Periodontoid calcium pyrophosphate dihydrate deposition disease: "pseudogout" mass lesions of the craniocervical junction

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.

Case Report: Posterolateral Epidural Supra-C2-Root Approach (PESCA) for Biopsy of a Retro-Odontoid Lesions in Same Sitting After Occipitocervical Fixation and Decompression in a Case of Crowned Dens Syndrome With Brainstem Compression and Displacement

Background

‘Crowned dens syndrome' (CDS) is a special form of calcium pyrophosphate dihydrate deposition disease which is characterized radiologically by a halo-like or crown-like distribution in the periodontoid region and clinically by cervical pain. Herein, we will describe our experience of posterolateral epidural supra-C2-root approach (PESCA) for biopsy of retro-odontoid lesions in one surgical session after occipitocervical fixation and decompression in a patient with CDS and massive brainstem compression.

Case Presentation

A 70-year-old woman presented to our department with a 4-week history of progressive walking impairment, neck pain, neck rigidity, fever, dizziness, slight palsy of the left hand, and multiple fall episodes. Magnetic resonance imaging (MRI) of the craniovertebral junction (CVJ) and cervical spine revealed a lesion of the odontoid process and the retro-odontoid region with mainly solid components, as well as small cystic components, and brainstem compression and displacement. In first step, fusion surgery of the CVJ C0–C4 was performed with occiptocervical decompression. After fusion and decompression the lower lateral part of the C1 arc and the lateral superior part of the left side of the C2 arc were removed. The entry point was located directly above the superior part of the C2 root. A biopsy of the lateral portions of the lesions was obtained by bioptic forceps under microscope guidance. Pathologic examination of the mass revealed deposition of birefringent crystals compatible with calcium pyrophosphate. In addition to the clinical symptoms (especially neck pain), the diagnosis of CDS was made. Non-steroidal inflammatory drugs (NSAIDs) and colchicine (and later magnesium) were started. At follow-up examination 6 months after surgery, an MRI scan of the cervical spine revealed regression of the pannus and the cyst with replacement of the brainstem, clinical improvement of walking, and increased strength of the left hand.

Conclusions

This study demonstrates that PESCA can be used to obtain tissue for pathological analysis in one surgical sitting after fusion and decompression and that fusion, decompression, and PESCA (in the same session) together with subsequent conservative management could be a good alternative for the treatment of CDS.

Calcium pyrophosphate dihydrate crystal deposition disease and retro-odontoid pseudotumor rupture managed via posterior occipital cervical instrumented fusion: illustrative case

BACKGROUND

Craniocervical junction and subaxial cervical spinal manifestations of calcium pyrophosphate deposition disease are rarely encountered. The authors presented a severe case of retro-odontoid pseudotumor rupture causing rapid quadriparesis and an acute comatose state with subsequent radiographic and clinical improvement after posterior occipital cervical fusion.

OBSERVATIONS

The authors surveyed the literature and outlined multiple described operative management strategies for compressive cervical and craniocervical junction calcium pyrophosphate deposition disease manifestations ranging from neck pain to paresthesia, weakness, myelopathy, quadriparesis, and cranial neuropathies. In this report, radiographic features of cervical and craniocervical junction calcium pyrophosphate deposition disease were explored. Several previously described surgical strategies were compiled, including patient characteristics and outcomes.

LESSONS

With this case report, the authors presented for the first time an isolated posterior occipital cervical fusion for treatment of a compressive retro-odontoid pseudotumor with rupture into the brainstem. They demonstrated rapid clinical and radiographic resolution after stabilization of cranial cervical junction only 12 weeks postsurgery.

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.

Symptomatic retro-odontoid pseudotumor causing calcium pyrophosphate dihydrate deposition combined with multilevel cervical spondylotic myelopathy

Introduction

Symptomatic retro-odontoid pseudotumor (ROP) caused by cervical compression and myelopathy is rare. Pathological diagnosis is recommended for differential diagnosis including the following: inflammatory disease, primary bone tumor, metastatic disease and calcium pyrophosphate dihydrate deposition (CPPD) also known as “crowned dens syndrome”. The authors report a rare case of ROP caused by CPPD deposition combined with multilevel cervical spondylotic myelopathy (MCSM) which was treated by tumor resectioning using a transoral approach combined with posterior decompression and fusion.

Case presentation

A 66-year-old male presented with progressive neck pain and spastic gait with no history of trauma. Radiographic imaging revealed degenerative change involving the atlanto-axial and atlanto-occipital joints with calcified enhancing soft tissue around the odontoid process causing cord compression and cervical instability at the C1-C2 level combined with MCSM and spinal cord compression at C3 to C7. Microscopic assisted transoral tumor resection combined with posterior decompression and fusion was performed at the occiput to T2. The pathology report describes a rhomboid-shaped crystal caused by calcium pyrophosphate dihydrate deposition (CPPD) disease. At the 6-month follow-up following the operation, the patient's neck pain and spastic gait were improved compared to the preoperative examination.

Discussion

Cervical compression and myelopathy from ROP causing CPPD combined with MCSM is rare. Pathology diagnosis and surgical management are highly recommended.

Conclusion

In this case, a combined surgical approach: tumor resection using a transoral approach and a posterior approach for decompression and fusion at occiput to T2 was an effective option for this condition.

•

Symptomatic retro-odontoid pseudotumor (ROP) caused by calcium pyrophosphate dihydrate deposition (CPPD) combined with multilevel cervical spondylotic myelopathy (MCSM) is rare.

•

Pathology diagnosis and surgical management are highly recommended.

•

Tumor resectioning using a transoral approach and posterior approach for decompression and fusion from the occiput to T2 is an effective option.

