Sundowning appears in infants as an abnormality of the eye and is typically a sign of illness or injury to the brain. Infants with sundowning eyes have a downward gaze, and the white part of the eye can be seen above the colored portion. Sundowning is displayed among infants who are in a relaxed state, yet the eyes gaze in a downward position rather than moving or staring ahead.
The front of a baby’s eye consists of the iris, pupil and sclera, which are surrounded by the folds of skin of the eyelids. The sclera is the white part of the eye; the iris is the colored circular middle; and the pupil is the black center. In front of these structures is the anterior chamber, which contains the aqueous humor, a substance that nourishes eye tissues and lubricates the eye for movement. Eye movement is controlled by the cranial nerves, which are located in the brain.
The brain and spinal cord are normally surrounded by cerebrospinal fluid, or CSF, which acts as a cushion for the sensitive brain tissue. The CSF circulates around the brain and spinal cord and is reabsorbed into the bloodstream. MedlinePlus states that an excess amount of CSF puts pressure on the brain, pushing it against the inside of the skull. The pressure causes sundowning in an infant’s eyes, as well as full fontanelles.
A medulloblastoma is a type of pediatric brain tumor that develops in the cerebellum, which is located toward the base of the brain. The cerebellum is responsible for a child’s gait and motor skills, as well as her attention span. Sundowning of the eyes occurs as pressure is placed on the area of the brain that controls eye movement, and is an early sign that parents notice with this type of brain tumor.
An infant may have sundowning if he has sustained injuries, typically those that are not accidental. Actions such as shaking, falls or any other type of force may cause an injury to the brain. According to the Congress of Neurological Surgeons, these types of injuries may cause brain bleeding or a pocket of blood known as a hematoma. If large enough, a hematoma can exert pressure on the brain, affecting the center that controls eye movement.
Sundowning is often treated by eliminating the cause of pressure on the brain. In patients with a hematoma causing increased intracranial pressure, surgery is indicated to remove the blood clot. Infants with hydrocephalus also need surgery to repair the blockage that is causing a buildup of CSF. If the blockage is unresolved, a shunt is implanted to displace the fluid. A baby may need brain surgery to remove a tumor, followed by chemotherapy. If CSF buildup is present due to the tumor, a shunt is also placed.