[Transoral decompression of the brain stem in a basilar impression secondary to rheumatoid arthritis. Description of a case and survey of the literature].

INTRODUCTION

The vertical subluxation or translocation of the odontoid process producing a basilar impression with compression of the brain stem is a late phenomenon in the course of rheumatoid arthritis; the appearance of symptoms in the spinal cord and the lower pairs of spinal nerves is a specific sign of this disorder. In this situation, the standard surgical aims are the decompression of the affected nerve structures followed by craniocervical stabilisation. The objective of this paper is to report on the improvement of the neurological deficit after decompressive transoral surgery (odontoidectomy), without associating any internal fixation system, in a female patient with a long history of rheumatoid arthritis and anterior compression of the brain stem caused by basilar impression and rheumatoid pannus. A survey of the literature showed that, with the odd isolated clinical case, there are no papers which describe the post operative development of surgical decompression of the brain stem carried out through an anterior approach in patients with rheumatoid subluxation of the odontoid process, without associating any internal stabilisation system.

CASE REPORT

Female aged 65, diagnosed as suffering from rheumatoid arthritis at the age of 25, who was admitted with symptoms of compression of the medulla oblongata secondary to a vertical subluxation of the odontoid process. She was submitted to transoral decompression of the brain stem (odontoidectomy and removal of pannus without posterior fixation), and made surprisingly favourable post operative progress. At 15 months after the surgical decompression she led an independent life.

CONCLUSIONS

The neurological improvement of our patient after the decompressive odontoidectomy suggests that the mechanical compression of the odontoid process with impaction of the brain stem was the predominant aetiological factor causing the symptoms in the medulla oblongata. Her clinical stabilisation, on the other hand, can be explained by a mechanism involving the spontaneous autofusion of the lateral masses of the atlas with the occipital condyle and with the axis. Lastly, we consider that, in certain cases of rheumatoid patients with atlantoaxial subluxation, impaction of the odontoid process in the foramen magnum and clinical features involving compression of the medulla oblongata, transoral decompression of the brain stem through an odontoidectomy is the choice initial surgical procedure, since it affords neurological improvement and clinical stabilisation. In any case, a strict neurological and radiological post operative follow up is needed in view of a possible craniocervical fixation occurring in the future.