Multilevel calcium pyrophosphate dihydrate deposition in cervical ligamentum flavum: clinical characteristics and imaging features

BACKGROUND

Involvement in cervical ligamentum flavum is a rare manifestation of the calcium pyrophosphate dihydrate deposition disease. Only few cases of this condition have been reported. We revealed eighteen cases of CPPD in cervical ligamentum flavum that diagnosed at a single medical center. In our case series, clinical characteristics and magnetic resonance imaging findings of patients are described.

METHODS

We retrospectively reviewed the medical charts and imaging studies of the eighteen patients with pseudogout attack of the cervical ligamentum flavum. In addition, we discussed the differences between this disease and ossification of ligamentum flavum in image manifestations.

RESULTS

There were fourteen men and four women aged between 59 and 87 years. Diabetes mellitus and hypertension were the most common comorbidities. Myelopathy and neck pain were presented in most patients. C4-5 and C5-6 were attacked most frequently, and multiple- rather than single-level involvement could be observed in our series. "Acute on chronic phenomenon" was a specific magnetic resonance image finding in patients whose symptom durations were between 2 to 5 months. Compared to ossification of ligamentum flavum, calcium pyrophosphate dihydrate crystal deposition had different image signs, including morphology, side of the involved ligament, no continuity with the lamina, acute on chronic phenomenon, and presence of retro-odontoid mass.

CONCLUSIONS

Nodular calcifications in cervical ligamentum flavum raise highly suspicion for calcium pyrophosphate dihydrate deposition and must be diagnosed by histological examination and polarized light microscopy. This disease is different from ossification of ligamentum flavum, and it could be recognized by specific image features.

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.

Cervical myelopathy due to subaxial calcium pyrophosphate dihydrate (CPPD) deposition with simultaneous asymptomatic crowned dens syndrome: two case reports

Background

There are few reports of cervical myelopathy caused by an attack of subaxial calcium pyrophosphate dihydrate (CPPD) deposition. Moreover, there has been no report on cervical myelopathy by subaxial CPPD deposition with simultaneous asymptomatic crowned dens syndrome (CDS) at the same time.

Case presentation

The first case was a 68-year-old male complaining of cervical myelopathic symptoms. Plain radiographs, computed tomography (CT) and magnetic resonance imaging (MRI) findings revealed spinal cord compression by calcified round lesions at C4 as well as a calcified lesion behind the dens. The second case was a 77-year-old female complaining of cervical myelopathic symptoms. Plain radiographs, CT and MRI findings revealed spinal cord compression by calcified round lesions at C3 and C4 as well as a calcified lesion behind the dens. In both cases, we believed that the calcified lesion behind the dens was an asymptomatic lesion. Therefore, the first patient received decompressive laminectomy of C3 and C4, removal of calcified round lesions, and posterior fixation from C3 to C5 due to associated kyphosis. The second patient underwent decompressive laminectomy of C3 and C4 and removal of calcified round lesions. Microscopic examination under polarized light showed dark blue calcifications with rhomboid crystals that were positively birefringent. The findings were consistent with those of CPPD.

Conclusions

This is the first study to report cervical myelopathy caused by subaxial CPPD deposition with simultaneous asymptomatic CDS. Surgical removal of the subaxial CPPD deposition alone achieved a satisfactory surgical outcome without recurrence.

Radiological identification and analysis of soft tissue musculoskeletal calcifications

Abstract

Musculoskeletal calcifications are frequent on radiographs and sometimes problematic. The goal of this article is to help radiologists to make the correct diagnosis when faced with an extraosseous musculoskeletal calcification. One should first differentiate a calcification from an ossification or a foreign body and then locate the calcification correctly. Each location has a specific short differential diagnosis, with minimal further investigation necessary. Intra-tendon calcifications are most frequently associated with hydroxyapatite deposition disease (HADD). In most cases, intra-articular calcifications are caused by calcium pyrophosphate dihydrate (CPPD) crystal deposition disease. Soft tissue calcification can be caused by secondary tumoural calcinosis from renal insufficiency, or collagen vascular diseases and by vascular calcifications, either arterial or venous (phlebolith).

Teaching Points

• Calcifications have to be differentiated form ossification and foreign body.

• A musculoskeletal MRI study must always be correlated with a radiograph.

• The clinical manifestations of calcifications may sometimes mimic septic arthritis or sarcoma.

• HADD and CPPD crystal deposition have a distinct appearance on radiograph.

• Calcinosis is more frequently caused by chronic renal failure and scleroderma.

Transdural approach to resection of retro-odontoid cysts in elderly patients: report of 3 cases

Retro-odontoid cysts that arise from the tectorial membrane are uncommon lesions that can occur in elderly patients. They arise secondary to degenerative changes, including calcium pyrophosphate deposition within the ligaments. Surgical treatment is indicated when these lesions result in intractable pain, instability, and/or myelopathy. Several surgical techniques to treat this condition exist, but the optimal approach in elderly patients with comorbidities remains controversial. Here, the authors present a case series of 3 patients who underwent successful resection of a retro-odontoid lesion performed through a transdural approach.

The patients were 70, 81, and 74 years old and presented with symptoms of cervical myelopathy. In consideration of their advanced age and the location of their lesion, resection via a posterior approach was considered. A 1- to 2-cm suboccipital craniectomy and C-1 and partial C-2 laminectomy were performed. These lesions could not be accessed via an extradural posterolateral approach, and so a transdural approach was performed. In the first 2 patients, a preexisting deformity prompted an instrumented fusion. In the third patient, only a lesion resection was performed. In each case, the dural opening was made using a paramedian ipsilateral-sided incision, and the lesion was resected through an incision in the anterior dura mater. Only the posterior dura was closed primarily. MR imaging evidence of excellent spinal cord decompression was evident in follow-up examinations.

Transdural resection of retro-odontoid cysts is a viable option for treating asymmetrical ventral extradural cysts. Results from this case series suggest that such an approach is safe and feasible and can provide an alternative to open or endoscopic anterior transpharyngeal approaches.

