Animal models of compression spinal cord injury.

Compression spinal cord injuries are a common cause of morbidity in people who experience a spinal cord injury (SCI). Either as a by-product of a traumatic injury or due to nontraumatic conditions such as cervical myelitis, compression injuries are growing in prevalence clinically and many attempts of animal replication have been described within the literature. These models, however, often focus on the traumatic side of injury or mimic short-term injuries that are not representative of the majority of compression SCI. Of this, nontraumatic spinal cord injuries are severely understudied and have an increased prevalence in elderly populations, adults, and children. Therefore, there is a need to critically evaluate the current animal models of compression SCI and their suitability as a method for clinically relevant data that can help reduce morbidity and mortality of SCI. In this review, we reviewed the established and emerging methods of animal models of compression SCI. These models are the clip, balloon, solid spacer, expanding polymer, remote, weight drop, calibrated forceps, screw, and strap methods. These methods showed that there is a large reliance on the use of laminectomy to induce injury. Furthermore, the age range of many studies does not reflect the elderly and young populations that commonly suffer from compression injuries. It is therefore important to have techniques and methods that are able to minimize secondary effects of the surgeries, and are representative of the clinical cases seen so that treatments and interventions can be developed that are specific.

[Boy with Coffin-Lowry syndrome associated with spinal cord injuries].

A 12-year-old male patient with Coffin-Lowry syndrome was scheduled for posterior cervical decompression and fusion for cervical spinal injuries. The patient had features of Coffin-Lowry syndrome including mental retardation, prominent forehead, a short nose with a wide tip, a wide mouth with full lips, short stature, microcephaly, and kyphoscoliosis. We anticipated major troubles related to anesthesia such as difficult ventilation and intubation, communication difficulty during induction and extubation, and difficulty in using a naso-pharyngeal airway. In addition, we had to stabilize neck alignments during intubation because cervical vertebrae were unstable and spinal cord has already been injured. Therefore, we scheduled slow induction with sevoflurane maintaining spontaneous respiration. As we found the full mouth opening of the patient after the induction, we inserted an intubating laryngeal mask, through which ventilation was successfully maintained. A tracheal tube was inserted through the intubating laryngeal mask. When the surgery was completed, we extubated using a tube introducer in the trachea. As we found that the patient's airway was open, we removed the introducer. In conclusion, with a thorough planning of the anesthetic management, we successfully managed anesthesia for cervical spinal surgery in a patient with Coffin-Lowry syndrome.

Case report of os odontoideum causing Ondine's curse.

Ondine's curse or central hypoventilation syndrome is most common congenital disorder which is diagnosed in infancy. In the majority of cases, no structural abnormality is identified. We describe the case of an 18-year-old patient who presented with Ondine's curse secondary to an os odontoideum.

[Analysis of anterior cervical spondylodesis using plate cage PCB Evolution for a 2 year period].

The aim of this study was to analyze treatment results of patients who underwent cervical fusion using plate cage PCB Evolution during 2 year period. 37 hybrid cages (titanium plate and PEEK cage) were implanted to 34 patients with degenerative disease of cervical spine. Assessment of results was performed by neurologic examination, neurovisualization data, visual analogue pain scale and Neck Disability Index. Mean duration of surgery was 92 min., blood loss - 42 ml, length of hospital stay - 8 days. Substantial decrease of frequency and intensity of neck and arm pain was observed after surgery in 91% of patients. Single asymptomatic complication occurred due to improper implant position owing to loosening of the upper screw. When properly performed, anterior cervical interbody fusion applying PCB Evolution plate cage is a simple and effective method with low complication rate.

Transmandibular Cervical Corpectomy for Persistent Spinal Cord Compression in a Patient With Klippel-Feil Syndrome: A Technical Note and Systematic Review.

