Family of 'Saving Private Ryan' actor Tom Sizemore told there's 'no further hope' after his brain aneurysm

• 'Saving Private Ryan' actor Tom Sizemore had a brain aneurysm on February 18.
• Doctors have told his family to make end-of-life decisions, according to his manager.

Doctors have told the family of "Saving Private Ryan" actor Tom Sizemore to decide on end-of-life matters for the actor after he ran out of treatment options following a brain aneurysm earlier this month, according to his manager

Sizemore, 61, has been in a critical condition in a coma in intensive care since February 18 after he experienced a brain aneurysm and was taken to hospital by paramedics, Charles Lago said.

Doctors told his family on Monday that there is "no further hope" for Sizemore and recommended they make an end-of-life decision, Lago said

The actor is best known for playing sergeant Mike Horvath in the 1998 movie "Saving Private Ryan" alongside Tom Hanks.

A brain aneurysm can cause a 'thunderclap headache'

A brain aneurysm is a bulge in a blood vessel in the organ caused by a weakness in the vessel wall.

It will rarely cause any symptoms if it hasn't burst, but an unruptured brain aneurysm can trigger visual disturbances such as loss of vision, pain above or around the eye, headaches, loss of balance, difficulty speaking, and difficulty concentrating, according to the UK's National Health Service.

Most aneurysms won't rupture, but if they do the first symptom is generally an agonizing headache described as a "thunderclap headache," similar to being hit on the head, the NHS said.

Other symptoms include sickness and vomiting, pain while looking at light, neck pain, sudden confusion, loss of consciousness, and seizures.

A ruptured vessel can lead to what is known as a subarachnoid hemorrhage — a rare type of stroke — where bleeding in the brain can cause brain damage, epilepsy, and depression.

Around 50% of ruptured brain aneurysms are fatal, according to the Brain Aneurysm Foundation.

Preventative treatment can be given to those at high risk of their brain aneurysm bursting. This includes filling the aneurysm with small metal coils, or having it sealed shut with a metal clip.

As the risk of rupture is generally low, most people with a brain aneurysm will be monitored regularly, but no treatment will be carried out.

Lago said Sizemore's aneurysm happened "as a result of a stroke."

Brain aneurysms are most prevalent in people aged 35 to 60

According to the Brain Aneurysm Foundation, a brain aneurysm ruptures every 18 minutes in the US.

Brain aneurysms are most prevalent in people aged 35 to 60, and affect women more than men at a ratio of 3:2, the Brain Aneurysm Foundation stated. Women are also around 1.5 times more likely for their brain aneurysm rupture.

To reduce the risk of a brain aneurysm, the NHS recommended avoiding activites that can damage blood vessels. This includes smoking, eating a high-fat diet, not monitoring blood pressure, and being overweight.