Pseudogout of the cervical and thoracic spine mimicking infection after lumbar fusion: case report

Pseudogout is a form of acute calcium pyrophosphate deposition (CPPD) disease that typically afflicts the elderly. CPPD commonly involves larger joints, such as the knees, wrists, shoulders, and hips, and has been known to involve the spine. The authors report the case of a 66-year-old woman with a recent history of lumbar laminectomy and fusion who presented 5 weeks postprocedure with a clinical and radiographic picture consistent with multilevel skip lesions involving the cervical and thoracic spine, thoracic discitis, and epidural abscess. Serial blood cultures and repeat biopsy samples were sterile. Subsequent wrist and ankle erythema, pain, and swelling led to synovial fluid analysis, and pseudogout was diagnosed. She was treated with an interleukin-1 inhibitor with immediate symptom relief. To the authors' knowledge, this is only the second report of spinal pseudogout presenting with a clinical and radiographic picture consistent with discitis and epidural abscess. This report is the first to report skip lesions of pseudogout occurring throughout the spine that are uniquely remote from a recent lumbar surgery.

Posterior C1-C2 calcium pyrophosphate dihydrate crystal deposition disease

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease rarely occurs in the posterior aspect of the craniocervical junction (CCJ). To the best of our knowledge, there have been only 2 previously reported cases of patients with posterior CPPD lesions in this region that have led to cervical myelopathy. We report the case of a 70-year-old man presenting with neck pain and cervical myelopathy with multilevel stenosis from C1-C6. The stenosis was worst at C1-C2, secondary to compression by a CPPD lesion posterior to the spinal cord. The patient underwent a C2-C6 laminectomy and fusion with resection of the CPPD lesion. In this report, we discuss the patient and present a novel theory to explain the preponderance of CPPD lesions in the CCJ occurring anteriorly and not posteriorly to the spinal cord.

Recurrent Craniocervical Pseudogout: Indications for Surgical Resection, Surveillance Imaging, and Craniocervical Fixation

BACKGROUND

Calcium pyrophosphate dihydrate (CPPD) crystallization is known to occur in the spine, leading to the development of visible calcification as seen by imaging. Occasionally, the deposition of this material can lead to larger accumulations that are seen as masses in the articular processes, intervertebral discs, and posterior longitudinal ligaments. A particularly significant manifestation of this process is at the craniocervical junction, where symptomatic presentations can arise.

CLINICAL PRESENTATION

 A 74-year-old woman presented after several falls from standing, complaining of leg and arm weakness. Imaging revealed a mass arising from the C1-C2 articulation dorsal to the dens, extending to the clivus. The mass compressed the medulla and cervicomedullary junction.

INTERVENTION

The patient underwent a left, far lateral craniotomy with C1 laminectomy to approach the cervicomedullary junction. The mass was cyst-like and contained scattered crystals and amorphous material consistent with pseudogout. There were no cells with an elevated Ki-67 index. The patient's symptoms and exam improved at follow-up two months later. However, seven months after surgery, she declined once again and was found to have a recurrence.

CONCLUSION

A subtotal resection of pseudogout may lead to recurrence. The recurrence can occur in a rapid fashion. Serial MRIs are indicated following resection. Occipitocervical fusion could reduce the likelihood of recurrence in such cases.

Pseudogout of the Transverse Atlantal Ligament: An Unusual Cause of Cervical Myelopathy

Background:

Calcium pyrophosphate dihydrate deposition in the cervical spine is infrequently symptomatic. This is especially true at the craniocervical junction and upper cervical spine.

Case Report:

A 70-year-old previously healthy woman presented with a progressive cervical myelopathy of four months duration.

Results:

Examination revealed sensorimotor findings consistent with an upper cervical myelopathy. Radiological studies (plain radiographs, computed tomography, and magnetic resonance imaging) revealed C1-2 instability, and a well-defined extradural 3cm x 1cm retro-odontoid mass causing spinal cord compression. Transoral resection of the mass was performed followed by posterior C1-2 stabilization. Histological examination of the mass confirmed calcium pyrophosphate dihydrate deposition. Follow-up examination showed marked clinical and radiological improvement.

Conclusion:

Although uncommon, calcium pyrophosphate dihydrate deposition disease should be considered in the differential diagnosis of extradural mass lesions in the region of the odontoid.

Acute neck pain caused by arthritis of the lateral atlantoaxial joint

BACKGROUND CONTEXT

Many diseases can cause acute neck pain in elderly individuals. We conducted the present prospective study based on the hypothesis that arthritis of the lateral atlantoaxial joint may be involved in acute neck pain in elderly patients with limited neck rotation.

PURPOSE

To clarify whether the lateral atlantoaxial joint is involved in acute neck pain among elderly individuals by conducting lateral atlantoaxial joint puncture.

STUDY DESIGN

A prospective study.

PATIENT SAMPLE

Twenty-seven patients (13 men, 14 women) aged 50 years or more who provided consent for atlantoaxial joint puncture met the following four inclusion criteria: acute neck pain with limited cervical rotation of less than 20° as the chief complaint; visual analog scale pain score of 70 mm or more at initial visit; tenderness in the paraspinal muscle of upper cervical vertebrae; and serum C-reactive protein level of 0.5 mg/dl or more.

OUTCOME MEASURES

Visual analog scale pain score and radiologic findings.

METHODS

Patients underwent puncture of the lateral atlantoaxial joint and were evaluated clinically and radiologically.

RESULTS

Computed tomography obtained before puncture showed calcification of the transverse ligament of the atlas in the posterior dens in 22 patients (81.5%), calcification in the longus colli in 2 patients (7.4%), and no calcification in 3 patients (11.1%). Of 27 patients who underwent lateral atlantoaxial joint puncture, joint fluid was collected from 16 patients (59.3%) and calcium pyrophosphate dihydrate crystals were identified in 10 patients (62.5%). For the entire patient population, mean VAS score before puncture was 81.9±16.3 mm, significantly improving to 35.6±24.4 mm by 30 minutes after puncture (p<.001).

