Level Of Spinal Cord Compression Research Articles

Single-cell analysis of immune and stroma cell remodeling in clear cell renal cell carcinoma primary tumors and bone metastatic lesions

BackgroundDespite therapeutic advances, once a cancer has metastasized to the bone, it represents a highly morbid and lethal disease. One third of patients with advanced clear cell renal cell carcinoma (ccRCC) present with bone metastasis at the time of diagnosis. However, the bone metastatic niche in humans, including the immune and stromal microenvironments, has not been well-defined, hindering progress towards identification of therapeutic targets.MethodsWe collected fresh patient samples and performed single-cell transcriptomic profiling of solid metastatic tissue (Bone Met), liquid bone marrow at the vertebral level of spinal cord compression (Involved), and liquid bone marrow from a different vertebral body distant from the tumor site but within the surgical field (Distal), as well as bone marrow from patients undergoing hip replacement surgery (Benign). In addition, we incorporated single-cell data from primary ccRCC tumors (ccRCC Primary) for comparative analysis.ResultsThe bone marrow of metastatic patients is immune-suppressive, featuring increased, exhausted CD8 + cytotoxic T cells, T regulatory cells, and tumor-associated macrophages (TAM) with distinct transcriptional states in metastatic lesions. Bone marrow stroma from tumor samples demonstrated a tumor-associated mesenchymal stromal cell population (TA-MSC) that appears to be supportive of epithelial-to mesenchymal transition (EMT), bone remodeling, and a cancer-associated fibroblast (CAFs) phenotype. This stromal subset is associated with poor progression-free and overall survival and also markedly upregulates bone remodeling through the dysregulation of RANK/RANKL/OPG signaling activity in bone cells, ultimately leading to bone resorption.ConclusionsThese results provide a comprehensive analysis of the bone marrow niche in the setting of human metastatic cancer and highlight potential therapeutic targets for both cell populations and communication channels.

Neurogenic dysfunction of the lower urinary tract in infectious and inflammatory diseases of the spine: is there a correlation with clinical and radiological variants of myelopathy? Preliminary result of the analysis of a single-center cohort

Objective.To study the relationship between clinical and radiation variants of myelopathy and types of the neurogenic dysfunction of the lower urinary tract in patients with infectious spondylitis.Material and Methods.A single-center cohort observational study was conducted with the analysis of medical records and a prospective examination of 20 patients with infectious spondylitis complicated by neurogenic dysfunction of the lower urinary tract.Results.Infectious spondylitis can be complicated by the development of various urodynamic disorders, including neurogenic detrusor hyperactivity (30 %), its combination with detrusor-sphincter dissinergia (30 %) and a decrease in detrusor contractility (40 %). In 50 % of patients, an urodynamic examination revealed an increase in detrusor pressure of more than 40 cm water. There was no connection between the development of any type of lower urinary tract dysfunction and MRI types of myelopathy according to Vendatam, as well as between the level of spinal cord compression and the severity of neurological disorders according to AIS.Conclusion.The results of the study do not confirm the existence of a relationship between the various characteristics of myelopathy in infectious spondylitis and the results of urodynamic examination. The limitation of the reliability of the results is the small number of observations. Studies with a larger sample are required to assess the relationship between the clinical and radiation characteristics of myelopathy and variants of neurogenic dysfunction of the lower urinary tract in patients with infectious spondylitis.

Abstract 631: Single-cell analysis of immune and stroma cell remodeling in renal cell carcinoma primary tumors and bone metastatic lesions

