Bussone G, Usai S
UO Headache and Cerebrovascular Diseases, National Neurological Institute C. Besta, Via Celoria 11, I-20133 Milan, Italy.
Neurol Sci. 2004 Oct;25 Suppl 3:S74-6. doi: 10.1007/s10072-004-0257-9.
The strictly unilateral headaches, more commonly known as trigeminal autonomic cephalalgias (TACs), are characterised by severe, strictly unilateral pain in the territory of the distribution of the trigeminal nerve, associated with autonomic manifestations. The recent International Headache Society classification lists the strictly unilateral headaches as cluster headache (CH), episodic and chronic paroxysmal hemicrania, and short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing. CH is the most common and best-defined of the TACs, whose pathophysiologies have not been adequately defined. Convincing proposals for pathophysiologic mechanisms must explain the trigeminal distribution of the pain, the homolateral autonomic manifestations; and, for CH, the usually periodic recurrence of the crises and clusters. With regard to CH, (i) the pain is always located periorbitally-frontally, implicating nociceptive mechanisms involving the trigeminal nerve; (ii) the autonomic manifestations homolateral to the pain seem to be both parasympathetic (lacrimation and rhinorrhoea) and sympathetic (ptosis and miosis); and (iii) the periodicity of the attacks and seasonal recurrence of the cluster periods suggest involvement of a biological clock within hypothalamus.
严格意义上的单侧头痛，更常见的名称是三叉神经自主性头痛（TACs），其特征为三叉神经分布区域内严重的、严格单侧性疼痛，并伴有自主神经症状。最近的国际头痛协会分类将严格意义上的单侧头痛列为丛集性头痛（CH）、发作性和慢性阵发性偏侧头痛，以及伴有结膜充血和流泪的短暂性单侧神经痛样头痛发作。丛集性头痛是最常见且定义最明确的三叉神经自主性头痛之一，但其病理生理学尚未得到充分阐明。关于病理生理机制的有说服力的提议必须解释疼痛的三叉神经分布、同侧自主神经症状；对于丛集性头痛而言，还需解释发作和丛集期通常的周期性复发。关于丛集性头痛，（i）疼痛总是位于眶周 - 额部，涉及三叉神经的伤害感受机制；（ii）与疼痛同侧的自主神经症状似乎既有副交感神经症状（流泪和流涕）又有交感神经症状（上睑下垂和瞳孔缩小）；（iii）发作的周期性和丛集期的季节性复发提示下丘脑内生物钟的参与。