CONCLUSIONS

The results of this study suggest that crystal-induced arthritis (pseudogout) of the lateral atlantoaxial joint may be closely involved with acute neck pain in the elderly.

Retro-odontoid calcium pyrophosphate dehydrate deposition: surgical management and review of the literature

Study Design Case report and review of the literature.

Objective A retro-odontoid mass is a rare cause of cervical compression and myelopathy. The differential diagnosis includes the following: metastatic disease, primary tumor, collagen disorder, or inflammatory disease. Calcium pyrophosphate dihydrate (CPPD) deposition has been referred to as “crowned dens syndrome” when there are periodontoideal calcifications. There are only a few reported cases where CPPD presents as a cystic retro-odontoid mass in the atlanto-dens interval. In previous descriptions of surgical intervention, transoral resection of the mass is associated with significant morbidity and usually requires stabilization. The objective of this article is to report a case of an unusual presentation of CPPD disease of C1/C2, where we used a novel, minimally invasive surgical technique for decompression without fusion.

Patients and Methods An 83-year-old female patient presented with progressive cervical myelopathy over a 3-month period. Computed tomography and magnetic resonance imaging demonstrated a cystic odontoid mass with a separate retro-odontoid compressive mass. A novel, minimally invasive transoral aspiration was performed. Histologic confirmation of CPPD was obtained.

Results Postop imaging showed satisfactory decompression, which was maintained at the 6-month follow-up. This correlated with clinical improvement postop and 6-month follow-up.

Conclusion CPPD in the atlanto-dens interval may present as a cystic retro-odontoideal mass and should be included in the differential. We used a transoral minimally invasive approach to aspirate the cyst. This novel technique avoided the need for a stabilization procedure or morbid transoral resection and provided excellent results immediately and at 6 months.

A rare case of crowned dens syndrome mimicking aseptic meningitis

Background

Crowned dens syndrome (CDS), related to microcrystalline deposition in the periodontoid process, is the main cause of acute or chronic cervical pain. Microcrystal-line deposition most often consists of calcium pyrophosphate dehydrate crystals and/or hydroxyapatite crystals.

Case Presentation

This report describes the case of an 89-year-old woman who presented with sudden onset, high fever, severe occipital headache, and neck stiffness. A laboratory examination revealed a markedly elevated white blood cell count (11,100/µl) and C-reactive protein level (23.8 mg/dl). These clinical findings suggested severe infection such as meningitis with sepsis. However, the results of blood culture, serum endotoxin, and procalcitonin were all negative, and cerebrospinal fluid studies revealed only a slight abnormality. The patient was first diagnosed with meningitis and treated with antiviral and antibiotic agents as well as non-steroidal anti-inflammatory drugs, but they only had limited effects. A cervical plain computed tomography (CT) scan and its three-dimensional (3D) reconstruction detected a remarkable crown-like calcification surrounding the odontoid process. On the basis of the CT findings, the patient was diagnosed as a severe case of CDS and was immediately treated with corticosteroids. The patient's condition drastically improved within a week after one course of corticosteroid therapy.

Conclusion

Some atypical symptoms of CDS are misleading and may be misdiagnosed as meningitis, as happened in our case. A CT scan, especially a 3D-CT scan, is necessary and useful for a definitive diagnosis of CDS. CDS should be considered as a differential diagnosis of a possible etiology for fever, headache, and cervical pain of unknown origin.

Craniovertebral junction database analysis: incidence, classification, presentation, and treatment algorithms

INTRODUCTION

The initial treatment of bony lesions at the craniocervical junction consisted of posterior decompression with enlargement of the foramen and removal of the posterior arch of the atlas and axis vertebra. This was regardless of the site of compression. Needless to say, the results were poor when an irreducible ventral lesion at the craniocervical junction caused compression of the cervicomedullary area. It was predictable that an adverse outcome would occur in approximately 35-40% of patients treated with dorsal decompression with a fixed anterior abnormality at the craniovertebral junction. Thus, it became essential to identify the causes of failure and recognize the pathology as well as attempt to improve the treatment. The need to identify natural history led to a prospective database. This database now lists 5,300 patients who were analyzed. Of these, 2,000 were children and this has been reviewed here.

CRANIOVERTEBRAL ABNORMALITIES IN CHILDREN

Review of symptoms showed that children with craniovertebral abnormalities present with failure to thrive, weakness, basilar migraine, dysphagia, sleep apnea, scoliosis, and the cervical central cord syndrome. Torticollis was seen in the very young.

IMAGING TECHNIQUES AND TREATMENT FOR CRANIOVERTEBRAL ABNORMALITIES

New imaging techniques were utilized as they became available. Unexplained neurological symptoms and signs associated with craniovertebral abnormalities in children required angiography which was performed with dynamic motion studies. All children with reducible craniocervical abnormalities underwent stabilization. In irreducible abnormalities, decompression was paramount with a fusion to be done immediately. The decompression was accomplished in the direction in which encroachment occurred.

TREATMENT ALGORITHM AND CLASSIFICATION

A treatment algorithm was formulated as a result of this database and a classification of the craniovertebral abnormalities; that holds good for the entire spectrum.

Syndrome of occipitoatlantoaxial hypermobility, cranial settling, and chiari malformation type I in patients with hereditary disorders of connective tissue

OBJECT

Chiari malformation Type I (CM-I) is generally regarded as a disorder of the paraxial mesoderm. The authors report an association between CM-I and hereditary disorders of connective tissue (HDCT) that can present with lower brainstem symptoms attributable to occipitoatlantoaxial hypermobility and cranial settling.

