Two-year prognosis of primary stabbing headache and its associated factors: a clinic-based study.

Background: Primary stabbing headache (PSH) is commonly seen in headache clinics, yet its long-term course remains inadequately explored. This study aimed to determine the 2-year recurrence rate of PSH and to identify associated risk factors.

Methods: Out of 1,756 patients who visited a specialized headache clinic due to headache complaints, 106 patients diagnosed with PSH were enrolled consecutively. Demographic and clinical information was collected, along with the time to achieve complete remission post-treatment. To evaluate the 2-year prognosis, all participants were contacted through telephone interviews. A total of 106 patients were interviewed by telephone at least 2 years after the onset of PSH. The authors examined the frequency and features of PSH recurrence and assessed clinical variables potentially linked to its recurrence.

Results: A recurrence of PSH occurred in 36.3% of the patients. Patients with recurrent PSH had more prior history of stabbing headache (55.2% vs. 29.4%, P = 0.023), comorbid migraine (17.2% vs. 3.9%, P = 0.043) and severe intensity of stabbing headache (41.4% vs. 17.7%, P = 0.020) than those with non-recurrent PSH. Multivariable Cox regression analysis revealed that an independent effect of comorbid migraine on the recurrence of PSH (adjusted hazard ratio, 2.791; 95% confidence interval, 1.012-7.701; P = 0.047).

Conclusions: Over one-third of individuals diagnosed with PSH experienced a recurrence within 2 years of the initial episode. Comorbid migraine was related to a recurrence of PSH, suggesting the potential role of shared pathophysiological mechanisms between migraine and PSH in influencing the prognosis of PSH.