Wilhelm H, Grodd W, Schiefer U, Zrenner E
Universitäts-Augenklinik Tübingen, Abteilung für Pathophysiologie des Sehens and Neuroophthalmologie, Germany.
Ger J Ophthalmol. 1993 Aug;2(4-5):234-40.
We report on eight patients who presented for evaluation of unexplained visual loss. They all showed a typical chiasmal visual field defect (bitemporal hemianopia, junction scotoma). In all patients, high-resolution computer-assisted tomographic (CT) scans of the sellar region were normal, and neither the medical history nor additional ophthalmological findings pointed to any explanation for the underlying disease. Six patients seemed to have suffered from chiasmal optic neuritis. Magnetic resonance imaging (MRI) scans could elucidate the diagnosis in five cases: white-matter lesions typical of multiple sclerosis (MS) were found and, additionally, in four cases an enlargement of the chiasm or barrier defect was revealed in post-gadolinium MRI. In one patient, MRI was normal. He recovered completely after megadose steroid therapy. One patient developed motoric symptoms of MS during the following year, another patient had mild sensory symptoms and recurrence of severe optic neuritis. An MR-proven chiasmal lesion due to a leukocytoclastic immunovasculitis combined with small subcortical white-matter lesions was diagnosed in another patient. The field defects disappeared spontaneously. In a 28-year-old woman a low vitamin B12 level was found in routine blood samples. Parenteral vitamin B12 substitution led to an almost complete recovery of the visual field defects. Chiasmal optic neuritis may occur isolated or during the course of MS. Megadose steroids may be of value if contraindications have been ruled out. A chiasmal visual field defect caused by vitamin B12 deficiency is very uncommon. A similar case was reported in 1961.
我们报告了8例因不明原因视力丧失前来评估的患者。他们均表现出典型的视交叉视野缺损（双颞侧偏盲、交界性暗点）。所有患者的蝶鞍区高分辨率计算机断层扫描（CT）均正常，病史及其他眼科检查结果均未提示任何潜在疾病的病因。6例患者似乎患有视交叉神经炎。磁共振成像（MRI）扫描在5例中明确了诊断：发现了多发性硬化（MS）典型的白质病变，此外，在4例患者中，钆增强MRI显示视交叉增大或屏障缺损。1例患者的MRI正常。他在接受大剂量类固醇治疗后完全康复。1例患者在接下来的一年中出现了MS的运动症状，另1例患者有轻度感觉症状且严重视神经炎复发。另1例患者被诊断为白细胞破碎性免疫血管炎合并小的皮质下白质病变导致的经MR证实的视交叉病变。视野缺损自行消失。在一名28岁女性的常规血液样本中发现维生素B12水平较低。胃肠外补充维生素B12使视野缺损几乎完全恢复。视交叉神经炎可能单独发生或在MS病程中出现。如果排除了禁忌证，大剂量类固醇可能有价值。维生素B12缺乏引起的视交叉视野缺损非常罕见。1961年曾报道过类似病例。