METHODS

The prevalence of HDCT was determined in a prospectively accrued cohort of 2813 patients with CM-I. All patients underwent a detailed medical and neuroradiological workup that included an assessment of articular mobility. Osseous structures composing the craniocervical junction were investigated morphometrically using reconstructed 3D computed tomography and plain x-ray images in 114 patients with HDCT/CM-I, and the results were compared with those obtained in patients with CM-I (55 cases) and healthy control individuals (55 cases).

RESULTS

The diagnostic criteria for Ehlers-Danlos syndrome and related HDCT were met in 357 (12.7%) of the 2813 cases. Hereditability was generally compatible with a pattern of autosomal dominant transmission with variable expressivity. The diagnostic features of HDCT/CM-I were distinguished from those of CM-I by clinical stigmata of connective tissue disease, a greater female preponderance (8:1 compared with 3:1, p < 0.001), and a greater incidence of lower brainstem symptoms (0.41 compared with 0.11, p < 0.001), retroodontoid pannus formation (0.71 compared with 0.11, p < 0.001), and hypoplasia of the oropharynx (0.44 compared with 0.02, p < 0.001). Measurements of the basion-dens interval, basion-atlas interval, atlas-dens interval, dens-atlas interval, clivus-atlas angle, clivus-axis angle, and atlas-axis angle were the same in the supine and upright positions in healthy control individuals and patients with CM-I. In patients with HDCT/CM-I, there was a reduction of the basion-dens interval (3.6 mm, p < 0.001), an enlargement of the basion-atlas interval (3.0 mm, p < 0.001), and a reduction of the clivus-axis angle (10.8 degrees, p < 0.001), clivus-atlas angle (5.8 degrees, p < 0.001), and atlas-axis angle (5.3 degrees, p < 0.001) on assumption of the upright position. These changes were reducible by cervical traction or returning to the supine position.

CONCLUSIONS

The identification of HDCT in 357 patients with CM-I establishes an association between two presumably unrelated mesodermal disorders. Morphometric evidence in this cohort-cranial settling, posterior gliding of the occipital condyles, and reduction of the clivus-axis angle, clivus-atlas angle, and atlas-axis angle in the upright position-suggests that hypermobility of the occipitoatlantal and atlantoaxial joints contributes to retroodontoid pannus formation and symptoms referable to basilar impression.

Calcium pyrophosphate dihydrate crystal deposition in the craniovertebral junction

Object

Calcium pyrophosphate dihydrate (CPPD) deposition is a rare cause of retroodontoid mass lesions in elderly individuals. However, this condition may be severely underdiagnosed if sufficient attention is not paid to imaging characteristics and clinical presentation. The authors sought to evaluate the decision-making process in both the diagnosis and surgical treatment of CPPD.

Methods

A retrospective review of University of Iowa medical records and radiographs accumulated between 1977 and 2006 was performed. The inclusion criterion was histopathological findings consistent with pseudogout at the craniovertebral junction (CVJ). Twenty-one patients with a mean age of 70.3 years and a mean symptom duration prior to presentation of 17.5 months were identified and included in this study.

Results

The patients presented most frequently with occipital and neck pain (85%) and numbness or paresthesias (61%). Lower cranial nerve deficits were seen in 29%. Calcification of the mass or transverse ligament was seen on computed tomography in all included patients. Gross-total resection was achieved in all patients: 19 of 21 patients underwent transoral–transpalatopharyngeal resection, with only 16 requiring concomitant dorsal occipital–cervical fusion. The mean follow-up duration was 15 months. Eighteen patients (86%) had improvement or resolution of symptoms after treatment, and 3 were lost to follow-up.

Conclusions

Although rare, CPPD deposition at the CVJ should be suspected on finding calcification of and around the transverse ligament on neuroimaging. Transoral–transpalatopharyngeal resection is preferred to halt the progression of neurological deterioration; dorsal fusion is not always mandatory as concomitant ligamentous calcification and atlantoaxial joint ankylosis may provide added stability.

Calcium pyrophosphate dihydrate deposition in the transverse ligament of the atlas: an unusual cause of cervical myelopathy

A 75-year-old male presented with progressive myelopathy due to massive retro-odontoid deposits of calcium pyrophosphate dehydrate (CPPD) crystals. Magnetic resonance imaging revealed a non-enhanced isointense extradural mass on a T1-weighted image and a heterogeneous intense mass on a T2-weighted image. Computed tomography (CT) showed linear calcification within the mass. The mass was resected via a posterolateral approach resulting in marked improvement of the symptoms. Histological examination revealed birefringent rhomboid crystals consistent with CPPD. The preoperative differential diagnosis of periodontoid CPPD deposition disease in the elderly population should be considered, particularly if CT studies demonstrate small areas of calcification within the retro-odontoid mass.

Cervicomedullary compression secondary to massive calcium pyrophosphate crystal deposition in the atlantoaxial joint with intradural extension and vertebral artery encasement

BACKGROUND

Deposition of CPPD crystals occurs in the fibrous and hyaline cartilage of the joints and intervertebral disks of the spine. Half of patients known to have chondrocalcinosis had asymptomatic calcification in the odontoid region. The cases of 12 patients with a spinal cord syndrome secondary to CPPD deposition in the odontoid region were published in the literature. In all those cases, the mass lesion was extradural in location with good outcome after surgical decompression via the transoral route.

CASE DESCRIPTION

We report on a rare case of large periodontoid CPPD deposition causing cervicomedullary compression, erosion of the overlying bone, and underlying dura with intradural extension and vertebral artery encasement.

CONCLUSIONS

Calcium pyrophosphate dihydrate is a rare cause of cervicomedullary compression. Intradural extension of periodontoid CPPD has not been reported on.

