occipital lobe tumor
Introduction
Introduction to occipital tumor The occipital lobe is small, and the tumor that occurs solely in the occipital lobe is also less. The occipital lobe tumor often affects both the parietal lobe and the posterior temporal lobe. More common tumors are gliomas, accounting for 1.46% of intracranial gliomas; meningioma accounts for 0.74% of intracranial meningioma; other tumors are less common. Physiologically, the occipital lobe is the most advanced visual analyzer, the so-called "visual hub." The main clinical manifestations of occipital lobe tumors are visual impairments. The disease is a neoplastic disease, which is currently thought to be caused by the activation of proto-oncogenes, but the specific cause is not clear, and may have certain correlation with environmental factors, genetic factors, dietary factors, and mood and nutrition during pregnancy. According to the location and infiltration of the tumor, the patient has only the defect of the contralateral field of vision, loss of amblyopia or color vision in the early stage. basic knowledge The proportion of illness: 0.0054% Susceptible people: no specific population Mode of infection: non-infectious Complications: optic tract lesions optic atrophy
Cause
Occipital tumor neoplasia
The disease is a neoplastic disease, which is currently thought to be caused by the activation of proto-oncogenes, but the specific cause is not clear, and may have certain correlation with environmental factors, genetic factors, dietary factors, and mood and nutrition during pregnancy.
Prevention
Occipital tumor prevention
It is very important to maintain a good attitude, to maintain a good mood, to have an optimistic, open-minded spirit, and to be confident in the fight against disease. Don't be afraid, only in this way can you mobilize your subjective initiative and improve your body's immune function.
Complication
Occipital tumor complications Complications, optic nerve atrophy
Mainly concurrent visual obstacles, oppression of other cranial nerves, tissue and so on.
Symptom
Occipital tumor symptoms common symptoms visual deformity quadrant hemianopia hemianopia isotropic hemianopia visual agnostic occipital lobe impaired color vision loss macular avoidance phenomenon
1. According to the location and infiltration degree of the tumor, the patient has only the defect of the contralateral field of vision in the early stage, and the amblyopia or color vision is lost.
2. When the tumor invades and damages the wedge leaf above the occipital lobes, complete hemianopia does not occur, only the contralateral 1/4 quadrant hemianopia; damage to the tongue below the sulcus is only when the contralateral side appears 1/4 of the quadrant hemianopia, when the tumor is large, it can cause contralateral symmetry of the lesion. This is because the central field of vision is dominated by the occipital lobe on both sides, and the macular fiber is projected to the bilateral occipital lobe, which is not easy to be fully involved. Therefore, when the unilateral occipital lobe lesions, the central visual field often stays, that is, the so-called macular evasion phenomenon, even if the bilateral occipital lobe is damaged, it is rare to have total blindness. Generally, the central visual field is always preserved, and the acute damage of one occipital lobe can be After a few hours of total blindness, the visual field of the healthy side recovered after a few hours, and the residual lesions were contralateral and unilaterally blunt. Clinically, the fiber damage between the bilateral occipital lobe and the thalamus was completely blind, but the patient did not feel blind. , called Anton synthesis.
3, visual seizures are common symptoms of occipital lobe tumors, central hemianopia (macular evasion), cortical blindness, visual agnosia, etc., visual stimuli when irritating lesions, sometimes a precursor to seizures, in 1954 The first year was described by Penfield. There was a simple visual hallucination in the contralateral field of the lesion. About 15 to 24% of the occipital lobe tumors had visual hallucinations. The characteristics of the visual hallucinations were mostly non-formed visual phenomena such as flashes, highlights, and circles. Lines, colors, etc., often appear in the contralateral field of view of the lesion, and there is a floating phenomenon. The hallucinations can occur alone or as a precursor to seizures. When epileptic seizures occur in occipital lobe lesions, the head and eyes are often rotated to the opposite side. It stimulates the "gaze center" of the occipital lobe.
4, the left occipital lobe (dominant hemisphere) tumor can also appear aphasia, visual distortion, etc., aphasia, that is, the patient loses the ability to recognize the item according to the shape of the object, the patient is not blind, but for the familiar person, Things, colors, etc. can not be distinguished, this situation is more common in the lesions on the outside of the left occipital lobe.