BACKGROUND: Few studies have described a transmandibular approach for decompression in a patient with Klippel-Feil syndrome (KFS) for cervical myelopathy. OBJECTIVE: To describe the transmandibular approach in a KFS patient with cervical myelopathy and to perform a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. METHODS: A systematic review was performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Embase and PubMed databases were searched from January 2002 to November 2022 for articles examining patients with KFS undergoing cervical decompression and/or fusion for cervical myelopathy and/or radiculopathy were included. Articles describing compression due to nonbony causes, lumbar/sacral surgery, nonhuman studies, or symptoms only from basilar invagination/impression were excluded. Data collected were sex, median age, Samartzis type, surgical approach, and postoperative complications. RESULTS: A total of 27 studies were included, with 80 total patients. Thirty-three patients were female, and the median age ranged from 9 to 75 years. Forty-nine patients, 16 patients, and 13 patients were classified as Samartzis Types I, II, and III, respectively. Forty-five patients, 21 patients, and 6 patients underwent an anterior, posterior, and combined approach, respectively. Five postoperative complications were reported. One article reported a transmandibular approach for access to the cervical spine. CONCLUSION: Patients with KFS are at risk of developing cervical myelopathy. Although KFS manifests heterogeneously and may be treated through a variety of approaches, some manifestations of KFS may preclude traditional approaches for decompression. Surgical exposure through the anterior mandible may prove an option for cervical decompression in patients with KFS.

Posterior atlantoaxial subluxation due to os odontoideum combined with cervical spondylotic myelopathy: a case report.

In patients with os odontoideum and posterior atlantoaxial subluxation are extremely rare. No reports have described posterior atlantoaxial subluxation associated with os odontoideum combined with cervical spondylotic canal stenosis, both of which require surgical treatment. We report one case of a 75-year-old female who underwent arthrodesis between the occiput and C3 using a hook-and-rod system and also a double-door laminoplasty from levels C3 to C7. The claw mechanism was applied between the C2 lamina and the C3 inferior articular process. The posterior atlantoaxial subluxation was completely reduced by the method that the rod gradually pushed the posterior arch of C1 anteriorly during connection to the occiput. Twelve months after surgery, the patient showed improvement in preoperative clumsiness and gait disturbance, and the latest plain radiographs showed solid osseous fusion, with no loss of correction or instrumentation failure.

Chronic posterior atlantoaxial subluxation associated with os odontoideum: a rare condition. A case report and literature review.

Introduction: Os odontoideum is a rare cervical lesion. This unusual condition is sometimes associated with atlantoaxial subluxation, which is mostly anterior subluxation. Posterior atlantoaxial subluxation due to os odontoideum is extremely rare. Case presentation: We report an unusual case of a 60-year-old Thai female, who was diagnosed as having chronic posterior atlantoaxial subluxation associated with os odontoideum with progressive myelopathy. The patient underwent posterior arch of C1 laminectomy and an occipito-C3 fusion using an occipital plate, C2 pedicle screws, C3 lateral mass screws and autologous iliac crest strut bone graft arthrodesis. During three years of follow-up, she was clinically significantly improved and postoperative radiographs showed a solid osseous fusion without loss of correction or implant failure. Discussion: Chronic posterior atlantoaxial subluxation associated with os odontoideum is rare. This condition can cause occipital-cervical pain, myelopathy, intracranial symptoms, or death. Surgical decompression and stabilization is the treatment of choice. Principles of treatment are to prevent sudden death from neurological compromise, improve neurological status, stabilize the cervical spine, and improve quality of life. Surgical options include atlantoaxial fusion, occipito-C2 fusion, and occipito-C3 fusion. Decision making depends on the location of spinal cord compression, area for arthrodesis, and bone quality.

Evaluation of spinal involvement in children with mucopolysaccharidosis VI: the role of MRI.

OBJECTIVE: To evaluate spinal MRI features of mucopolysaccharidosis (MPS) VI and to assess the correlation with clinical findings. METHODS: We retrospectively evaluated spinal MRI scans and clinical findings at the time of imaging in 14 patients (8 male, 6 female) with MPS VI. Craniometric measurements were performed and the images were assessed for bony anomalies, spinal stenosis and spinal cord compression. The degree of cervical cord compression was scored and correlated with neurological examination findings at the time of imaging. Vertebral alignment, structural changes in spinal ligaments and intervertebral discs were also assessed. RESULTS: All patients had cervical stenosis due to bony stenosis and thickened retrodental tissue (median: 6.05 mm, range 3.3-8 mm). Retrodental tissue thickness was found to increase with age (p = 0.042). Compressive myelopathy was detected at upper cervical level in 11 (79%) and lower thoracic level in 2 patients (14%). Significant inverse correlation was found between cervical myelopathy scores and neurological strength scores. The most common bony changes were hypo/dysplastic odontoid; cervical platyspondyly with anterior inferior beaking; thoracic posterior end plate depressions and lumbar posterior scalloping. Kyphosis due to retrolisthesis of the beaked lumbar vertebrae and acute sacrococcygeal angulations were other remarkable findings. CONCLUSION: MRI is an essential component in evaluation of spinal involvement in MPS VI, and scanning of the entire spine is recommended to rule out thoracic cord compression. Advances in knowledge: This study provides a detailed description of spinal MRI findings in MPS VI and underlines the role of MRI in management of cord compression.