Atlas Hypoplasia Associated With Non-traumatic Retro-odontoid Mass

A 38-year-old man presented with progressive cervical myelopathy due to atlas hypoplasia associated with non-traumatic retro-odontoid mass. The neuroimaging findings suggested hypertrophy of the transverse ligament of the atlas. No histological confirmation of the retro-odontoid mass was obtained. Clinical manifestations improved after posterior decompression. Decompressive laminectomy of the atlas with or without fusion can achieve a good outcome in such cases.

Cervical myelopathy induced by pseudogout in ligamentum flavum and retro-odontoid mass: a case report

STUDY DESIGN

Retrospective case study.

OBJECTIVES

Report a rare case of cervical myelopathy induced by calcium pyrophosphate dehydrate (CPPD) deposition in multiple cervical levels.

SETTING

An area teaching hospital in Taiwan.

METHOD

A patient with cervical myelopathy was evaluated by computerized tomography (CT) scan and magnetic resonance (MR) image. CPPD deposition known as pseudogout was diagnosed and approved by a polarized microscope.

RESULT

A prominent hypertrophy of ligmentum flavum and a retro-odontoid bulging mass induced cord compression were found in CT scan and MR image. CPPD deposition was confirmed by the histological examinations in the ligamentum flavum at the spinal levels of C3-C6. After decompression surgery of spine and comprehensive rehabilitation, the patient's neurological symptoms subsided and her neurological functions improved leading to a good prognosis.

CONCLUSION

CPPD deposition in cervical spine occurring at multiple levels is rare. Image studies with CT scan and MR are complementary in the diagnosis of CPPD-induced myelopathy. Surgical decompression is always required and expected to have a good outcome.

Pseudogout showing meningoencephalitic symptoms: crowned dens syndrome

We report a 70-year-old man who presented symptoms resembling those of meningoencephalitis and who was subsequently diagnosed as having a crowned dens syndrome. The patient exhibited severe neck pains, headache, high fever and a pain in his knee joints together with symptoms of the central nervous system. The patient's cerebrospinal fluid was almost clear and showed no sign of viral infection. An analysis of the synovial fluid in the right knee joint revealed typical calcium pyrophosphate dehydrate crystal deposition and a diagnosis of pseudogout was therefore made. A tomographic examination of the neck showed periodontoid calcification. The patient was first treated with non-steroidal anti-inflammatory drug, but its effect was only minimal. On the other hand, the administration of corticosteroid resulted in a dramatic improvement in his condition.

Primary amyloidoma of the axis and acute spinal cord compression: a case report

BACKGROUND

Localized primary amyloidosis is a disease characterized by a single tumor and localized amyloid deposit (amyloidoma) with no evidence of generalized amyloidosis. The occurrence of an amyloidoma in the spine is rare and only three cases affecting the axis have been previously reported. We describe the case of a 79-year-old woman presenting with a mass involving the odontoid process, responsible for an acute tetraparesia. Diagnosis of local primary amyloidosis was made after surgical excision.

RESULTS

Despite the critical presentation, outcome was excellent after total excision of the mass. This case can be classified as a primary localized amyloidoma. The patient did not exhibit any infection, tumor or inflammatory disease, and continued investigations failed to demonstrate other amyloid deposit after one-year follow-up.

CONCLUSIONS

Amyloidoma must be discussed in presence of a tumor-like mass of the odontoid process and may be responsible, as in our case, for spinal cord compression.

Tumoral calcium pyrophosphate dihydrate deposition disease of the ligamentum flavum

OBJECTIVE

Calcium pyrophosphate dihydrate (CPPD) deposition disease (CPPDD), also known as pseudogout, is rarely known to affect the spine. The purpose of this article is to report our experience with six cases involving massive focal deposition of CPPD crystals in the ligamentum flavum.

METHODS

Between January 1998 and June 2002, we treated six patients with CPPDD involving the ligamentum flavum of the cervical and thoracic spine. Their ages ranged from 45 to 70 years. There were five female patients and one male patient. The cervical spine was involved in two cases and the thoracic spine in four. All except one patient presented with an insidious onset of myelopathy. The remaining patient presented with paraplegia after trauma. None of the patients exhibited any systemic features of CPPDD or other metabolic conditions that can lead to CPPD deposition. Plain x-rays often yielded inconclusive results. Computed tomography and magnetic resonance imaging were useful in confirming the diagnoses. Decompressive laminectomy, with removal of the ossified ligamenta flava, was performed for all patients. Polarized-light microscopic examinations of the excised ligamenta flava revealed the characteristic rod-shaped, birefringent crystals.

RESULTS

Five of the six patients experienced significant improvements in their myelopathic symptoms after surgery. The remaining patient experienced improvements in sensations but no appreciable improvement in motor power. During the follow-up periods, which ranged from 7 months to 3 years, none of the patients presented with a recurrence of CPPD crystal deposition at the previously treated level. However, one patient who exhibited improvement after surgery presented 2 years later with a recurrence of myelopathic features attributable to ossification of the ligamentum flavum at a new level.

CONCLUSION

Tumoral CPPDD of the ligamentum flavum is rare. It commonly occurs among middle-age or elderly female patients and presents with progressive myelopathy. Computed tomography and magnetic resonance imaging are complementary in the diagnosis of this condition. Surgery, if performed early, leads to good improvement. However, long-term follow-up monitoring of these patients is necessary, because surgery provides only symptomatic relief and does not treat the underlying disease. With the increasing availability of magnetic resonance imaging, ossification of the ligamentum flavum is being more frequently recognized. In every case of ossified ligamentum flavum, the excised specimen should be examined with polarized-light microscopy. We think that this simple, inexpensive method will lead to the recognition of more cases of spinal CPPDD.

