A neurodegenerative disease refers to a type of disease caused due to the progressive loss of structure or function of neurons. This whole process is known as neurodegeneration. This process can occur at several levels of neuronal circuitry in the brain, which ranges from molecular to systemic. Various types of neurodegenerative diseases include, Parkinson's disease, multiple system atrophy, Alzheimer's disease, amyotrophic lateral sclerosis, prion diseases, multiple sclerosis and Huntington's disease. A common pathogenic feature of various neurodegenerative diseases is the buildup of aggregated proteins, which can induce cellular dysfunction and ultimately lead to cell death. Neurodegenerative diseases might be categorized on the basis of their primary clinical characteristics, major molecular abnormality or anatomic distribution of neurodegeneration. The understanding of the molecular aspects of a variety of neurodegenerative diseases, like Alzheimer's or Parkinson's disease can help to improve patient management from a basic or clinical standpoint. This book contains some path-breaking studies neurodegenerative diseases. It aims to shed light on molecular and clinical pathology of these diseases. This book will serve as a reference to a broad spectrum of readers.