Radiographic progression of a Chiari I malformation after minor head trauma: Final increment of obstruction to create pathophysiology
Introduction The Chiari I malformation is a rare pathological condition that is characterized by a downward herniation of the cerebellar tonsils and brainstem through the foramen magnum. The transformation from an asymptomatic to symptomatic Chiari I malformation is poorly understood, but the major inciting factor associated with this transformation has been trauma. Here, we report the first documented case of radiographic and clinical progression from an asymptomatic to symptomatic Chiari I malformation after a traumatic injury and provide a possible pathologic mechanism related to an occult cerebrospinal fluid (CSF) leak. Clinical Presentation A 32 year old woman presented with a history of intermittent headaches and an MRI demonstrating 8 mm of tonsillar decent. After a traumatic motor vehicle collision, she developed bifrontal tussive headaches and neck and arm burning numbness with progression of tonsillar descent to 12 mm. Intervention The patient underwent a suboccipital craniectomy and partial C1 laminectomy with a duroplasty, in addition to a subpial partial tonsillectomy. Postoperatively, symptoms improved with the exception of persistent positional recurrent headache. Myelogram demonstrated a cervical CSF leak that resolved with an epidural blood patch coincident with resolution of the patients symptoms. Conclusion We document radiographic and symptomatic progression of a Chiari I malformation after a traumatic induction of an occult CSF leak. We believe this may provide some insight into the pathophysiology of Chiari malformation in a subset of patients. © 2011 Surgisphere Corporation.
