Combined Deficit of the Four Lower Cranial Nerves also Known as the Syndrome of Collet-Sicard: A Systematic Review and Meta-analysis

Combined deficit of the four lower cranial nerves (CN IX, X, XI, and XII) was originally described by French physicians Collet (1915) and Sicard (1917) during World War I. To date though, this rare neurological clinical picture lacks systematic evidence regarding its epidemiology, clinical presentation, treatment strategies, and outcome. We conducted a systematic review and meta-analysis concerning Collet-Sicard syndrome (CSS) on Medline database in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The research yielded 84 articles among which 73 individual case reports were eventually retained. Mean age was 53.7 (± 16) years old and the male-to-female ratio was 1.8/1. CSS was firstly caused by tumors (38.4%), following by vascular etiologies (28.8%), trauma (16.4%), and infection (6.8%), among others. Temporary enteral nutrition was required for 17 patients (23.3%). The four CN presented significant chances of complete or partial recovery: 52.1% for CN IX (p < 0.001), 46.6% for CN X and CN XII (p < 0.001), and 39.7% for CN XI (p = 0.002). Tumoral causes presented significantly lower chances of favorable CN recovery (7.1%) compared to infection (60%), vascular (52.4%), and trauma (41.7%) (p < 0.001). Older age (> 53 years old) was not associated with a dismal CN prognostic (p = 0.763). Most patients (71.2%) presented a favorable outcome (Glasgow Outcome Scale score ≥ 4). All the patients who died (6.8%) suffered from skull base tumors. CSS is a rare condition requiring prompt clinical and radiologic diagnostic and multidisciplinary management. Vascular or infectious-related CSS seem to present a rather good prognostic, closely followed by trauma, whereas tumoral-related CSS seem to suffer from a more dismal prognostic.