Anesthetic management of pseudotumor cerebri in the parturient
Abstract Number: S2D-7
Abstract Type: Case Report/Case Series
Introduction: Pseudotumor cerebri, also known as idiopathic intracranial hypertension (IIH), is a condition in which there is an increase in ICP without hydrocephalus or a mass lesion without CSF composition change. We describe a case of a patient with IIH and the considerations related to labor epidural placement.
Case: A 25 y.o. G4P3 female at 40w1d with supermorbid obesity (BMI 50) and IIH presented in labor dilated at 6 cm requesting an epidural. She previously had epidurals for labor without issue but none since the diagnosis of her IIH 2 years ago (relief with LP but no shunt placed). She reported intermittent headaches several days weekly, usually resolved with acetaminophen. She denied any visual impairments. After uneventful neurological and visual exam including fundoscopy were performed, an uncomplicated epidural was placed at L4/L5 interspace. 0.0625% bupivacaine with 2 mcg/mL fentanyl was infused at a rate of 10 mL/hr without any bolus dosage. The patient delivered a healthy newborn via spontaneous vaginal delivery about 6 hours later and the epidural was later removed. The patient was followed afterwards and did not have headache, vision impairment, or any other complications from the epidural.
Discussion: IIH usually occurs in obese women of childbearing age and signs/symptoms include headache, tinnitus, abducens nerve palsy, papilledema, and vision loss. Management of IIH typically includes serial LP to remove CSF, weight control, acetazolamide, furosemide, and steroids with the goal of controlling ICP to preserve visual function. Our patient was not actively taking any of these medications. When administering labor epidural analgesia, there is some concern that medication in the lumbar epidural space will cause a compression of the dural sac which can affect compliance of the spinal subarachnoid space and displace CSF towards the cranium to increase ICP. Baseline lumbar epidural pressures are also higher in laboring parturients compared to nonpregnant women. Slower dosing of epidural medication may be safer for symptomatic patients due to a slow increase in epidural pressure which would slow the rate of ICP elevation.
While our patient did not have a shunt, extra caution must be taken if one is present to avoid shunt damage with needle instrumentation. Another consideration with epidural placement is the potential for inadvertent dural puncture. However with IIH, there is no obstruction of CSF flow and no baseline pressure difference between intracranial and spinal CSF compartments. An accidental dural puncture resulting in a drop in CSF volume will be rapidly accommodated by caudal flow of CSF and therefore will not result in brain shift or herniation.
Our case is consistent with several previous reports of uneventful labor epidurals for IIH patients and it is important to emphasize that neither epidural nor vaginal delivery are contraindicated.