The short duration of medulloblastoma is determined by the biology of the tumor, with nearly half of patients having a disease duration of less than 1 month and a few up to several years. The duration of the disease is reported in the literature to be 4-5 months, with the duration becoming longer as the patient ages. Due to the insidious growth of medulloblastoma, early symptoms lack characteristics and are often overlooked by patients’ relatives and doctors. The first symptoms are headache, vomiting and unsteady gait, and later diplopia, ataxia and vision loss may occur. The symptoms of medulloblastoma are as follows: Increased intracranial pressure Due to the growing tumor in the cerebellar earthworm, the fourth ventricle and/or the middle cerebral aqueduct are compressed, resulting in obstructive hydrocephalus and increased intracranial pressure. Clinical manifestations include headache, vomiting and fundus optic disc edema. In younger children, cranial suture dehiscence may be present, with vomiting being the most common and may be the only early clinical manifestation. In addition to increased intracranial pressure, direct stimulation of the vagal nucleus at the base of the fourth ventricle by the tumor is also an important cause of vomiting. Vomiting is usually seen in the morning and is often accompanied by hyperventilation. Optic disc edema is less common in children than in adults, probably because the increased intracranial pressure in children is partially compensated by separation of the cranial sutures, whereas in adults it is almost always present. Cerebellar damage is mainly a trunk ataxia caused by cerebellar earthworm damage. Patients may show gait staggering, widening distance between walking feet, or even unsteadiness and swaying in standing. The tumor invades the superior cerebellar earthworm and the patient leans forward, while the tumor in the inferior cerebellar earthworm leans backward. As tumors invading the lower cerebellum are more common, posterior tilt is also more common. The development of tumor on one side may cause different degrees of cerebellar hemispheric symptoms, mainly manifesting as ataxic movement disorder of the affected limb. Those with primary cerebellar hemispheres may show cerebellar speech, and more than half of the patients show oculomotor ataxia mostly as horizontal nystagmus. Tumor compression of the medulla oblongata may lead to choking and cone bundle sign. 2/3 of the children showed hypotonia and tendon reflexes. In this group, 88.3% of the children had cerebellar signs. Other manifestations 1. Diplopia: Bilateral incomplete paralysis of the abducens nerve due to increased intracranial pressure is manifested by limited abduction of both eyes with internal strabismus. The presence of unilateral adductor nerve palsy with ipsilateral peripheral facial palsy often indicates that the tumor has invaded the facial nerve thalamus at the base of the fourth ventricle. 2.Facial palsy: The tumor directly invades the facial nerve thalamus at the base of the fourth ventricle, which is less common. 3.Forced head position: When the tumor or the lower herniated cerebellar tonsils penetrate into the vertebral canal, it stimulates and compresses the cervical nerve root causing the patient’s protective position response. 4.Cranial enlargement and McCewen’s sign: Mostly seen in younger children, due to increased intracranial pressure and separation of cranial sutures. 5. Cone bundle sign: caused by the increase of tumor volume and forward pressure pushing the brainstem, and pathological reflexes are more common in both lower limbs. 6.Choking: It occurs when the tumor compresses the brainstem and/or the Ⅸth and Xth cerebral nerves, and the gag reflex is weakened or disappeared in clinical examination. 7.Cerebellar crisis: Due to cerebrospinal fluid circulation disorder, subungual herniation of cerebellar tonsils or direct compression of brainstem by tumor, it causes loss of consciousness, slowed breathing and elevated blood pressure with positive bilateral pathological reflexes, and even deactivation of brain. Death may occur within a short period of time due to rapid respiratory arrest. 8.Subarachnoid hemorrhage: Tumor hemorrhage in medulloblastoma is one of the main sources of hemorrhage in children with non-traumatic posterior cranial recess subarachnoid hemorrhage.