Clinical manifestations There are many forms of intracranial tumor onset, generally in the form of slowly progressive neurological dysfunction, such as progressive visual impairment and various sensory-motor impairment. However, it can also manifest as sudden convulsions or progressive increase in intracranial pressure. Less common are stroke-like episodes, most of which are caused by sudden hemorrhage, necrosis or cystic degeneration of the tumor. The main manifestations of intracranial tumor are two categories: 1. Symptoms of increased intracranial pressure Intermittent headache with gradual intensification, more frequent in the early morning after waking up from sleep and in the evening. Most of them are in the two temporal areas and may involve the posterior occipital and orbital areas. The headache worsens with activities such as coughing, exerting force, sneezing, bending over, or lowering the head. When the headache is severe, it may be accompanied by vomiting, often in the form of jets. In severe cases, the patient is unable to eat and vomits immediately after eating, which may affect the patient’s nutritional status. Optic papilledema is an objective sign of increased intracranial pressure and has a greater diagnostic value if present. In addition, the increased intracranial pressure may also cause abductor nerve palsy in both eyes, diplopia, vision loss, darkness, dizziness, sudden collapse, impaired consciousness, etc. Depending on the location of the tumor, various symptoms and syndromes may appear, here we can only briefly introduce the common clinical manifestations of brain tumors in each location. Tumor in central area: including the precentral gyrus of frontal lobe and postcentral gyrus of parietal lobe and its adjacent parts. There is contralateral central facial paresis, monoparesis or hemiparesis and hemianesthesia. Motor aphasia may occur with involvement of the dominant hemisphere. If there are seizures, generalized seizures are more frequent, and there may be transient paralysis of the convulsing limb after the seizure, called Todd palsy. Frontal lobe tumor: The main manifestations are mental symptoms, such as apathy, lack of concern for surrounding affairs, emotional euphoria, and lack of initiative. Memory, attention, comprehension and judgment deteriorate, intelligence decreases, and one does not pay attention to one’s own neatness, and one is often unaware of urination and defecation. In typical cases, there are strong grip reflexes and groping movements. Generalized seizures are also common. There is motor aphasia and aphasia in the dominant hemisphere. Frontal lesions may cause loss of smell and vision loss. Parietal tumors: Sensory deficits are predominant, characterized by deficits in localization and discrimination of sensations. The patient is unable to distinguish the shape, size, weight and texture of objects by touch. The position sensation of the limbs is also reduced or lost, and thus there may be sensory ataxia signs. The dominant lesion may include inability to calculate, loss of reading and writing, loss of self-recognition, and loss of orientation and location. Patients are thus often disoriented from time to time. Seizures are often preceded by sensory symptoms. If the tumor involves the parietal central lobule, there may be bilateral spastic paralysis of lower limbs and urinary retention. Temporal lobe tumor: there may be contralateral isotropic quadrant blindness or hemianopsia. The dominant lesion has sensory aphasia and seizures characterized by psychomotor seizures. There are aura of phantom smell, phantom hearing, fantasy, déjà vu and dream state. Occipital tumors: also have hallucinations, often dominated by simple images, flashes of light or colors. There is contralateral isotropic hemianopia, but the central visual field is often preserved. The dominant side of the lesion may have visual loss of recognition, loss of reading, and larger or smaller visual acuity. Insula tumor: The main manifestations are visceral reactions, such as eructation, nausea, abdominal discomfort, salivation, chest tightness, “upward rush of air” and vasomotor reactions. Tumor of corpus callosum: characterized by progressive dementia. Tumors in the middle of the corpus callosum have bilateral motor sensory impairment due to invasion of motor sensory cortex on both sides, with the lower extremities more than the upper extremities. The tumor in the posterior part of the corpus callosum may cause symptoms similar to those in the pineal region due to compression of the tetraspanic body, including bilateral pupil inequality, loss of light response and regulatory response, and inability to see upward with both eyes, which is called Parinaud syndrome. Because the cerebral aqueduct is easily accessible, hydrocephalus and intracranial pressure increase symptoms are also more likely to appear. Third ventricular tumor: It mainly shows symptoms of intermittent intracranial pressure increase, which is closely related to certain position of the head. When the head is in this position, it can suddenly develop, with severe headache, vomiting, consciousness disorder and even coma, accompanied by flushing, sweating and other vegetative symptoms, and sometimes can lead to respiratory arrest and death. It can also manifest as a sudden loss of muscle tone in both lower limbs and fall down, but consciousness remains awake. Changing the position of the head can relieve the symptoms. When the tumor invades the base of the third ventricle, there