optic tract lesions
Introduction
Introduction to optic tract lesions Most of the ocular lesions are lesions caused by tumors, vascular lesions or demyelinating diseases of adjacent tissues. It is manifested as contralateral side of the lesion and bilateral hemianopia. For example, left ocular beam lesions cause a visual field defect in the nasal side of the left eye and the temporal side of the right eye. Since the nerve fibers that intersect and do not intersect in the optic tract are not symmetrically arranged on both sides, the visual field defects of both eyes may be inconsistent. Because the pupillary fibers are accompanied by the optic tract, the ocular beam lesions can manifest Wernicke blunt pupillary rigidity, that is, the sulcus light illuminates the blunt side of the retina without causing pupillary contraction. Late optic tract lesions can also cause descending optic atrophy. basic knowledge The proportion of sickness: 0.01% Susceptible people: no special people Mode of infection: non-infectious Complications: optic neuromyelitis hemangioma
Cause
Causes of ocular beam lesions
Causes:
In the skull base stroke range is small, and then covered by the temporal lobe, rarely alone, the cause of the disease is mostly caused by adjacent tissue diseases, such as optic neuromyelitis, hemangioma of the posterior branch of the traffic, etc. In addition to the same hemianopia, more often accompanied by systemic symptoms, such as the appearance of partial sensation and dyskinesia on the opposite side of the lesion.
Prevention
Vision lesion prevention
1. Eat more foods rich in vitamin A, such as animal liver, snail, oyster, rape, spinach, leeks, sage, celery, sweet potato, mango, and medlar.
2, should eat more foods with eyesight and anti-inflammatory effects, such as chrysanthemum, leeks, medlar, Malan head, snails, abalone, sea otters, sea turtles.
3, should eat more anti-eye tumor food: Malan head, carrot, stone ear, mulberry tree, dandelion, big leafy vegetables, burdock and root, sheep brain.
4, should eat foods that have reduced side effects of radiotherapy and chemotherapy, such as leek, asparagus, reed rhizome, holly, sugar cane, kiwi, plum, mung bean sprouts, olives, loofah, glutinous rice, squid, squid, herring, squid, snail.
5, should eat more foods rich in vitamin B2: animal liver, eggs, squid, crab, leafy vegetables, soybeans, milk, bean paste, black fungus.
6, should eat more foods rich in vitamin C, such as fresh dates, grapefruit, citrus, kiwi, leeks, rape, bitter gourd, guava, hawthorn, lemon, beans, potatoes and other fresh vegetables, fruits.
Complication
Contrast tract complications Complications optic neuromyelitis hemangioma
More with optic neuromyelitis, hemangioma of the posterior branch of the traffic.
Symptom
Symptoms of optic tract lesions common symptoms changes in the same direction of blunt blindness
1. Visual field change: Optic nerve fibers from both eyes occupy a certain position in the optic tract, and are not completely mixed. Therefore, when one side of the visual beam is damaged, the optic nerve fiber is often more affected than the other eye. Complete (non-overlapping) co-directional hemianopia (ie, the nature, extent, size, and speed of the ipsilateral half-field defect in both eyes) and macular division are one of the characteristics of visual beam damage.
2. Fundus changes: early fundus is normal, usually three months later, the eyes of the two-eye optic disc can appear pale, such as the right eye bundle damage, there will be right eye optic disc and half of the left eye optic disc nasal half pale , is the second characteristic of the optical beam damage.
3. Pupil change: Since the afferent afferent nerve fibers pass through the 2/3 segment of the optic tract, after the segment is damaged, the slit lamp beam is used to illuminate the binocular side of the bilateral retina from the hemian side, and the pupils of the eyes are directly unresponsive to light or Disappeared, called eccentric blind pupil rigidity, and when the third third of the optic tract was damaged, because the pupillary afferent pathway was separated from the visual beam here, the pupil afferent nerve fibers were not affected, and the pupil responded to light normally. The third feature of the visual beam damage.
4. Other manifestations: When the beginning of the optic tract is damaged, it is often due to simultaneous violation of the optic chiasm. In addition to the same hemianopia, there may be symptoms of optic chiasm; the middle is damaged, often involving the cerebral peduncle at the same time. On the opposite side, there are partial sensation and dyskinesia, the same side can affect the ocular eye, the trochlear and abducted cranial nerves, and the ocular dyskinesia occurs.
Examine
Examination of ocular lesions
Observing the fundus changes: the early fundus is normal. Generally, after three months, the side of the optic disc disease may appear pale in color. If the right eye beam is damaged, the right eye half of the optic disc and the nasal side of the left eye optic disc will appear pale. It is a characteristic of the beam damage.
Diagnosis
Diagnosis and differentiation of ocular beam lesions
Diagnosis can be based on medical history, clinical symptoms, and laboratory findings.
Need to identify the lateral geniculate lesions, visual radiation lesions, occipital lobe lesions.
