- What pattern of injury is seen in this case?
There has been a cerebral infarction with liquefactive necrosis. The gross appearance shows the appearance after a couple of weeks. The microscopic image has lipid-laden macrophages cleaning up the debris. The CT scan reveals a dark area that is the cystic area from the resolved liquefactive necrosis.
- What is the relationship of diabetes mellitus to this process?
Persons with diabetes mellitus ten to have accelerated, advanced atherosclerosis with an increased incidence of vascular problems. They are at increased risk for a "stroke" (a cerebrovascular accident, or CVA).
- What is the outcome in this case?
The problems depend upon the size and location of the CNS tissue that is damaged. Large infarcts may cause death. The patient can be left with residual neurologic deficits. Over time, function may be regained. Physical therapy can help.
- What is meant by "persistent vegetative state" (PVS) and "brain death" ? Is this patient likely to have either of these conditions?
A patient who has had a "stroke" from a cerebral infarct leading to extensive cerebral liquefaction and loss of higher mental function often still has intact brain stem function as clinically measured by testing reflexes, such as cranial nerve reflexes. In that case the patient is said to be in a PVS. This usually can be diagnosed with 90% confidence after 3 months. Patients in a PVS can be kept alive through their normal lifespan, if that is the goal.
Brain death is supposed to mean the loss of functions of the entire brain, although even that is a bit of an overstatement. The determination of death by brain criteria was first proposed in the 1960s when techniques of organ transplantation advanced to the point where there was a need for more well perfused (or "live" ) organs that could be "harvested" from newly dead people. Thus, it was important to find a point where death was certain and irreversible, but the organs still usable. As a result, the declaration of "brain death" is based upon loss of brain stem reflexes, but does not require waiting until diabetes insipidus is present (antidiuretic hormone is still being produced).
The patient in this case has lost some motor function, but not consciousness or purposeful movement. Patients who suffer a "stroke" abruptly lose one or more functions, but they typically do not have a progressive downhill course with continued loss of function. Their residual CNS function remains stable, or they may even gain back function. However, patients who have had one "stroke" may have additional "strokes" that lead to further stepwise loss of function.
