The nonmotor features of Parkinson's disease: pathophysiology and management advances

In recent years progress has been made in the detection and evaluation of nonmotor symptoms in Parkinson's disease. The pathophysiology is better understood and new treatment is available, which will be discussed in this review.

The most intriguing recent finding is the fact that Parkinson's disease may be a spreading disease. From the environment a toxin, bacteria, or virus may start in genetically susceptible patients a cascade of α-synuclein aggregation which reaches via the olfactory and the enteric system of the gut the brain where further spreading causes symptoms, such as sleep disturbances, motor impairment, and neuropsychiatric symptoms. New treatment should address the abnormal α-synuclein folding. If this would be achieved premotor signs, such as hyposmia, rapid eye movement-sleep behavior disorder, constipation, or depression may be a kind of biomarkers which allow together with other diagnostic tools, such as parenchymal sonography, iodobenzamide-scintigraphy and dopamine transporter scans the prediction whether somebody might be under way to develop the full-blown Parkinson's disease syndrome.

Parkinson's disease seems to be a spreading disease which causes not only a dopaminergic deficit as major cause for the movement disorder but also impairs function of many other brain centers which leads to a multitransmitter malfunction.