Occipital lobe damage

Introduction Impaired occipital lobe is a symptom manifested by diseases such as occipital lobe tumor, occipital lobe cerebral infarction. The patient's occipital lobe was damaged Mainly manifested as visual obstacles. In the case of unilateral occipital lobe lesions, the central visual field often stays, which is called the phenomenon of macular avoidance. Even if the bilateral occipital lobe is damaged, total blindness rarely occurs, and the central field of view is generally retained. Acute damage to one side of the occipital lobe can cause transient blindness. After a few hours, the visual field of the healthy side recovers, and the left side of the disease is unilaterally hemophilic. Clinically, it can be seen that the fiber damage between the bilateral occipital lobe and the thalamus is completely blind, but the patient does not feel blind, called Anton syndrome.

Cause

Mainly because the occipital lobe tumor often affects both the parietal lobe and the posterior temporal lobe. The degree of influence depends on the location and extent of tumor growth.

an examination

Related inspection

Brain CT examination EEG examination

1. First, do a flat slice of the skull, and diagnose according to the manifestation of the flat slice of the occipital tumor.

2. The electroencephalogram of occipital lobe tumors is characterized by localized slow waves appearing in the occipital or posterior occipital region, so the diagnosis is based on the EEG.

3. Because the occipital lobe is small, tumors that are limited to the occipital lobe are relatively rare. Tumors often compress the occipital angle of the ventricle, so that the occipital angle is narrowed or closed, but it must be differentiated from normal ventricular variability. If it is a variation range, the lateral ventricle system has no displacement. The larger occipital lobe tumor 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 triangle area, and the filling defect, and the third ventricle pushes forward.

Differential diagnosis

1. The clinical symptoms of the tumor in the occipital area are mainly the changes of visual impairment, and the symptoms gradually change from light to heavy. It should be distinguished from the symptoms of visual impairment caused by lesions in various parts of the visual pathway. However, the clinical symptoms produced by the lesions in various parts of the visual pathway have their typical performance. The typical symptoms of occipital lobe tumors are Anton syndrome and unformed hallucinations, and lesions in other areas of this symptom are absent. Phantoms such as temporal lobe tumors are generally shaped and are accompanied by other symptoms of temporal lobe lesions. Careful inspection is easy to identify. Another symptom of occipital lobe tumors is contralateral isotropic hemianopia. Because the central visual field is dominated by the bilateral occipital lobe, its fiber distribution is wide, and it is not easy to be fully involved. Therefore, when the unilateral occipital lobe lesion is present, the central visual field is often retained, that is, the macula is evaded. This point can be distinguished from contralateral isotropic hemianopia caused by oppression of the top and temporal lobe tumors.

2. Visual episodes of occipital lobe tumors should be distinguished from migraine, certain drug poisoning or schizophrenia. The visual episodes caused by occipital lobe tumors are characterized by: the location of the visual hallucinations is relatively constant, and generally occurs in the contralateral field of view of the lesion; the frequency of seizures gradually increases, and as the number of episodes increases, other localized symptoms such as hemianopia, loss of recognition, Aphasia and so on appear one after another; seizures have nothing to do with the environment. The hallucinations of schizophrenia are related to the environment and are accompanied by other symptoms of the mind.

In addition, the onset of hallucinations caused by tumors is often accompanied by head and eye to the opposite side of the lesion. Migraine and certain drug poisoning caused by phantoms have no features of tumor-induced illusion, so it is easy to identify.

1. First, do a flat slice of the skull, and diagnose according to the manifestation of the flat slice of the occipital tumor.

2. The electroencephalogram of occipital lobe tumors is characterized by localized slow waves appearing in the occipital or posterior occipital region, so the diagnosis is based on the EEG.

3. Because the occipital lobe is small, tumors that are limited to the occipital lobe are relatively rare. Tumors often compress the occipital angle of the ventricle, so that the occipital angle is narrowed or closed, but it must be differentiated from normal ventricular variability. If it is a variation range, the lateral ventricle system has no displacement. The larger occipital lobe tumor 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 triangle area, and the filling defect, and the third ventricle pushes forward.

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