These are less-easily measured than cognitive functions, but certain trends are nevertheless observable and may seriously disturb the lives of aged persons and those around them. Many old people become more opinionated, repetitive, self-centered, and rigid and conservative in their thinking; the opposite qualities—undue pliancy, vacillation, and the uncritical acceptance of ideas—are observed in others. Often these changes can be recognized as exaggerations of lifelong personality traits. Elderly persons tend to become increasingly cautious; many of them seem to lack self-confidence and require a strong probability of success before undertaking certain tasks. These changes may impair their performance on psychologic testing. Kallman’s studies of senescent monozygotic twins suggest that genetic factors are more important than environmental ones in molding these traits.
Effects of Aging on Stance and Gait and Related Motor Impairments (See Also Chap. 6)
These are among the most conspicuous manifestations of the aging process. Motor agility actually begins to decline in early adult life, even by the 30th year; it seems related to a gradual decrease in neuromuscular control as well as to changes in joints and other structures. The reality of this motor decrement is best appreciated by professional athletes who retire at age 35 or thereabout because their legs give out and cannot be restored to their maximal condition by training. They cannot run as well as younger athletes, even though the strength and coordination of their arms, when tested independently of other functions, are relatively preserved. More subtle and imperceptibly evolving changes in stance and gait are ubiquitous features of aging (see Chap. 6). Gradually the steps shorten, walking becomes slower, and there is a tendency to stoop. The older person becomes less confident and more cautious in walking and habitually touches the handrail in descending stairs, to prevent a misstep.
To be distinguished from the ubiquitous and subtle changes in gait of the “normal” older population is a more rapidly evolving and inordinate deterioration of gait that afflicts a small proportion of the aging population while they remain relatively competent in other ways. In all likelihood, this latter disorder represents an age-linked degenerative disease of the brain, as most instances of it are sooner or later accompanied by mental changes. The basis of this gait disorder is probably a combined frontal lobe–basal ganglionic degeneration, the anatomy of which has never been fully clarified, as discussed in “Frontal Lobe Disorder of Gait” in Chap. 6. However, in many of such patients we have observed, there is no disproportionate atrophy or reduction of blood flow in the frontal lobes, making the cause of the gait disorder obscure. It has also been postulated that age-related changes in the substantia nigra are the cause of the parkinsonian appearance of the gait of the aged, but it does not respond to l-dopa or to any other therapeutic measure. An important differential diagnostic consideration is normal-pressure hydrocephalus, correctable sometimes by a ventriculoperitoneal shunt, which accounts for the gait disorder of a group of these elderly patients, as discussed in Chaps. 6 and 29. Parkinson disease is yet another potentially treatable cause of walking difficulty. Progressive supranuclear palsy is a degenerative process in which gait and stability are affected early and profoundly.
Urinary incontinence, defined as a state in which involuntary loss of urine is a social or hygienic problem and is objectively demonstrated, is a common occurrence in the elderly (Wells and Diokno). Doubtless this complex of sphincteric impairments is based on the aforementioned neuronal losses in the spinal cord, cerebellum, and cerebrum as well as on mechanical factors.
Falls in the Elderly