Diagnosis of Parkinson Disease: Imaging and Non-Imaging Techniques

Parkinson’s disease (PD) is a disorder of the nervous system caused due to the consequence of dopaminergic neuron loss in the brain’s substantia nigra region. The neurological disorder leads to disability, and it is the second major cause of death worldwide. In 1990, the number of PD patients recorded was 2.5 million people, and in 2016, the count became 6.1 million people. This alarming prevalence rate shows that it has doubled in 17 years. About 276 million PD cases suffer from disability-adjusted life years (DALYs) [1]. Parkinson’s disease is an aberrantly increasing, progressive neurodegenerative disease that affects individuals, families, and society. PD is often termed as an idiopathic disease since the cause of the disease is unknown. The diagnosis of PD is clinical since no particular test can conclude the disease. There are various diagnostic tools used in combination to diagnose multiple symptoms of the disease. This paper comprehensively gives the different PD stages, the respective clinical tools (imaging and non-imaging techniques), and the research tools (imaging and non-imaging techniques) used to diagnose PD accurately. The sensitivity of current clinical diagnosis using gold standard techniques is just 23% for non-responsive PD subjects [2]. Thus, the risk of increasing PD subjects’ burden can be controlled by choosing appropriate diagnostic tools. The chapter aims to review various imaging and non-imaging tools used in multiple stages of the disease to identify the more accurate and sensitive diagnostic tool. Brain imaging using PET, SPECT, TCS, MRI, and thermal imaging for finding autonomic dysfunction are some of the non-invasive techniques that can diagnose the disease. In this article, various imaging techniques used for the diagnosis of early stages of PD is reviewed.