What Is Normal Neurological Aging?
The diagnosis of neurological disease in the older adult requires recognition not only of abnormal signs and symptoms but also an understanding of what changes are expected as part of the normal aging process. To distinguish neurological dysfunction related to disease from the neurological changes associated with normal aging, the clinician must conduct a comprehensive mental status and neurological examination. When establishing a neurological diagnosis, the clinical history (i.e., history of the present illness, past medical history, social habits, occupational experience, family illness, and disorders) assists the clinician in generating a differential diagnosis that can be further explored and refined by pertinent observations documented on the mental status and neurological examinations. The mental status assessment should evaluate cognition, emotion, and behavior. Because cognitive and affective disorders occur commonly in older adults, historical information should be obtained not only from the patient but a reliable informant such as the spouse, adult child, or caregiver. The neurological examination should be performed on all older adults regardless of the chief complaint as up to 60% of older patients have either a primary or secondary neurological sign or symptom. A complete mental status and neurological examination provides the necessary data to develop reasonable diagnostic hypotheses and drive the necessary laboratory, imaging, or specialized assessments to care for the patient.
Age-Related Changes in the Neurological Examination
Before discussion of the individual components of the examination, it would be useful to discuss changes that are expected as part of the aging process (Table 12-1). Normal age-related changes are due to progressive and irreversible changes associated with tissue senescence and the inability of nervous system to repair and regenerate secondary to the ravages of time. The frequency and qualitative characteristics of these changes vary from individual to individual but are present in many older adults.
Table 12-1 Neurological Changes Associated with Normal Aging |Favorite Table|Download (.pdf)
Table 12-1 Neurological Changes Associated with Normal Aging
Decreased visual acuity
Smaller pupil size
Decreased ability to look upward
Decreased auditory acuity, especially for spoken language
Decreased muscle bulk
Mild motor slowing
Decreased vibratory sensation
Mild swaying on Romberg test
Mild lordosis and restriction of movement in neck and back
Depression of Achilles tendon reflex
There continues to be a debate as the extent of cognitive changes associated with aging due largely to differences between cross-sectional and longitudinal study designs. When comparing older adults to young adults on similar cognitive tasks such as the Wechsler Adult Intelligence Scale, older adults generally score lower on both performance and verbal subtests. However, when differences in performance are considered in light of motor slowing and educational attainment, these changes are less apparent. Longitudinal evaluation of older adults has generally demonstrated little change in verbal intelligence with aging while performance is influenced ...