Citations

While “sinus” headache is a widely accepted clinical diagnosis, many medical specialists consider it to be an uncommon cause of recurrent headaches. Unnecessary diagnostic studies, surgical interventions, and medical treatments are often the result of the inappropriate diagnosis of sinus headache. Both the International Headache Society and the American Academy of Otolaryngology–Head and Neck Surgery have attempted to characterize conditions leading to headaches of rhinogenic origin. However, they have done so from different perspectives and in isolation from the other specialty groups. An interdisciplinary ad hoc committee recently convened to discuss the role of sinus disease and the nose in the etiology of headache and to review recent epidemiologic studies suggesting that sinus headache (headache of rhinogenic origin) and migraine are frequently confused with one another. Clinical trial data are presented which clearly indicate that the majority of sinus headaches can actually be classified as migraines. This committee reviewed scientific evidence available from multiple disciplines and concludes that considerable research and clinical study are needed to further understand and explain the role of nasal pathology and autonomic activation in migraine and headaches of rhinogenic origin. However, there was a consensus from this group that greater diagnostic and therapeutic attention needs to be given to patients complaining of sinus headache that may indeed be due to the nose.

Cluster headache is the most severe of the primary headaches. Positron emission tomography and functional MRI studies have shown that the ipsilateral posterior hypothalamus is activated during cluster headache attacks and is structurally asymmetric in these patients. These changes are highly specific for the condition and suggest that the cluster headache generator may be located in that brain area; they further suggest that electrical stimulation of that region might produce clinical improvement in chronic cluster headache sufferers refractory to medical therapy. In five patients with severe intractable chronic cluster headache, hypothalamic electrical stimulation produced complete and long-term pain relief with no relevant side-effects. We therefore consider it essential to propose criteria for selecting chronic cluster headache patients for hypothalamic deep brain stimulation before this procedure is undertaken at other academic medical centres.

Triptans are the treatment of choice for acute migraine. While seemingly a homogenous group of drugs, results from a meta-analysis reveal significant differences in efficacy and tolerability among oral triptans. The incidence of drug-related central nervous system (CNS) side-effects with some triptans is as high as 15% and may be associated with functional impairment and reduced productivity. The occurrence of adverse events associated with triptans in general, and CNS side-effects in particular, may lead to a delay in initiating or even avoidance of an otherwise effective treatment. Potential explanations for differences among triptans in the incidence of CNS side-effects may relate to pharmacological and pharmacokinetic differences, including receptor binding, lipophilicity, and the presence of active metabolites. Of the triptans reviewed, at clinically relevant doses, almotriptan 12.5 mg, naratriptan 2.5 mg and sumatriptan 50 mg had the lowest incidence of CNS side-effects, while eletriptan 40 and 80 mg, rizatriptan 10 mg and zolmitriptan 2.5 and 5 mg had the highest incidence. The most likely explanations for the differences in CNS side-effects among triptans are the presence of active metabolites and high lipophilicity of the parent compound and active metabolites. Eletriptan, rizatriptan and zolmitriptan have active metabolites, while lipophilicity is lowest for almotriptan and sumatriptan. If CNS sideeffects are a clinically relevant concern in the individual patient, use of a triptan with a low incidence of CNS side-effects may offer the potential for earlier initiation of treatment and more effective outcomes.

Triptans are effective and well tolerated in the treatment of acute migraine. Chest symptoms are a common adverse effect unrelated to coronary vasoconstriction in most patients. Although the aetiology of chest symptoms remains to be fully defined, pulmonary vasoconstriction is a possible underlying mechanism. Preclinical studies of isolated human blood vessels were used to identify the cerebral selectivity of triptans and ascertain if selectivity vs the pulmonary vasculature predicts a lower rate of chest symptoms. Controlled clinical trials and post-marketing surveillance studies were reviewed to document the incidence of chest symptoms after triptan therapy. In clinical trials, the incidence of chest symptoms at usual therapeutic doses ranged from 1 to 4% depending on the triptan and study design, whereas in post-marketing surveillance studies, up to 41% of patients specifically asked about chest symptoms reported them. A comparative clinical trial showed that almotriptan was associated with lower incidence of chest symptoms than sumatriptan (0.3 vs 2.2%). The intrinsic activity of almotriptan, a second-generation triptan, on human pulmonary arteries and veins was lower than that of sumatriptan. Pre-clinical studies of isolated pulmonary blood vessels may predict the clinical likelihood of chest symptoms; however, additional comparisons are needed.