Cerebrospinal fluid leak presented with the C1-C2 sign caused by spinal canal stenosis: a case report.

BACKGROUND: Intracranial hypotension is a disorder characterized by low cerebrospinal fluid (CSF) pressure typically caused by loss of CSF. Although some mechanisms account for the CSF leakage have been elucidated, spinal canal stenosis has never been reported as a pathological cause of intracranial hypotension. C1-C2 sign is a characteristic imaging feature, which indicates CSF collection between the spinous processes of C1 and C2, occasionally observed on magnetic resonance imaging (MRI) in patients with intracranial hypotension. CASE PRESENTATION: A 58-year-old man was presented to our institute with complaints of posterior cervical pain persisting for 3 months, along with numbness and muscle weakness of extremities. A fat suppression T2-weighted image of MRI illustrated fluid collection in the retrospinal region at C1-C2 level, and an 111In-DTPA cisternoscintigram clearly revealed the presence of CSF leakage into the same region. The MRI also showed stenosis in spinal canal at C3/4 level, and a computed tomography (CT) myelogram suggested a blockage at the same level. We gave a diagnosis as intracranial hypotension due to the CSF leakage, which might be caused by the spinal canal stenosis at C3/4 level. Despite 72 h of conservative therapy, a brain CT showed the development of bilateral subdural hematomas. We, therefore, performed burr-hole drainage of the subdural hematoma, blood-patch therapy at C1/2 level, and laminoplasty at C3-4 at the same time. Improvement of symptoms and imaging features which suggested the CSF leak and subdural hematoma were obtained post-operatively. CONCLUSION: The present case suggested the mechanism where the CSF leakage was revealed as fluid collection in the retrospinal region at C1-C2 level. Increased intradural pressure due to the spinal canal stenosis resulted in dural tear. CSF leaked into the epidural space and subsequently to the retrospinal region at C1-C2 level, due to the presence of spinal canal stenosis caudally as well as the vulnerability of the tissue structure in the retrospinal region at C1-C2 level. Thus, our theory supports the mechanisms of previously reported CSF dynamics associated to C1-C2 sign, and also, we suggest spinal canal stenosis as a novel etiology of intracranial hypotension.

Axial loading during MRI reveals insufficient effect of percutaneous interspinous implants (Aperius™ PerCLID™) on spinal canal area.

PURPOSE: To evaluate the effect on the spinal canal at the treated and adjacent level(s), in patients treated for lumbar spinal stenosis (LSS) with percutaneous interspinous process device (IPD) Aperius™ or open decompressive surgery (ODS), using axial loading of the spine during MRI (alMRI). MATERIALS: Nineteen LSS patients (mean age 67 years, range 49-78) treated with IPDs in 29 spine levels and 13 LSS patients (mean age 63 years, range 46-76) operated with ODS in 22 spine levels were examined with alMRI pre- and 3 months postoperatively. Radiological effects were evaluated by measuring the dural sac cross-sectional area (DSCSA) and by morphological grading of nerve root affection. RESULTS: For the IPD group, no DSCSA increase was observed at the operated level (p = 0.42); however, a decrease was observed in adjacent levels (p = 0.05). No effect was seen regarding morphological grading (operated level: p = 0.71/adjacent level: p = 0.94). For the ODS group, beneficial effects were seen for the operated level, both regarding DSCSA (p < 0.001) and for morphological grading (p < 0.0001). No changes were seen for adjacent levels (DSCSA; p = 0.47/morphological grading: p = 0.95). Postoperatively, a significant difference between the groups existed at the operated level regarding both evaluated parameters (p < 0.003). CONCLUSIONS: With the spine imaged in an axial loaded position, no significant radiological effects of an IPD could be detected postoperatively at the treated level, while increased DSCSA was displayed for the ODS group. In addition, reduced DSCSA in adjacent levels was detected for the IPD group. Thus, the beneficial effects of IPD implants on the spinal canal must be questioned. These slides can be retrieved under Electronic Supplementary Material.

[Minimally invasive decompression techniques for spinal cord stenosis]. / Minimal-invasive Dekompressionsverfahren der Spinalkanalstenose.

