[Neuropsychiatric non motor symptoms of Parkinson's disease]

In the last decade we have witnessed substantial progress towards the understanding of Parkinson's disease. According to pathological and neuroimaging studies, the traditional view of Parkinson's disease that begins with the development of motor symptoms such as bradykinesia, rigidity and tremor, has begun to change. It is now understood that there would be a "premotor" or "preclinical" period in which the alphasynuclein pathology begins outside of the substantia nigra in the lower brainstem and autonomic nervous system. Although the pathophysiology of this phase is still unclear, it is currently thought that its symptoms would correspond to the so-called "non-motor symptoms". Hyposmia, depression, constipation and REM sleep disorders are one of the most relevant non-motor symptoms at this "premotor" stage. The spectrum of non-motor symptoms is very broad and covers the domains of neuropsychiatric, dysautonomic, gastrointestinal and sensory symptoms as well as sleep disorders. Neuropsychiatric symptoms such as depression, impulse control disorder, psychosis and dementia, are a major cause of disability as they are directly related to quality of life.