A nursing student recently wrote a private message to me asking for information concerning management of delivery in people with syringomyelia. She was concerned that vaginal delivery may aggravate the syringomyelia and asked about Caesarian sections whether and epidural anesthesia should be used.
I did a literature search on the subject. There is not much data on the subject. Based on the published literature, I don't see any convincing evidence that vaginal delivery aggravates syringomyelia. In 2005, Meuller & Oro  described 7 patients who had known Chiari I Malformations. According to the abstract, "none of the patients reported significant increase or recurrence of Chiari-related symptoms during delivery or postpartum." Furthermore, "four of the women had epidural anesthesia for delivery and reported no related symptoms."
In 2001, Daskalakis, et al.  described a case of a woman who had syringomyelia associated with spinal cord injury and they did elective Caesarian on the woman to deliver the baby. They were acting on the fear that the straining and pushing during delivery would aggravate the syringomyelic cyst. In 1996, Castello, et al.  did the same. One has to search all the way back to 1965  and 1948  to find cases of syringomyelic cysts complicating pregnancy and delivery. There have been several case reports of uneventful vaginal deliveries of babies in women with Arnold-Chiari syndromes. For example, Newhouse, and Kuczkowski  reported successful vaginal delivery of a child under epidural anesthesia in a mother who has Arnold-Chiari and sickle cell anemia. In 2002, Parker, et al.  presented two cases. One is a woman who presented with worsening neurological symptoms and had a Caesarian. The second case was one in which the woman had an "operative vaginal delivery" without expulsive efforts.
When faced with such questions, most doctors tend to duck the question (Source) by saying that a Caesarian is recommended if there is a medical condition. When faced with the question neurosurgeons tend to be play it safe: "Pregnancy and vaginal delivery can be a relative contraindication for patients with syringomyelia. Pregnant patients may require special care because pushing and straining during vaginal delivery can potentially enlarge a syrinx. Although a C-section may be recommended, patients should have a full discussion with their obstetrician." (Source)
In my opinion, an Arnold-Chiari syndrome is different from a spinal cord syringomyelic cyst that is secondary to spinal cord injury or meningitis. In the former, increased intracerebral pressure may increase the risk of brainstem and cerebellar herniation through the foramen magnum. If the foramen magnum has been adequately decompressed, there is probably no reason to deny vaginal delivery and force a woman to under a Caesarian. I think that the risk of a spinal cord syringomyelic cyst enlarging during pregancy and delivery is low. Of course, the presence of the syringomyelic cyst should be noted and if the patient develops worsening neurological symptoms during the delivery, a Caesarian should be carried out.
- Mueller DM and Oro J (2005). Chiari I malformation with or without syringomyelia and pregnancy: case studies and review of the literature. Am J Perinatol 22: 67-70. Division of Neurosurgery, University Health Care, Columbia, MO 65212, USA. Women with Chiari I malformation with or without syringomyelia are of particular concern because of the potential risk of increased intracranial pressure during pregnancy and delivery. The following questions are most often asked in the clinical setting: Is it safe to have a planned pregnancy? Will the symptoms become worse or recur during pregnancy and will the baby be normal? Seven patients with Chiari I malformation, with and without syringomyelia, submitted checklists of self-reported symptoms experienced during pregnancy, labor, and postpartum. Seven patients with Chiari I malformation with and without syringomyelia were queried for symptoms during pregnancy, labor, and postpartum. None of the patients reported significant increase or recurrence of Chiari-related symptoms during delivery or postpartum. Four of the women had epidural anesthesia for delivery and reported no related symptoms. This series represents a small number of women with Chiari I malformation who had uncomplicated pregnancy, labor, and delivery.
- Daskalakis GJ, Katsetos CN, Papageorgiou IS, Antsaklis AJ, Vogas EK, Grivachevski VI and Michalas SK (2001). Syringomyelia and pregnancy-case report. Eur J Obstet Gynecol Reprod Biol 97: 98-100. First Department of Obstetrics and Gynaecology, Alexandra Maternity Hospital, University of Athens, 80 Vas. Sofias Ave., Athens 115 28, Greece. The course of a pregnancy in a woman with syringomyelia is presented. She was first admitted at 28 weeks' gestation suffering neurologic symptoms associated with a spinal cord injury, which had happened in the past. The disease was diagnosed with a magnetic resonance imaging (MRI). Delivery was accomplished by elective caesarean section under general anaesthesia at 37 weeks, in order to avoid straining during the second stage of an imminent labour.
