Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA.
Headache. 2013 Jul-Aug;53(7):1034-53. doi: 10.1111/head.12149. Epub 2013 Jun 28.
Spontaneous intracranial hypotension typically results from spontaneous cerebrospinal fluid (CSF) leak, often at spine level and only rarely from skull base. Once considered rare, it is now diagnosed far more commonly than before and is recognized as an important cause of headaches. CSF leak leads to loss of CSF volume. Considering that the skull is a rigid noncollapsible container, loss of CSF volume is typically compensated by subdural fluid collections and by increase in intracranial venous blood which, in turn, causes pachymeningeal thickening, enlarged pituitary, and engorgement of cerebral venous sinuses on magnetic resonance imaging (MRI). Another consequence of CSF hypovolemia is sinking of the brain, with descent of the cerebellar tonsils and brainstem as well as crowding of the posterior fossa noted on head MRI. The clinical consequences of these changes include headaches that are often but not always orthostatic, nausea, occasional emesis, neck and interscapular pain, cochleovestibular manifestations, cranial nerve palsies, and several other manifestations attributed to pressure upon or stretching of the cranial nerves or brain or brainstem structures. CSF lymphocytic pleocytosis or increase in CSF protein concentration is not uncommon. CSF opening pressure is often low but can be within normal limits. Stigmata of disorders of connective tissue matrix are seen in some of the patients. An epidural blood patch, once or more, targeted or distant, at one site or bilevel, has emerged as the treatment of choice for those who have failed the conservative measures. Epidural injection of fibrin glue of both blood and fibrin glue can be considered in selected cases. Surgery to stop the leak is considered when the exact site of the leak has been determined by neurodiagnostic studies and when less invasive measures have failed. Subdural hematomas sometimes complicate the CSF leaks; a rebound intracranial hypertension after successful treatment of a leak is not rare. Cerebral venous sinus thrombosis as a complication is fortunately less common, and superficial siderosis and bibrachial amyotrophy are rare. Short-term recurrences are not uncommon, and long-term recurrences are not rare.
自发性颅内低血压通常是由于自发性脑脊液（CSF）漏引起的，通常发生在脊柱水平，很少发生在颅底。一旦被认为是罕见的，现在被诊断为比以前更常见，并且被认为是头痛的一个重要原因。CSF 漏导致 CSF 量的损失。考虑到颅骨是一个刚性的不可塌陷的容器，CSF 量的损失通常通过硬脑膜下积液和颅内静脉血液的增加来补偿，这反过来又导致脑膜增厚、垂体增大和脑静脉窦充血在磁共振成像（MRI）上。CSF 低血容量的另一个后果是脑下沉，小脑扁桃体和脑干下降，以及后颅窝拥挤在头部 MRI 上注意到。这些变化的临床后果包括头痛，这些头痛常常但不总是直立性的，恶心，偶尔呕吐，颈部和肩胛间疼痛，耳蜗前庭表现，颅神经麻痹，以及其他一些归因于颅神经或脑或脑的压力或伸展的表现脑干结构。CSF 淋巴细胞增多或 CSF 蛋白浓度增加并不少见。CSF 开放压力通常较低，但也可能在正常范围内。结缔组织基质紊乱的迹象在一些患者中可见。硬膜外血贴，一次或多次，靶向或远离，一个部位或双水平，已成为那些对保守治疗失败的人的首选治疗方法。在神经诊断研究确定了漏口的确切位置且微创措施失败的情况下，可以考虑在选定的病例中进行硬膜外注射血液和纤维蛋白胶的纤维蛋白胶。当通过神经诊断研究确定了漏口的确切位置并且微创措施失败时，考虑手术以停止漏口。硬膜外血肿有时会使 CSF 漏复杂化；成功治疗漏口后出现颅内压反跳并不罕见。脑静脉窦血栓形成作为并发症是不幸的较不常见，而表浅性铁质沉着症和臂丛性肌萎缩症则罕见。短期复发并不少见，长期复发也并不少见。