BACKGROUND: Lumbar spinal canal stenosis is frequently found among elderly patients and significantly limits their quality of life. Non-surgical therapy is an initial treatment option; however, it does not eliminate the underlying pathology. Surgical decompression of the spinal canal has now become the treatment of choice. OBJECTIVE: Minimalization of surgical approach strategies with maintaining sufficient decompression of the spinal canal and avoiding disadvantages of macrosurgical techniques, monolateral paravertebral approach with bilateral intraspinal decompression, specific surgical techniques. MATERIALS AND METHODS: Minimally invasive decompression techniques using a microscope or an endoscope are presented and different surgical strategies depending on both the extent (mono-, bi-, and multisegmental) and the location of the stenosis (intraspinal central, lateral recess, foraminal) are described. RESULTS: Minimally invasive microscopic or endoscopic decompression procedures enable sufficient widening of the spinal canal. Disadvantages of macrosurgical procedures (e. g., postoperative instability) can be avoided. The complication spectrum overlaps partially with that of macrosurgical interventions, albeit with significantly less marked severity. Subjective patient outcome is clearly improved. CONCLUSIONS: Referring to modern minimally invasive decompression procedures, surgery of lumbar spinal canal stenosis represents a rational and logical treatment alternative, since causal treatment of the pathology is only possible with surgery.

Effects of spine loading in a patient with post-decompression lumbar disc herniation: observations using an open weight-bearing MRI.

PURPOSE: Our objective was to use an open weight-bearing MRI to identify the effects of different loading conditions on the inter-vertebral anatomy of the lumbar spine in a post-discectomy recurrent lumbar disc herniation patient. METHODS: A 43-year-old male with a left-sided L5-S1 post-decompression re-herniation underwent MR imaging in three spine-loading conditions: (1) supine, (2) weight-bearing on standing (WB), and (3) WB with 10 % of body mass axial loading (WB + AL) (5 % through each shoulder). A segmentation-based proprietary software was used to calculate and compare linear dimensions, angles and cross sections across the lumbar spine. RESULTS: The L5 vertebrae showed a 4.6 mm posterior shift at L5-S1 in the supine position that changed to an anterior translation >2.0 mm on WB. The spinal canal sagittal thickness at L5-S1 reduced from supine to WB and WB + AL (13.4, 10.6, 9.5 mm) with corresponding increases of 2.4 and 3.5 mm in the L5-S1 disc protrusion with WB and WB + AL, respectively. Change from supine to WB and WB + AL altered the L5-S1 disc heights (10.2, 8.6, 7.0 mm), left L5-S1 foramen heights (12.9, 11.8, 10.9 mm), L5-S1 segmental angles (10.3°, 2.8°, 4.3°), sacral angles (38.5°, 38.3°, 40.3°), L1-L3-L5 angles (161.4°, 157.1°, 155.1°), and the dural sac cross sectional areas (149, 130, 131 mm2). Notably, the adjacent L4-L5 segment demonstrated a retro-listhesis >2.3 mm on WB. CONCLUSION: We observed that with weight-bearing, measurements indicative of spinal canal narrowing could be detected. These findings suggest that further research is warranted to determine the potential utility of weight-bearing MRI in clinical decision-making.

Kinematic analysis of cervical spine canal diameter and its association with grade of degeneration.

