Forestier disease associated with a retroodontoid mass causing cervicomedullary compression

Craniocervical instability in patients with Ehlers-Danlos syndrome: controversies in diagnosis and management

Ehlers-Danlos syndrome (EDS) is a rare hereditary condition that can result in ligamentous laxity and hypermobility of the cervical spine. A subset of patients can develop clinical instability of the craniocervical junction associated with pain and neurological dysfunction, potentially warranting treatment with occipitocervical fixation (OCF). Surgical decision-making in patients with EDS can be complicated by difficulty distinguishing from hypermobility inherent in the disease and true pathological instability necessitating intervention. Here we comprehensively review the available medical literature to critically appraise the evidence behind various proposed definitions of instability in the EDS population, and summarize the available outcomes data after OCF. Several radiographic parameters have been used, including the clivo-axial angle, basion-axial interval, and pB-C2 measurement. Despite increasing recognition of EDS by spine surgeons, there remains a paucity of data supporting proposed radiographic parameters for spinal instability among EDS patients. Furthermore, there is a lack of high-quality evidence concerning the efficacy of surgical treatments for chronic debilitating pain prevalent in this population. More standardized clinical measures and rigorous study methodologies are needed to elucidate the role of surgical intervention in this complex patient population.

Upper Cervical Compression Myelopathy Caused by the Retro-Odontoid Pseudotumor With Degenerative Osteoarthritis and Calcium Pyrophosphate Dihydrate Disease: A Case Report and Literature Review

The retro-odontoid pseudotumor is often concurrent with atlantoaxial subluxation (AAS). Therefore, the pseudotumor is relatively common in rheumatoid arthritis (RA) but rare in primary osteoarthritis (OA). This is a case report of an elderly male patient suffering from neck pain and compression myelopathy caused by the craniocervical pseudotumor with OA but without atlantoaxial instability. He had long-lasting peripheral and spinal pain treated by nonsteroidal anti-inflammatory drugs. Imaging found upper cervical spondylosis without AAS or dynamic instability but with periodontoid calcifications and ossifications, suggesting calcium pyrophosphate dihydrate (CPPD) crystal deposition. Based on a comprehensive literature search and review, CPPD disease around the atlantodental joint is a possible contributor to secondary OA development and retro-odontoid pannus formation through chronic inflammation, which can be enough severe to induce compression myelopathy in non-RA patients without AAS. The global increase in the aged population advises caution regarding more prevalent upper cervical spine disorders associated with OA and CPPD.

Surgical Management of Retro-Odontoid Cystic Mass with Cervicomedullary Compression

Retro-odontoid cysts are a rare cause of cervicomedullary compression. The etiology of these lesions is not completely understood. Previous trauma and instability at the cervicomedullary junction may be the precipitating event in the development of retro-odontoid cysts in rare cases. We discussed the neurosurgical evaluation of a patient who presented with progressive and rapid neurological deterioration secondary to cervicomedullary compression. Posterior occipitocervical fusion was performed. The patient made an excellent neurological recovery, and postoperative imaging studies demonstrated resolution of the compression and intramedullary cyst.

Nonrheumatoid Retro-Odontoid Pseudotumors: Characteristics, Surgical Outcomes, and Time-Dependent Regression After Posterior Fixation

Objective

Although a retro-odontoid pseudotumor associated with rheumatoid arthritis is a well-known clinical entity, little is known about retro-odontoid pseudotumors not associated with rheumatoid arthritis due to their rarity.

Methods

Between 2006 and 2019, consecutive patients with nonrheumatoid pseudotumors were included and retrospectively compared with patients with rheumatoid pseudotumors.

Results

Nineteen patients had nonrheumatoid pseudotumors (mean age, 73 ± 6 years; male, 53%). All had cervical lesions including ossified anterior and posterior longitudinal ligaments with a history of cervical surgery in 5. The mean thickness of the pseudotumors at diagnosis was 8.1 mm (range, 4.2–17.2 mm). Pseudotumor thickness had a significant negative correlation with the atlantodental interval (p = 0.008) and the subaxial range of motion (p = 0.049). In comparison with 7 rheumatoid pseudotumor patients, nonrheumatoid pseudotumor patients were older (p = 0.042), had a higher proportion of males (p = 0.023), had a smaller atlantodental interval (p = 0.007), and had larger pseudotumors at diagnosis (p = 0.030). Of the 19 patients, 18 received posterior fixation with or without C1 laminectomy, while the other received C1 laminectomy alone. The percent pseudotumor thickness at follow-up to those at diagnosis was 91%, 77%, 68%, 46%, 58%, and 49% at 1, 3, 6, 12, 24, and 36 months after surgery, respectively.

