Chiari I Malformation Presenting as a Persistent Postdural Puncture Headache
Abstract Number: 69
Abstract Type: Case Report/Case Series
Introduction: About 75% of patients experiencing a dural puncture during epidural placement develop a postdural puncture headache (PDPH). For such patients, an epidural blood patch (EBP) is usually effective in relieving symptoms.(1) In the patients failing such standard therapy, the differential diagnosis for their headache should be expanded.
Case Report: A 26 year old G2P1 parturient at 34 weeks presented with a placental abruption. An uncomplicated epidural was placed, but the patient achieved a T3-4 sensory level after 10mL of 0.25% bupivacaine. Five hours after epidural placement, the patient complained of a postural headache. Conservative management and two EBPs yielded only temporary relief. Her symptoms increased in severity and included pre-syncope with standing. Imaging demonstrated cerebellar tonsils 23mm below the foramen magnum, midbrain compression, and a small syrinx at C2-3, consistent with a Chiari I malformation. Other MRI findings indicated a likely CSF leak. Her symptoms resolved 11 days after epidural placement.
Discussion: Chiari I malformations are characterized by caudal displacement of the cerebellar tonsils at least 3mm below the level of the foramen magnum and may be associated with a syrinx. Chiari malformation was considered a congenital disorder but is now recognized to have an acquired variant. The neurosurgical literature discusses case reports of acquired Chiari I malformations that occurred after lumboperitoneal shunting in patients with previous radiological evidence of a normal hindbrain.(2) Progressive tonsillar descent following multiple lumbar punctures has also been reported.(3) A single case of a Chiari malformation presenting as a recurrent spinal headache has been reported in the anesthesia literature. It was uncertain in that case if the patient had a congenital malformation or if the Chiari malformation was acquired following the dural puncture.(4) Our current report describes the presentation of a previously undiagnosed Chiari I malformation following a presumed dural puncture during epidural placement. Our patient had two "normal" head CTs prior to developing symptoms of a PDPH, but in retrospect, low lying tonsils were present on those earlier CTs. In any patient with a PDPH who fails traditional therapy, consideration must be given to other headache causes, including congenital or acquired/iatrogenic Chiari I malformations.
1. Safa-Tisseront V, et al. Effectiveness of Epidural Blood Patch in the Management of Post-Dural Puncture Headache. Anesthesiology 2001; 95: 334-339.
2. Payner T, et al. Acquired Chiari Malformations: Incidence, Diagnosis, and Management. Neurosurgery 1994; 34:429-434.
3. Sathi S and Stieg P. "Acquired" Chiari I Malformation after Multiple Lumbar Punctures: Case Report. Neurosurgery 1993; 32: 306-309.
4. Hullander RM, et al. Chiari I Malformation Presenting as Recurrent Spinal Headache. Anesth Analg 1999; 75: 1025-6.