Neurodegenerative disease is a range of conditions affecting the brain neurons. Neurons are the building blocks of the nervous system which includes the brain and spinal cord. Neurons normally don’t reproduce or replace themselves, so when they become damaged or die they cannot be replaced by the body. Examples of neurodegenerative diseases include Parkinson’s, Alzheimer’s, and Huntington’s disease. Neurodegenerative diseases are incurable and can have debilitating conditions that result in progressive degeneration and/or death of nerve cells causing problems with movement and/or mental functions. Dementia is responsible for the degeneration associated with Alzheimer's.