Optic nerve damage

Outlined the optic nerve conduction is central beam, Optic nerve damage within the optic pathway due to some causes conduction dysfunction diseases. Etiopathologic disease triggered by optic nerve damage causes a lot, a common cause of trauma, ischemia, poisoning, demyelination, tumor suppression, inflammation, metabolism, such as syphilis. Their common pathogenesis is caused by optic nerve conduction dysfunction. A clinical performance. Visual impairment for the most common clinical manifestation of the most important and often the initial orbital back pain and swelling, and blurred version. Succeeding symptoms increased significantly decreased performance or visual loss. 2. Visual field defects can be divided into two categories : ① double temporal hemianopsia : oppression such as tumor induced nerve conduction both sides of the nasal retina to the visual fiber involvement, Bilateral unacceptable optical stimuli double temporal hemianopsia. Tumor gradually grow up, as a result of heavy pressure side lost visual function of the blind side, the other side of the temporal hemianopsia. Finally both sides showed the blind. ② Blind to the same : as the beam or the lateral geniculate body after access the damage, can produce nasal side with the other side of temporal visual field defect, called to the same hemianopsia. As with the central beam the Blind, the former accompanied by light reflex disappeared, the latter reflection exist; The former Blind integrity, and the latter was more incomplete sexual heminopia quadrant; The former patients subjective symptoms than the latter significantly, the latter have no symptoms; The latter vision eyesight kept in the center, was evasive macular phenomenon. A differential diagnosis. visual impairment or loss (1) traumatic brain injury (craniocerebral injury) When the skull base sphenoid bone fracture after fracture unit sudden injury or internal carotid artery, could cause carotid-cavernous fistula, performance of the head or orbital continuous noise, pulsating exophthalmos, restricted eye movement and visual sexual and other receded. Under a clear history of trauma, X-ray skull fractures and brain angiography clinical diagnosis is not difficult. (2) the optic nerve myelitis (optic nearomyelitis) disease a few days to two weeks before it can be upper respiratory tract infection. Be the first from the eye symptoms or symptoms of spinal cord, can be both simultaneously, usually the first to suffer a few hours to a few weeks, Another focus will incidence. Dysopia general development of a fast pace and a dark center, as occasionally almost total blindness. Ocular lesions can be optic papillitis or retrobulbar optic neuritis. If the former is imminent palilledema, in the case of the latter, as a normal nipple. Myelitis symptoms appear in ocular symptoms, the first symptoms of back pain or shoulder pain, radiotherapy to the upper arm or chest. Then there abdomen and lower extremities paresthesia, lower extremity weakness and urinary retention. Although the initial tendon reflexes weakened, but still reflected bilateral plantar hyperextension. Loss of sensation or abnormal-thoracic. Peripheral blood leukocytes increased erythrocyte sedimentation rate slightly faster. (3) Multiple Sclerosis (multiple sclerosis) in more than 20 ~ 40 years of incidence , a variety of clinical manifestations, as the first visually impaired performance of monocular (sometimes blindfolded) dysopia. Fundus examination showed optic papillitis change. Cerebellum levy, the levy and the pyramidal tract dysfunction after REQUEST are common. Deep hyperreflexia, shallow reflex reflector and plantar hyperextension. Ataxia, the barriers between structure and intention tremor three simultaneous, that constitute the so-called Charcot (Charcot) triple the levy. The disease course of the typical remission and relapse occur. Evoked Potentials, CT or MRI can be found no clinical manifestations of demyelinating lesions, increased CSF immunoglobulin, normal protein quantitative ceiling or slightly higher. (4) optic neuritis (optic neuritis) can be divided into as papillitis with retrobulbar optic neuritis two. Mainly rapid visual impairment or blindness, eye pain, vision centers appear dark spot, physiological blind expansion of the pupil to expand, direct-response disappeared offered photosensitive reaction exist, and many of them unilateral. As papillitis with regard nipple change, the fringe unclear, the color red, or venous filling Yu Qu, a small unit bleeding, As nipple has a significant high. As papillitis palilledema sublimity, which is rapidly lost their sight early, photophobia, eye