Headache is one of the most common ailments; migraine is one of the most prevalent and disabling neurological disorders and cluster headache presents as one of the most excruciating pain disorders. Both are complex disorder characterized by recurrent episodes of headache. A key feature is that various triggers can set off an attack providing the opportunity to explore disease mechanisms by experimentally inducing attacks. This review summarizes neuroimaging and hemodynamic studies in human in provoked and spontaneous attacks of migraine and cluster headache.
Oxygen is the standard of care for acute treatment of cluster headache. CMS, the US Centers for Medicaid and Medicare Services, has made the indefensible decision to not cover oxygen for cluster headache for patients with Medicaid and Medicare insurance, despite the evidence and professional guidelines. Commercial insurance generally covers oxygen for cluster headache.
Calcitonin gene-related peptide (CGRP) is a key signaling molecule involved in migraine pathophysiology. Efficacy of CGRP monoclonal antibodies and antagonists in migraine treatment has fueled an increasing interest in the prospect of treating cluster headache (CH) with CGRP antagonism. The exact role of CGRP and its mechanism of action in CH have not been fully clarified. A search for original studies and randomized controlled trials (RCTs) published in English was performed in PubMed and in ClinicalTrials.gov. The search term used was “cluster headache and calcitonin gene related peptide” and “primary headaches and calcitonin gene related peptide.”
The objectives of the study, which covered each of the US states, were to map the current market landscape of medical grade oxygen for use in CH and to develop a cost simulator based on a patient’s needs and geography. Results from our study showed that the current costs for oxygen use as an acute therapy in CH are not prohibitively expensive for patients and healthcare insurance providers. Apart from CMS, many insurers do reimburse the cost of oxygen use for CH. Our study suggests that further research is needed to determine if a lack of physician awareness about treatments and ways to prescribe are barriers for patients to access the high-flow oxygen treatment.
We present a patient with known episodic cluster headache, who presented with cluster-like headache in the course of internal carotid artery dissection (ICAD) and discuss possible pathophysiological links between the two diseases. It is well known that cluster-like headache could be the presenting symptom of ICAD. However, ICAD occurring in a patient with a known episodic cluster headache was only once previously described.