OBJECTIVES: To investigate the cervical spinal canal diameters variance under positional MRI, and also the relationship between cervical canal diameter variance rate and grade of degeneration. METHODS: From January 2013 to January 2015, a consecutive of 273 symptomatic patients (166 males and 207 females) with an average age of 44.6 years (range 21-89 years) underwent positional cervical MRI. T2-weighted sagittal images of 1638 cervical intervertebral discs from 273 subjects were classified into five grades. The canal diameter and canal diameter variance rate at three positions and their comparison among five grade of degeneration were evaluated. The measurements were tabulated and analyzed using SPSS. 13.0. p values less than 0.05 were considered to indicate a statistically significant difference. RESULTS: The sagittal cervical canal diameter at the C5/6 level were the smallest compared with the other levels regardless of neutral, flexion or extension positions, C5/6 level had the largest canal diameter variance rate in both flexion and extension (8.14 ∓ 0.38 and 7.81 ∓ 0.31 %, respectively), second was C4/5 level (7.65 ∓ 0.39 and 7.67 ∓ 0.32 %, respectively). A total of 1638 discs were classified into 5 groups, each level showed the similar tendency that no matter what position, with the increasing grade of degenerative disc degree, spine canal diameter decreased gradually. For C5/6 under extension and flexion position, significant difference was also noted between grade 2 and 3; For C4/5 under extension position, significant difference existed between grade 1 and 2, grade 1 and 3, while under flexion position, significant difference existed between grade 2 and 4, and the results also showed no significant difference at the same degree of degeneration on both levels between extension and flexion position. CONCLUSIONS: C5/6 and C4/5 is of higher risk of suffering SCI than other levels, C4/5 level predispose SCI at earlier stage than C5/6, patients presenting with intermediate signal and slight decreased disc height on T2 weighted MRI at C4/5 level should be paid attention.

Periosteal chondroma with spinal cord compression in the thoracic spinal canal: a case report.

Periosteal chondroma is a very unusual cartilaginous neoplasm of the spinal canal. We herein report a case of periosteal chondroma in a 41-year-old male who presented with gait disturbance and paresthesia of both lower extremities. Magnetic resonance (MR) images showed an extradural mass which caused compression of the spinal cord at the T5/6 level. The mass showed iso-signal intensity on T1-weighted images, high signal intensity on T2-weighted images, and nodular and peripheral rim enhancement on post-contrast T1-weighted images. Computed tomography (CT) images showed a mass with punctate calcifications and extension into the left T5/6 neural foramen. MR and CT images showed extrinsic cortical bone erosion of the posterior inferior body of T5 and superior pedicle of T6, bone remodeling with overhanging margins, and sclerosis adjacent to the tumor. The patient underwent a complete excision of the mass by left T5/6 hemi-laminectomy and exhibited complete resolution of his symptoms. Histopathologic examination revealed periosteal chondroma. Tumor recurrence was not recorded during the 18-month follow-up period.

Flexible active electrode arrays with ASICs that fit inside the rat's spinal canal.

Epidural spinal cord electrical stimulation (ESCS) has been used as a means to facilitate locomotor recovery in spinal cord injured humans. Electrode arrays, instead of conventional pairs of electrodes, are necessary to investigate the effect of ESCS at different sites. These usually require a large number of implanted wires, which could lead to infections. This paper presents the design, fabrication and evaluation of a novel flexible active array for ESCS in rats. Three small (1.7 mm(2)) and thin (100 µm) application specific integrated circuits (ASICs) are embedded in the polydimethylsiloxane-based implant. This arrangement limits the number of communication tracks to three, while ensuring maximum testing versatility by providing independent access to all 12 electrodes in any configuration. Laser-patterned platinum-iridium foil forms the implant's conductive tracks and electrodes. Double rivet bonds were employed for the dice microassembly. The active electrode array can deliver current pulses (up to 1 mA, 100 pulses per second) and supports interleaved stimulation with independent control of the stimulus parameters for each pulse. The stimulation timing and pulse duration are very versatile. The array was electrically characterized through impedance spectroscopy and voltage transient recordings. A prototype was tested for long term mechanical reliability when subjected to continuous bending. The results revealed no track or bond failure. To the best of the authors' knowledge, this is the first time that flexible active electrode arrays with embedded electronics suitable for implantation inside the rat's spinal canal have been proposed, developed and tested in vitro.

Does Co-Existing Lumbar Spinal Canal Stenosis Impair Functional Outcomes and Activity Levels after Primary Total Hip Arthroplasty?