Examine
Examination of occipital lobe tumor
1. Skull flat film: Skull plain film examination is almost a routine examination method for intracranial tumors. The cranial plain film of occipital lobe tumors is mainly based on the nature of the tumor, and the growth rate can be expressed as increased intracranial pressure, skull destruction and odor proliferation. In order to determine if further auxiliary inspection items are needed.
2. EEG: EEG manifestations of occipital lobe tumors are characterized by localized slow waves occurring in the occipital or posterior occipital region. Therefore, sometimes it is difficult to distinguish from parietal lobe tumors, posterior tibial tumors or occipital occipital tumors, but More tumors in the parietal lobe lead to changes in the posterior or posterior EEG and show a wider, more pronounced delta wave, wave; posterior tibial tumors are usually accompanied by abnormal waves in the anterior tibial region; The wave with the same degree of abnormality in the top, the top and the occipital region, and the wave in the background of the electroencephalogram of the occipital lobe tumor are all obstacles. In particular, the wave of the occipital side of the diseased side has a significant inhibition or disappearance, accounting for about half. The typical wave pattern of occipital lobe tumors is a localized delta wave on the background of occipital desynchronization or significant inhibition of alpha waves, while fast wave asymmetry is less common.
3. Ventricular angiography: Because the occipital lobe is small, tumors limited to the occipital lobe are relatively rare. The tumor often compresses the occipital angle of the ventricle, which makes the occipital angle narrow or closed, but must be differentiated from the normal ventricular variability. There is no displacement of the lateral ventricle system, and the occipital lobe is larger. It often protrudes into the lateral ventricle triangle or the posterior part of the third ventricle. The tumor invades the occipital sac and the lateral ventricle, the triangular area, and the filling defect. The third ventricle Push forward.
4. Cerebral angiography: The cerebral angiography of occipital lobe tumor is characterized by: in the anterior and posterior images, the lateral displacement of the anterior cerebral artery is very light, and there is little change in the movement. The lateral image shows the trunk and convex surface of the middle cerebral artery. The branch pushes forward or partially disperses and straightens up. The posterior cerebral artery can be thickened when developing. The distal branch group is separated or pressed, and the deep tumor often invades the cerebellum. Therefore, the cerebellar incisional artery can be developed and falsified. Crude.
Diagnosis
Diagnosis and diagnosis of occipital lobe tumor
Differential diagnosis
(1) The clinical symptoms of the tumor in the occipital area are mainly the changes of visual dysfunction, and the symptoms gradually change from light to heavy. It should be distinguished from the visual dysfunction caused by the lesions in various parts of the visual pathway, but the lesions in various parts of the visual pathway The clinical symptoms produced have their typical manifestations, and the typical symptoms of occipital lobe tumors are Anton syndrome and unformed illusion. There are no lesions in other parts of this symptom. For example, the illusion of the temporal lobe tumor is generally shaped. It is also accompanied by other symptoms of temporal lobe lesions, which are easy to identify.
Another symptom of occipital lobe tumor is contralateral isotropic hemianopia. Because the central visual field is dominated by bilateral occipital lobe, its fiber distribution is wide and not easy to be fully involved. Therefore, in unilateral occipital lobe lesions, the central visual field often remains. That is, the macula evas the observation, which can be distinguished from the contralateral isotropic hemianopia caused by the oppression of the top and temporal lobe tumors.
(B) visual episodes of occipital lobe tumors should be noted with migraine, certain drug poisoning or schizophrenia and other visual hallucinations, the visual episodes caused by occipital lobe tumors are: Constant, generally appear in the contralateral field of view of the lesion; the frequency of seizures gradually increases, with the increase in the number of episodes, other localized symptoms such as hemianopia, loss of recognition, aphasia, etc.; seizures have nothing to do with the environment, the illusion of schizophrenia The seizures are related to the environment, and are accompanied by other symptoms of the spirit. In addition, the pseudoscopic episodes caused by the tumor are often accompanied by contralateral deviation of the head and the eye, and the migraine caused by migraine and certain drug poisoning has no tumor. The characteristics of the view are easy to identify.
