Conservative treatment of an atlantoaxial degenerative articular cyst: case report

Abstract

Background: Atlantoaxial degenerative articular cysts are rare lesions that can cause extradural compression of the cervicomedullary junction. When symptomatic, they usually require surgical treatment. We report an unusual case of spontaneous regression of an atlantoaxial degenerative articular cyst after conservative treatment with an external cervical brace along with a systemic therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) and steroids. We also discuss the potential pathogenetic mechanisms involved.

Purpose: To describe a case of significant volume reduction of an atlantoaxial articular degenerative cyst in a patient treated with a Philadelphia collar and anti-inflammatory drugs.

Study design: Case report with analysis of the literature.

Methods: A 80-year-old patient was admitted to our institution with a history of progressive tetraparesis, ataxic gait, and cervical pain. A cervical spine magnetic resonance imaging (MRI) scan showed an extradural mass lesion behind the dens of C2 causing significant compression of the cervicomedullary junction, suggesting the diagnosis of atlantoaxial degenerative articular cyst. The patient refused surgery in favour of a conservative treatment with a Philadelphia collar and a short-term course of NSAIDs and corticosteroids.

Results: After 6 weeks, the patient's neurological condition improved, and a 6-month follow-up cervical spine MRI scan revealed an almost complete regression of the atlantoaxial cystic lesion. At a 1-year follow-up, his clinical condition was further improved.

Conclusions: Atlantoaxial articular degenerative cysts are rare lesions that should be included in the differential diagnosis of those extradural lesions that can cause a ventral or ventrolateral compression of the cervicomedullary junction. They most commonly occur in elderly female patients affected by diffuse arthrosic degeneration of the cervical spine, with or without clear radiological signs of atlantoaxial instability, and have a typical appearance on MRI imaging. Surgery, with direct excision of the cyst and/or a C1-C2 fusion, is the first treatment of choice. Nevertheless, our report points out the possibility of a significant spontaneous regression of these lesions following a simple conservative strategy based on the use of an external cervical brace together with a systemic anti-inflammatory therapy.