Excessive and even drenching episodes of sweating are common in Parkinson’s, particularly in mid to late stages of the disease, when off-states begin to occur. Excessive sweating can be a consequence of damage to the autonomic nervous system as Parkinson’s progresses or a side effect of anti-parkinson’s medications.
The autonomic nervous system regulates the body’s autonomic, or automatic, functions such as heartbeat, blood pressure, and temperature control. The dopamine depletion that characterizes Parkinson’s affects the functions of autonomic nervous system structures including parts of the basal ganglia that participate in directing smooth (involuntary) muscle activity. The subthalamic nucleus (STN) and the thalamus, a structure in the mid-brain that modulates nerve signals to and from the cerebellum, play roles in transmitting nerve signals that control smooth muscle tissue such as in the walls of the blood vessels. Dilation of the blood vessels is part of the body’s process for cooling itself, moving larger volumes of blood closer to the skin’s surface. This process releases heat from within the body. Sweating is an element of this process and typically occurs in coordination with blood vessel dilatation.
People who have Parkinson’s often experience sweating when Levodopa and other dopaminergic drugs reach peak levels in the body and during off-states. such sweating can be intense, drenching the person within minutes. Adjusting medication dosages sometimes relieves or at least moderates this response; a dance to find dosages high enough to relieve Parkinson’s symptoms without causing such responses ensues. anticholinergic medications such as benztropine (Cogentin) and biperi-den (Akineton) provide relief by suppressing the actions of acetylcholine on smooth muscle. alpha-ADRENERGIC BLOCKER (ANTAGONIST) medications such as Prazozin (Minipress) and clonidine (Catapres) suppress the actions of epinephrine to similar effect.
Temperature regulation is a complex process that involves a number of body systems including the endocrine system, a network of hormone-producing structures and their hormones. Thyroid imbalance, which becomes increasingly common with advancing age, also can be a culprit in dysfunctions of temperature regulation. usually a few simple blood tests can determine whether the thyroid gland is properly functioning, and thyroid replacement hormone can correct imbalances. Episodes of excessive sweating often are embarrassing as well as uncomfortable for the person with Parkinson’s. changing into dry clothing when the sweating episode ends restores comfort and prevents the further discomfort of chilling. Some people with Parkinson’s find that warm temperatures trigger excessive sweating or experience chronic excessive sweating involving the face and head. This condition can exacerbate skin problems such as dandruff and sebaceous dermatitis.
