Normal pressure hydrocephalus and polyneuropathy.
Normal pressure hydrocephalus and polyneuropathy.
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正常压力脑积水和多发性神经病。
DOI：
10.1097/01.smj.0000223694.03309.bd
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
M. Tisell
中科院分区：
文献类型：
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作者：
M. Tisell
正常压力脑积水（NPH）是一种可治疗的痴呆症，因此很重要。1965年，Hakim及其同事将其描述为一种临床综合征，发生于颅内压正常（ICP）的特发性或“隐匿性”脑积水患者，这些患者可从分流手术中获益。NPH的特征是步态和平衡障碍、智力退化和尿失禁的临床三联征。以前，脑积水与颅内压升高和头痛、乳头水肿和失眠等症状密切相关。重要的是要记住，许多NPH患者并不表现为完整的经典三联征。因此，步态障碍，这往往是老年NPH患者的主要症状，可能不存在于年轻患者中，其中姿势障碍是常见的。姿势和运动任务的功能障碍之间存在很强的关联，因此可以想象，由于更好的代偿机制，年轻患者的步态受影响较小。当前病例很好地说明了NPH的诊断挑战，该病例描述了一名患有多发性神经病和脑积水的患者，“掩盖”了传统症状。正常压力脑积水的病理生理和症状仍然没有很好的理解。如病例研究所述，脑脊液（CSF）穿刺试验通过清除CSF模拟分流管的作用。有趣的是，当移除的CSF已经被新形成的CSF替换并且IC压力已经恢复到基线时，可以在穿刺后几小时定期观察到穿刺试验后的改善。这表明脑内可逆的代谢紊乱导致脑积水症状。已经发现NPH症状与大脑的几个区域有关，例如额叶的基底部分，颞叶的内侧部分，脑室周围区域和上脑干。最近一些关于腰椎和脑室CSF标记物的研究表明，脑积水患者的可逆性神经元损伤导致NPH症状，但脑积水症状背后的真正机制仍有待研究。本病例所述的多发性神经病与NPH之间的关系是什么？很可能是两种共存的疾病，因为很难找到脑积水状态和周围神经损伤之间的因果关系。腿部无力可能与步态和平衡障碍患者的不活动引起的肌肉萎缩有关。然而，在NPH患者中很少发现多发性神经病的体征，与不活动相关的虚弱和萎缩可能在分流术后得到改善。成人脑积水的发病高峰年龄在70多岁;在这个年龄组，有各种中枢性脑萎缩疾病，临床和放射学上类似于NPH。为了预测NPH分流手术的结果，有一些补充研究，包括抽头试验，输液测压，放射性核素脑池造影，脑血流量测量，ICP波分析，CSF分析和专门的临床检查。目前，大多数研究者推荐脑脊液穿刺试验或腰椎外引流术进行预测。大多数作者认为，需要改进诊断和预测方法，特别是因为分流术的并发症发生率相当高。然而，现代系列的围手术期死亡率接近于零。据报道，年龄最大手术组的相对改善率与其他年龄组相当，因此年龄不应排除患者接受手术。脑积水并不是一种罕见的痛苦，并导致痴呆症的新病例的显着比例。在瑞典，脑积水手术的年发病率为每10万成年居民3.4例。此外，该国不同地区之间的手术发生率存在显著差异。由于NPH是一种慢性疾病，发病缓慢，老年患者的非典型病例很容易被忽视。这是可能的，提高认识的条件将导致增加转诊率。由于脑积水是一种可治疗的疾病，因此重要的是要广泛传播有关其症状和基本诊断的知识，特别是因为这些患者可获得的治疗通常会大大提高他们的生活质量。
Normal Pressure Hydrocephalus (NPH) is a treatable form of dementia and therefore important. It was described by Hakim and coworkers in 1965 as a clinical syndrome occurring in patients with idiopathic or “occult” hydrocephalus with normal IC pressure (ICP) who could benefit from shunt surgery. NPH is characterized by the clinical triad of gait and balance disturbance, mental deterioration and urinary incontinence. Previously, hydrocephalus had been strongly associated with increased ICP and symptoms such as headache, papillary edema and impaired wakefulness. It is important to bear in mind that many patients with NPH do not present with the whole classic triad. Thus, gait disturbance, which often is the dominating symptom in older NPH patients, might be absent in younger patients in whom postural disturbance is frequently seen. There is a strong association between dysfunction in postural and motor tasks, and it is thus conceivable that younger patients have less affected gait due to better compensatory mechanisms. The diagnostic challenge of NPH is well illustrated in the current case, which describes a patient with polyneuropathy and hydrocephalus that “mask” the traditional symptoms. The pathophysiology and symptoms of normal pressure hydrocephalus are still not well understood. The cerebrospinal fluid (CSF) tap test, as described in the case study, mimics the effect of the shunt by removing CSF. Interestingly, the improvement after a tap test regularly can be observed some hours after the tap when the removed CSF already has been replaced with newly formed CSF, and the IC pressure has returned to baseline. This indicates that reversible metabolic disturbances in the brain cause the hydrocephalic symptoms. NPH symptoms have been found to be linked to several regions of the brain, such as the basal parts of the frontal lobes, the mesial part of the temporal lobes, the periventricular region and the upper brainstem. Some recent studies on lumbar and ventricular CSF markers suggest that reversible neuronal damage in hydrocephalus patients causes the NPH symptoms, but the true mechanisms behind hydrocephalus symptoms remain to be studied. What is the relationship between the polyneuropathy, described in this case, and NPH? Most likely they are two, coexisting diseases, since it is difficult to find any causal connection between the hydrocephalic state and peripheral nerve damage. Weakness in the legs can be related to atrophy of the muscles caused by inactivity in a patient with disabled gait and balance. However, signs of polyneuropathy are very seldom found in patients with NPH, and weakness and atrophy related to inactivity are likely to improve after shunt surgery. The peak age of onset of adult hydrocephalus is in the 70s; and in this age group, there are various disorders with central brain atrophy that clinically and radiologically resemble NPH. To predict the outcome of shunt surgery in NPH, there are a number of complementary investigations, including the tap test, infusion manometry, radionuclide cisternography, measurement of cerebral blood flow, analyses of ICP waves, CSF analyses and specialized clinical examinations. Currently, most researchers recommend the CSF tap test or the external lumbar drainage procedure for prediction. Most authors agree that there is a need for improved diagnostic and predictive methods, especially since shunt surgery has a rather high complication rate. However, the perioperative mortality rate in modern series is close to zero. The relative improvement rate among the oldest operated group has been reported to be equivalent to that of other age groups, and thus age should not exclude patients from surgery. Hydrocephalus is not an uncommon affliction and causes a significant proportion of new cases of dementia. In Sweden, the annual incidence of surgery for hydrocephalus is 3.4 per 100,000 adult inhabitants. Furthermore, there are significant differences in the incidence of surgery between different regions of the country. Since NPH is a chronic disease with a slow onset, atypical cases in elderly patients easily go unnoticed. It is likely that an increased awareness of the condition will lead to an increased referral rate. Since hydrocephalus is a treatable condition, it is important that knowledge about its symptoms and basic diagnostics be widely disseminated, particularly because the treatment available to these patients often drastically improves their quality of life.