Hackett P H, Yarnell P R, Hill R, Reynard K, Heit J, McCormick J
School of Health Professions, University of Alaska, Anchorage, USA.
JAMA. 1998 Dec 9;280(22):1920-5. doi: 10.1001/jama.280.22.1920.
Because of its onset in generally remote environments, high-altitude cerebral edema (HACE) has received little scientific attention. Understanding the pathophysiology might have implications for prevention and treatment of both this disorder and the much more common acute mountain sickness.
To identify a clinical imaging correlate for HACE and determine whether the edema is primarily vasogenic or cytotoxic.
Case-comparison study.
Community hospitals accessed by helicopter from mountains in Colorado and Alaska.
A consecutive sample of 9 men with HACE, between 18 and 35 years old, 8 of whom also had pulmonary edema, were studied after evacuation from high-altitude locations; 5 were mountain climbers and 4 were skiers. The control group, matched for age, sex, and altitude exposure, consisted of 3 subjects with high-altitude pulmonary edema only and 3 who had been entirely well at altitude. Four patients with HACE were available for follow-up imaging after complete recovery.
Magnetic resonance imaging (MRI) of the brain during acute, convalescent, and recovered phases of HACE, and once in controls, immediately after altitude exposure.
Seven of the 9 patients with HACE showed intense T2 signal in white matter areas, especially the splenium of the corpus callosum, and no gray matter abnormalities. Control subjects demonstrated no such abnormalities. All patients completely recovered; in the 4 available for follow-up MRI, the changes had resolved entirely.
We conclude that HACE is characterized on MRI by reversible white matter edema, with a predilection for the splenium of the corpus callosum. This finding provides a clinical imaging correlate useful for diagnosis. It also suggests that the predominant mechanism is vasogenic (movement of fluid and protein out of the vascular compartment) and, thus, that the blood-brain barrier may be important in HACE.
由于高原脑水肿（HACE）通常在偏远环境中发病，因此很少受到科学关注。了解其病理生理学可能对这种疾病以及更为常见的急性高原病的预防和治疗具有重要意义。
确定HACE的临床影像学关联，并确定水肿主要是血管源性还是细胞毒性的。
病例对照研究。
通过直升机从科罗拉多州和阿拉斯加的山区抵达的社区医院。
对9名年龄在18至35岁之间的HACE男性患者进行了连续抽样研究，其中8人还患有肺水肿，这些患者从高海拔地区撤离后接受了研究；5名是登山者，4名是滑雪者。对照组在年龄、性别和海拔暴露方面进行了匹配，由3名仅患有高原肺水肿的受试者和3名在高原完全健康的受试者组成。4名HACE患者在完全康复后可进行随访成像。
在HACE的急性期、恢复期和康复期对大脑进行磁共振成像（MRI）检查，对照组在海拔暴露后立即进行一次MRI检查。
9名HACE患者中有7名在白质区域，尤其是胼胝体压部出现强烈的T2信号，且灰质无异常。对照组未出现此类异常。所有患者均完全康复；在4名可进行随访MRI检查的患者中，病变已完全消失。
我们得出结论，HACE在MRI上的特征是可逆的白质水肿，以胼胝体压部为著。这一发现为诊断提供了有用的临床影像学关联。它还表明主要机制是血管源性的（液体和蛋白质从血管腔隙中移出），因此血脑屏障在HACE中可能很重要。