Abstract Background: Renal cell carcinoma (RCC) is the most common renal tumor in adults, and among these clear cell RCC (ccRCC) is most common subtype and accounts for most renal cancer-related deaths. One-third of patients with advanced ccRCC present with bone metastases at the time of diagnosis. Despite therapeutic advances, once cancer has metastasized to the bone, it represents a highly morbid and ultimately lethal disease. Comprehensive genomic studies in ccRCC have provided important insights into the somatic alterations and intra-tumor heterogeneity. However, the bone metastatic niche in humans, including the immune and stromal microenvironments, has not been well-defined. Methods: We collected fresh patient samples directly from the operating room and performed single-cell transcriptomic profiling of human ccRCC tumors (ccRCC primary), solid metastatic tissue (Bone Met), liquid bone marrow at the vertebral level of spinal cord compression (Involved), liquid bone marrow from a different vertebral body distant from the tumor site but within the surgical field (Distal), as well as bone marrow stroma cells from patients undergoing hip replacement surgery (Benign) as control. We provide a comparative single cell transcriptomic analysis between ccRCC primary tumors and bone metastatic lesions. Results: Comparison of malignant cells from primary and metastatic sites reveal a distinct transcriptional signature that is predictive of metastatic potential and patient survival. The bone marrow in metastatic patients has sustained immune-suppressive microenvironment, featuring increased, exhausted CD8+ cytotoxic T-cells, T-regulatory cells and tumor-associated macrophages (TAM) with distinct transcriptional states in metastatic lesions. Bone marrow stroma from tumor samples demonstrated a tumor-associated mesenchymal stromal cell population (TA-MSC) that appears to be supportive of epithelial-to mesenchymal transition (EMT), bone remodeling, and a cancer-associated fibroblast (CAFs) phenotype. This stromal subset is associated with poor progression-free and overall survival, markedly upregulates bone remodeling through the dysregulation of RANK/RANKL/OPG signaling activity in bone cells, ultimately leading to bone resorption. Conclusions: These results provide insights into mechanisms underlying of ccRCC tumors progression leading bone metastasis. We also highlight potential communication channels and therefore therapeutic targets within both the immune and the tumor cell populations. Citation Format: Shenglin Mei, Adele M. Alchahin, Ioanna Tsea, Youmna Kfoury, Taghreed Taghreed, Hirak Sarkar, Shulin Wu, Alexander O. Subtelny, Yida Zhang, Keyan Salari, Chin-Lee Wu, Mark A. Randolph, David T. Scadden, Douglas Dahl, John Shin, Peter Kharchenko, Philip Saylor, David Sykes, Ninib Baryawno. Single-cell analysis of immune and stroma cell remodeling in renal cell carcinoma primary tumors and bone metastatic lesions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 631.

Prognostic MRI parameters in acute traumatic cervical spinal cord injury

PurposeThe aim of this study is to estimate the prognostic value of some features documented on preoperative MRI study in patients with acute cervical spinal cord injury.MethodsThe study was conducted in patients operated for cervical spinal cord injury (cSCI) from April 2014 to October 2020.The quantitative analysis on preoperative MRI scans included: length of the spinal cord intramedullary lesion (IMLL the canal diameter at the level of maximal spinal cord compression (MSCC) and the presence of intramedullary hemorrhage. The canal diameter at the MSCC was measured on the middle sagittal FSE-T2W images at the maximum level of injury.The America Spinal Injury Association (ASIA) motor score was used for neurological assessment at hospital admission. At 12-month follow-up all patients were examined with the SCIM questionnaire.ResultsAt linear regression analysis, the length of the spinal cord lesion [β coefficient −10.35, 95% confidence interval (CI)−13.71 to−6.99; p < 0.001], the diameter of the canal at the level of the MSCC (β coefficient 6.99, 95% CI 0.65 to 13.33; p = 0.032), and the intramedullary hemorrhage (β coefficient − 20.76, 95% CI − 38.70 to − 2.82; p = 0.025), were significantly associated with the score at the SCIM questionnaire at one year follow-up: shorter spinal cord lesion, greater diameter of the canal at the level of the MSCC, and absence of intramedullary hemorrhage were predictors of better outcome.ConclusionAccording to the findings of our study, the spinal length lesion, canal diameter at the level of spinal cord compression and intramedullary hematoma documented by the preoperative MRI study were associated with the prognosis of patients with cSCI.

Acute spontaneous spinal subdural hematoma presenting with Takotsubo cardiomyopathy: a rare case report and literature review.

Spontaneous spinal subdural hematoma (SSDH) is a rare and dangerous intraspinal hematoma that usually occurs in the thoracic vertebra. The influence of early cardiovascular changes secondary to spinal cord injury is an important emergent issue.Herein, we report a case of a middle-aged woman with clinical manifestations of back pain and motion and sensory disturbances below the level of spinal cord compression. During the disease course, she also developed changes indicative of myocardial injury, such as tachycardia, markedly increased concentrations of brain natriuretic peptide and cardiac troponin I, and a decreased left ventricular ejection fraction, which were consistent with the diagnosis of Takotsubo cardiomyopathy (TTC). After the administration of supportive therapies, the symptoms of myocardial injury rapidly resolved. With the absorption of SSDH, the symptoms and clinical signs were alleviated. We also reviewed the literature on cases of concomitant SSDH and TTC.This rare case broadens the symptom spectrum of SSDH and highlights the need for clinicians to be aware of concomitant SSDH and TTC. Initial conservative treatment is a viable option for SSDH with concomitant TTC. However, urgent surgery may be a better option if the SSDH progressively enlarges and causes spinal cord compression.

