Cognition and Mental Fitness
By Douglas S. Laher, MBA, RRT

At times, it happens so frequently it's "d�j� vu all over again." It is like the re-run of your favorite "Seinfeld" episode in which you know the lines, song, and verse�

Cognitive decline
The term cognition (in Latin meaning "to know" or "to recognize") is the scientific definition for processing information. Also used to describe an individual's psychological function, cognition, in more generic terms, is responsible for a person's thoughts and actions. As people age, their cognitive function declines. Cognitive brain function becomes impaired by decreases in nerve impulses, nerve cells, and neurotransmitters. Poor perfusion to the brain (occurring naturally through aging or from vascular disease) also contributes to nerve cell damage.

Symptoms of impaired cognition include slowed thinking, a reduced ability to learn, and memory loss. For the geriatric population struggling to maintain independence, the most simplistic tasks are hard to remember: Lock up the house before you go to bed? Check. Turn off the coffee maker after a fresh cup of java in the morning? Maybe. Remember how to self manage a chronic disease? Forget about it.

Aside from age, other factors that contribute to mild cognitive decline (MCD) are diets high in fat¹ and metabolic syndrome (abnormalities that include high blood pressure, diabetes, obesity, and blood lipid levels associated with increased risk of heart attack and stroke).² Unstable molecular reactions caused by free radicals also cause damage to brain cells, leading to a decrease in cognition.³

According to data from the Aging, Demographics and Memory Study, roughly 22% of all Americans older than 71 years of age suffer from cognitive impairment without dementia.⁴ While race was not significantly associated with cognitive impairment, it is more prevalent in women and those less educated (not attending college).

Cognition and the COPD patient
For patients with COPD, causes in brain decline most likely are a result of many years of smoking. According to European researchers, smokers (current and previous) are five times more likely to see cognitive decline than do people who never smoked.⁵ While nicotine may aid in reaction time, learning, and memory, smoking increases risk factors associated with cardiovascular disease, which has a greater affinity for MCD than does the nicotine for symptomatic treatment.⁶ In addition, chronic hypoxemia associated with COPD also contributes to brain impairment. According to a randomized controlled study by Incalzi et al, lifestyle changes, education, nutritional counseling, pharmacologic treatment modalities, and other cognitive training are proven ineffective for patients suffering from hypoxic COPD.⁷ Couple this with the MCD that naturally takes place with aging, and the chronically ill COPD patient has a "perfect storm" on their hands.

Diagnosis
While there are no standard methods to diagnose MCD, collaboratively there are a series of tests — both diagnostic and neuropsychological examinations — that provide physicians with a strong indication of the patient's medical condition.

Neuropsychological testing is helpful but not definitive for the diagnosis of MCD. Typical cognitive domains tested and commonly used tests include:

• delayed episodic verbal and logical recall (Hopkins Verbal Learning Test, Wechsler Memory Delayed Recall),
• verbal category and semantic fluency (animals, words beginning with F-A-S),
• attention (digit span, forward and backward),
• processing speed (Trail Making Test part A),
• visuoconstructional function (clock drawing test, Rey-Osterrieth Complex Figure Test), and
• executive functioning (Trail Making Test part B, symbol-digit substitution).⁸

Brain imaging testing is not routinely used to diagnose mild cognitive brain impairment and is rarely covered by medical insurance. Diagnostic laboratory testing that includes a full metabolic work-up (complete blood count, thyroid function tests, and vitamin B12) is relied upon to support findings from neurological evaluations.⁸

Treatment
Outside of some experimental pharmacologic agents currently being used in Europe, there is no cure for MCD and there are no drugs approved by the U.S. Food and Drug Administration for the treatment or prevented progression of cognitive and functional deficits. There are, however, alternatives to prevent or lower the risk of MCD. They include natural hormone replacement therapy, nutrients, and other supplements.

