Comparison of the Diagnostic Values of Neutrophil, Neutrophil to Lymphocyte Ratio, and Platelet to Lymphocyte Ratio in Distinguishing Spontaneous Subarachnoid Hemorrhage from Nontraumatic Acute Headache.

Background: To compare the diagnostic values of neutrophil, neutrophil to lymphocyte ratio (NLR), and platelet to lymphocyte ratio (PLR) in distinguishing between spontaneous subarachnoid hemorrhage (SSAH) and non-traumatic acute headache.

Methods: Of the 125 patients with headache symptoms, 54 patients were diagnosed with SSAH (SAH group) and 71 cases with nontraumatic acute headache due to other causes (non-SAH group) were enrolled in this retrospective study. The levels of peripheral blood neutrophil counts, lymphocyte counts, platelet counts, NLR and PLR were recorded and compared between two groups. Student's t-test of independent samples was adopted for comparing the mean between two groups. Model discrimination was evaluated using the area under the receiver operating characteristic curve (AUC). Comparison of AUC was performed using the Z-test.

Results: The levels of neutrophil counts, NLR and PLR were significantly increased in the SSAH group compared with the non-SAH group (all p < 0.01), while there were no significantly statistical differences of the lymphocyte counts and platelet counts (all p > 0.05); moreover, AUC in distinguishing between SSAH and nontraumatic acute headache was 0.918 (95% confidence interval (CI), 0.855 to 0.960) for neutrophil counts, 0.828 (95% CI, 0.751 to 0.890) for NLR and 0.616 (95% CI, 0.524 to 0.701) for PLR, and there were significant statistical differences (all p < 0.05) after pairwise comparison. Finally, the cutoff values were 4.7 x 109/L in distinguishing patients with SSAH from those with nontraumatic acute headache (specificity 88.73%, sensitivity 85.19% and Youden index 0.739) for neutrophil counts, 4 (specificity 98.59%, sensitivity 64.81% and Youden index 0.634) for NLR and 175 (specificity 92.96%, sensitivity 44.44% and Youden index 0.374) for PLR.

Conclusions: Neutrophils can demonstrate more accurate and reliable diagnostic value than NLR and PLR, sug-gesting that it is a useful and potential tool in distinguishing between SSAH and nontraumatic acute headache.