Neurodegenerative disease occurs when the nerve cells of the brain and peripheral nervous system lose their function over time and eventually die. Currently, there are no cures that can permanently cure or slow down the progression of these diseases. The risk of developing neurodegenerative diseases increases dramatically with age. Parkinson's and Alzheimer's disease are the two most common neurodegenerative diseases. The risk factor for neurodegenerative diseases is a combination of environmental and genetic factors. A person might have a gene that can make them more susceptible to a particular neurodegenerative disease. But the time and severity of the disease depends on the environmental exposures throughout life. This book presents the complex subject of neurodegenerative diseases in the most comprehensible and easy to understand language. It is compiled in such a manner, that it will provide in-depth knowledge about the innovations in diagnosis and therapy of these diseases. This book will provide comprehensive knowledge to the readers.