A 40-year-old Japanese primigravida with American Society of Anesthesiologists Performance Status 1 was scheduled for an elective cesarean section because of a low-lying placenta at 38 weeks of gestation. Her past, pertinent medical history was unremarkable. Combined spinal-epidural anesthesia (CSEA) was planned for the surgery. The patient was placed in a right lateral recumbent position. Eighty-three percent alcohol with 0.5% chlorhexidine was used for skin preparation. A 16-gauge CSEcure® needle (Smiths Medical Japan, Tokyo, Japan) was inserted at the L2–3 interspace. Loss of resistance to saline was noted at 3.3 cm using a median approach. A 27-gauge pencil point needle was introduced by 5 mm. On advancing the spinal needle, the patient experienced radiating pain in her right leg, which, unfortunately, caused her to move. At this time, we identified UDP with a constant stream of clear cerebrospinal fluid. The epidural needle was immediately removed. CSEA was again performed at the L3–4 interspace using an identical 16-gauge needle, with a loss of resistance to saline at 3.0 cm followed by an uneventful needle-through-needle spinal tap. We injected 8 mg of hyperbaric bupivacaine and 20 μg of fentanyl intrathecally, and placed a 17-gauge Perifix® catheter (B Braun, Tokyo, Japan) epidurally. There were no signs of CSF backflow nor blood backflow through the needle or the catheter. CSEA resulted in an inadequate block at the level of Th12. A decision was made to perform supplemental epidural anesthesia at the Th12-L1 interspace using a 17-gauge Uniever® needle (Unisys, Tokyo) with 6 mL of epidural 0.75% ropivacaine, which yielded adequate anesthesia for the operation, without complications. The remainder of the delivery was uneventful. Eighteen hours after delivery, the patient reported postural headache and stiff neck, consistent with PDPH. Her symptoms were refractory to conservative management, such as intravenous hydration and bed rest, as well as oral loxoprofen sodium. An AEBP was performed approximately 44 h after delivery using 20 mL of autologous blood injected at the L3–4 interspace with a median approach using a 17-gauge Tuohy needle. Back pain or neurologic symptoms were not noticed at this time. Symptoms transiently disappeared, but recurred 2 days later. Five days after delivery, a repeat AEBP was performed with 20 mL of autologous blood at the L2–3 interspace, where the UDP had occurred, using a paramedian approach. These procedures were performed by the most experienced anesthesiologists available, using loss-of-resistance to saline technique without difficulty. Blood was obtained using 10% povidone iodine skin preparation for each procedure. During the second AEBP, the patient reported pain in the back, buttocks, and posterior aspect of the lower extremities, as well as bilateral S1 radicular pain. Following the second AEBP, PDPH quickly resolved, but severe and transient symptoms were observed. The patient was unable to extend her legs beyond 135° due to radiating pain. No dysuria was present. MRI demonstrated intrathecally extending subdural hematoma around an aggregated cauda equina from L3 to L4 and another similar lesion at the L5 vertebral level. No signs of epidural hematoma or infection were identified. Subdural hematoma and adhesive arachnoiditis were diagnosed and oral analgesic therapy was continued. Eight days later, a repeat MRI examination demonstrated partial improvements. One month after delivery, her residual neurologic symptoms included occasional discomfort in the right posterior thigh. The patient decided to request further evaluation only if symptoms were to worsen and declined further radiologic studies at the time.