Mild Cognitive Impairment: Causes

Pathogenesis (development of disease)

Physical causes of mild cognitive impairment (MCI) lie in damage to brain structures required for cognition. In addition to normal aging processes (“continuity hypothesis”), specific diseases (“specificity hypothesis”) may be the cause.The following is a listing of known risk factors. There was a dose-response relationship between beta-amyloid load and episodic memory function: as memory function decreased, amyloid load increased. This fact was more pronounced in the 30- to 49-year-old age group and weaker in the 50- to 69-year-old age group.

Etiology (Causes)

Biographical Causes

  • Blood type – blood group AB (1.82-fold increased risk).
  • Age – increasing age (> 60 years).
  • Hormonal factors – Premature menopause (premature menopause; climacterium praecox) – premature ovarian failure (POF, Premature Ovarian Failure): a woman may enter menopause prematurely if the oocyte reserves are depleted prematurely.The average age for entering menopause (menopause) is currently circa 51 years. However, if the oocyte reserves are used up prematurely (due to follicular atresia), ovulation will not occur and menstruation may also stop prematurely. If this happens in women under 40 years of age, it is called premature menopause. This occurs in 1-4% of women.

Behavioral causes

  • Nutrition – see .below under causes/vitamin deficiency.
  • Consumption of stimulants
    • Alcohol (woman: > 20 g/day; man: > 30 g/day) → dose-dependent decreasing gray matter density, especially in the hippocampus and parts of the amygdala
    • Tobacco (smoking)
  • Drug use
    • Cannabis (hashish and marijuana)
  • Psycho-social situation
    • Stress
  • TV consumption (> 50 years of age and > 3.5 hours of TV consumption) → TV-related dementia (= degradation of verbal memory).

Disease-related causes.

Endocrine, nutritional, and metabolic diseases (E00-E90).

Cardiovascular system (I00-I99)

Infectious and parasitic diseases (A00-B99).

  • Chronic meningitis – meningitis that can be caused by many different pathogens; these include Borrelia, Treponema pallidum (syphilis), or HIV.

Psyche – Nervous System (F00-F99; G00-G99).

  • Alcohol abuse
  • Depression
  • Nicotine addiction
  • Post-traumatic stress disorder (PTSD) – in the long-term course more often limitations of cognitive function.

Symptoms and abnormal clinical and laboratory findings not classified elsewhere (R00-R99)

  • Weight loss in old age – people over 70 years of age who lose weight may be at increased risk for cognitive impairment (= risk factor for dementia)

Genitourinary system (kidneys, urinary tract – sex organs) (N00-N99).

Injuries, poisonings, and other consequences of external causes (S00-T98).

  • Violent impact on the skull, unspecified (e.g., cerebral contusion (brain contusion))

Laboratory diagnoses – laboratory parameters that are considered independent risk factors.

Medication

  • ACE inhibitors
  • Antiarrhythmics
  • Antibiotics
    • SS-lactam antibiotics
    • Fluoroquinolones
    • Penicillin in high doses
  • Alpha blockers
  • Anticholinergics
  • Antidepressants
  • Antidiabetic agents, oral – which induce hypoglycemia.
  • Antiepileptic drugs, including phenytoin.
  • Antihypertensives
    • Seniors still taking antihypertensives at age >85 years were more likely to have cognitive impairment and increased mortality risk; low systolic blood pressure was also associated with accelerated cognitive decline.
  • Anticonvulsants
  • Antivertiginosa
  • Benzodiazepines
  • Beta blockers
  • Calcium antagonists
  • Digoxin
  • Diuretics
  • Glucocorticoids
  • MAO inhibitors
  • Neuroleptics (D2 antagonists and serotonin–dopamine antagonists).
  • Nonsteroidal anti-inflammatory drugs (NSAIDs).
  • Nitrates and other vasodilators.
  • Lidocaine
  • Opiates/opioid analgesics
  • Parkinson’s disease medications, e.g., bromocryptine, amantadine
  • Psychotropic drugs
  • Sedatives; these include diazepam in particular.
  • Sedating H1 antihistamines
  • Statins (statins (simvastatin, atorvastatin; both agents are lipophilic and cross the blood-brain barrier): In one study, physicians had reported various memory disturbances (ranging from isolated memory lapses to retrograde amnesia) in 3.03% of statin users during the course of therapy. These disturbances also occurred in 2.31% of statin nonusers. The adjusted odds ratio was 1.23, which was significant at a 95% confidence interval of 1.18 to 1.28. This indicates a slight increase in memory disorders. The association was more marked in the first 30 days of therapy (0.08% of statin users versus 0.02% of nonusers).
  • Theophylline

Operations

  • Postoperative cognitive dysfunction (POCD) (protective association of longer duration of education and risk of POCD).

Environmental exposures – intoxications (poisonings).

  • Radiofrequency electromagnetic fields (e.g., cell phones; smartphones, cell phones) – cumulative brain RF EMF exposure from cell phones may adversely affect the development of figural memory in adolescents
  • Solvent encephalopathy (brain changes from exposure to solvents):
    • Benzene (e.g., contained in: motor gasoline).
    • Chlorinated hydrocarbons (e.g., contained in: Solutions for dry cleaning, cleaning agents for engines and in paint and grease removers).
    • Petroleum-based solvents (e.g. contained in: Furniture care products and carpet adhesives as well as paints and varnishes).
  • Drug-induced hyponatremia (sodium deficiency) such as by diuretics (diuretics that promote the formation and excretion of urine), antiepileptic drugs or occasionally by ACE inhibitors – this can lead to secondary dementia
  • Perchloroethylene
  • Mercury
  • Heavy metal poisoning (arsenic, lead, mercury, thallium).