Temporary homonymous hemianopsia after epidural blood patch
A 33-year-old pregnant woman had been transferred to our outpatient clinic with the concern for preterm labor at 23 weeks gestation but was ultimately sent home. After a triplet pregnancy achieved through an in vitro fertilization embryo transfer in a private clinic, the patient underwent a McDonald operation at 16 weeks gestation due to the risk of preterm birth in multiple gestations. The patient then presented to the emergency department of our hospital at 30 weeks and 2 days gestation due to premature rupture of membranes. She was prepared for an urgent Caesarean section at 31 weeks and 3 days gestation due to sudden contractions. In a seated position, the patient underwent a midline approach to the L3-4 interspinous space using an 18 G Tuohy needle. Cerebrospinal fluid leaked while identifying the epidural space using the loss of resistance (LOR) technique with 2.5 mL of air. Dural puncture was suspected, and the needle was removed. As a result, the initially scheduled epidural anesthesia was changed to spinal anesthesia. Subsequently, we successfully initiated spinal anesthesia using a 26 G Quincke needle in the same location. The patient was move to a supine position after administering 10 mg of bupivacaine. The Caesarean section was initiated after confirmation of adequate anesthesia up to the fourth thoracic segment. All three babies and the placenta were delivered. All vital signs were stable before and after the anesthetic injection, and no abnormal findings were observed at the time of the procedure. The patient was advised postoperative bed rest and began early ambulation on the first postoperative day. Since the patient complained of mild tinnitus during ambulation without any other associated symptoms, closer follow-up was initiated.\nOn the second postoperative day, she complained of headache, nausea, and other symptoms, and she began complaining of a stiff neck and vomiting on the third postoperative day. These symptoms were alleviated in the supine position but recurred when the patient assumed standing or sitting positions. No other focal neurologic symptoms were identified at that time, and vital signs were stable. Despite conservative management including bed rest, the administration of fluid, analgesics and anti-nauseants, her symptoms persisted. The patient was sent to the Department of Neurology on the fourth postoperative day for suspected PDPH. She was encouraged to undergo epidural blood patch. We were initially planning to perform EBP after the confirmation of PDPH based on computed tomography (CT) scans; however, the scanning was delayed after the procedure due to limited availability. Subsequently, the patient was placed in the left lateral position, and the epidural space was identified using about 2.5 mL of air with the LOR technique at the L4-5 spinal level. No leakage of cerebrospinal fluid was detected at that time. Fifteen milliliters of the patient's own blood were injected using an aseptic technique. No specific physical findings were identified at the time of the procedure. The patient stayed on bed rest in the supine position and slept in the same posture. The CT scan taken immediately after the EBP procedure demonstrated pneumocephalus in the prepontine and premedullar cisterns (). After waking on the fifth postoperative day, the first postprocedure day following the EBP, she started to complain of an abrupt vision abnormality. Her vital signs were stable and no neurological symptoms were detected other than her visual disturbance, apart from her persistent mild headache. Visual field and fundal examinations were conducted in the Department of Ophthalmology. A right homonymous hemianopia was detected in the Humphrey visual field test (), but no abnormal findings were identified on fundal examination. Magnetic resonance imaging (MRI) was performed due to the clinical suspicion of homonymous hemianopsia, and demonstrated air bubble movement toward the left retrochiasmal visual pathways ().\nAfter pneumocephalus was identified as the cause of her visual disturbance and headache, we administered prophylactic antibiotics and highly concentrated oxygen. The patient was then placed on bed rest. Her symptoms of visual disturbance improved considerably over the course of the day, and a follow-up CT scan was performed. No further air density was observed. Although her mild headache remained, the visual disturbance completely disappeared by the end of the fifth postoperative day. The patient was discharged on the sixth postoperative day and was asymptomatic at her outpatient follow-up visit one week later.