Dr Lange, as this was used before exercise, immediately after exercise (both in clinic) then 3 additional times at home (6-12, 24 and 48 hours after exercise). 

Dr Lange discussed a selection of the results found. The speed of performance study showed a very clear difference between ME/CFS patients and healthy controls where ME/CFS patients were always slower across all time points. Similar results were found for tests which looked at identification and memory. Due to PEM, 20% of ME/CFS patients couldn’t complete the task 6-12 hours later (compared to 14% of controls). The results most likely show that problems with learning and memory seen in ME/CFS patients are due to processing speed. 

Dr Lange also discussed the results seen through a tests called “Groton maze learning test). The results showed that when looking at the total errors made there is no difference between ME/CFS patients and controls. However, if you look at the correct moves made by second there is a difference between groups. This clearly shows that when not under pressure ME/CFS patients have no difference in cognitive function than healthy controls. 

In summary, the results from this study showed that ME/CFS patients have normal levels of information processing accuracy (involving learning and multi-tasking) but significantly slower processing speed. Furthermore, further poorer performance is seen when decision making is needed under time pressure and working memory is involved.  

The study also looked into the relationship between exercise and cognitive testing finding the combined effect further lowered performance over cognitive testing only. The results also showed that it took 15 days for ME/CFS patients to return to their pre-exercise function. 

Dr Lange finished by emphasising the advantage of the use of CogState in this study as repeated screening of patients can be continued away from the clinic. 

Katrina Pears, Research Correspondent, ME Association