Purpose: This study aims to investigate the usability of ultrasonographic optic nerve diameter measurement and plasma neuron-specific enolase (NSE) levels in detecting secondary causes of headaches in patients with refractory headaches in emergency department.
 Materials and Methods: The study was conducted in a university-based adult emergency department over 3 years. Sixty-six consecutive patients presenting to the emergency department with refractory headaches and 50 healthy volunteers for the control group were included. Information recorded included the duration of complaints, type and location of headache, symptoms, co-morbidities, results of imaging studies, optic nerve diameters, results of lactate, arterial blood gas and NSE levels.
 Results: A total of 66 patients were included, comprising 33 females. The mean age was 43.05 ± 17.06 years. Secondary causes of headache were identified in 45 patients (68.2%). Evaluation of ultrasonographic optic nerve diameter revealed that 17 (25.8%) right and 21 (31.8%) left optic nerve diameters were ≥5 mm. Optic nerve diameter values were significantly higher in patients diagnosed with secondary headache compared to those with primary headache, with no statistically significant difference observed in NSE values. Lactate levels in patients with secondary headaches were significantly higher than those in patients with primary headaches.
 Conclusion: In patients admitted to the emergency department with refractory headaches and normal imaging, ultrasonographic optic nerve diameter measurement may be preferred as an easily accessible method to guide the detection of secondary causes. NSE was not an effective in the early selection of patients with secondary headaches.
Read full abstract