NORMAL CHANGES OF AGING
Changes in Cognition
A longitudinal study of cognitive capacity in a cohort of men followed from 1919 to 1961 described increments in verbal ability and total intellectual performance from age 20 to age 50. although mathematical ability declined slightly. From 50 to 60 yr of age, scores of intellect showed little change. These studies were among the first to raise serious doubts about the presumed normal decline in mental ability with aging, which had been inferred from earlier cross-sectional research.
A 12-yr longitudinal study of older men (median age, 71 yr) con-dueled by the National Institute of Mental Health examined a broad range of variables. Physical and psychiatric disease was absent or minimal; the goal was to separate the impact of aging from that of illness. As these healthy men moved from their 70s to their 80s. various intellectual functions declined while others improved. For example, quality of cognitive operations, draw-a-person exercises, and sentence completions declined, while vocabulary and picture arrangement ability improved. This suggests that older persons may have difficulty with activities requiring a quick reaction lime or a high degree of precision, although they maintain the ability to understand their situation and learn from new experiences.
Moreover, men who developed arteriosclerotic cardiovascular disease had significantly greater decrements in intellectual performance than those who remained healthy. Therefore, significant changes in intellectual performance should not be dismissed as normal consequences of aging but should be evaluated as potentially modifiable manifestations of disease (psychiatric as well as general medical). For example, both depression and hypothyroidism are treatable problems that can be covert and cause cognitive impairment.
Changes in Behavior and Personality
Corresponding to the stereotype of inevitable intellectual decline with aging are stereotypes of regressive behavior and increasing inflex-ibilily of personality traits. However, these are more a sign of psychiatric disturbance than a manifestation of aging. Consider the issue of cautiousness. Research shows that (he elderly are more cautious than younger adults about risk taking when the payoff is predictable and constant. If the size of the payoff depends on the degree of risk, however, older persons are no more cautious than younger persons.
Anxiety can resull in cautiousness, causing delays in decision making and reactions. In other words, excessive cautiousness in the elderly may signal underlying anxiety or a related clinicaldisorder. However, it is entirely appropriate for a frail or disabled older person to he more careful in general. A maladaptive overcautiousness resulting from anxiety must be distinguished from an appropriate, adaptive response to reality.
If older adults appear to be more rigid lhan younger adults, then cohort differences (ie, generational differences that stem from having grown up during different hisloric periods)—and no! age differences— are more likely involved. Research shows no( only that personalities remain stable with aging but also that behavioral and psychologic adap-tiveness continues and docs not normally give way to regression or rigidity. If certain behaviors or traits become increasingly exaggerated, maladaptive, and unmodifiable, neurosis rather than normal aging may be to blame. Treatment rather than acceptance is in order.

NORMAL CHANGES OF AGING
Age-related structural and functional changes in skin are summarized in TABLE 101-1. Age-related changes in hair and nails are discussed below.
Hair Changes
Hair begins turning gray in about 50% of persons by age 50.
Frontotemporal hair loss (androgenic alopecia) in men begins in the second or third decade; by the seventh decade, 80% of men are substantially bald. In women, the same pattern of hair loss may occur after menopause, although it is rarely pronounced.
Diffuse alopecia normally occurs in both sexes with advancing age; however, it can also result from iron deficiency or hypothyroidism, so these conditions should be excluded when indicated. Certain drugs (especially anabolic steroids and antimetabolites), chronic renal failure, hypoproteinemia, and severe inflammatory skin disease such as erythroderma can also cause diffuse alopecia.
Hair loss with scarring is relatively rare and not associated with aging but with disease. It can be caused by deep bacterial or fungal infections; granulomatous disorders such as sarcoidosis, tuberculosis, or syphilis; and inflammatory disorders such as lichen planus and cutaneous lupus erythematosus. Cicatricial pemphigoid is a chronic bullous eruption that affects mucous membranes and sometimes the scalp. Biopsy of the scalp is usually necessary to make these diagnoses.
Hirsutism, excessive or unwanted hair, is also common after the fifth decade, especially in women, presumably as a result of the altered estrogen-androgen balance in hormonally sensitive hair follicles. In women, the most common complaint is the appearance of scattered terminal hairs in the beard area. Men may note increased hairs in the eyebrows, nares, or ears.
Treatment: Topical minoxidil solution can be used to treat physiologic age-associated hair loss. When applied daily to bald areas, it stimulates regrowth in 25% to 30% of patients, particularly in those who begin treatment early. However, cosmetically significant regrowth occurs in < 10%, and even these patients usually begin to lose hair again within 1 yr. Hair transplantation can be performed by several techniques, including one in which punch grafts from the occipital areas are transplanted to the bald temporal areas. The cosmetic results of this procedure can be enhanced by scalp reduction. Hair loss from endocrine, metabolic, inflammatory, or nutritional disorders can be fully reversed by correcting the underlying disorder.
Unwanted hairs can be repeatedly plucked or cut. Alternatively, the follicle can be permanently destroyed by electrolysis.
Nail Changes
The thickness, shape, color, and growth rate of the nails change with age, reflecting changes in the supporting nail bed and germative matrix. They become dry and brittle and flat or concave instead of convex, often with longitudinal ridging. The color may vary from yellow to gray. Occasionally, the nails become grossly thickened and distorted, a condition known as onychogryphosis.
Treatment: No effective treatment exists for these nail changes. For the patient’s safety and comfort, a podiatrist should trim thickened toenails with an electric drill and burrs or a carbon dioxide laser. Wearing gloves while doing housework and laundry protects brittle fingernails. Nails should be kept short, and use of nail polish remover, which dehydrates the nail, should be minimized. Evaluation by an experienced examiner can determine treatable conditions, such as fungal infections.