Abstract and Introduction
Background. Laughing is a rare precipitating factor for headaches, and the pathogenesis underlying laugh-induced headache (LH) remains unclear.
Methods. Two cases of headache triggered predominantly by laughing were presented in this article. We also reviewed the published English literature regarding LH, summarized the clinical characteristics of LH, and discussed the probable pathophysiological mechanisms.
Results. In the first patient, magnetic resonance imaging of the brain revealed cerebellar tonsillar herniation through the foramen magnum. In the second patient, we did not find any evidence of intracranial disease. The literature review showed that LH is a mild to severe, non-pulsating headache. In most cases, the duration of each attack was limited to a few minutes. The headache usually bursts after laughing and reaches its peak almost immediately. In some cases, the headache can only be induced by mirthful laughing rather than by fake laughing.
Conclusion. LH can be categorized as primary LH and secondary LH. Changes in the spatial structure in the posterior cranial fossa and cerebrospinal fluid circulation may contribute to the development of secondary LH. Primary LH, primary cough headache, and primary exercise headache may share some common pathogenesis. And we speculate that the regions of the brain associated with the expression of mirth might be associated with LH.
There are many triggers of headaches, including weather changes, stress, menses, missed meals, glare, oversleeping, perfumes, cigarette smoke, and sexual activity.[1,2] Laughing has also previously been reported as a trigger of headache. In 1956, Symonds reported 21 patients who had severe headache precipitated by coughing, laughing, sneezing, straining to defecate, or stooping. In this article, we presented two patients with headache triggered by laughing. We also reviewed previous reports of similar cases to summarize the characteristics of laugh-induced headache (LH) and investigated the probable pathogenesis of this specific clinical phenomenon.
Headache. 2017;57(10):1498-1506. © 2017 Blackwell Publishing