Parkinson病治療の長期計画

抄録

Parkinson disease (PD) is a neurodegenerative disorder affecting over 150,000 patients in Japan as of February 2025. It is caused by a progressive loss of dopaminergic neurons in the substantia nigra of the midbrain, leading to dopamine deficiency and resulting in motor symptoms such as akinesia, muscle rigidity, and tremor. While symptomatic treatments, particularly those involving L–dopa formulations, are effective, no treatment has been established to prevent the onset or slow the progression of the disease.

The life expectancy of PD patients differs from the general population by only two to three years on average, making long–term care unavoidable. Therefore, it is crucial to select appropriate symptomatic treatments at the right time to maintain the patient's quality of life. As shown in the figure, the clinical course of PD progresses through the following stages : risk stage → preclinical stage → prodromal stage → motor symptom onset stage.

The prodromal stage, which is estimated to last more than ten years, may present with prodromal symptoms such as REM sleep behavior disorder, olfactory impairment, constipation, and orthostatic dysregulation, and mild parkinsonism is not uncommon. When the motor symptom onset stage begins, symptomatic and physical therapy are initiated. While individual variations exist, many patients become wheelchair–bound or bedridden within approximately 15 to 20 years. Therefore, a long–term treatment strategy assuming a total disease course of around 20 to 30 years is essential.