Hormone therapy includes the following:

• Testosterone — Testosterone may provide a protective mechanism against age-related mental decline as well as Alzheimer's disease. According to a 2001 study by Hogervorst et al, lower levels of testosterone were present in men with Alzheimer's disease than in controls.⁹ It would appear that higher testosterone levels protect the brain cells from toxic peptides. Effects of low levels of testosterone on the brain include decreased ability to concentrate, moodiness and emotionality, reduced intellectual agility, feelings of weakness, passive attitudes, and reduced interest in surroundings.¹⁰
• Melatonin — A hormone to help regulate and improve the quality of sleep, melatonin also improves the body's immune system and reduces the negative effects of free-radicals.¹¹
• Thyroid hormone — Hypothyroidism is a well-known and relatively common cause of reversible dementia and the most treatable cause of cognitive decline in the older population. In a recent study by Davis et al, subclinical hypothyroidism may be a predisposing factor for depression, cognitive impairment, and dementia.¹²

Nutrients and other supplements: An antioxidant is a molecule capable of slowing or preventing the oxidation of other molecules. Oxidation is a chemical reaction that transfers electrons from a substance to an oxidizing agent. Oxidation reactions can produce free radicals, which start chain reactions that damage cells.¹³ Eating foods high in antioxidants like red beans, berries (e.g., wild, cranberry, strawberry, raspberry, blackberry), artichokes, prunes, apples, and plums will terminate these chain reactions by removing free radical intermediates and inhibit other oxidation reactions by being oxidized themselves.

Other free-radical scavengers include ginkgo biloba and ginseng. Ginkgo extracts prevent induced lipid peroxidation in neural tissue¹⁴ and has been shown to relax blood vessel walls, inhibit platelet-activating factor, enhance microcirculation, and stimulate neurotransmitters.¹⁵ When taken in combination with ginkgo, ginseng has also proven highly successful in one's ability to learn and show improvements in long-term memory gain.¹⁶ Vitamins B6 and B12, Vitamin C, and Vitamin E are also nutritional supplements proven to slow MCD but should only be taken under the strict supervision of a physician.

Lifestyle changes: Evidence from population-based longitudinal epidemiologic studies suggests that exercise and physical activity are associated with a lower risk of dementia,¹⁷ and moderate exercise (i.e., walking three times a week) appears sufficient to demonstrate this association.¹⁸ In addition to diet and exercise, there is also an association with hobbies and other leisurely activities that stimulate the brain to reduce the likelihood of dementia and MCD. Engaging in activities such as crossword puzzles, word association games, sudoku, and activities that stimulate the verbal and language skills also reduces the risk of dementia.¹⁷

Documented evidence even finds that playing video games or games requiring forethought and strategy will enhance cognitive skills and may even attenuate cognitive decline in aging adults.^19,20 Pulmonary rehabilitation facilities all over the country are turning to the Nintendo Wii as a fun, exciting, and interactive way to stimulate the mind, body, and spirit. This game playing provides patients with the physical interaction to build endurance and muscle, hand-eye coordination, and (depending on the game) may even enhance cognitive skills. While many would think that such gamesmanship is only for the young-at-heart, rehabilitation facilities offering these activities as adjuncts to their program may offer the chronically ill COPD patient a "one-stop-shop" for all of their physical, pulmonary, and neurological needs.

Next time, think twice
Given this information, you as the respiratory therapist may want to give Mr. Jones a second thought during his next admission to the hospital. As the content expert, the next time you provide discharge instructions, establish rehabilitation exercises, or prescribe a treatment regimen, take time to consider that although your patients may have the motivation and desire to follow through, they may be unable to do so because of cognitive issues. Should you suspect that one of your patients suffers from MCD, do what your instincts tell you to do for any patient who presents with an unhealthy lifestyle: advise a low-fat diet (high in antioxidants), vitamin supplements, regular exercise three to four times per week, and activities to keep their brain stimulated. Not only will it promote good health for the body but for the mind as well.

About The Author
Douglas S. Laher, MBA, RRT, is director of respiratory care at Fairview Hospital in Cleveland, OH.

REFERENCES

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