Management of non-motor complications in Parkinson’s disease

This paper summarizes the methods we devised for the treatment of psychosis, orthostatic hypotension, and mood disorders among the various non-motor complications of Parkinson’s disease. Psychosis may not manifest when a patient believes in his/her delusions. If left untreated over a prolonged period, however, the delusions progress to paranoia that is very difficult to cure. Accordingly, enquiries should be made during routine examinations to detect the presence of psychosis and facilitate early discovery. Atypical antipsychotics are used when psychosis does not improve after reducing the doses of antiparkinson drugs. We achieved favorable results by using mianserin hydrochloride prior to this step, with efficacy being observed for hallucinations and mild delusions that often manifested at night. This drug does not act as a dopamine receptor blocker, so it has the advantage of not aggravating motor symptoms. With this therapy, it is also possible to improve motor symptoms without inducing psychosis by reducing the doses of antiparkinson drugs and locally stimulating the motor loop by deep brain stimulation of the subthalamic nucleus. We previously introduced leg-holding exercises for the treatment of orthostatic hypotension, through which blood pooled in the veins is returned to the systemic circulation by holding the knees. This can be done easily and is free of adverse reactions. Mood disorders are difficult to cope with in patients with Parkinson’s disease, but may be treated by selecting an appropriate dopamine agonist while giving consideration to affinity for the dopamine D3 receptor. However, treatment becomes complicated when the dopamine receptor is overstimulated. Here we report on cases of successfully treated pathological gambling and dopamine dysregulation syndrome, which are considered difficult to manage. The solution may differ depending on a patient’s environment, and it is not easy to prescribe therapy based on evidence-based medicine. The best therapy should be selected by maintaining communication with the patient and developing a relationship built on trust.