Neurological and Neurocognitive Dysfunction
Neurological abnormalities represent one of the most consistently documented features of ME/CFS and provide critical insight into the pathophysiology of this complex disorder. The landmark NIH deep phenotyping study by Walitt et al. (2024) provided unprecedented detail on central nervous system dysfunction, identifying specific brain regions, neurotransmitter abnormalities, and mechanisms underlying the characteristic fatigue and cognitive impairment of ME/CFS (Walitt et al. 2024).
One candidate link between the gut microbiome and the neurocognitive symptoms discussed below is the aryl-hydrocarbon-receptor (AhR) axis: a direct ME/CFS study found elevated gut-microbial AhR-agonist activity specifically in patients with neurocognitive symptoms (Section Replication Status: Not Yet Replicated of Chapter Gastrointestinal and Microbiome Dysfunction; Hypothesis AhR-Gut-Microbiome Axis: Tryptophan-Derived Ligands Modulate Intestinal Barrier and Immune Tone). This is an early, subgroup-specific finding that requires replication and does not establish causality.
For patients: read the CNS abnormalities and cognitive-dysfunction sections to understand brain fog and the sleep-cognition link. The auditory/tinnitus section is relevant if you experience those symptoms.
For caregivers: read the cognitive-dysfunction and summary integrated-model sections to understand how neurological symptoms constrain daily activity. The autonomic section helps explain orthostatic crashes.
For clinicians: read the autonomic, cerebral-blood-flow, and cognitive sections for the physical signs and assessment relevant to presentation. The GLP-1 neuroprotection and retinal-window miscellany are research-grade β low clinical priority.
For researchers: read the blood-brain-barrier and peripheral-nervous-system sections, plus the summary integrated model. The AhR gut-brain link points to Chapter Gastrointestinal and Microbiome Dysfunction.