Arnold-chiari type I malformation with cervical syringomyelia in a pregnant woman in labor: case report and review of the literature

Arnold-Chiari type I malformation (ACM-I) is characterized by herniation of cerebellar tonsils (to at least 3-5 mm below the foramen magnum) into the spinal canal. It may be associated with syrinx. In most of the cases, it becomes symptomatic in adulthood with symptoms secondary to medullary distress. Pregnancy is usually uneventful, but many doubts are connected to delivery (operative vaginal delivery vs elective cesarean section) and for anesthetic management (general anesthesia versus spinal/epidural anesthesia). In case of vaginal delivery maternal effort should be avoided during the second stage of labor. Anesthetic alerts in women with ACM-I are related to: possible increase of cerebro-spinal liquor (CSF) pressure associated with pregnancy and labor; possible decrease of spinal pressure related to loss of liquor after spinal anesthesia or accidental dural puncture during peridural performance, with an increased differential pressure between CSF pressure above and below the foramen magnum. This increased differential pressure may lead to a further drop of the tonsils through the foramen magnum, with compression of the brainstem. Each anesthetic management plan has risks, and there is not a gold standard treatment for all patients due to rarity of syndrome and to the small scientific experience described in literature. We reported a case report of a patient affected by ACM-I with syrinx who delivered with elective cesarean and general anesthesia.