Conclusion

This study revealed markedly clinical and radiological differences between nonrheumatoid and rheumatoid pseudotumors. The main etiology for nonrheumatoid pseudotumors was subaxial cervical degeneration and ossified lesions. There were good outcomes following posterior fixation and time-dependent pseudotumor regression within 12 months.

Thinking beyond pannus: a review of retro-odontoid pseudotumor due to rheumatoid and non-rheumatoid etiologies

Retro-odontoid pseudotumor, or mass-like retro-odontoid soft tissue thickening, is an uncommon but important imaging finding that may be associated with rheumatoid arthritis, crystal deposition diseases, as well as non-inflammatory conditions such as cervical degenerative changes and mechanical alterations. Retro-odontoid pseudotumor is commonly associated with atlantoaxial microinstability or subluxation. MRI and CT have an important role in the detection and diagnosis of retro-odontoid pseudotumor. However, due to a wide range of imaging characteristics and ambiguous etiology, it is a frequently misunderstood entity. The purpose of this article is to review relevant anatomy of the craniocervical junction; describe various imaging appearances, pathophysiology and histology in both rheumatoid and non-rheumatoid etiologies; and discuss differential diagnosis of retro-odontoid pseudotumor in order to help guide clinical management.

Retroodontoid Pseudotumor Related to Development of Myelopathy Secondary to Atlantoaxial Instability on Os Odontoideum

Retroodontoid pseudotumor (ROP) is a nonneoplasic lesion of unknown etiology, commonly associated with inflammatory conditions, and the term of pannus is usually used. Less frequently, ROP formation can develop with other noninflammatory entities, with atlantoaxial instability as most accepted pathophysiological mechanism for posttraumatic or degenerative ROP. As it can clinically and radiologically mimic a malignant tumor, it is paramount for the radiologist to know this entity. Magnetic resonance imaging is the modality of choice to reveal the possible severe complication of ROP in the form of a compressive myelopathy of the upper cervical cord. The purpose of the surgical treatment is the regression or complete disappearance of ROP, with posterior decompression by laminectomy and posterior C1-C2 or occipitocervical fixation. We present the case of an elderly patient with retroodontoid soft tissue mass secondary to a chronic atlantoaxial instability on os odontoideum, an extremely rare cause of ROP. The patient developed a posttraumatic cervical myelopathy related to the decompensation of this C1-C2 instability responsible for the formation of a compressive ROP. We will overview the retroodontoid pseudotumor and its differential diagnosis.

Spontaneous regression of retro-odontoid post traumatic cicatrix following occipitocervical fixation

This case report describes a patient who presented with myelopathy secondary to a large retro-odontoid post traumatic cicatrix. The objective of this study was to discuss the clinical presentation, pathogenesis, imaging, and surgical management of pseudoarthrosis tissue mass associated with odontoid nonunion. Atlantoaxial subluxation (AAS) has been widely reported in patients with rheumatoid arthritis. AAS leads to repeated cycles of partial tear and repair of ligaments around the altantoaxial complex, resulting in the formation of periodontoid mass (pseudotumor). It is thought that formation of retro-odontoid post traumatic mass (cicatrix), in certain cases of odontoid fracture, is because of similar pathology. This is a retrospective review of case note. Here, the patient underwent posterior decompression through a C1-C2 laminectomy and occipitocervical (C0-C4) fusion with instrumentation, which resulted in dramatic improvement in his symptoms and spontaneous regression of retro-odontoid post traumatic cicatrix. We have described an interesting and a rare case of a large pseudoarthrosis tissue mass associated with odontoid nonunion, which regressed following stand-alone posterior instrumentation. To the best of our knowledge, only a handful of such cases of spontaneous regression of retro-odontoid post traumatic cicatrix following occipitocervical fixation have been described in literature, and our case adds to the growing list of such cases and may help in understanding the natural history of the disease process one day. Although rare, post traumatic cicatrix should be considered as a differential diagnosis of enhancing retro-odontoid mass, especially if there is any history of cervical spine trauma.

Is Hypoglossal Nerve Palsy Caused by Craniocervical Junction Degenerative Disease an Underrecognized Entity?

Isolated hypoglossal nerve palsy is uncommon, and underlying craniocervical junction degenerative disease has rarely been reported as an underlying cause. To improve understanding of this entity, we present a retrospective series of 18 patients with hypoglossal palsy in whom twelfth cranial nerve compression within the premedullary cistern or hypoglossal canal, or both, was found secondary to craniocervical junction juxta-articular cysts, retro-odontoid fibrous pseudotumors, and osteophytes. The imaging techniques and characteristic craniocervical junction degenerative disease lesion imaging findings presented here might help clinicians interpreting hypoglossal palsy imaging studies avoid perceptual and interpretive errors commonly found in the present series.