may be drowsiness, urinary collapse, obesity and hypogonadism. Some patients have premature aging. Fourth ventricle tumor: the symptoms are less obvious, early vomiting is more prominent. When the outlet of the fourth ventricle is blocked, it may cause hydrocephalus manifestation. Lateral ventricular tumor: the symptoms are insidious, and the symptoms of increased ICP are the main ones. Patients may suffer from apathy, drowsiness, memory loss, or even dementia. Emotional agitation, psychiatric symptoms, persecution, delirium and various hallucinations, and endocrine symptoms. Women have menstrual disorders, polyuria, and obesity, while men are predominantly hypersexualized. When the ventral lateral part of the thalamus is involved, there may be subjective sensory disturbance and mild hemiparesis. The medial thalamus may be involved with decreased intelligence. In the late stage, there are symptoms of increased ICP. Some patients have tremor, tardive dyskinesia and chorea. However, typical thalamic spontaneous pain is very rare. Basal ganglia tumor: The main symptom is subjective sensory disturbance, early stage may have mild hemiparesis, increased muscle tone, tremor, chorea, and tardive dyskinesia. Ataxia and nystagmus are also common. The occurrence of epilepsy is seen in 20% of cases, with small episodes of dyscalculia being common. Psychiatric symptoms such as dementia and memory loss are seen in about 25% of cases. Brainstem tumors: characterized by the presence of crossed paralysis, i.e., cranial nerve paralysis on the side of the disease and hemiparesis on the opposite side. (1) If the midbrain tumor is located at the base, there is spastic hemiparesis and hemianesthesia on the contralateral side and actinic nerve palsy on the diseased side (Weber syndrome). Tumors in the parietal part of the midbrain can cause gross tremulous movements, choreographic movements and Magnus positional reflexes (when turning the head to one side, the upper limb on that side is flexed and the lower limb is straightened; if the head is turned to the opposite side, the limb on the opposite side appears in the above posture). Parinaud’s syndrome can be caused when the tumor is located in the midbrain tetralogy of Fallot. (2) Pontocerebral tumor produces peripheral facial palsy and adductor nerve palsy, diplopia, and contralateral hemiparesis on the diseased side. If the tumor involves the trigeminal mesencephalic tract, there may be hyperalgesia, dull or absent corneal reflex, and weakness of chewing. If the tumor is lateralized, there may be spontaneous horizontal or vertical nystagmus. In advanced stage, there may be bilateral ataxia sign. (iii) Vomiting and eructation are the prominent symptoms of delayed brain tumor. The symptoms of Ⅸ, Ⅹ, Ⅺ, Ⅻ cranial nerve palsy are loss of laryngeal reflex, choking and coughing, soft palate palsy, deviation of the uvula to the contralateral side, hoarseness of laryngeal voice, atrophy of the lingual muscles accompanied by fibrillation of the lingual muscles, and contralateral hemiparesis. Cerebellar hemispheric tumor: There are impaired coordination of the affected limbs, slurred speech, nystagmus, significantly reduced muscle tone of the limbs, blunted tendon reflexes, staggering gait when walking, easy to fall to the affected side, etc. Cerebellar earthworm tumor: unstable gait (duck gait), gradually progressing to inability to walk. The tumor may lean backward when standing. The coordination movement disorder of the limbs is often not obvious. If it causes obstruction of the fourth ventricle, the symptoms of increased intracranial pressure and hydrocephalus will appear. Pontocerebellar horn tumor: vertigo, tinnitus on the affected side, progressive hearing loss to deafness. There is partial paralysis of the trigeminal and facial nerves on the affected side, nystagmus and cerebellar signs on the diseased side. In the late stage, there are symptoms of cranial nerve paralysis and increased intracranial pressure such as Ⅸ, X and D. Early symptoms are endocrine disorders, mainly menopause, lactation, infertility and obesity in women, and hypogonadism, hair loss and increased subcutaneous fat in men. When the tumor extends to the suprasellar area, bilateral temporal hemianopia and bilateral blindness may occur. The fundus of the eye shows primary atrophy of the optic nerve papilla. Growth hormone adenomas have symptoms of hyperpituitarism (gigantism or acromegaly), but the effect on vision is not as pronounced as that of prolactin adenomas. Parasellar and slope tumors: Early symptoms are mononeural palsy of the abducens or trigeminal nerve, manifesting as diplopia, inward turning of the eye on the diseased side, and loss of facial sensation. Later on, increased intracranial pressure and cone bundle sign may appear. Treatment of intracranial tumor 1.Surgical treatment For brain tumor with benign nature, intact envelope and easy to be peeled off, and short course of disease, there is more hope for surgical cure. However, for those with high malignancy or other metastatic cancer, palliative surgery, such as partial resection, decompression, ventriculo-ventricular fistula and ventriculo-ventricular shunt, is feasible. 2.Radiotherapy Currently, radiotherapy surgery is mostly used, which is also called three-dimensional irradiation, and adopts all-round rotational radiotherapy technology to make the tumor shrink or even disappear after being irradiated in multiple directions, so as to achieve the same effect as surgery.