Degenerative lumbar spinal stenosis (LSS) is a cause for substantial morbidity in the elderly population: many often undergo total hip arthroplasty for associated hip arthritis. With a matched cohort we investigated the effect of co-existing LSS on aseptic survivorship, functional outcomes, activity levels, overall subjective physical and mental health status, and satisfaction rates in patients undergoing primary THA. The aseptic-implant survivorship was similar in LSS and non-stenosis cohort. Although both cohorts significantly improved, the LSS cohort achieved lower improvements in HHS, UCLA, SF-36 physical, and satisfaction rates than the matched non-stenotic cohort. Surgeons should consider cautioning patients with LSS that although they can expect relief of their arthritic symptoms following THA, they may continue to expect limitations in function, physical-status, activity-levels, and satisfaction rates.

Compressive loading of the spine may affect the spinal canal encroachment of burst fractures.

STUDY DESIGN: Spinal canal encroachment of burst fractures under different compressive loading. OBJECTIVE: To assess whether the application of different compressive loads affect the spinal canal encroachment (SCE) of thoracolumbar burst fractures and to relate any significant encroachment differences to the fracture morphology. SUMMARY OF BACKGROUND DATA: The SCE is an important part of the evaluation process of thoracolumbar burst fractures. It is, however, not well understood how a variation in spinal internal loads resulting from a change in patient posture may affect the SCE after a burst fracture. The application of a compressive load on fractured vertebrae may displace bony fragments further into the canal and increase the encroachment. METHODS: Ten thoracolumbar functional spinal units harvested from mature minipigs and compressed to create burst fractures were imaged by computed tomography under 3 loading conditions: without compressive force and with 2 compressive forces analogous to the load expected in vivo. SCE were measured for all loading cases and compared with each other to identify whether they systematically changed between loading cases and to discriminate which specimens were affected by an increase in the loading. RESULTS: The application of a compressive loading did not systematically increase the SCE. However, specimens with a large bony fragment originating from the superior and posterior aspect of the vertebral body with a centrifugal orientation had a significant increase of SCE when loaded. CONCLUSIONS: An increase in spinal internal loads resulting from a change in the patient posture may increase the SCE of burst fracture. Measurement of the SCE should take into account the bony fragment distribution of burst fracture.

Effect of spinal level and loading conditions on the production of vertebral burst fractures in a porcine model.

Vertebral burst fractures are commonly studied with experimental animal models. There is however a lack of consensus as to what parameters are important to create an unstable burst fracture with a significant canal encroachment on such model. This study aims to assess the effect of the loading rate, flexion angle, spinal level, and their interactions on the production of a vertebral thoracolumbar burst fracture on a porcine model. Sixteen functional spinal units composed of three vertebrae were harvested from mature Yucatan minipigs. Two loading rates (0.01 and 500 mm/s), two flexion angles (0° and 15°), and two spinal levels (T11-T13 and T14-L2) were studied, following a full factorial experimental plan with one repetition. Compression was applied to each functional unit to create a vertebral fracture. The load-to-failure, loss of compressive stiffness, final canal encroachment, and fracture type were used as criteria to evaluate the resulting fracture. All specimens compressed without flexion resulted in burst fractures. Half of the specimens compressed with the 15° flexion angle resulted in compression fractures. Specimens positioned without flexion lost more of their compressive stiffness and had more significant canal encroachment. Fractured units compressed with a higher loading rate resulted in a greater loss of compressive stiffness. The spinal level had no significant effect on the resulting fractures. The main parameters which affect the resulting fracture are the loading rate and the flexion angle. A higher loading rate and the absence of flexion favors the production of burst fractures with a greater canal encroachment.

Inflammatory myofibroblastic tumor in the intradural extramedullary space of the lumbar spine with spondylolisthesis: case report and review of the literature.

An inflammatory myofibroblastic tumor (IMT) is a rare disease entity reported to arise in various organs but still thought to be a neoplastic or reactive inflammatory condition controversially. The author reports an extremely rare case of intradural extramedullary IMT of lumbar spine which was presenting radiculopathy and neurogenic intermittent claudication due to concomitant spondylolisthesis.

The Felix-trial. Double-blind randomization of interspinous implant or bony decompression for treatment of spinal stenosis related intermittent neurogenic claudication.