Tumoural calcium pyrophosphate dihydrate crystal deposition disease presenting clinically as a malignant soft tissue mass diagnosed on fine needle aspiration biopsy

Tumoural calcium pyrophosphate dihydrate crystal deposition is a rare manifestation of calcium pyrophosphate deposition disease (CPPD). We present the case of a 75-year-old male with a previously resected rectal adenocarcinoma who developed a 5-cm right-sided mass at the base of his neck. Clinically and radiologically the lesion was suspicious for malignancy, possibly of metastatic origin. A bedside fine needle aspirate was performed and the smears were mildly cellular showing histiocytes with numerous intracellular and extracellular crystals. These colourless crystals were mostly short and rhomboid shaped and demonstrated weakly positive birefringence. A diagnosis of tumoural CPPD was made. This case is only the second in the English literature diagnosed on fine needle aspiration biopsy. Tumoural CPPD is well known to be a clinical, radiological and occasionally pathological mimic of malignancy. Several cases have been reported where unnecessary radical surgery was performed for this condition. Fine needle aspiration biopsy, as in this case, can provide a rapid and accurate diagnosis of CPPD, avoiding the need for invasive procedures. Polarisation microscopy is a vital adjunct to confirm this diagnosis.

Forestier disease associated with a retroodontoid mass causing cervicomedullary compression

OBJECT

Forestier Disease (FD) is a progressive skeletal disorder affecting predominantly older men. It is also known as diffuse idiopathic skeletal hyperostosis (DISH) and is characterized by massive anterior longitudinal ligament calcification that forms a bridge on the anterior border of the thoracic and subaxial cervical spine. To the authors' knowledge, retroodontoid masses associated with FD have not been described.

METHODS

Five patients with FD and multilevel subaxial cervical fusion were treated for retroodontoid masses and cervicomedullary junction (CMJ) compression. There were four men and one woman (mean age 73 years, range 54-86 years). All patients suffered progressive neurological symptoms resulting from anterior compression of the CMJ. Four patients underwent combined transoral resection of the ligamentous mass followed by an occipitocervical fusion procedure. One patient with circumferential CMJ compression underwent a posterior decompression and occipitocervical fusion. Histopathological examination of the mass showed hypertrophic degenerative fibrocartilage. Early postoperative neurological improvement was noted in all patients. The follow-up period ranged from 4 to 19 months. At the end of the follow-up period, four patients experienced neurological improvement. One patient died 3 weeks postsurgery of pulmonary complications.

CONCLUSIONS

The osseous elements of the occipitoatlantoaxial complex are not directly affected by FD. The ligamentous structures of the odontoid process, however, are exposed to significantly altered biomechanics resulting from fusion of the subaxial cervical spine associated with FD. Stress-induced compensatory ligamentous hypertrophic changes at the craniovertebral junction cause CMJ compression and subsequent neurological deterioration. This previously undescribed entity should be considered in patients with FD or DISH who present with progressive quadriparesis. Transoral decompression and posterior fusion are often needed in patients with large masses and severe progressive neurological deficits. Selected patients with smaller masses and milder neurological symptoms may be treated with posterior fusion alone.

Tumoral calcium pyrophosphate dihydrate crystal deposition disease. A clinicopathologic analysis of five cases

We describe five cases of tumoral calcium pyrophosphate dihydrate crystal deposition disease (CPPDCD) and discuss the clinical, radiological and pathological features. Patients included 4 males and 1 female, ranging in age from 49 to 70 years (median, 63 yrs). The wrist was involved in two patients. The thumb, palmar aspect of the proximal phalanx of the middle finger and dorsum of the carpal bone of the hand were involved in one patient each. In one patient, a preoperative diagnosis of chondrosarcoma had been made. Macroscopically, the lesion was a circumscribed whitish-gray mass with a more or less chalky appearance, measuring between 1.0 to 6.2 cm (median, 2.5 cm). Histologically, all five lesions contained areas of calcification with crystal deposits and chondroid metaplasia. The majority of crystals were rhomboid in shape, characteristic of CPPD, but some needle-shaped crystals were also identified, which resembled urate crystals. A review of the 54 reported cases of tumoral CPPDCD including our series indicated that they could be divided into two categories based on anatomic location: central (head and neck) type (n = 33) and distal (extremity) type (n = 21). Patients of these two groups were not different with respect to age and gender, but those with the central type often presented with a painful mass (15 patients, 46%), or neurological disturbances (11 patients, 33%). Patients with the distal type presented with a painless mass or swelling (12 patients, 57%), but none had neurological signs, although 8 (38.1%) presented with acute attack similar to tophaceous gout. Tumoral CP-PDCD should be differentiated from tophaceous gout, tumoral calcinosis, and malignant or benign tumors.

Foramen magnum syndrome secondary to calcium pyrophosphate crystal deposition in the transverse ligament of the atlas

STUDY DESIGN

This report illustrates two rare cases of foramen magnum syndrome caused by a retro-odontoid mass in which calcium pyrophosphate dihydrate crystals were found.

OBJECTIVES

To analyze the preoperative studies and the diagnostic criteria and to discuss the surgical treatment. The present cases will be compared with previous ones described in the literature.

SUMMARY OF BACKGROUND DATA

Deposition of calcium pyrophosphate dihydrate crystals occurs into the fibrous and hyaline cartilage of the joints and intervertebral discs of the spine. Half of the patients known to have a chondrocalcinosis had asymptomatic calcification in the odontoid region. Ten patients were published in the literature as having a spinal cord syndrome secondary to calcium pyrophosphate dihydrate deposition in the odontoid region.

METHODS

In both cases the preoperative studies were analyzed, and the retro-odontoid mass was resected and histologically examined. Both had an anterior transoral approach and have been followed for 1 year.

RESULTS

According to the preoperative radiographs the diagnosis was suspected and confirmed histologically. Transoral approach was done with no need in either case for a posterior stabilization.