- Castello C, Fiaccavento M, Vergano R and Bottino G (1996). [Syringomyelia and pregnancy. Report of a clinical case and review of the literature]. Minerva Ginecol 48: 253-7. Reparto di Ostetricia e Ginecologia, USSL 5-Ospedale Civile, Giaveno. The authors describe a case of pregnancy in a patient previously affected by Arnold-Chiari malformation associated with syringomyelia; from clinical experience and a review of the literature, the possibility is deduced of carrying out the pregnancy physiologically, although by observing close precaution while performing delivery which, by our experience, should be accomplished by partus caesarius in general anaesthesia, taking great care to the evaluation of neurologic parameters.
- Cantu Esquivel MG, Benavides de Anda L and Benavides de la Garza L (1994). [Syringomyelia and pregnancy. A case report]. Ginecol Obstet Mex 62: 302-3. Hospital, Clinica y Maternidad Conchita, A.C. Monterrey, N.L. This report refers to the case of a 39-year-old woman, fourth gestation, who during her first pregnancy developed neurologic deficit of the left hand, which slowly progressed getting to affect during seven years, all the left upper extremity and the right hand. During this time, she had two abortions, and between the third and fourth pregnancies, because of the clinical suspicion, laboratory tests were done, finding by electromyography, lesion of anterior process of spinal chord at cervical level. During this fourth pregnancy, neurologic deficit increased and it was decided to interrupt pregnancy by cesarean section under epidural block at 38 weeks of gestation. According to our knowledge this syringomyelia case and pregnancy, is the first one reported in our country.
- Gusev VA (1965). [Syringomyelia and pregnancy]. Vrach Delo 6: 134-5.
- Baker JT and Stoll J, Jr. (1948). Report of a case of syringomyelia complicating pregnancy. Bull Sch Med Univ Md 32: 163-5.
- Newhouse BJ and Kuczkowski KM (2007). Uneventful epidural labor analgesia and vaginal delivery in a parturient with Arnold-Chiari malformation type I and sickle cell disease. Arch Gynecol Obstet 275: 311-3. Department of Anesthesiology, UCSD Medical Center, University of California-San Diego, 200 W. Arbor Drive, San Diego, CA 92103-8770, USA. Arnold-Chiari malformation is a disorder of the hindbrain which can lead to altered craniospinal pressures and abnormal flow of cerebrospinal fluid. The possibility of increased intracranial pressure imparts significant risk during labor and delivery, and has led to concern over the use of neuraxial anesthesia. Sickle cell disease is a disorder of abnormal hemoglobin that is prone to sickling under stressful conditions. The physiologic and metabolic changes associated with pregnancy and labor can precipitate sickling, which increases risks for both the mother and the fetus. Vaso-occlusive pain crisis in a parturient with sickle cell disease has been shown to improve with the initiation of neuraxial anesthesia. We present the first reported case of a parturient with both Arnold-Chiari malformation type I and sickle cell disease who presented to labor and delivery with acute pain crisis and who subsequently received epidural labor analgesia and underwent successful vaginal delivery. We include a discussion of the risks associated with pregnancy, labor, neuraxial anesthesia, and delivery in a patient with Arnold-Chiari malformation type I and sickle cell disease.
- Parker JD, Broberg JC and Napolitano PG (2002). Maternal Arnold-Chiari type I malformation and syringomyelia: a labor management dilemma. Am J Perinatol 19: 445-50. Division of Maternal-Fetal Medicine, Madigan Army Medical Center, Tacoma, Washington, USA. Arnold-Chiari type I malformations consists of elongation of the cerebellar tonsils with their displacement below the foramen magnum. Syringomyelia is an associated cyst that accumulates cerebrospinal fluid in the cord that can impinge on local nerve fibers. Pregnant women with either of these disorders are of special concern due to the potential risk of brain stem herniation and or spinal column compression from physiological changes that occur during labor. We present two cases. The first case is a patient with syringomyelia who was admitted in labor with worsening peripheral neurological symptoms. Epidural anesthesia was placed and she underwent an uncomplicated cesarean delivery with resolution of her symptoms postpartum. The second case is a patient with an Arnold-Chiari type I malformation and syringomyelia who presented in labor. The patient had an epidural placed and was allowed to progress to complete dilation and effacement at +2 station. She underwent a successful operative vaginal delivery without voluntary maternal expulsive efforts. Both patients had uncomplicated postpartum courses. Although these are rare disorders with significant potential morbidity, labor can be managed by either mode of delivery with careful patient selection. We caution that this review has insufficient numbers of patients to address the safety and efficacy of either delivery mode but rather focuses on alternatives for delivery. This report is the first to document a case of a patient with an Arnold-Chiari malformation and syringomyelia successfully managed in labor with a vaginal delivery.