The goal of this clinical trial is to establish a predictive model for post-dural puncture headache. The main questions it aims to answer are:

Changes in intracranial pressure after spinal puncture (or lumbar puncture). When post-dural puncture headache occurs, the optic nerve sheath diameter (ONSD) change When the optic nerve sheath diameter (ONSD) and (or) Intraocular Pressure (IOP) reaches a certain threshold, does proactive treatment reduce the incidence of postoperative headaches? Researchers will measure the optic nerve sheath diameter (ONSD) using ultrasound and ( or ) magnetic resonance imaging (MRI) before and after spinal puncture.

Researchers will measure the Intraocular Pressure (IOP) using ICARE before and after spinal puncture.

Participants will:

Undergo ultrasound and (or) magnetic resonance imaging (MRI) examinations before and after spinal puncture Undergo ICARE examinations before and after spinal puncture

Post-dural Puncture Headache (PDPH) refers to a specific type of headache that occurs after patients receive intrathecal anesthesia or a lumbar puncture, resulting from the leakage of cerebrospinal fluid (CSF) due to the puncture of the dura mater and arachnoid mater. This type of headache typically occurs within 24 to 48 hours after the puncture and is characterized primarily by positional headaches, meaning that the headache worsens when the patient is standing or sitting and improves when lying down. The headache is often accompanied by symptoms such as neck stiffness, nausea, vomiting, tinnitus, and blurred vision.

The primary mechanism of PDPH is the leakage of cerebrospinal fluid from the puncture site after the dura and arachnoid are punctured, leading to a decrease in CSF pressure. The reduction in cerebrospinal fluid can cause several physiological changes:Decreased CSF Pressure: The reduction of CSF leads to a drop in intracranial pressure, which alters the mechanisms that support the brain, resulting in pain.Meningeal Tension: The decrease in CSF may cause tension on the meninges and nerve roots, leading to pain sensations.Vasodilation: The drop in intracranial pressure can trigger a reflexive dilation of cerebral blood vessels, further exacerbating the pain.The incidence of PDPH is associated with various factors, including the patient's age, sex, body type, type of surgery performed, and the type and size of the puncture needle used. Smaller needles (such as 25G or thinner) and non-cutting needles (such as Sprotte needles) can significantly reduce the incidence of PDPH, whereas larger and cutting needles (such as Quincke needles) are associated with a higher incidence. Younger patients and females are more prone to developing PDPH. Additionally, multiple punctures increase the risk of PDPH.

Timely and effective treatment can significantly reduce the occurrence of PDPH; however, there is currently a lack of monitoring methods for PDPH. This study aims to establish a predictive model for the occurrence of PDPH by measuring postural cerebrospinal fluid pressure using ultrasound, which can enable early prediction and treatment of PDPH, thereby significantly improving patient comfort and recovery processes.

The goal of this clinical trial is to establish a predictive model for post-dural puncture headache,with the goal of implementing proactive interventions and treatments to reduce the incidence of PDPH and improve clinical management. Therefore, establishing an effective early warning model is crucial Participants will receive ultrasound, magnetic resonance imaging (MRI) and (or ) ICARE examinations before and after spinal puncture

Inclusion Criteria:

BMI ≤ 30 kg/m² Normal liver and kidney function before surgery Normal coagulation function before surgery Hemoglobin > 70 g/L Platelet count > 80 × 10⁹/L

Exclusion Criteria:

Patients who experience major bleeding during or after surgery Patients with cerebrospinal fluid leakage or other serious malformations Patients with mental health disorders or cognitive dysfunction

patients who need dural puncture