As their very name indicates, these tumors are located in the brain, a nervous system structure that connects the spinal cord, the brain and the cerebrum.

The brain stem is a part of our body that is extremely important for normal functioning. It hosts several regulating nuclei and is the origin of many nerves (cranial pairs) that regulate a wide range of functions spanning from functions as vital as breathing and heart rate, to the control of most facial muscles (9 of the 12 cranial pairs originate in the brain stem), the extremities, including arms and legs, as well as balance coordination.

The symptoms and limitations of the child presenting this tumour vary and evolve depending on the cranial pairs and central nervous fibre tracts involved in the growth of the tumour. Common symptoms are impaired coordination, balance, difficulties or inability to walk, arm or hand movement, paralysis of facial muscles and, in the most severe cases, inability to talk or swallow any solid foods or liquids.

Brain stem tumors account for approximately 20% of brain tumors in children.This percentage translates into 20 new annual cases in Spain and nearly 200 in the United States. It should be noted that brain tumors are the most frequent solid tumors in children and the second most common type of cancer in children by number of cases following leukemias.

Based on the type of cells that are found in this tumour, and not just its location, we can classify most brain stem tumors as gliomas. That is why they are often referred to simply as brain stem gliomas. Gliomas are tumors of the central nervous system and can appear in any part of the brain or spinal cord.

As a curious fact, brain stem glioma presents almost exclusively in children. The age of onset is between 5 and 7 years, even though it can also be diagnosed in children under and over this age.

This information has been checked by the Department of Paediatric Oncology, Hospital Sant Joan de Deu.