Cluster headache due to structural lesions: A systematic review of published cases

BACKGROUND: Cluster headache (CH) is a severe incapacitating headache disorder. By definition, its diagnosis must exclude possible underlying structural conditions. AIM: To review available information on CLH caused by structural lesions and to provide better guides in the distinguishing process and to ensure that there is not a potentially treatable structural lesion. METHODS: We conducted a systematic review of 77 published cases of symptomatic CH and cluster-like headache (CLH) in PubMed and Google Scholar databases. RESULTS: Structural pathologies associated with CH were vascular (37.7%), tumoral (32.5%) and inflammatory (27.2%). Brain mass-like lesions (tumoural and inflammatory) were the most common diseases (28.6%), among which 77.3% lesions were at the suprasellar (pituitary) region. Cases of secondary CH related to sinusitis rose dramatically, occupying 19.5%. The third most common disease was internal carotid artery dissection, accounting for 14.3%. Atypical clinical features raise an early suspicion of a secondary cause: Late age at onset and eye and retroorbital pains were common conditions requiring careful evaluation and were present in at least one-third of cases. Abnormal neurological examination was the most significant red flag for impaired cranial nerves. CLH patients may be responsive to typical CH treatments; therefore, the treatment response is not specific. CLH can be triggered by contralateral structural pathologies. CLH associated with sinusitis and cerebral venous thrombosis required more attention. CONCLUSION: Since secondary headache could perfectly mimick primary CH, neuroimaging should be conducted in patients in whom primary and secondary headaches are suspected. Cerebral magnetic resonance imaging scans is the diagnostic management of choice, and further examinations include vessel imaging with contrast agents and dedicated scans focusing on specific cerebral areas (sinuses, ocular and sellar regions). Neuroimaging is as necessary at follow-up visits as at the first observation.