Brain fog is a set of symptoms related to decreased cognitive abilities, cognitive fatigue, slow thinking, difficulty in focusing, confusion, lack of concentration, poor memory recall and reduced mental acuity.
Please have a look at these useful RG links.
Article What is brain fog? An evaluation of the symptom in postural ...
Article Caught in the thickness of brain fog: Exploring the cognitiv...
Article MENTAL HAZE, ITS IDENTIFICATION, CONSEQUENCES, AND TREATMENT...
Article Gluten‐induced cognitive impairment (“brain fog”) in coeliac disease
Brain Fog - is a diminished cognitive capacity or ability such that memory, recall and the ability to learn new information is slowed, altered, and/or reduced. We are understanding that this occurs at a molecular chemical level due to alteration in neuroconductivity(neurotransmission - electro and chemical) precipitated by inflammation, microglia, cytokines and free radicals. Reversal of "Brain Fog" does occur with improvement in the Neuro-Permissive Environment of the brain.
Brain fog is a general term that reflects subjective cognitive impairment resulting from chemotherapy, radiation or a psychoneuroimmunological insult such as occurs with a connective tissue disorder. The causative parameters are not yet well-defined.