DOWN'S SYNDROME AND ALZHEIMER'S DISEASE
Glossary

Some of the common terms are defined below:
Alzheimer's disease
- a physical disease which causes a progressive decline in the ability to remember, to learn, to think, and reason

Amyloid deposits
- the accumulation in the brain of an excessive quantity of beta protein which then forms filament or fibril-like structures called amyloid (also know as beta amyloid protein)

Cortical atrophy
- a process whereby areas of the brain appear to shrink; it is associated with the cerebral cortex - the grey matter covering the cerebrum containing millions of nerve cells

Dementia
- a condition or set of conditions that result in the progressive loss of mental functions and abilities

Hypothyroidism
- a clinical state resulting from an underactive thyroid gland; the thyroid is a gland in the neck which produces hormones that control growth and body metabolism; underfunction is often associated with weight gain and loss of energy resulting in loss of interest in activities (see the Down's Syndrome Association pamphlet, "Thyroid disorder among people with Down's syndrome: notes for parents and carers" (Sept 1993))

Neurofibrillary tangles
- one of the abnormal brain cell formations that are characteristic of Alzheimer's disease; they occur inside brain cells, particularly the larger neurones, which eventually die; each tangle is made up of many smaller fibrils

Neuropathology
- the physical changes in the brain that are characteristic of different diseases or dementias

Senile plaques
- one of the brain cell formations present in large numbers in people with Alzheimer's disease; their centre is formed from amyloid surrounded by degenerating nerve cells