Post-traumatic Collet–Sicard syndrome: personal observation and review of the pertinent literature with clinical, radiologic and anatomic considerations

The lesion of the lower four cranial nerves, commonly called Collet–Sicard syndrome, can be caused by a blunt head and neck trauma. It may be associated to an isolated fracture of the occipital condyle or of the atlas.

The aim of this report is to assess the modality of the trauma, the type of fracture, the anatomic characteristics, the treatment and clinical results of this syndrome.

We discuss 14 cases of fracture of occipital condyle and of atlas and 1 personal case.

We analyzed 14 cases collected from the literature between 1925 and 2013, reported a further personal case and performed an anatomical study of the paracondylar, atlas and styloid process region. The anatomical dissection was performed to assess the anatomic relationships in the site of transit in which the nerves IX, X, XI and XII are injured.

A total of 14 cases of p-CSS were collected: 9 caused by a condyle fracture and 5 by an atlas fracture. The patients were 13 males and only 1 female, 10 of them had a blunt trauma due to the result of axial loading (force directed through the top of the head and through the spine) falling on the head. The nine cases with a condyle fracture were associated to the dislocation of part of it, while those with atlas fractures showed the fracture and/or disjunction of the articular mass. The anatomical evaluations reveal that the lower four cranial nerves, at their emergency, pass through a close osteo-ligamentous space in relationship to the condyle. Below they run through a little wider channel between the articular mass of C1 and the styloid process. Two cases underwent surgical procedure. All the other cases were treated conservatively with immobilization of the cervical spine. During follow-up three cases with condylar fractures were found to be clinically unchanged and six showed modest improvements while one case with atlas fracture had a complete recovery and four improved significantly.

The p-CSS is caused by force directed through the top of the head. We suppose that the nerve injuries are due to their laceration caused by a displacement of a condyle fragment or to their compression and stretching when they pass between the lateral mass of the atlas and the styloid process. These modalities of trauma explain the better clinical results in patients affected by C1 fractures. Conservative treatment is the option of choice. Surgical option, when choosed, is not considered to fix nerve damages.