CONCLUSIONS

Compression of the spinal cord by calcium pyrophosphate dihydrate deposition may occur. The preoperative diagnosis may be highly suspected after radiographic study and histologically confirmed. Transoral resection is the treatment of choice. Posterior stabilization should be considered only in cases of craniovertebral instability.

Magnetic resonance imaging in rheumatic disorders of the spine and sacroiliac joints

OBJECTIVE

To review the value of magnetic resonance imaging (MRI) in diagnosis and evaluation of rheumatic diseases of the spine and sacroiliac joints.

METHODS

A review of the literature on MRI of the spine and sacroiliac joints in rheumatoid arthritis (RA), ankylosing spondylitis (AS), infectious spondylodiscitis, infection of the sacroiliac joint (SIJ), gout, calcium pyrophosphate deposition disease, nontraumatic vertebral compression fractures, insufficiency fracture of the sacrum, avascular necrosis of the vertebral body, sarcoidosis, and Paget's disease was performed. The reports were obtained from a Medline search.

RESULTS

In RA, AS, and crystal deposition disease, synovial tissue, atlantoaxial and subaxial subluxations, crystal deposition, and neurologic compromise can be adequately diagnosed with MRI of the cervical spine. Studies on MRI of SIJs in AS indicate that MRI enables early diagnosis of sacroiliitis. In most cases of infectious spondylodiscitis, avascular necrosis of the vertebral body, nontraumatic vertebral compression fractures, and insufficiency fractures of the sacrum characteristic findings on MRI suggest the correct diagnosis. Moreover, soft tissue abnormalities and neurologic compromise can be visualized. In infection of the SIJ, MRI shows findings suggesting an inflammatory process. In Paget's disease, MRI does not provide additional information as compared with plain radiography (PR) or computed tomography (CT).

CONCLUSION

In evaluation of spinal and SIJ abnormalities in many rheumatic diseases, MRI, in addition to PR, can replace conventional tomography, CT, and myelography. Moreover, MRI can visualize soft tissue abnormalities and neurologic compromise without use of intrathecal contrast.

Calcium pyrophosphate dihydrate crystal deposition in and around the atlantoaxial joint: association with type 2 odontoid fractures in nine patients

PURPOSE

To investigate the histopathologic anatomy of calcium pyrophosphate dihydrate (CPPD) crystal deposition in and around the atlantoaxial joint and the association between CPPD crystal deposition and subchondral cysts, erosions, and fracture involving the odontoid process of the axis.

MATERIALS AND METHODS

One adult cadaver demonstrating calcification in the retro-odontoid area at computed tomography (CT) was selected for further radiography, CT, and magnetic resonance (MR) imaging at the C1-2 level. Anatomic sectioning and histologic evaluations were performed in the specimen. For clinical study, radiographs (n = 5), CT scans (n = 8), and MR images (n = 6) in nine patients (mean age, 74.4 years) with odontoid process fractures and CPPD crystal deposits in and around the atlantoaxial joint were reviewed.

RESULTS

In the cadaveric specimen, radiography and CT demonstrated calcifications in the transverse ligament; histologic evaluation confirmed that these calcifications were CPPD crystal deposits. In all nine patients, radiography (n = 5) and CT (n = 8) also showed calcification in areas adjacent to the odontoid process, which included the transverse ligament. T1- and T2-weighted MR imaging showed a retro-odontoid mass of low signal intensity that compressed the cervical cord in six patients. CT, MR imaging, or both demonstrated subchondral cysts, osseous erosions, or a type 2 odontoid fracture in all patients.

CONCLUSION

CPPD crystal deposition disease involving the C1-C2 articulation can be a clinically important entity that may place affected patients at increased risk of pathologic fracture of the odontoid process.

Retro-odontoid massive calcium pyrophosphate crystal deposition--case report

An 86-year-old male presented with progressive myelopathy due to retro-odontoid massive deposits of calcium pyrophosphate dihydrate (CPPD) crystals. Magnetic resonance imaging revealed a non-enhanced isointense extradural mass on the T1-weighted image and heterogeneously intense mass on the T2-weighted image. Computed tomography showed typical punctate and linear calcifications within the mass. The mass was resected via a lateral approach resulting in marked improvement of the symptoms. Histological examination revealed birefringent rhomboid crystals consistent with CPPD. CPPD deposition should be considered in the differential diagnosis of retro-odontoid extradural mass because surgical therapy is beneficial even for elderly patients.

Calcification of the cervical ligamentum flavum--case report

A 52-year-old male presented with calcification of the cervical ligamentum flavum manifesting as hypesthesia of the bilateral middle, ring, and little fingers and ulnar halves of both forearms, as well as motor weakness in the bilateral upper extremities and gait disturbance. Cervical x-ray tomography detected a round calcified mass on the posterior wall of the cervical canal at the C-5 level. Computed tomography showed the round, nodular calcified mass more clearly. Magnetic resonance imaging showed an epidural low intensity mass compressing and distorting the cervical cord at the C-5 level on both T1- and T2-weighted images. Administration of gadolinium-diethylenetriaminepenta-acetic acid caused marginal enhancement of the mass. The lesion was eventually removed by posterior laminectomy. The mass was composed of a very hard crystal-like calcified deposition in the ligamentum flavum. X-ray diffraction analysis of the histological specimen showed calcium pyrophosphate dihydrate (CPPD) and hydroxyapatite in the crystal-like substance, confirming that CPPD is responsible for calcification of the cervical ligamentum flavum.

The crowned dens syndrome: a rare form of calcium pyrophosphate deposition disease

The crowned dens syndrome has been termed as acute neck pain ascribed to CPPD deposits associated with a tomographic appearance of calcification surrounding the odontoid process. This rare entity resulting in cervical cord compression is generally seen in older female patients. We present a 26-year-old woman with cervical cord compression due to massive calcification in the periodontoid area and discuss the X-ray and CT findings of the disease.