Levodopa impairs lysosomal function in sensory neurons in vitro

Patients are diagnosed on the basis of slowness of movement and/or tremor and/or stiffness. However, many symptoms that are not movement related are now well recognized.

Patients show changes in skin sensation, and the vast majority of patients show loss of sensory neurites, which enable sensation in skin. These changes in skin sensation occur prior to diagno-sis; however, sensory issues may also be exacerbated by levodopa, an important drug used in the treatment of PD. Undoubtedly, levodopa is critical for the treatment of PD, but at high doses, it has repeatedly been shown to impair sensation in PD patients.