Symptoms in the later stages of CNS leukemia may include headache, nausea, vomiting, aphasia, convulsions, drowsiness, coma, visual impairment, hemiparesis, and so on. CNS leukemia is the infiltration of leukemia cells into the brain, the infiltration of brain tissues leads to lesions in the brain, and corresponding neurological and psychiatric symptoms may appear in the lesions in the brain, such as headache, nausea, vomiting with increased intracranial pressure, aphasia if the language center is affected, and visual impairment if the optic nerve is affected. If the motor center is damaged, hemiparesis may occur, and in severe cases, convulsions, drowsiness and coma may occur. CNS leukemia should be treated in a timely manner in a hospital, and the doctor should determine whether it is caused by the disease itself according to the specific condition.