BACKGROUND: Decompressive laminotomy is the standard surgical procedure in the treatment of patients with canal stenosis related intermittent neurogenic claudication. New techniques, such as interspinous process implants, claim a shorter hospital stay, less post-operative pain and equal long-term functional outcome. A comparative (cost-) effectiveness study has not been performed yet. This protocol describes the design of a randomized controlled trial (RCT) on (cost-) effectiveness of the use of interspinous process implants versus conventional decompression surgery in patients with lumbar spinal stenosis. METHODS/DESIGN: Patients (age 40-85) presenting with intermittent neurogenic claudication due to lumbar spinal stenosis lasting more than 3 months refractory to conservative treatment, are included. Randomization into interspinous implant surgery versus bony decompression surgery will take place in the operating room after induction of anesthesia. The primary outcome measure is the functional assessment of the patient measured by the Zurich Claudication Questionnaire (ZCQ), at 8 weeks and 1 year after surgery. Other outcome parameters include perceived recovery, leg and back pain, incidence of re-operations, complications, quality of life, medical consumption, absenteeism and costs. The study is a randomized multi-institutional trial, in which two surgical techniques are compared in a parallel group design. Patients and research nurses are kept blinded of the allocated treatment during the follow-up period of 1 year. DISCUSSION: Currently decompressive laminotomy is the golden standard in the surgical treatment of lumbar spinal stenosis. Whether surgery with interspinous implants is a reasonable alternative can be determined by this trial. TRIAL REGISTER: Dutch Trial register number: NTR1307.

Incidence and severity of epidural fibrosis after back surgery: an endoscopic study.

BACKGROUND: Epidural fibrosis has been implicated in the etiology of persistent pain after back surgery (Failed Back Surgery Syndrome [FBSS]). Using spinal endoscopy to view the lumbosacral epidural cavity, the incidence, severity, and appearance of epidural fibrosis was evaluated in patients with FBSS. METHODS: A prospective cohort observational study using epidural endoscopy was done involving 78 patients with persistent pain after back surgery. Patients were evaluated prospectively for the presence of epidural fibrosis and fibrosis was rated using a 4-level grading system based on appearance and resistance to epiduroscope advancement. The incidence of fibrosis detected by epiduroscopy vs. the incidence as reported in magnetic resonance imaging (MRI) studies for the same patients were compared. RESULTS: As diagnosed with epiduroscopy, 83.3% of all patients with persistent pain after back surgery had severe (grade 3 or 4) epidural fibrosis, while 91.0% had significant (grade 2, 3, or 4) fibrosis. In patients who had undergone more extensive surgery, severe fibrosis was present in 91.1% and significant fibrosis in 95.6%. Using MRI, epidural fibrosis was diagnosed only in 16.1% of these patients. All patients with severe epidural fibrosis had a filling defect on epidurography. Concordant pain was present in 84.3% of patients and depended on the severity of fibrosis. Results were statistically evaluated using analysis of frequencies and t-test. P < 0.05 was considered statistically significant. CONCLUSIONS: Epiduroscopy demonstrates that the prevalence of severe epidural fibrosis after FBSS is substantially higher than is generally reported in MRI evaluations. Severe epidural fibrosis is an underlying pathology in most patients with FBSS.

Application of intraoperative electrophysiological monitoring in vertebral canal decompression surgery for acute spinal cord injury.

OBJECTIVE: This study aimed to evaluate the joint monitoring of somatosensory evoked potentials (SEPs) and motor evoked potentials (MEPs) in vertebral canal decompression surgery for acute spinal cord injury. METHODS: Twenty-four patients, who were admitted to the hospital for the surgical treatment of spinal cord injury with SEP and MEP monitoring, were assigned to the intraoperative monitoring group (group I). In addition, 24 patients who were admitted to the hospital for the surgical treatment of spinal cord injury without SEP or MEP monitoring were assigned to the control group (group C). RESULTS: In group I, there were significant changes before and after decompression surgery in the P40 latency and amplitude, and in the latency of MEP in the abductor hallucis brevis (AHB), in patients with improved spinal nerve function following surgery. In contrast, there were no significant differences in the P40 latency or amplitude, or the latency of MEP in the AHB, in patients who showed no improvement after surgery. CONCLUSION: In vertebral canal decompression surgery for acute spinal cord injury, the application of joint MEP and SEP monitoring can timely reflect changes in spinal cord function.

