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AUTONOMIC SYSTEM AND PD (Feb 1997) Normally, we don't pay much attention to body functions such as breathing, blood pressure, pulse rate, digestion, peristalsis, etc. Unlike conscious activity such as talking, reading, riding a bike, the body takes care of unconscious functions by itself. Except in PD. IMHO too little attention is given, both in literature for PWP and in research on management of the disease. Books for PWP, for example the one by R. Duvoisin, mention some autonomic symptoms, but skip any explanation of their relation to dopamine and how they are caused. So here is a bit of info, limited by the amount of current work as well as my slight knowledge, to help PWP understand the disease better. My reference material is old, dating as far back as 1972, but I think still OK. First, a few definitions: The human nervous system is divided into the central system, consisting of the brain and spinal cord, and the peripheral system, which is everything else. The peripheral system includes nerves to muscles and sense organs, for example, and the autonomic system. The autonomic system is further divided into the sympathetic (outgoing or efferent) system and the parasympathetic (incoming or afferent) system. Those two components form a feedback loop for each of many connected organs, muscles, or functions. For example, the brain senses a need for more blood, and sends a signal raising blood pressure and pulse rate. Then it receives a signal back when the needed increase has occurred. The process is continuous, as are all other autonomic functions, and although some people can learn to influence it consciously, that is not necessary. For another example, we can all hold our breath (briefly) or take a deep breath, when we want to. But if we ignore breathing, as usual, the autonomic system, using the very same muscles, tends to it. I don't know if sleep apnea is associated with PD, but it might be. Dopamine circulates in the blood, to mediate action at the distal terminals of the autonomic system. Symptoms of autonomic failure, presumably due to dopamine deficiency of PD, include: difficulty swallowing; drooling (either excess salivation or failure to swallow enough); insufficient or excess sweating; urinary retention or hesitancy; sexual (in men) dysfunction; seborrhea (not dandruff as some neurologists seem to think}; constipation (which can be life-threatening); conjunctivitis, from reduced tear secretion; solid matter in eyes (from excess tear secretion?); poor muscular endurance (abnormal fatigue); poor sensation of temperature or poor temperature regulation; dizziness on suddenly arising (postural hypotension). Paradoxically, one severe form of autonomic (non-PD) failure is congenital lack of the enzyme that converts dopamine to norepinephrine, resulting in excess, rather than deficiency, of plasma dopamine. Much of the above is my conjecture, since there doesn't seem to be much literature on the relation of the autonomic system to PD, nor have I found any current research on it. More of either would probably help PWP a lot. Joe J. R. Bruman (818) 789-3694 3527 Cody Road Sherman Oaks CA 91403