Olympic rower Pete Reed is paralysed after a spinal stroke - but what is it?

A spinal stroke has left the triple Olympic gold medallist Pete Reed paralysed from the chest down.

The former athlete, 38, won gold at three successive Games - Beijing 2008, London 2012 and Rio 2016 - as well as at five World Rowing Championships.

READ MORE: Three-time Olympic gold medalist Pete Reed paralysed after spinal stroke

Reed took to Instagram to announce the diagnosis following his shock retirement from rowing last year.

In yesterday’s post, Reed said “doctors can’t be certain what caused his stroke”, adding there is a “very small chance he will make no recovery and a very small chance he will make a full recovery”.

Yahoo UK looks at what a spinal stroke is and the symptoms to look out for.

What is a spinal stroke?

A spinal stroke is a rare condition that occurs when the blood supply to the vertebrae is cut off, leaving it unable to function as normal, according to the Brain and Spine Foundation.

This can result in injury or tissue damage that prevents nerve impulses travelling along the backbone.

These impulses are required for different parts of the body to “communicate”, like telling the arms to move or the bladder to “release” urine.

READ MORE: Mother reveals shock after healthy 10-year-old daughter suffers stroke

Spinal strokes make up just 1.25% of all strokes in the UK.

Overall, around 100,000 strokes occur every year in the UK, Stroke Association statistics show.

In the US, more than 795,000 people have a stroke annually, according to the Centers for Disease Control and Prevention.

What causes a spinal stroke?

Most spinal strokes are caused by blood clots.

These usually form in hard, narrow arteries due to a build up of cholesterol, known as atherosclerosis.

If the clot blocks an artery that “feeds” the spinal cord, a stroke may occur.

This form of spinal stroke becomes more common with age, as the arteries naturally harden and narrow.

People with high blood pressure or cholesterol and heart disease or diabetes are more at risk.

READ MORE: Sharon Stone warns people about the early signs of a stroke

Smoking, a high alcohol intake and inactivity also raise the odds.

Spinal strokes can also come about when a blood vessel that supplies the backbone bursts.

This is usually due to high blood pressure, which weakens arteries so they are more likely to tear.

Less common causes include spinal cord compression, tumours or surgery.

Writing on Instagram, Reed said: “Doctors can’t be certain what caused his stroke”.

What are the symptoms of spinal stroke?

Spinal stroke symptoms usually start with sudden and severe back or neck pain.

Sufferers may also endure weakness in their legs, an unusual sensation in their lower body and double incontinence.

This can come on within just minutes of the stroke occurring.

Muscle weakness can then quickly progress to complete paralysis of the legs, as well as spasms.

Over the long term, many endure permanent paralysis, pain, double incontinence and depression.

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When it comes to sex, the ability for a paralysed man to become erect depends on his injury.

Erections occur when the brain sends messages through the nerves of the spinal cord to the penis in response to erotic thoughts or stimulation.

A man with an incomplete injury, where he still has some feeling in his legs, lower in his spine is more likely to achieve arousal than those with “complete” damage higher up, according to the Christopher & Dana Reeve Foundation.

Erections can also be “reflex” actions if the penis or other erogenous zones are touched without any sexual thoughts.

The nerves that control these erections, S2-S4, are located in a different part of the spinal cord.

Most paralysed men can have a reflex erection unless the S2-S4 nerves specifically are damaged.

Writing on Instagram, Reed said, “there is no crystal ball” when it comes to his recovery, which depends on “the extent of the damage and how well he does in rehab”.

How is a spinal stroke treated?

Treatment depends on the part of the spine affected, with most strokes being in the anterior - or front - section of the backbone.

Drugs can help to reduce spasms and incontinence, as well as restoring sexual function.

The prognosis varies from person-to-person.

If the stroke was caused by a clot, blood-thinning drugs may make the blood less “sticky” to prevent a second event.

In cases where blood pressure or cholesterol was to blame, medication may be given to target the root of the problem.