Minimally invasive surgery for degenerative spondylolisthesis: transforaminal or oblique lumbar interbody fusion.

Aim: To compare the outcomes of minimally invasive surgery (MIS) for degenerative spondylolisthesis transforaminal lumbar interbody fusion (TLIF) and oblique lumbar interbody fusion (OLIF). Materials & methods: The clinical and surgical characteristics and outcomes of 38 patients with MIS-OLIF and 55 with MIS-TLIF were retrospectively evaluated. Results: Procedures and hospital stay were shorter and blood loss was less, with MIS-OLIF than with MIS-OLIF. The clinical and radiographic outcomes were similar. Postoperative changes in disk height and foraminal dimension were greater and patient satisfaction was better with MIS-OLIF than with MIS-TLIF. Conclusion: The clinical findings associated with the two procedures were similar; but patients preferred MIS-OLIF, which is less invasive, to MIS-TLIF. Clinical trial registration number: ChiCTR1800019443.

Automated measurement of anteroposterior diameter and foraminal widths in MRI images for lumbar spinal stenosis diagnosis.

Lumbar Spinal Stenosis causes low back pain through pressures exerted on the spinal nerves. This can be verified by measuring the anteroposterior diameter and foraminal widths of the patient's lumbar spine. Our goal is to develop a novel strategy for assessing the extent of Lumbar Spinal Stenosis by automatically calculating these distances from the patient's lumbar spine MRI. Our method starts with a semantic segmentation of T1- and T2-weighted composite axial MRI images using SegNet that partitions the image into six regions of interest. They consist of three main regions-of-interest, namely the Intervertebral Disc, Posterior Element, and Thecal Sac, and three auxiliary regions-of-interest that includes the Area between Anterior and Posterior elements. A novel contour evolution algorithm is then applied to improve the accuracy of the segmentation results along important region boundaries. Nine anatomical landmarks on the image are located by delineating the region boundaries found in the segmented image before the anteroposterior diameter and foraminal widths can be measured. The performance of the proposed algorithm was evaluated through a set of experiments on the Lumbar Spine MRI dataset containing MRI studies of 515 patients. These experiments compare the performance of our contour evolution algorithm with the Geodesic Active Contour and Chan-Vese methods over 22 different setups. We found that our method works best when our contour evolution algorithm is applied to improve the accuracy of both the label images used to train the SegNet model and the automatically segmented image. The average error of the calculated right and left foraminal distances relative to their expert-measured distances are 0.28 mm (p = 0.92) and 0.29 mm (p = 0.97), respectively. The average error of the calculated anteroposterior diameter relative to their expert-measured diameter is 0.90 mm (p = 0.92). The method also achieves 96.7% agreement with an expert opinion on determining the severity of the Intervertebral Disc herniations.

Response of ependymal progenitors to spinal cord injury or enhanced physical activity in adult rat.

Ependymal cells (EC) in the spinal cord central canal (CC) are believed to be responsible for the postnatal neurogenesis following pathological or stimulatory conditions. In this study, we have analyzed the proliferation of the CC ependymal progenitors in adult rats processed to compression SCI or enhanced physical activity. To label dividing cells, a single daily injection of Bromo-deoxyuridine (BrdU) was administered over a 14-day-survival period. Systematic quantification of BrdU-positive ependymal progenitors was performed by using stereological principles of systematic, random sampling, and optical Dissector software. The number of proliferating BrdU-labeled EC increased gradually with the time of survival after both paradigms, spinal cord injury, or increased physical activity. In the spinal cord injury group, we have found 4.9-fold (4 days), 7.1-fold (7 days), 4.9-fold (10 days), and 5.6-fold (14 days) increase of proliferating EC in the rostro-caudal regions, 4 mm away from the epicenter. In the second group subjected to enhanced physical activity by running wheel, we have observed 2.1-2.6 fold increase of dividing EC in the thoracic spinal cord segments at 4 and 7 days, but no significant progression at 10-14 days. Nestin was rapidly induced in the ependymal cells of the CC by 2-4 days and expression decreased by 7-14 days post-injury. Double immunohistochemistry showed that dividing cells adjacent to CC expressed astrocytic (GFAP, S100beta) or nestin markers at 14 days. These data demonstrate that SCI or enhanced physical activity in adult rats induces an endogenous ependymal cell response leading to increased proliferation and differentiation primarily into macroglia or cells with nestin phenotype.