A comparison of changes over time in cervical foraminal height after tricortical iliac graft or polyetheretherketone cage placement following anterior discectomy.

OBJECT: The authors prospectively evaluated cervical foraminal height changes after anterior cervical discectomy and fusion. To their knowledge, this prospective study is the first in which foraminal height changes over time are compared following the placement of a tricortical graft or a polyetheretherketone (PEEK) cage. METHODS: The patients were randomly divided in two groups. In one group, 30 patients underwent anterior cervical microdiscectomy and free bone graft (FBG) insertion at 46 levels via the Smith-Robinson technique. The FBG was harvested from the right iliac crest. Another 35 patients underwent the same operation, but fusion was provided by the insertion of PEEK intervertebral cages at 41 levels. Fusion status and the C2-7 Cobb angle, interspace height, and foraminal height changes were observed on anterior, lateral, and oblique radiographs obtained at the 18-month follow-up examination. There were no differences between the groups with regard to clinical recovery, fusion status, and Cobb angle. A significant interspace height reduction was observed in the FBG group during the 1st postoperative month. In the FBG group, the mean heights (+/- standard deviation) of the foramina were 8.2 +/- 2.7 mm preoperatively, 10.8 +/- 2.6 mm on postoperative Day 2, and 8.1 +/- 1.5 mm after 18 months of follow up. In the PEEK cage group, the mean heights were 8.4 +/- 2.8 mm preoperatively, 10.3 +/- 1.1 mm on postoperative Day 2, and 9.6 +/- 1.2 mm after 18 months of follow up. The increase in foraminal height was significantly preserved at the 6th, 12th, and 18th months in the cage group. CONCLUSIONS: In both groups the foraminal height increased sufficiently and the nerve root was decompressed postoperatively. The PEEK cages may provide sufficient preservation of foraminal height even 1.5 years after the operation.

Endoscopic Endonasal Odontoidectomy.

Odontoidectomy is the treatment of choice for irreducible ventral cervical-medullary compression. The endonasal endoscopic approach is an innovative approach for odontoidectomy. The aim of this article is to identify in which conditions this approach is indicated, discussing variants of the technique for selected cases of craniovertebral malformation with platybasia. We believe that the technical difficulties of this approach are balanced by the advantages for patients. Some conditions related to the patient and to the anatomy of the craniovertebral junction may favor adoption of the endoscopic endonasal approach, which should be considered complementary and not alternative to standard approaches.

Ventral brain stem compression in pediatric and young adult patients with Chiari I malformations.

OBJECTIVE: The purposes of this study were as follows: 1) to determine the incidence and degree of ventral brain stem compression (VBSC) in pediatric and young adult patients with Chiari I malformations, and 2) to correlate VBSC with other imaging and clinical factors to help determine what amount of VBSC is successfully treated with a posterior decompressive procedure alone. METHODS: The magnetic resonance images and clinical histories of 40 pediatric and young adult patients with Chiari I malformations were analyzed for subjective grade of VBSC, distance of tonsillar descent, odontoid's relation to Chamberlain's and Wackenheim's line, clival length, foramen magnum diameter, syringomyelia, scoliosis, hydrocephalus, presenting clinical status, treatment, and outcome. To objectively measure the amount of ventral cervicomedullary encroachment by the odontoid and its investing tissues into the rostral spinal canal, a line (B-C2) was drawn between the basion and posteroinferior aspect of the C2 body on a sagittal magnetic resonance image. A line perpendicular to this line, pB-C2, was drawn through the odontoid tip to the ventral dura, and a distance (representing the amount of ventral canal encroachment) was measured. RESULTS: Flattening and distortion of the ventral brain stem were present in 48 and 28% of the patients, respectively. Only two patients had basilar invagination by traditional definitions. pB-C2 measurements correlated with the subjective grade of VBSC (P < 0.05), age, and distance of tonsillar descent (P < 0.05). Eye motion abnormalities and upper cervical osseous anomalies were associated with higher pB-C2 measurements. All patients with a pB-C2 measurement of less than 9 mm were treated successfully with posterior fossa decompression alone despite any subjective VBSC. Some patients with pB-C2 measurements greater than 9 mm had either preoperative neurological deficits or neurological worsening after posterior fossa decompression referable to VBSC. CONCLUSION: Patients with a pB-C2 measurement of less than 9 mm do not require treatment directed at VBSC. In select patients with pB-C2 measurements of 9 mm or greater, reduction of VBSC may be prudent before posterior fossa decompression.

