Surgical relief of progressive upper limb paralysis in Arnold-Chiari malformation.

Two cases of delayed progressive paralysis of the upper limbs in an adult and a teenage patient, without neurological deficits in other regions of the body, are presented. In both cases, the pathology appeared to be a traction lesion of the middle cervical and lower cervical nerve roots, due to abnormal angulation of the nerve roots, which first ran up and then downward in the neural foramina and canal. Re-routing of the nerve roots by removing part of the floor of the neural canal, or by a facetectomy, appeared to offer extensive improvement or full recovery.