Myelopathy due to multilevel cervical canal stenosis with Forestier disease: case report

A 56-year-old woman presented with multilevel myelopathy associated with Forestier disease (FD). The patient was hospitalized for dysphagia, bilateral shoulder pain, and progressive gait disturbance. The diagnosis was confirmed by radiography and magnetic resonance imaging which demonstrated coalescent anterior osteophyte formation extending from C2 to C7 with atlanto-axial dislocation and persistence of mobility at C3-4, and a hyperintense area in the spinal cord at the C1 and C3-4 levels on T(2)-weighted images. Dynamic radiography showed no instability at the C1 and C3-4 levels. Decompressive laminectomy of the atlas, dome-like laminectomy, and facet fusion at C3-4 were performed, resulting in symptomatic improvement. Myelopathy is very rare in patients with FD and is due to mechanical stress at the level where mobility persists. Strategic intervention should be considered based on evaluation of mobile levels and stenotic lesions.

A case of foramen magnum syndrome caused by atlanto-occipital assimilation with intracanal fibrosis

We describe a case of foramen magnum syndrome secondary to atlanto-occipital assimilation with spinal-cord compression caused by retro-odontoid fibrous pannus. Association of atlanto-occipital assimilation with the occurrence of severe neurological symptoms resulting from upper spinal cord compression remains rare in the literature. The embryonic process leading to this malformation is discussed. The anatomy and pathogenesis of this syndrome are described.

Cervical myelopathy caused by soft-tissue mass in diffuse idiopathic skeletal hyperostosis

A rare case of cervical spinal cord compression in diffuse idiopathic skeletal hyperostosis (DISH or Forestier's Disease) caused by a craniocervical mass of soft-tissue is reported. The objective is to describe an uncommon mechanism of spinal cord compression in DISH. Three weeks after a cardiac infarction a 69-year-old man slowly developed spastic tetraparesis. Magnetic resonance tomography showed a craniocervical tumor compressing the spinal cord and a massive DISH of the cervical spine. An extended mass of yellowish amorphous material was removed from between the dura, the posterior odontoid process and the posterior aspect of vertebral body C2 reaching to the upper part of C3.The histologic appearance indicated connective tissue and cell-degenerated cartilaginous tissue. There was no inflammatory component and no evidence of neoplasia. No ossification of the posterior longitudinal ligament (OPLL) was found. After removal and craniocervical stabilization the patient's neurologic function improved remarkably. The increase of mechanical stress on the atlantoaxial segment and enhanced proliferation reaction of the connective tissue in DISH are suggested as the underlying pathomechanisms in the formation of this soft-tissue mass.

Myelopathy by lesions of the craniocervical junction in a patient with forestier disease

STUDY DESIGN

The authors report a case of a patient with diffuse idiopathic skeletal hyperostosis (DISH) associated with basilar impression resulting in tetraparesis.

OBJECTIVE

To describe neurologic compromise associated with DISH.

SUMMARY OF BACKGROUND DATA

Neurologic deficits due to DISH are very rare, and only 1 case of basilar impression associated with DISH has previously been reported in the literature.

METHODS

Diagnosis was confirmed by radiograph and MRI, which demonstrated basilar impression associated with a hyperintense signal in the spinal cord on T2-weighted sequences. Transoral resection of the dens associated with posterior occipitocervical fixation was performed during the same anesthesia.

RESULTS

Postoperative outcome demonstrated regression of the pyramidal signs without recovery of unassisted walking.

CONCLUSION

Early MRI should be performed in the evidence of spinal cord suffering in patients with DISH. Transoral approach allowed a good decompression of the spinal cord.

[Surgical management of cervical radiculopathy in Forestier's disease. Case report and review]

Forestier's disease now called DISH (diffuse idiopathic skeletal hyperostosis) is a non inflammatory enthesopathy ossifying the anterolateral spine and sparing the disc and joint space in elderly men, mostly at thoracic levels. Radiology performed for minor trauma or to explore a stiff neck provides the diagnosis. The main differential diagnosis is ankylosing spondylitis presenting an inflammatory profile as well as previously existing alterations of the sacroiliac joint. Retinoic acid treatment or ossification of the posterior longitudinal ligament should also be discussed. Dysphagia is the most frequent symptom, but neurological signs are rarely observed. We report a case observed at the cervical level. Anterior decompression and cage-fusion was indicated. Ongoing hyperostosis was also documented. Surgery in DISH is mainly indicated for dysphagia and rarely after cervical trauma. Of note are associated lesions such as OPLL (ossification of the posterior longitudinal ligament) or synovial cysts responsible for the exceptional and severe myelopathy presentation. The neurosurgical community should become better aware of Forestier's disease.

Periodontoid pseudotumor: CT and MRI imaging

Periodontoid pseudotumor (PP) can be a severe and disabling disease. This disease process typically presents in elderly patients with a longstanding history of myelopathy. We reviewed four cases of PP in order to summarize the clinical and imaging features.