Functional outcome after surgical treatment of cavernous malformation involving ocular motor cranial nerves: A systematic review

Abstract Background: Cavernous malformations (CMs) of cranial nerves (CN) III, IV, and VI are extremely rare, and limited studies have assessed the functional outcomes after treatment. This systematic review investigated the clinical features of CMs in ocular motor CNs, including treatment results, and compared different surgical methods for functional preservation of ocular motor CNs. Methods: ‘PubMed’, ‘SCOPUS’, ‘Web of Science’, and ‘Google Scholar’ databases were searched to identify case reports and studies published between January 1980 and December 2018. This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Results: Twenty-seven patients were identified (median age, 46 years; range, 3 months-71 years). CN III was involved in 17 patients (63.0%), CN IV in 8 (29.6%), and CN VI in 2 (7.4%). Treatments included gross total resection (GTR) and nerve transection in 6 patients (22.2%), GTR and nerve continuity preservation in 7 (25.9%), subtotal resection (STR) and nerve continuity preservation in 4 (14.8%), GTR and end-to-end anastomosis in 5 (18.5%), and conservative care in 3 (11.1%), while the treatment method for 2 (7.4%) patients was not described in the literature. In 22 patients who underwent surgical treatment, functional changes included improvement in 9 patients (40.9%), no change in 10 (45.5%), and worsening symptoms in 3 (13.6%). Functional preservation was achieved in 12 (54.5%) of the 22 patients; the nerve continuity preservation method conferred significant advantage for functional preservation compared with other surgical methods ( p =0.004). Conclusion: Functional preservation of ocular motor CNs can be achieved by nerve continuity preservation. Key Words: cavernous malformation; cranial nerve; treatment outcome