Functional abnormalities of the cervical cord and lower medulla and their effect on pain: observations in chronic pain patients with incidental mild Chiari I malformation and moderate to severe cervical cord compression.

OBJECTIVE: Abnormalities of central sensory processing may play a role in the pathogenesis of chronic pain. The Chiari I malformation is a congenital hindbrain anomaly characterized by protrusion of the cerebellar tonsils into the upper cervical canal, with variable effects on the lower brain stem and cervical cord. The purpose of this study was to compare sensory function and pain among patients with chronic pain who had these disorders incidentally diagnosed, to assess the effect on pain in these patients in comparison with those without central nervous system disease. DESIGN: Retrospective study in which pain, mood, and sensory function in 32 patients with chronic pain who had mild Chiari I malformation were compared with that in 53 patients with chronic pain who had moderate to severe compression of the cervical spinal cord and 52 patients with chronic pain who had no apparent central nervous system disorder. Data had been collected previously as part of standard clinical assessments, including clinical neurological examinations, quantitative sensory testing, pain drawings, and psychometric testing with the Symptom Checklist 90. PATIENTS: All subjects were patients of a hospital-based pain management practice who had been accepted for treatment over a 5-year period. RESULTS: Both the Chiari I and cervical compression groups had long tract signs evident on clinical neurological examination. Quantitative sensory testing indicated elevations in the trigeminal territory among patients with Chiari I malformation and on the neck, hands, and feet in both the Chiari I and cervical compression groups. The extent of pain and mood disturbance was greatest in the Chiari I group and least in the group with no central nervous system disorder. Complex regional pain syndrome, fibromyalgia, and temporal mandibular joint disorder were more common among the Chiari I malformation group than among the other groups. CONCLUSIONS: Quantitative sensory analysis indicates sensory dysfunction associated with Chiari I malformation and cervical cord compression. The pattern of sensory abnormality is consistent with medullary dysfunction among the patients with Chiari I malformation and cervical cord dysfunction among cord compression patients. There were differences in the types and extent of pain and the associated disorders of mood observed among the cohorts defined above. These differences may be partly due to the presence and location of central sensory dysfunction.

Compression of the upper cervical spinal cord causing symptoms of brainstem compromise. A case report.

STUDY DESIGN: A case is reported in which a flexion-induced compression of the upper cervical spinal cord caused symptoms of brainstem compromise in the absence of radiographic evidence of osseous instability. OBJECTIVES: A 41-year-old woman developed postoperative cervical instability with flexion-induced neurologic symptoms referable to the brainstem. The instability was caused by direct compression at the third cervical vertebral body, which in turn was caused by differential movements between the neuraxis and skeletal elements in the upper cervical spine. SUMMARY OF BACKGROUND DATA: Pathologic processes at the craniocervical junction may cause brainstem compromise with neurologic symptoms. The mechanism of brainstem involvement is usually either vertebrobasilar insufficiency or direct mechanical compression. In cases where the brainstem is compressed by skeletal elements, the compressing osseous structures usually are the walls of the foramen magnum or the odontoid process, or, less frequently, the atlas or axis vertebrae. Symptoms of brainstem dysfunction caused by dynamic compression at the level of the third cervical vertebra in the absence of hindbrain herniation are unusual and, to the best of the authors' knowledge, have not been described previously. METHODS: The patient underwent initial examination, evaluation, and periodic follow-up examination with magnetic resonance imaging from the time of her first visit until 26 months after the surgical treatment. The patient experienced postsurgical instability with dynamic compression by the C3 vertebral body, which caused brainstem compromise. Surgical treatment consisted of decompressive C3 corpectomy and fusion of C2 to C6, supplemented by anterior fixation. RESULTS: After undergoing surgical decompression of C3, reconstruction, and anterior internal fixation of C2 to C6, the patient had dramatic neurologic improvement. Diplopia, paresthesia, and nystagmus disappeared immediately after surgery. Swallowing difficulties, hoarseness, and vertigo improved gradually. At follow-up examination 26 months after surgery, the patient was asymptomatic. Magnetic resonance imaging showed good position of the construct, with no evidence of compression of the spinal cord or brainstem. CONCLUSIONS: Instability of the cervical spine may result in symptoms of brainstem dysfunction, even in the absence of hindbrain herniation. This instability is explained by the differential movement between the bony structures and neuraxis in the upper cervical region. Diagnosis and adequate management of this instability alleviates the neurologic symptoms and prevents possible hazardous complications.

