Cruccu Giorgio
Continuum (Minneap Minn). 2017 Apr;23(2, Selected Topics in Outpatient Neurology):396-420. doi: 10.1212/CON.0000000000000451.
Although trigeminal neuralgia is well known to neurologists, recent developments in classification and clinical diagnosis, new MRI methods, and a debate about surgical options necessitate an update on the topic.
Currently, a worldwide controversy exists regarding the classification, diagnostic process, and surgical treatment of trigeminal neuralgia. This controversy has been caused on one side by the recognition that some 50% of patients with trigeminal neuralgia, apart from characteristic paroxysmal attacks, also have continuous pain in the same territory, which results in greater diagnostic difficulties and is associated with a lower response to medical and surgical treatments. In contrast, recent developments in MRI methods allow differentiation between a mere neurovascular contact and an effective compression of the trigeminal root by an anomalous vessel, which implies more difficulties in the choice of surgical treatment, with the indication for microvascular decompression becoming more restricted.
This article proposes that the diagnosis of trigeminal neuralgia, with or without concomitant continuous pain, must rely on clinical grounds only. Diagnostic tests are necessary to distinguish three etiologic categories: idiopathic trigeminal neuralgia (nothing is found), classic trigeminal neuralgia (an anomalous vessel produces morphologic changes of the trigeminal root near its entry into the pons), and secondary trigeminal neuralgia (due to major neurologic disease, such as multiple sclerosis or tumors at the cerebellopontine angle). Carbamazepine and oxcarbazepine (ie, voltage-gated, frequency-dependent sodium channel blockers) are still the first-choice medical treatment, although many patients experience significant side effects, and those with concomitant continuous pain respond less well to treatment. The development of sodium channel blockers that are selective for the sodium channel 1.7 (Nav1.7) receptor will hopefully help. Although all the surgical interventions (percutaneous ganglion lesions, gamma knife radiosurgery, and microvascular decompression) are very efficacious, precise MRI criteria for differentiating a real neurovascular compression from an irrelevant contact will be of benefit in better selecting patients for microvascular decompression.
尽管三叉神经痛为神经科医生所熟知，但分类与临床诊断的新进展、新的磁共振成像（MRI）方法以及关于手术选择的争论使得有必要对该主题进行更新。
目前，关于三叉神经痛的分类、诊断过程及外科治疗在全球范围内存在争议。一方面，这种争议源于认识到约50%的三叉神经痛患者除特征性阵发性发作外，在同一区域还存在持续性疼痛，这导致诊断难度加大，且对药物及手术治疗的反应较低。另一方面，MRI方法的最新进展使得能够区分单纯的神经血管接触与异常血管对三叉神经根的有效压迫，这意味着手术治疗的选择更加困难，微血管减压术的适应证变得更加受限。
本文提出，无论有无伴发持续性疼痛，三叉神经痛的诊断都必须仅基于临床依据。诊断性检查对于区分三种病因类别是必要的：特发性三叉神经痛（未发现异常）、典型三叉神经痛（异常血管在三叉神经根进入脑桥处附近引起形态学改变）以及继发性三叉神经痛（由重大神经系统疾病引起，如多发性硬化或桥小脑角肿瘤）。卡马西平和奥卡西平（即电压门控、频率依赖性钠通道阻滞剂）仍然是首选药物治疗，尽管许多患者会出现明显的副作用，且伴有持续性疼痛的患者对治疗反应较差。对钠通道1.7（Nav1.7）受体具有选择性的钠通道阻滞剂的研发有望有所帮助。尽管所有手术干预措施（经皮神经节毁损、伽玛刀放射外科治疗和微血管减压术）都非常有效，但用于区分真正的神经血管压迫与无关接触的精确MRI标准将有助于更好地选择适合微血管减压术的患者。
