Disease Fact Sheets

Creutzfeldt-Jakob disease is a human prion disease caused by a normal protein that becomes misshapen into a “prion,” builds up in the brain and disrupts normal brain function. It is a rare disorder that is fatal, usually within 6 months of diagnosis and a year of the first symptom.

Alzheimer’s disease (AD) is a progressive, degenerative brain disease that slowly erodes memory and thinking skills, and eventually even the ability to carry out simple tasks. It is the most common cause of dementia.

Amyotrophic lateral sclerosis (ALS, commonly called “Lou Gehrig's disease” in the US) is the most common motor neuron disease in adults. Motor neuron diseases are neurodegenerative diseases that cause selective loss of the nerve cells that directly connect the brain to muscles.

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

Frontotemporal dementia is a group of related conditions resulting from the progressive degeneration of the temporal and frontal lobes of the brain. These areas of the brain play a significant role in decision-making, behavioral control, emotion and language.

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.

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.

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.

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.

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.

Vascular dementia is a subtly progressive worsening of memory and other cognitive functions due to chronic, reduced blood flow in the brain, eventually resulting in dementia. Clinically, patients with vascular dementia may look very similar to patients with Alzheimer's, and the two diseases are very difficult to distinguish from each other.