Cranio-vertebral pathology in Down syndrome.

Cranio-vertebral malformations, especially atlanto-axial dislocation, are frequently seen in Down patients. However, symptomatic forms in mongolism are rare. Pyramidal signs have a signal value. In symptomatic malformations surgical treatment should be advised, i.e. posterior fixation after pre-operative reduction by traction or transoral odontoidectomy if no reduction is achieved.

Tetraparesis following dental extraction: case report and discussion of preventive measures for cervical spinal hyperextension injury.

This concerns a patient with compression myelopathy following passive hyperextension of the cervical spine during a dental procedure. Although he had been asymptomatic prior to the procedure, subsequent cervical spinal imaging revealed advanced spondylosis and spinal stenosis. Spinal stenosis is often asymptomatic for a long time. However, when radiculomyelopathy occurs after minor trauma to the head or neck, the patient is often found to have spinal stenosis. Specifically, hyperextension of a cervical spine with spondylotic changes can lead to compression myelopathy. Acquired spinal stenosis correlates positively with aging. As the size of the elderly population continues to increase the prevalence of cervical spondylotic radiculo-myelopathy will likely increase as well. Since appropriate precautions against potential neurologic damage can be undertaken, we suggest radiographic screening for pre-existing spinal stenosis prior to a procedure requiring hyperextension of the neck. Preventive measures for individuals with asymptomatic spondylotic changes and education of all health-care professionals to avoid abrupt or prolonged hyperextension of the cervical spine is emphasized.

Spinal cord compression by heterotopic ossification associated with pseudohypoparathyroidism.

This report describes a 37-year-old man presenting with a gait disturbance due to spastic paraparesis. Physical findings showed typical features of Albright's hereditary osteodystrophy, including short stature, obesity, brachydactyly and dental hypoplasia. He was diagnosed as having pseudohypoparathyroidism type Ia, on the basis of his hypocalcaemia, hyperphosphataemia, increased plasma level of parathyroid hormone (PTH), and the unresponsiveness to exogenous PTH loading of his urinary excretion of both nephrogenous cyclic adenosine monophosphate and phosphate. Magnetic resonance imaging and myelographic computed tomographic scans clearly demonstrated severe compression of the spinal cord at T 9/10 by tumour-like ossifications of the paravertebral ligaments. Neurosurgical decompression therapy was, therefore, performed to alleviate his spastic paraparesis. This was a rare case of pseudohypoparathyroidism complicated with spinal cord compression caused by ectopic ossification of the ligaments.

Metastatic paraspinal abscess and paraplegia secondary to dental extraction.

An unusual case of metastatic paraspinal abscess and paraplegia is presented. This was a consequence of simple dental extractions and subsequent bacteraemia from a neglected mouth. Neurosurgical intervention and tissue culture yielded organisms almost certainly of dental origin. No alternative primary nidus of infection could be found. The importance of oral health to general health is emphasised.

Sporadic Ehlers-Danlos syndrome with neurologic, cardiac and dental involvement.

A sporadic case of Ehlers-Danlos syndrome associated with atlantoaxial dislocation, mitral valve prolapse and dental abnormalities is presented. This case could not be assigned to any of the nine defined types of the syndrome.

[A malformation to know: os odontoideum. Report on two pediatric cases]. / Une malformation à connaître : l'os odontoideum. À propos de deux cas pédiatriques.

The os odontoideum, or mobile odontoid apophysis, is a malformation of the cervico-occipital hinge caused by missing unity in the ossification center of the dens on the body of the axis. This malformation induces atloaxial instability and exposes the subject to the risk of bulbar-medullary compression. The true incidence of this condition is difficult to determine because many cases are asymptomatic. The pathogenesis is discussed. Congenital and traumatic theories have been advanced. Clinically, the defect can be discovered incidentally or revealed by neck pain, a stiff neck, dizziness, or deficient syndrome. CT and MRI imaging can detect the defects, and allow one to study the impact on the contents of the spinal canal and detect lesions. We report two new os odontoideum observations in children aged 5 and 14 years who were referred for equilibrium disorders and tetraparesis, respectively.