Persistent CN VI Palsy After Inadvertent Dural Puncture
Abstract Number: 75
Abstract Type: Case Report/Case Series
Background: Inadvertent dural puncture is complication of epidural placement (1). The resulting cerebral spinal fluid (CSF) leak can cause intracranial hypotension, leading to further complications such as postdural puncture headache (PDPH), and more rarely, cranial nerve palsy (CNP). We report the case of a patient who developed a persistent 6th CNP after an inadvertent dural puncture with a 17gauge Touhy needle.
Case: A 38 year old G2P0 presented for induction of labor due to gestational hypertension. Midline combined spinal-epidural (CSE) anesthesia was initiated with the patient in the sitting position using a loss-of-resistance, needle-through-needle technique at the L3-4 interspace. Loss of resistance to air was performed using a 17g Touhy needle. Following removal of the 27 gauge spinal needle, there was free-flow of CSF through the Touhy. The epidural needle was withdrawn and the epidural catheter was placed at the L4-5 level. The patient had an uncomplicated vaginal delivery. On the 4th post-partum day, the patient reported a PDPH which was initially managed with fluids and oral analgesics. On the 7th day post-partum, the headache (HA) persisted and she developed diplopia and esotropia, at which time an epidural blood patch (EBP) was placed. Following the EBP, she had immediate resolution of the HA, however, the abducens palsy persisted for over 11 weeks.
Discussion: Cranial nerve palsy is a known complication of inadvertent dural puncture (1). The proposed mechanism for CNP is traction of the nerves due to a decrease in intracranial pressure (ICP). Sixth CNP usually presents 2-5 days postpartum and is almost always preceded by a HA. In addition, it may cause extra-ocular muscle paralysis. Following EBP, patients with 6th CNP often have resolution of the HA, however the nerve palsy may not improve (2). Some sources suggest that early EBP placement may help prevent persistent CNP (3), but this is not well supported. Current treatment of abducens palsy includes eye patch or prism. The CNP usually resolves spontaneously after 6-8 months, but approximately 10% of cases may be permanent, requiring surgical treatment (2). Based on this case report and the supporting literature, we recommended that anesthesiologists be actively involved in follow up of all inadvertent dural punctures, especially if there are evolving neurological changes.
1 Reg Anesth Pain Med 1999; 24(5):470-2
2 Obstet Gynecol 2008; 111(2):540-1
3 Can J Anesth 2004; 51(8): 821-23