The Importance of Optic Nerve Sheath Diameter in Post-dural Puncture Headache Diagnosis and Follow-up

Intracranial hypotension-induced headache is caused by reduction in the volume or pressure of the cerebrospinal fluid. Headache might develop secondary to lumbar puncture. In the detection of intracranial hypotension, when compared with invasive methods, there is a good correlation between ultrasound-guided optic nerve sheath diameter (ONSD) and invasive methods. The aim of the study is to investigate the effectiveness of alteration in ultrasound-guided ONSD in diagnosis and treatment of post-dural puncture headache (PDPH) induced by intracranial hypotension. Our study involved 40 adult patients aged 18-65 scheduled to have surgery under spinal anesthesia. Patients were randomized into two groups consisting of PDPH (Group H, n=20), and control (Group C, n=20) during their post-operative period. The ONSDs of patients were measured via ultrasound, pain severity with Numeric Rating Scale (NRS) pre-operatively, at 24 , 26 and 48 hours post-operatively. Conservative treatment was started on the 24 hour in PDPH group. There was no significant difference between the groups in terms of demographic data. In Group H, the reduction in ONSD from 3.8±0.2 to 3.2±0.3 mm in postoperative 24 hours (p=0.001) and an increase to 4.4±0.3 mm in postoperative 48 hours (p=0.03) were significant. When compared to postoperative 24 hours, ONSD in postoperative 26 (3.9±0.3 mm) and 48 hours (4.4±0.3 mm) were significantly higher (p=0.007 and p=0.01; respectively) in Group H. NRS values in Group H at postoperative 26 and 48 hours were significantly lower compared to postoperative 24 hours (p=0.001). We believe that serial measurement of ultrasound-guided ONSD, which is considered a simple and non-invasive procedure in the determination of intracranial pressure changes, is a more objective method in the follow-up of intracranial hypotension-induced headache compared to NRS evaluation.