Comparative Study Between Cognitive Phenotypes of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Multiple Sclerosis, 2025, Sebaiti et al

Comparative Study Between Cognitive Phenotypes of Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Multiple Sclerosis

Mehdi Aoun Sebaiti, Nadia Oubaya, Yannick Gounden, Chloé Samson, Emmanuele Lechapt, Abir Wahab, Alain Creange, Mathieu Hainselin, François-Jérôme Authier

Objective
Cognitive impairments are one of the most common and disabling symptoms associated with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Here, we address the possibility of a specific cognitive profile inherent to ME/CFS. Due to the occurrence of cognitive deficits, fatigue, and pain in both pathologies, multiple sclerosis (MS) is a relevant comparison model. For this purpose, we carried out a comparative study between cognitive profiles of patients with ME/CFS and patients suffering from MS.

Methods
In total, 40 ME/CFS and 40 MS patients were included. A complete screening of all cognitive functions was carried out through an extensive battery of tests routinely used in clinical practice.

Results
ME/CFS and MS patients showed deficits in episodic memory retrieval, visual selective attention and reading speed. ME/CFS patients also elicited a lower level of performance than MS patients regarding consolidation. For both groups, levels of performance on these cognitive tests did not correlate with levels of fatigue, pain, and depression.

Conclusions
This study highlighted both similarities and differences in the cognitive profiles of ME/CFS and MS patients. While both groups exhibited deficits in episodic memory retrieval, visual selective attention, and reading speed, ME/CFS patients showed distinct impairment in consolidation processes. These cognitive deficits were not correlated with fatigue, pain, or depression, reinforcing the hypothesis of intrinsic cognitive dysfunction in ME/CFS. These findings define a specific cognitive phenotype for ME/CFS, which could improve diagnostic accuracy and therapeutic strategies. Future research, particularly in functional imaging, may elucidate the neurobiological mechanisms underlying these impairments.

Link | PDF (Diagnostics) [Open Access]

 

No idea if the evidence in the study supports this, as I don’t have the energy to read, but that is a useful sentence for advocacy.

 

Strange that they don't describe the selection method a bit more: were these 40 patients selected because they had the most severe or most notable cognitive symptoms? So they likely were not representative of ME/CFS patients as a whole?

 

They only assessed patients that reported cognitive difficulties:

Patients were not included if they did not report cognitive difficulties or had received a diagnosis outside the defined age range (18–65 years). Exclusion criteria included the presence of neurological or psychiatric disorders, like a history of head trauma, stroke, or neurodegenerative disease, that could significantly impact cognitive performance.

I wonder what they mean by ‘consecutive’ in your quote. Is it consecutive if they excluded some in the sequence?

Due to the retrospective nature of the study, they could have cherry-picked the ME/CFS sequence.