Diagnostic delay of cluster headache: A cohort study from the Danish Cluster Headache Survey.

AIM: To investigate the influence of clinical and demographic features on diagnostic delay in cluster headache patients, in order to discuss diagnostic pitfalls and raise disease awareness. METHODS: A large, well-characterized cohort of 400 validated cluster headache patients from the Danish Cluster Headache Survey, diagnosed according to ICHD-II, were investigated. ANOVA was applied to investigate differences in diagnostic delay between groups. Selected independent variables were assessed in relation to diagnostic delay using a gamma regression model. RESULTS: Diagnostic delay was significantly reduced for each decade of cluster headache onset from 1950-2010 (p < 0.001). Onset after 1990 was associated with shorter diagnostic delay (OR = 0.28, p < 0.001), whereas attack duration > 180 minutes (OR = 1.62, p < 0.034), migraine-like features (OR = 1.30, p < 0.043) and nocturnal attacks (OR = 1.39, p < 0.021) were associated with prolonged diagnostic delay. Further, diagnostic delay decreased with age of onset (age < 20: 13.8 years, age 20-40: 5.4 years and age > 40: 2.1 years, p < 0.001). CONCLUSION: Diagnostic delay was reduced for every decade investigated, whereas some atypical cluster headache features were associated with prolonged diagnostic delay. Better medical education and more disease awareness are needed to prevent misdiagnosis and prolonged diagnostic delay.

Oxygen therapy for cluster headache. A mask comparison trial. A single-blinded, placebo-controlled, crossover study.

Purpose The purpose of this article is to investigate possible differences in effect between three types of masks in the acute treatment of cluster headache (CH). Patients and methods Fifty-seven CH patients according to ICHD-II-criteria participated in a single-blinded, semi-randomized, placebo-controlled, crossover inpatient study, and 102 CH attacks were treated with 100% oxygen delivered by demand valve oxygen (DVO), O2ptimask or simple mask (15 liters/min) or placebo delivered by DVO for 15 minutes. Primary endpoint: Two-point decrease of pain on a five-point rating scale within 15 minutes. Results Only 10 CH patients had multiple attacks and reached the point of placebo. There were no significant differences between masks in the primary endpoints ( p = 0.412). After 15 minutes 48% had a two-point decrease using the DVO compared to 45% with placebo ( p = 0.867). After 30 minutes 68% were pain free or had pain relief using DVO and 45% by placebo ( p = 0.061). The DVO was preferred by 62% compared to 5% and 33% for simple mask ( p < 0.0001) and O2ptimask ( p = 0.061). In the first attack the DVO was significantly better at achieving pain relief at 15 minutes ( p = 0.018). Treatment with DVO or O2ptimask reduced the need for rescue medication compared to the simple mask (23%, 19%, 50%, respectively). No treatment-related adverse events were observed. Conclusion The primary endpoint with pain relief at 15 minutes was non-significant; however, a post hoc analysis of the first attack significantly favored DVO. Further, therapy by O2ptimask and DVO resulted in a decreased need for rescue medication. We recommend that CH patients be offered DVO or O2ptimask before oxygen therapy is abandoned.