Dementia is a general term for loss of memory, language, problem-solving, and other thinking abilities that are severe enough to interfere with daily life. Alzheimer's is the most common cause of dementia.

• Alzheimer's disease
• Vascular dementia
• Lewy Body disease
• Frontotemporal dementia
• Alcohol-related dementia
• Down syndrome and Alzheimer's disease
• HIV associated dementia

Neurodegeneration is the progressive loss of structure or function of neurons, including their death. Neurodegeneration can be found in many different levels of neuronal circuitry ranging from molecular to systemic. The greatest risk factor for neurodegenerative diseases is aging. Mitochondrial DNA mutations as well as oxidative stress both contribute to aging.

Brain imaging is the use of various techniques to either directly or indirectly images the structure, function, or pharmacology of the nervous system. It is a relatively new discipline within medicine, neuroscience, and psychology. The main advantage of neuroimaging techniques is Computed Tomography.

Schizophrenia is a psychiatric disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Negative symptoms are deficits of normal emotional responses, or of other thought processes.

Huntington's chorea is a neurodegenerative disease is typically inherited from an affected parent, who carries a mutation. The earliest known description of the disease was in 1841 by American physician Charles Oscar Waters.

Parkinson’s is a long-term degenerative disorder of the central nervous system that mainly affects the motor system. The symptoms usually emerge slowly and, as the disease worsens, non-motor symptoms become more common.

A neural circuit is a population of neurons interconnected by synapses to carry out a specific function when activated. Neural circuits interconnect to one another to form large scale brain networks. The connections between neurons in the brain are much more complex than those of the artificial neurons used in the connectionist neural computing models of artificial neural networks.

A brain tumor occurs when abnormal cells form within the brain. There are two main types of tumors i.e.  Malignant tumors and Benign tumors. All types of brain tumors may produce symptoms that vary depending on the part of the brain involved. The cause of most brain tumors is unknown.

Cerebrovascular disease includes a variety of medical conditions that affect the blood vessels of the brain and the cerebral circulation. The most common presentation of cerebrovascular disease is an ischemic stroke or mini-stroke and sometimes a hemorrhagic stroke. Idiopathic diseases are those that occur spontaneously without a known cause. Congenital diseases are medical conditions that are present at birth that may be associated with or inherited through genes.

A nerve is an enclosed, cable-like bundle of nerve fibers called axons, in the peripheral nervous system. A nerve provides a common pathway for the electrochemical nerve impulses called action potentials. In the central nervous system, the analogous structures are known as nerve tracts. The nervous system is the part of an animal that coordinates its actions by transmitting signals to and from different parts of its body.