Brain Dead

Dr. Rex Martin (Bill Pullman), a renowned neurosurgeon studying brain malfunctions, delves into his own mind to save himself from a megalomaniacal corporation after a car accident leaves him injured and disoriented. He agrees to operate on Jack Halsey (Bud Cort), a former genius mathematician who was institutionalized as a paranoid psychotic, in an attempt to unlock corporate secrets within his brain. As the surgery progresses, Martin's grip on reality begins to slip, making it unclear whether he is the doctor or the patient succumbing to delusion. In the end, it is revealed that Martin died from his injuries and became a sentient brain in a jar.