D

Degenerative

A degenerative disease is one in which there is a worsening of physical qualities affecting particular tissues or parts of the body, often leading to
impairment of function.

Delusions

Delusions are abnormal, false ideas or beliefs that people may develop, and that are not shared by those around them. For example, someone may be convinced that a stalker is trying to kill them or that they have
been possessed by the devil.They may be features of primarily psychiatric disorders such as depression or schizophrenia, but may also be linked to neurological brain disease, such as variant CJD.

Dementia

Dementia is a term for the loss of mental function, such as thinking abilities and memory. Affected individuals become forgetful, confused, unable to understand and to do things that were previously easy for them.
Dementia occurs in various brain diseases such as Alzheimer’s disease and CJD.

Demyelination

Loss of the protective “insulating” myelin sheath that covers nerve fibres.

Dermatome

An area of skin known to be supplied by one particular spinal nerve.

Dexamethasone

A potent steroid used to treat brain swelling and spinal cord compression.

Diabetes

Disturbed blood sugar control (due to insufficient circulating insulin) with raised blood sugar.

Diaphragm

A dome-shaped sheet of muscle and fibre that forms a partition between the thoracic cavity in which the lungs are housed and the abdomen. It is lowered when breathing in and raised when breathing out.

Discs

The shock-absorbing cushions between vertebrae (‘building blocks’) in the spine.

Disc protrusion

The bulging or ‘bursting out’ of the disc material beyond its normal margin, often into the spinal canal.

Differential diagnosis

The term used by doctors to refer to the various possible causes of a patient’s symptoms.

Dilated

Enlarged or expanded - used when describing hollow organs such as blood vessels.

Dietician

A specialist in providing advice and information on the most appropriate food or liquids to be taken depending on a person’s state of health and ability to manage different types of food.

Diplopia

Double vision.The affected person sees two of everything, either side-by-side or on top of each other. It is caused by the eyes not looking in the same direction (i.e. a squint).

Disability

Any restriction or lack of ability (resulting from an impairment) to perform an activity in the manner or within the range considered normal for a human being.

Discography

The process of injecting contrast medium into the disc nucleus so that its structure will show up on an X-ray film - the discogram.

Diuretic

A drug that helps to remove excess water from the body by increasing the amount lost in urine.

Dopamine

A chemical messenger which is found in reduced levels in the brains of people with Parkinson’s disease.

Drip

An apparatus for the continuous transfusion of fluids into the body via a vein.

Dura mater

The fibrous, outer membrane covering the brain.

Dysarthria

This is a medical term meaning slurred speech.

Dyslexia

Although most people have heard of children with dyslexia they do not realise that it can affect adults who have had a stroke. People with dyslexia can see the letters which make up words but cannot make sense of them. They oten have problems with writing and spelling.

Dyskinesia

Abnormal movements or the muscles resulting in twisting, jerking or writhing.

Dysphasia

This is a medical term which refers to a problem with language. Typically people with dysphasia know what they want to say but can’t think of the word, or they might use the wrong word. They can have similar problems with understanding, so that it is almost as if they are listening to a foreign
language.

Dystonia

Dystonia is the name given to involuntary movements that result from disturbances in certain parts of the brain.They may affect the face, limbs, neck or trunk and give rise to odd positions or postures. They may be seen in various disorders, including CJD.