Effect of Anodal Transcranial Direct Current Stimulation on Postdural Puncture Headache

Post-dural puncture headache (PDPH) is the most prevalent complication in patients undergoing diagnostic or therapeutic lumbar puncture (LP). The pathophysiology of PDPH is primarily attributed to the mechanical traction on pain-sensitive intracranial nerves (e.g., the upper cervical, 5th, 9th, and 10th cranial nerves) and vascular structures, mediated by persistent dural damage leading to cerebrospinal fluid (CSF) leakage and subsequent CSF pressure reduction. According to the International Classification of Headache Disorders 3rd edition (ICHD3), PDPH is classified as a headache subtype due to low CSF pressure. It typically manifests as an orthostatic headache within a few days post-LP, accompanied by symptoms such as neck pain, tinnitus, auditory changes, photophobia, and nausea. While PDPH usually resolves within 7-10 days, it can result in extended hospital stays and increased need for medication. The use of atraumatic needles is the most effective preventive measure for PDPH, though other commonly recommended practices such as bed rest, fluid administration, and caffeine have questionable efficacy. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation (NIBS) technique that applies low-voltage electrical currents through surface electrodes on the scalp. Depending on the stimulation type-anodal or cathodal-tDCS can induce long-lasting increases or decreases in neuronal excitability and vascular-neuronal activity coupling. Research has shown that anodal tDCS (a-tDCS) applied to the primary motor cortex (M1) can alleviate various pain conditions, including fibromyalgia, neuropathic pain, and headaches. The pain-relieving effects of M1 a-tDCS are believed to follow the modulation of intracortical inhibitory GABAergic transmission, and the descending connections from M1 to the thalamus and periaqueductal gray. Although short-term a-tDCS treatment has shown promise in preventing migraines and medication-overuse headaches, its role in p