杏林荟萃之医学英语6：病例分析
在之前的医学英语栏目中我们学习了神经系统的一些基础词汇，包括神经系统解剖以及卒中、癫痫等两大常见疾病的相关内容。现在我们通过几个usmle step1中的病例题来在应用当中复习一下。
A 52-year-old female complains of sudden visual abnormalities. Her history reveals a 30 pack-year （pack-year is a quantification of cigarette smoking,It is calculated by multiplying the number of packs of cigarettes smoked per day by the number of years the person has smoked. ）history of smoking, hypertension, and hypercholesterolemia. A head CT shows a lesion in the right occipital lobe and an angiogram reveals an embolic stroke of the right posterior cerebral artery. What type of visual deficit is she most likely experiencing?
A. Bitemporal hemianopia
B. Central scotoma
C. Left homonymous hemianopia
D. Left superior quadrantanopia
E. Right homonymous hemianopia
F. Right superior quadrantanopia
G. Total left eye blindness
H. Total right eye blindness
Explanation:
The correct answer is C. The posterior cerebral arteries supply the cortical surfaces of the occipital and medial temporal lobes. Damage to one occipital lobe (e.g., by trauma or by ischemia/infarction due to stroke) usually produces a contralateral homonymous hemianopia. Occlusion of the right posterior cerebral artery would therefore result in a left homonymous hemianopia;blindness in the left half of the visual field in both eyes. In addition, involvement of the medial temporal lobe might give rise to peduncular hallucinosis;visual illusions or elementary (unformed) hallucinations. Bilateral lesions would cause "cortical" blindness, which does not affect the pupillary reflexes.
Bitemporal hemianopia (choice A) is a loss of vision in the temporal quadrants of the visual field. (It is also termed heteronymous hemianopia). This occurs in lesions of the optic chiasm, which may occur with pituitary tumors.
Central scotoma (choice B) is a loss of vision in the center of the visual field, with preservation of the peripheral fields. It is associated with optic neuritis, a common complication of multiple sclerosis.
Superior quadrantanopia (choices D and F) is caused by lesions in the upper portion of the contralateral temporal lobe.
Right homonymous hemianopia (choice E) would result from left posterior cerebral artery occlusion. Total blindness in one eye (choices G and H) occurs when its optic nerve is severed.
52岁女性主诉突发视觉异常。她有30包×年吸烟史，高血压史和高胆固醇血症史，头部CT示右枕叶病变，血管造影示右侧大脑后动脉栓塞性卒中。她的视野缺损最有可能是哪一种？
a.双眼颞侧偏盲
b.中心性盲点
c.左侧同向性偏盲
d.左侧上四分之一象限同向性偏盲
e.右侧同向性偏盲
f.右侧上四分之一象限同向性偏盲
g.左眼全盲
h.右眼全盲
解释：正确答案是C。大脑后动脉供应枕叶和颞叶底部。一侧枕叶受损通常会导致对侧同向性偏盲。右侧大脑后动脉阻塞因此会导致左侧同向性偏盲，也就是两眼的左侧视野偏盲。此外，颞叶底部受损会导致大脑脚幻觉，可以是视觉幻觉或要素性幻觉。两侧损伤会导致皮质盲，皮质盲不影响瞳孔反射。
其他选项解释请大家自己了解。