Cluster‐Tic Syndrome: A Cross‐Sectional Study of Cluster Headache Patients

Objective To determine the prevalence and nature of trigeminal neuralgia in a large group of cluster headache patients. Background Cluster-tic syndrome is a rare headache syndrome in which trigeminal neuralgia and cluster headache co-occur. The existence of cluster-tic syndrome as a separate entity is questioned, and figures on prevalence of simultaneous existence of cluster headache and trigeminal neuralgia are not available. Methods As part of a nationwide study on headache mechanisms in cluster headache (Leiden University Medical Centre Cluster headache Neuro Analysis programme), we collected clinical data of 244 cluster headache patients using a semistructured telephone interview in a cross-sectional design. Results In 11 (4.5%) cluster headache patients, attacks fulfilling International Headache Society criteria for trigeminal neuralgia were also present. In all cases, trigeminal neuralgia occurred ipsilateral to cluster headache and in the majority (82%) in the ophthalmic branch. In 8 of these 11 patients (73%), the frequency and time pattern of trigeminal neuralgia seemed to parallel cluster headache and was likely a part of the cluster headache spectrum. In the 3 remaining patients, cluster headache and trigeminal neuralgia were unrelated in time and appeared to occur independently. Conclusion Trigeminal neuralgia co-occurred in 11/244 (4.5%) of cluster headache patients. In only 3 (1.2%) patients, trigeminal neuralgia seemed to occur independently from cluster headache episodes. Trigeminal neuralgia (-like) attacks in cluster headache patients are most of the time part of the cluster headache spectrum and should then probably not be treated separately. A shared underlying pathophysiological mechanism of cluster headache and trigeminal neuralgia is not supported by this study.