Published online by Cambridge University Press: 01 February 1997
Autonomic disorders in old age can be attributed to several main features associated with aging: the intrinsic neurobiological changes that occur with age, degenerative changes in effector organs innervated by autonomic nerves, and secondary involvement of the autonomic nervous system (ANS) in disease processes. As in most areas of clinical geriatrics, the distinction between disorders ascribed to ‘normal’ aging and those attributable to diseases of old age is difficult to make with any degree of certainty. Neurobiological changes with age have become the subject of intense investigation in recent years, with improvements in techniques for assessing autonomic nerve structure and function. This has included a better understanding of neurotransmitter and receptor transformations during development and aging. The versatility of the ANS, or ‘plasticity’, involves interactions with target organs, e.g. via nerve growth factor (NGF) and with other neurons, and it is as vital to the mature and aging autonomic neuron as it is during development. Some neurotrophic features of aging in the ANS and in disease processes in old age are considered in this paper.