pain, Dark spots and center as the nipple with less than a high refraction characteristics, and the latter is easy to identify. Retrobulbar optic neuritis and visual papillitis similar, but ignore nipple changes. (5) optic atrophy (optic atrophy) is divided into primary and secondary two. The main symptoms for the visually impaired, depending on the color of pale nipple and the pupillary light reflex. Primary optic atrophy of the optic nerve, optic chiasm or, as the beam due to tumors, inflammation, injury, poisoning, vascular diseases and other reasons, blocking visual stimulation. Secondary optic atrophy of the optic disk edema, as papillitis with retrobulbar optic neuritis caused. (6) acute ischemic optic neuropathy (acute ischemic optic nearitis) Infarct refers to the optic nerve caused by the loss of eyesight, sudden onset, often lost their sight immediately reached its peak. Dysopia decision to the extent the distribution infarction. Fundus examination can be regarded as papillary edema and hemorrhage line around the nipple. Often secondary to Erythrocytosis, migraine headaches, gastrointestinal bleeding, cerebral arteritis and diabetes, more of hypertension and arteriosclerosis. According to the primary disease and dramatically decreased visual acuity clinical diagnosis easier. (7) chronic alcoholism (chronic alcoholism) is the visually impaired subacute, Alcoholism accompanied by symptoms, such as slurring in speech, unsteady gait and a total economic movement disorders, there will be serious alcoholism mental disorders. (8) intracranial tumor (see visual field defect) 2. vision defect (1) - a temporal hemianopsia. pituitary tumor (pituitary adenoma) Early Chui body tumor often without visual interference. If tumor growth and upward extension suprachiasmatic oppression, occur vision defects, the upper outer quadrant first affected. Red vision first shown. At this time the patient was walking on a road when the collision easy roadside pedestrians or obstructions. After the disease increases, oppression heavier, white vision are also affected gradually to a double-temporal hemianopsia. If not treated in time, the visual field defect can be further enlarged, and vision have receded, resulting in the blind. Apart from a pituitary tumor eyesight vision changes, the most common symptoms of endocrine, such as growth hormone cell adenoma, Clinical manifestations of acromegaly, in the event of the past puberty, can present with the Giants. If prolactin cell adenomas in female patients, there will be amenorrhea, lactation, such as infertility. Pituitary tumor patients X-ray of an expanded Sella, saddle end damage, CT, MRI tumor growth, examine the various endocrine hormones increased. 2. Craniopharyngioma (17.2%) mainly for childhood growth retardation, intracranial hypertension. When the optic nerve compression arise Visual barriers. Since tumor growth direction is often not the law, the degree of optic nerve compression on both sides, on both sides of the visually impaired so many different levels. Outlook change is also inconsistent, about half of the performance-temporal hemianopsia. Early tumor upward pressure suprachiasmatic can double performance for the Blind temporal quadrant. Tumors occurred in saddle downward performance of the oppressor could double blind infratemporal quadrant. Partial tumor side can be expressed as monocular temporal hemianopsia. Skull films intracranial calcification and CT, MRI and endocrine function in the clinical diagnosis more clear. 3. Tuberculum meningiomas (tuberde of sellae resorption fibrobl astoma) clinical performance to the visually impaired and headache symptoms are relatively common. Visual impairment is chronic progress. Preemptive unilateral visual decline or asymmetrical distribution of decreased visual acuity, or simultaneous side two temporal visual field defect. After the development of the two temporal hemianopsia, and eventually to blindness. Fundus a primary optic atrophy signs. Advanced cases of intracranial hypertension caused symptoms. CT scanning, tuberculum meningiomas typical signs of the suprasellar region show the contrast-enhanced images blob. Uniform density. (2) with regard to the Blind and visually beam radiation can cause damage to two opposite to the vision of the Blind. More common in the internal capsule and hemorrhagic infarction appeared to hemianopsia with contralateral side who feel obstacles and temporal lobe, to the medial parietal lobe tumor as oppression and visually beam radiotherapy arising from the contralateral to the same hemianopsia. These diseases can be more clinical performance and head CT diagnosis.