每日一题_2025.07.26

A 50-year-old woman presented to the emergency department with a 10-day history of a throbbing headache that had suddenly started after she had felt a “pop” in her back. The headache worsened with upright positioning and improved with lying flat. Physical examination, including fundoscopy, was normal. Magnetic resonance imaging of the brain showed diffuse pachymeningeal enhancement (arrow; upper left image, axial view, T1 sequence with contrast). It also showed protrusion of the cerebellar tonsils (arrow) into the foramen magnum, flattening of the pons with effacement of the prepontine cistern (arrowhead), and enlargement of the pituitary gland owing to increased blood flow (asterisk; right image, T1 sequence without contrast). Which of the following is the most likely diagnosis?

一位50岁女性因突发搏动性头痛10天就诊急诊科，其头痛始于背部突然”啪”的一声响后。该头痛在直立位时加重，平卧时缓解。体格检查（包括眼底镜检查）未见异常。脑部磁共振成像显示：弥漫性硬脑膜强化（箭头所示；左上图，轴位T1增强序列）；小脑扁桃体疝入枕骨大孔（箭头）；脑桥受压变平伴桥前池消失（箭头所示）；垂体因血流增加而增大（星号；右图，T1平扫序列）。以下哪项是最可能的诊断？

A. Chiari-Type 1 Malformation小脑扁桃体下疝畸形Ⅰ型

B. Leptomeningeal carcinomatosis软脑膜癌病

C. Neurosarcoidosis神经结节病

D. Spontaneous Intracranial Hypotension自发性颅内低压

E. Subdural hygroma硬膜下积液

答案解析：

磁共振成像（MRI）显示硬脑膜强化、小脑扁桃体异位、桥前池消失以及垂体充血——这些表现均符合自发性颅内低压的特征。自发性颅内低压是一种体位性头痛，由非医源性脑脊液（CSF）漏导致脑组织下沉引起。本例中，CT脊髓造影显示在T12-L1椎间隙腹侧存在硬膜外漏（箭头所示，左下图），病因是该节段的骨赘（骨刺）。经硬膜外血贴术治疗后，患者头痛症状完全缓解。