Optic nerve subarachnoid space measurement as the best predictor of post-dural puncture headache after intravertebral anesthesia

Intravertebral anesthesia is a commonly used method during surgery due to its easy administration, rapid effects, muscle relaxation, and pain control. However, post-dural puncture headache (PDPH) is a frequent complication following intravertebral anesthesia. The primary mechanism of PDPH is the leakage of cerebrospinal fluid (CSF) through the dural puncture site, leading to a decrease in intracranial pressure (ICP). Symptoms typically include a headache that worsens when sitting or standing and improves when lying down, along with possible neck stiffness, nausea, and photophobia. The optic nerve subarachnoid space (ONSS), located behind the globe of the eye within the orbit, is filled with CSF and is continuous with the cranial subarachnoid space. The pressure in this space, often referred to as intraocular pressure (IOP) when discussing eye-related conditions, is typically discussed in the context of its relation to ICP when considering the optic nerve subarachnoid space. Therefore, the measurement of pressure in the ONSS by optic nerve sheath diameter (ONSD) may serve as the best predictor for PDPH, which might be an effective way to reflect changes in intracranial pressure after intravertebral anesthesia, offering valuable information for accurate prediction and prevention of PDPH.