NEUROLOGIC FUNCTION

Changes at the structural, chemical, and functional levels of the nervous system occur with normal aging, but overall, they do not interfere with day-to-day routines unless spe­cific neurologic diseases come into play. The weight of the brain decreases with age, and there is a loss of neurons in the brain and spinal cord. Neuron loss is most pronounced in the cerebral cortex, especially in the superior temporal area. Additional changes take place in the neurons and supporting cells. Atrophy of the neuronal dendrites re­sults in impaired synaptic connections, diminished elec­trochemical reactions, and neural dysfunction. Synaptic transmissions also are affected by changes in the chemical neurotransmitters dopamine, acetylcholine, and serotonin. As a result, many neural processes slow. Lipofuscin deposits (i.e., yellow, insoluble intracellular material) are found in greater amounts in the aged brain.²²,²³

Sensorimotor changes show a decline in motor strength, slowed reaction time, diminished reflexes (espe­cially in the ankles), and proprioception changes. These changes can cause the balance problems and slow, more deliberate movements that are frequently seen in older individuals.²⁴

Even though changes in the brain are associated with aging, overall cognitive abilities remain intact. Although language skills and attention are not altered with ad­vanced age, performance and constructional task abilities can decline, as can short-term memory and immediate recall. A change in personality or significant cognitive de­ficits is considered unusual with normal aging, and if either occurs, evaluation is in order. Dementia or depression can frequently be the cause.