NERVE ROOT COMPRESSION AFTER EPIDURAL BLOOD PATCH
Abstract Number: 219
Abstract Type: Case Report/Case Series
Intro: Epidural blood patch (EBP) is an efficacious treatment for post-dural puncture headache (PDPH), with 85-95% of patients reporting relief of symptoms within 24 hr.1 Although EBP placement is a safe procedure, rarely, neurologic complications may result. We report the development of nerve root compression secondary to extravasated blood from EBP placement for treatment of PDPH.
Case: A 36 yo G2 P1 underwent a combined spinal-epidural for labor analgesia complicated by dural puncture with a 17-Ga Tuohy needle. 10 hr after delivery, she developed a 7/10 positional bifrontal headache along with ear fullness and neck stiffness. After failing conservative management, she underwent uneventful EBP with 20mL of autologous blood. She had no immediate relief of her symptoms, but 15 hr later, did report significant relief of her headache. On PPD#2, the patient had sudden recurrence of her symptoms upon standing. She underwent repeat EBP, resulting in resolution of symptoms 10 hr later. She was discharged home and followed-up for 3 days, during which she had no recurrence of symptoms. On PPD #10, she called complaining of acute onset of severe low back pain and bilateral lower extremity weakness. She was immediately referred to the ER for evaluation of epidural hematoma/abscess. MRI showed hyperdensity along the posterior aspect of the spinal canal from L5-S1and mild bunching of the S3-S5 nerve roots; these findings were attributed to her EBP. Although her symptoms were concerning for cauda equina syndrome, there were neurologic deficits on exam. She was subsequently discharged home on pain medication and reported resolution of her symptoms within 3 days.
Discussion: The exact mechanism by which EBP treats PDPH is unknown, but is hypothesized to be the result the clot tamponading the dural puncture site, as well as acting as an anti-inflammatory. Few studies have evaluated MRI findings in patients after EBP. Vakharia et al showed that 45 minutes post-EBP, blood spreads cephalad and caudad in the epidural space, causing a slight compression of the intrathecal sac in the distribution of the clot.2 Beards et al noted a similar phenomenon and also showed that by 18 hours post-EBP the large blood clot had broken down into small clots.3 Our patient presents a unique scenario in that her MRI findings showed intrathecal extravasation of blood resulting in nerve root compression. Given that her MRI was performed 9 days after the most recent EBP, one would expect any blood from the patch to have reabsorbed. Additionally, the mechanism by which the blood entered the intrathecal space was unknown; possible scenarios include extravasation through the dural tear or inadvertent intrathecal placement of the EBP, although the latter is less likely.
1. Taivainene T, et al. Acta Anesthesiologica Scandinavia 1993; 37:702-5
2. Vakharia SB, et al. Anesthesia and Analgesia 1997; 84:588-90
3. Beards SC, et al. British Journal of Anaesthesiology 1993; 71: 82-