Chiari malformation presenting as a focal motor deficit. Report of two cases.

Chiari malformations may present with a wide range of symptoms and signs. Nevertheless, focal foot weakness as a presentation of a Chiari malformation has not been described in the pediatric neurosurgical literature. Two children with Chiari malformations and holocord syringomyelia presented with manifestations of a supposed isolated lumbar radiculopathy. Neurological deficits completely resolved after decompressive suboccipital craniectomy and cervical laminectomy. These cases emphasize the importance of imaging the entire craniospinal axis and avoidance of therapeutic intervention specifically aimed at a radiculopathic process when initial imaging fails to show a structural abnormality at the spinal level of deficit. The possible pathophysiological origins for this unusual presentation are discussed. Based on the experience gained with these patients, recommendations are made regarding the diagnostic workup and management of this entity in children presenting with focal deficits that are not supported by imaging of the affected root levels. Chiari malformations may rarely masquerade as lower motor and sensory deficits, and appropriate treatment may result in excellent recovery of function.