The relationship between the cervical spinal canal diameter and the pathological changes in the cervical spine.

A congenitally narrow cervical spinal canal has been established as an important risk factor for the development of cervical spondylotic myelopathy. However, few reports have described the mechanism underlying this risk. In this study, we investigate the relationship between cervical spinal canal narrowing and pathological changes in the cervical spine using positional magnetic resonance imaging (MRI). Two hundred and ninety-five symptomatic patients underwent cervical MRI in the weight-bearing position with dynamic motion (flexion, neutral, and extension) of the cervical spine. The sagittal cervical spinal canal diameter and cervical segmental angular motion were measured and calculated. Each segment was assessed for the extent of intervertebral disc degeneration and cervical cord compression. Based on the sagittal canal diameter, the subjects were classified into three groups: A, subjects with a congenitally narrow canal, diameter of less than 13 mm; B, subjects with a normal canal, diameter of 13-15 mm; C, subjects with a wide canal, diameter of more than 15 mm. When compared with Groups A and B, the disc degeneration grades at the C3-4, C5-6, and C6-7 segments and the cervical cord compression scores at the C3-4 and C5-6 segments showed significant differences. Additionally, when compare with Groups A and C, the disc degeneration grades at all segments, except C2-3, and the cervical cord compression scores at all segments, except C2-3, showed significant differences. With respect to the cervical kinematics, few differences in the kinematics were observed between Groups B and C, however, the kinematics in Group A was different with other two groups. In Group A, the segmental mobility at the C4-5 and C6-7 segments were significantly higher than those observed in Group B, and the segmental mobility at the C3-4 segment was significantly lower than that observed in Groups B or C. We demonstrated the unique pathological and kinematic traits of cervical spine that exist in a congenitally narrow canal. We hypothesize that kinematic trait associated with a congenitally narrow canal may greatly contribute to pathological changes in the cervical spine. Our results suggest that cervical spinal canal diameter of less than 13 mm may be associated with an increased risk for development of pathological changes in cervical intervertebral discs. Subsequently, the presence of a congenitally narrow canal can expose individuals to a greater risk of developing cervical spinal stenosis.

The awakened intraspinal glass shard.

Penetrating spinal injuries from foreign bodies are an exceedingly rare pathological entity. In this report we present an unusual clinical report of an in-driven shard of glass in the cervical spine that remained without symptoms for many years and became symptomatic possibly because of narrowing of the diameter of the vertebral canal.

Vertebral artery dissection as an extremely rare cause of spinal epidural hematoma: case report and review of the literature.

OBJECTIVE: To present a patient with a cervico-thoracic ventrally located epidural hematoma caused by dissection and subsequent bleeding of the cervical portion of the vertebral artery. SUMMARY AND BACKGROUND DATA: Non traumatic epidural hematoma is a rare entity. The etiology usually is not clarified: a venous origin is usually suspected although an arterial source is also possible. CLINICAL REPORT: A 32-year-old woman presented with a ventrally located cervico-thoracic epidural hematoma caused by non traumatic dissection and dissecting aneurysm rupture of the cervical portion of the vertebral artery. The dissection was demonstrated by magnetic resonance imaging and digital subtraction angiography. The patient had no neurological symptoms and was treated by conservative methods. Follow up imaging showed healing of the vertebral artery and resorption of the epidural hematoma. CONCLUSION: Dissection of the cervical portion of the vertebral artery with subsequent perivascular bleeding is not well recognized as a possible cause of a spinal epidural hematoma. Even though this entity and the underlying cause may be rare, we suggest a vigilant search for vertebral artery injury in cases of ventrally located cervical and upper thoracic epidural hematoma.