By Cynthia Bissell
Even in my nursing career, I had never heard this diagnosis before. I only knew that it didn’t sound good. When I asked Eric’s neonatologist what this meant, he answered simply, "cerebral palsy."
Periventricular leukomalasia (PVL) is a type of brain injury involving an ischemic infarction (inadequate blood circulation) of the white matter of the brain adjacent to the lateral ventricles. Peri means near; ventricular refers to the ventricles or fluid spaces of the brain, leukomalasia is softening of the white matter of the brain. The softening occurs because brain tissue in this area has died. Since PVL results in the loss of vital areas of neural tissue, particularly motor fibers that control muscle movements, cerebral palsy (CP) develops in most cases. It is likely to be of a moderate to severe degree and either spastic diplegia or spastic quadriplegia, with the legs more involved than the upper extremities. Mild to severe mental retardation may occur, but some children with PVL and spastic CP have normal intelligence. However, they will have learning disabilities secondary to their motor delays, because children learn by doing. Visual impairment is also possible if the injury involves the occipital region. Seizure disorders may occur but are not commonly associated with PVL.
After the injury, necrosis occurs (tissue death). While the body works to clean out the dead tissue (a process called phagocytosis), cysts develop, which are visible via a head ultra sound, CT scan or MRI (magnetic resonance imaging). Motor and cognitive outcomes have been associated with the presence, location and extent of periventricular cysts. Ultra sounds are used routinely in the NICU, because it is easier and can be done at the bedside.
Reabsorption of the cysts may occur over a period of months, then the ventricles (fluid filled spaces in the brain) take over the space of the lost brain tissue. This was seen as significantly enlarged ventricles (ventriculomegaly) on Eric’s MRI, which was done when he was 10 months old.
Preemies are particularly susceptible to developing PVL, because of poorly developed cerebral vascular systems. The injury is thought to be caused by hypotension (low blood pressure), which can be secondary to a number of things including sepsis, seizures, meningitis, intraventricular hemorrhages (IVH), cardio-respiratory arrest or significant apnea.
After much research, clearly there is no way to be sure exactly how or when Eric’s injury occurred. Eric’s membranes were ruptured for 3 weeks, leaving him vulnerable to infection and Eric seemed to have been in fetal distress just before birth. The injury also might have occurred in the NICU shortly after birth when Eric was in critical condition and his doctors were having difficulty maintaining his blood pressure.
As for Eric’s long-term outcome, it has been a waiting game for us and although we know a bit more now than we did when he was an infant, it is still a bit too soon to tell. We do know that he has spastic quadriplegia CP, but we are optimistic about his intellect.
In spite of his problems, Eric is an alert and determined little boy. He works hard with his therapist and is making slow but sure progress and we are very proud of him.