A brain tumor is a mass of abnormal cells that develops within the brain tissue. The most common type of brain tumors in babies and children are medulloblastoma or astrocytoma brain tumors. According to the American Brain Tumor Association, 2,200 children in the United States are diagnosed with brain tumors each year. Symptoms of a brain tumor in infants may be difficult to spot at first.
Bulging Fontanelles
The bones of an infant's skull are separate at birth to allow the baby's head to move through the birth canal. As the baby grows, the skull closes and the sutures fuse together at a soft spot in the skull known as the fontanelle. A baby with a brain tumor may experience increased fluid on the brain or increased pressure from the tumor that can cause the fontanelle to bulge, according to the University of Maryland Medical Center. Even if a child doesn't have a tumor, when he is lying down, crying or vomiting it may appear as if the fontanelle is bulging, but it returns to normal when the child is calm.
Separated Sutures
The sutures at the back of an infant's skull should fully close by one to two months of age. The sutures at the top of the skull take longer, between seven and 19 months. If, after 19 months, the sutures in the baby's skull remain separated, this may indicate that the child has a brain tumor that is causing an increase in pressure or fluid, which prevents the sutures from closing.
Positive Babinski's Reflex
A positive Babinski's reflex can often indicate a brain tumor. If the big toe moves toward the top of the foot and the other toes fan out when the bottom of the foot is firmly stroked, this is considered a positive Babinski's reflex. When a baby has a brain tumor, she may have a positive Babinski's reflex if the tumor is putting pressure on the corticospinal, or pyramidal tract, a tract that runs from the cerebral cortex of the brain to the spine.
