L

Labyrinth

The inner ear, which contains the cochlea - the hearing organ - and the vestibular organs - the organs of balance.

Labyrinthitis

An inflammation, usually caused by viruses, of the labyrinth. The hearing is usually not affected.

Laminectomy

An operation to remove the bony arches at the back of the spine, either to decompress nerves in the spine or to provide access to these nerves so that more involved procedures can take place, e.g. removal of tumours.

Larynx

The organ, also known as the voice-box, in the throat that is responsible for voice production and for preventing food from entering the airway during swallowing.

Lesion

Area of tissue with impaired function as a result of damage by disease or wounding.

Level of consciousness

The level of consciousness of a person can vary between being fully conscious and being in a deep coma, and there are many levels between these two extremes. Medical staff will assess a person’s level of consciousness by checking for certain responses, which include eye opening, verbal response and response to stimulation.

Ligaments

These are tough bandlike structures with slightly elastic properties which help to hold bones together at joints.

Low grade tumour

A tumour that develops slowly over a number of years.

Lumbar

The name given to the lowest mobile portion of the spine, sometimes referred to as the small of the back.

Lumbar puncture

A medical test, involving taking a small sample of fluid from the lower spine using a needle, a bit like a blood test. This is usually done with some local anaesthetic when the person is lying on their side on a bed or couch.There are no serious side effects, although some people may get a headache afterwards.

Locked-in syndrome

A condition resulting from a stroke affecting the brain stem which usually results in total paralysis, including loss of speech and swallowing, but in which the intelligence of the person is not affected. Sometimes eye movement is still possible and can be used as a mode of communication.