A practice pathway for the initial diagnostic evaluation of sixth cranial nerve palsies

Purpose. To establish practice recommendations for the evaluation and management of sixth nerve palsy. Methods. An English language Medline literature search from 1966 to 1995 using the terms "sixth nerve palsy," "abducens nerve palsy," and "lateral rectus palsy" was performed to define recommendations for the management of the sixth nerve palsies (Note: Only case reports and antidotal publications comprise the literature). We divided sixth nerve palsies into six types: 1. Non-isolated 2. Traumatic 3. Congenital 4. Vasculopathic 5. Non-vasculopathic 6. Progressive or unresolved. The suggested practice pathway was applied to a retrospective chart review of 100 charts of sixth nerve palsy seen at the Houston Eye Associates and the Department of Ophthalmology at Baylor College of Medicine. All patients were evaluated by a neuro-ophthalmologist or a strabismologist and the results of medical testing as well as results of neuroimaging, if performed, were reviewed. Pre-referral neuroimaging costs were then compared retrospectively with the hypothetical evaluation that the patient would have received based upon the recommendations of our practice pathway. Results. Initial data analysis suggests that younger-aged patients or those without vasculopathic risk factors may require neuroimaging. Conclusions. In summary, the recommendations of this practice pathway are supported by our retrospective literature review and are useful and cost-effective. To further validate the proposed pathway, a prospective clinical trial needs to be conducted.