Samuel Monroe Jr. remains hospitalized in Los Angeles on life support with his health rapidly declining ... and his family is getting close to making some extremely difficult decisions.

Samuel's wife, Shawna Stewart, tells TMZ ... a recent CT scan showed the actor is suffering from encephalopathy and his brain tissue is deteriorating due to all his severe ailments.

Because Samuel's immune system is so weak, we're told he's in a negative pressure room -- a quarantine location -- and he currently has a regimen consisting of 6 antibiotics.

Shawna tells us ... she's the power of attorney and she has to consider his quality of life. She says her husband is a fighter and she's praying for his recovery, but no decision has been made on where to go from here.

As we reported ... the actor has been battling for his life for weeks in the hospital ... requiring multiple blood transfusions in a matter of days, as his body is decimated by MRSA pneumonia and meningitis, among other ailments. He's been placed on dialysis.

Shawna says he's opened his eyes a few times recently ... but she believes that has been a reflex due to the pain he feels when he is moved.

The family launched a GoFundMe as medical bills continue to mount ... and they’ve asked fans to chip in whatever they can.