The infiltration of gliomatosis spreads through the entire central nervous system. The range of symptoms is therefore extensive and depends on the areas affected. The most common symptoms are weakness and numbness of the extremities. Such symptoms of loss of strength or sensitivity result from the infiltration of the motor and sensory nerves. Another very common symptom in children is the occurrence of seizures. When the infiltration is large, it leads to increased intracranial pressure, causing headaches, impaired vision and nausea and in very advanced cases, decreased consciousness. Where the brain stem is affected, it causes weakness in the facial and ocular nerves, and those controlling swallowing and speech. If the cerebellum is affected, it causes instability when walking and loss of balance. The alteration of brain function can cause mood swings, changes to personality and memory loss.