Cognitive dysfunction

Cognitive dysfunction is a required symptom in most diagnostic criteria for ME/CFS; some patients call it "brain fog". It is also a common symptom of fibromyalgia and patients refer to it as "fibro fog."

Cognitive dysfunction in ME/CFS can take many different forms. Cognitive issues commonly observed in ME/CFS include attention deficit, auditory sequencing problems, brain fog, concentration problems, difficulty comprehending social cues, dyscalculia, dyslexia, executive function problems, linguistics reversals, memory loss, multi-tasking problems, planning problems, receptive language problems, slowed thought, spatial disorientation, word-finding problems, cognitive overload, slow processing of information and poor working memory. A 2016 study found that IQ scores of adolescents with CFS tested lower than the IQ scores of healthy peers with an equivalent school level. Currently it is not known whether lower IQ outcomes are due to concentration problems, a lowered processing speed or the illness itself.

Mandatory ME/CFS symptom
Cognitive dysfunction is a mandatory diagnostic symptom for ME/CFS with the Canadian Consensus Criteria (CCC).

Optional ME/CFS symptom
Cognitive dysfunction is an optional symptom in Systemic Exertion Intolerance Disease (SEID) diagnostic criteria and the International Consensus Criteria (ICC) for myalgic encephalomyelitis (ME).

Other causes
Cognitive dysfunction is also is one of the most common Long COVID symptoms

Diagnosis

 * Cognitive Dysfunction and “Brain Fog” in POTS

Possible causes
Mady Hornig has found evidence in the cerebrospinal fluid (CSF) of ME/CFS patients that may explain their cognitive dysfunction.

Other causes
Cognitive dysfunction can be caused or made worse by other health conditions, most of which should be ruled out or identified during diagnostic process for ME/CFS:
 * Cancer or cancer treatment ("chemo brain")
 * Depression
 * Fibromyalgia
 * Lupus
 * Menopause
 * Multiple sclerosis
 * Pregnancy
 * Sleep dysfunction or sleep disorders

Exercise and cognitive dysfunction
A healthy person becomes more alert after exercise, but people with ME/CFS find their cognitive difficulties increase, they become much slower at mental activities, and cognitive tasks seem to take extra effort.

Potential treatments
Drugs, supplements and other treatments that have been suggested for improving brain fog:
 * Acetyl-L-carnitine
 * Arabinoxylan (ineffective)
 * B vitamin complex
 * B vitamin
 * Clonidine hydrochloride (ineffective)
 * Dexamphetamine
 * Dynamic Neural Retraining System
 * Fludrocortisone (ineffective)
 * Histamine
 * Hydrocortisone (most trials show some positive effective)
 * Methylene blue
 * Methylphenidate and the experimental treatment KPAX002
 * Modafinil (ineffective)
 * Moclobemide
 * Neurolinguistic programming
 * Nimodipine
 * Phenelzine (ineffective in ME/CFS)
 * Rintatolimod (Ampligen)
 * Stellate ganglion block in dysautonomia linked to long COVID
 * Valganciclovir (ineffective)
 * Yoga

Drugs, supplements or interventions that may cause cognitive problems:
 * Diphenhydramine
 * Exercise
 * Graded exercise therapy (GET) / Graded Activity Therapy
 * Certain pain killers, particularly opioids, gabapentin (Neurontin), tricyclic antidepressants including amitriptyline (Elavil, Endep) and nortriptyline (Aventyl, Pamelor)
 * sleep medications

Notable studies

 * 2001, Neuropsychological functioning in chronic fatigue syndrome: a review - (Abstract)
 * 2006, Cognitive dysfunction relates to subjective report of mental fatigue in patients with chronic fatigue syndrome - (Full text)
 * 2015, Less efficient and costly processes of frontal cortex in childhood chronic fatigue syndrome - (Full Text)
 * 2016, Cognitive Dysfunction in Chronic Fatigue Syndrome: a Review of Recent Evidence - (Abstract)
 * 2016, The impact of chronic fatigue syndrome on cognitive functioning in adolescents - (Full text)
 * 2016, qEEG / LORETA in Assessment of Neurocognitive Impairment in a Patient with Chronic Fatigue Syndrome: A Case Report - (Full text)

"Our case study confirmed the pattern of dysregulation in the cortex reviewed in the introduction. Furthermore, since both periods of phase shift/lock durations were found to be significantly shorter, that might contribute to an increased rate of phase reset, also seen in our data. Phase reset deregulation--phase locking periods being too brief and phase reset happening too often—appear to be consistent with the associated lower rate of information processing and reaction times found in the ME and CFS literature. These deregulated states represent the brain during nonoptimal functioning, rendering it inefficient for most types of information processing functioning, whether it is executive functioning, memory, perceptual reasoning or information processing speed. When phase lock is significantly less than normal, as in this data set, the ability of the brain to sustain commitment of resources to mediate different functions is severely compromised. Phase shift duration in this data is also hypoactive, meaning that significantly less neurons are being recruited to perform a function than normal. The results here indicate slowed verbal comprehension, executive functions, perceptual reasoning, processing speed and memory, the sum total of which is known as cognitive impairment."



Notable studies

 * 2001, Neuropsychological functioning in chronic fatigue syndrome: a review - (Abstract)
 * 2006, Cognitive dysfunction relates to subjective report of mental fatigue in patients with chronic fatigue syndrome - (Full text)
 * 2015, Less efficient and costly processes of frontal cortex in childhood chronic fatigue syndrome - (Full Text)
 * 2016, Cognitive Dysfunction in Chronic Fatigue Syndrome: a Review of Recent Evidence - (Abstract)
 * 2016, The impact of chronic fatigue syndrome on cognitive functioning in adolescents - (Full text)
 * 2016, qEEG / LORETA in Assessment of Neurocognitive Impairment in a Patient with Chronic Fatigue Syndrome: A Case Report - (Full text)

"Our case study confirmed the pattern of dysregulation in the cortex reviewed in the introduction. Furthermore, since both periods of phase shift/lock durations were found to be significantly shorter, that might contribute to an increased rate of phase reset, also seen in our data. Phase reset deregulation--phase locking periods being too brief and phase reset happening too often—appear to be consistent with the associated lower rate of information processing and reaction times found in the ME and CFS literature. These deregulated states represent the brain during nonoptimal functioning, rendering it inefficient for most types of information processing functioning, whether it is executive functioning, memory, perceptual reasoning or information processing speed. When phase lock is significantly less than normal, as in this data set, the ability of the brain to sustain commitment of resources to mediate different functions is severely compromised. Phase shift duration in this data is also hypoactive, meaning that significantly less neurons are being recruited to perform a function than normal. The results here indicate slowed verbal comprehension, executive functions, perceptual reasoning, processing speed and memory, the sum total of which is known as cognitive impairment."



Disability
In 2018 Brian Vastag was able to prove the severity of his chronic fatigue syndrome cognitive dysfunction with qEEG and cognitive tests, which proved he had "significant problems with visual perception and analysis, scanning speed, attention, visual motor coordination, motor and mental speed, memory, and verbal fluency" winning his long term disability (LTD) claim in the United States.

Learn more

 * 2015, Dr. Gudrun Lange Reviews Neuropsychological Testing for CFS and FM
 * 2016, Case Study: "Brain Fog" in CFS can be seen in qEEG/Loreta
 * 2018, Study Identifies the Types of Cognitive Dysfunction That Are Most Prevalent in Fibromyalgia
 * Jun 4, 2018, Victory For ME Disability Claim – U.S. Court Upholds Plaintiff's Lawsuit After Being Denied Disability