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A to Z of neurological topics

In this section we feature information on a number of tests, treatments and conditions, with links for more information either within this website or on external sites where possible. If you can't find what you're looking for, you may wish to speak with one of our Helpline team who may be able to answer your questions. Send an email to [email protected] or call free on 0808 808 1000.

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    An abnormal sensation often caused by pressure or damage to a nerve, and includes feelings of tingling, pricking, burning or numbness.



    A loss of muscle function in part of your body.


    Useful links:

    Spinal Injuries Association

    Parkinson's disease


    A progressive, degenerative condition that affects the brain and can cause problems with movement, rigidity, tremors, and speech.


    See our Parkinson’s disease fact sheet

    Perineural cyst


    A fluid filled sac that affects nerve roots, often those at the level of the sacrum. These cysts don’t usually cause symptoms, but if they are compressing the nerve root they may cause low back pain, sciatica, incontinence, and other neurological symptoms.

    Persistent vegetative state (PVS)


    A disorder of consciousness in which someone appears to be unaware of their environment and are largely unresponsive but experiences a ‘sleep-wake cycle’ and has their eyes open at times, referred to as wakefulness.


    Useful links:

    Persistent Vegetative State Support Group



    A physical form of therapy that aims to help restore movement, mobility and normal body function.


    Useful links:

    Rainbow House Charity

    Pineal cyst


    A pineal cyst is a cyst found on the pineal gland in the brain. They are often asymptomatic but in some cases can cause headaches and other symptoms.

    Piriformis syndrome


    A condition in which the sciatic nerve is compressed or irritated by the piriformis muscle, which is located in the buttocks. It can cause pain, numbness or tingling along the back of the leg and down in to the foot, and can be very similar in presentation to sciatica.

    Pituitary adenoma


    A type of tumour that occurs in the brain, and develops from the pituitary gland.

    Pituitary disorders


    Useful links:

    The Pituitary Foundation


    (also known as polio)


    An infectious disease caused by the polio virus. Most people may not experience any symptoms, but in some cases it can cause problems such as muscle weakness, paralysis, and meningitis.


    Useful links:

    British Polio Fellowship

    Polio Survivors Network

    Post-herpetic neuralgia


    A complication of shingles (a condition caused by the chickenpox virus) that affects nerve fibres in the skin and causes a burning pain that continues in an area previously affected by shingles.


    See our Face pain booklet

    Post-traumatic stress disorder (PTSD)


    An anxiety disorder that is caused by very stressful or distressing events. Someone with PTSD can experience nightmares or flashbacks to the event, and may also have emotional difficulties, problems sleeping, and other symptoms such as panic attacks.

    Posterior fossa


    The space in the back of the skull where the cerebellum usually sits.

    Postural hypotension

    (also known as orthostatic hypotension)


    A form of low blood pressure that occurs when you change position from sitting or lying down, to standing up, and can cause symptoms including light-headedness, dizziness, and headache.


    See our Dizziness and balance problems booklet

    Postural orthostatic tachycardia syndrome (POTS)

    (also known as postural tachycardia syndrome)


    A disorder that is characterised by an abnormal increase in heart rate that occurs after sitting up or standing, and that can cause symptoms including dizziness, light-headedness, headaches, and fainting.

    Progressive supranuclear palsy (PSP)


    A progressive condition that affects the brain and can cause problems with balance, movement, vision, speech, and swallowing.


    Useful links:

    Progressive Supranuclear Palsy Association



    An abnormal collection of cerebrospinal fluid, sometimes found around the surgery site after decompression surgery.