A biomechanical approach to diagnosis and monitoring of Parkinson's disease

Parkinson's disease is an idiopathic and degenerative disorder of the central nervous system. Among the symptoms, the tremor at rest is one of the prominent symptoms. The challenge however is that there are no definitive diagnostic test that can confirm the presence or severity of Parkinson's disease. This is a serious handicap especially since the drugs usually prescribed to control these symptoms have serious side effects and their dosages have to be tuned extensively. Also, the exact origin of tremor is unknown. There have been recent efforts [19] to understand the mechanism behind the Parkinsonian tremor, from a control-system perspectives. From these efforts, it appears that increased sensorimotor loop delay may be a cause for Parkinsonian tremor and thus serve as a key distinguishing feature. In the current work, we adopted this hypothesis and with the help of a relatively straightforward analysis of the motor control loop along with the help of some simulation and experimental examples, we first attempt to explain several qualitative observations relating to Parkinson's Disease. Further, we explore the possibilities of for progress tracking, diagnosis, and early diagnosis before onset of tremor using biomechanical means.