Progressive supranuclear palsy (PSP) is a degenerative disease of the brain leading to difficulties with walking and balance, problems with eye movements, changes in behavior, difficulty with speech and swallowing, and dementia.

Primary progressive aphasia is caused by degeneration in the areas of the brain that control speech and language. This type of aphasia begins gradually, with speech or language symptoms that will vary depending on the brain areas affected by the disease.

Posterior cortical atrophy (PCA), also called Benson's syndrome, is the visual variant of Alzheimer’s disease. It is a clinical syndrome in which complex visual processing is progressively disrupted owing to a neurodegenerative disorder.

In contrast to Alzheimer's where other cognitive skills are affected, mild cognitive impairment (MCI) is defined by deficits in memory that do not significantly impact daily functioning. Memory problems may be minimal to mild and hardly noticeable to the individual.

The human immunodeficiency virus (HIV) causes chronic inflammation throughout the body and brain. Without treatment, over 50% of subjects will develop clinically relevant central nervous system (CNS) symptoms. While antiretroviral therapies that reduce inflammation have greatly decreased the frequency of dementia in HIV, milder forms of impairment remain frequent.

Huntington disease (HD) is a progressive, neurodegenerative disorder typically characterized by involuntary movements (chorea), behavioral and personality changes and cognitive decline (dementia). It is caused by a dominantly inherited gene mutation that can be passed down from generation to generation. HD is an illness with profound neurological and psychiatric features.

Lewy body dementias include dementia with Lewy bodies (DLB) and Parkinson’s disease with dementia (PDD) and are the second most frequent cause of dementia in elderly adults. Common symptoms include problems with movement, visual hallucinations, and fluctuations in thinking skills or attention.

Corticobasal degeneration is a progressive neurological disorder that affects nerve cells that control walking, balance, mobility, vision, speech and swallowing.