Morphologic Characteristics of the Deep Cervical Paraspinal Muscles in Patients with Single-Level Cervical Spondylotic Myelopathy

This study aimed to compare morphologic changes of deep paraspinal muscles at C4-7 in patients with C5-6 single-level cervical spondylotic myelopathy (CSM), and to evaluate the relationship between morphologic changes and the level of spinal cord compression. The study included 15 patients with C5-6 single-level CSM and 15 age- and sex-matched healthy subjects. Cross-sectional area (CSA) and functional CSA of the bilateral longus capitis (LCap), longus colli (LC), multifidus (MF), semispinalis cervicis (SSC), semispinalis capitis, splenius capitis, and splenius cervicis were measured on preoperative magnetic resonance images at C4-7, and calculated as ratios with respect to the corresponding vertebral body CSA. The mean maximum spinal cord compression was 22.30% in the CSM group. At the cranial level (C4-5), the CSM group had more fat infiltration in the MF and SSC (P < 0.05). At the spinal cord compression segment and caudal adjacent segment (C5-6 and C6-7), the degree of fat infiltration of all paravertebral muscles was aggravated, accompanied by atrophy of LCap, LC, and MF (P < 0.05). Compared between different levels, fat infiltration in the MF at C5-6 was greater than adjacent levels. In patients with C5-6 single-level CSM, fat infiltration and atrophy of deep paraspinal muscles, especially the Lcap, LC, and MF, mainly occurred in the level of spinal cord compression and caudal adjacent level. In the cranial adjacent segment, the degree of MF and SSC fat infiltration in patients with CSM was also aggravated. This may suggest that multiple mechanisms are involved in paraspinal muscles degeneration in CSM.

Haemodynamic changes during prone positioning in anaesthetised chronic cervical myelopathy patients.

Background and Aims:Anaesthetised patients, when positioned prone, experience hypotension and reduction in cardiac output. Associated autonomic dysfunction in cervical myelopathy patients predisposes them to haemodynamic changes. The combined effect of prone positioning and autonomic dysfunction in anaesthetised patients remains unknown.Methods:Thirty adult chronic cervical myelopathy patients, aged 18-65 years with Nurick grade ≥2 were recruited in this prospective observational study. Heart rate, mean blood pressure, cardiac output, stroke volume, total peripheral resistance and stroke volume variation were measured using NICOM® monitor. Data were collected in supine before anaesthetic induction (baseline), 2 minutes after induction, 2 minutes after intubation, before and after prone positioning and every 5 minutes thereafter until skin incision. Repeated measures analysis of variance (ANOVA) was used to analyse the haemodynamic parameters across the time points. Bivariate Spearman's correlation was used to find factors associated with blood pressure changes. A P value <0.05 was kept significant.Results:Cardiac output during the entire study period remained stable (P = 0.186). Sixty percent of the patients experienced hypotension. At 15 and 20 minutes after prone positioning, mean blood pressure decreased (P = 0.001), stroke volume increased (P = 0.001), and heart rate and total peripheral resistance decreased (P < 0.001, P = 0.001, respectively). These changes were significant when compared to pre-prone position values. Number of levels of spinal cord compression positively correlated with the incidence of hypotension.Conclusion:Cervical myelopathy patients experienced hypotension with preserved cardiac output in prone position due to a reduction in total peripheral resistance. Hypotension correlated with the number of levels of spinal cord compression.

MRI Analysis of the Combined Prospectively Collected AOSpine North America and International Data: The Prevalence and Spectrum of Pathologies in a Global Cohort of Patients With Degenerative Cervical Myelopathy.

An ambispective analysis. The aim of this study was to report the global prevalence of specific degenerative cervical pathologies in patients with degenerative cervical myelopathy (DCM) through detailed review of magnetic resonance imaging (MRIs). DCM encompasses a spectrum of age-related conditions that result in progressive spinal cord injury. MRIs of 458 patients (age 56.4 ± 11.8, 285 male, 173 female) were reviewed for specific degenerative features, directionality of cord compression, levels of spinal cord compression, and signal changes on sagittal T2-weighted imaging (T2WI) and sagittal T1-weighted imaging (T1WI). Data were analyzed for differences between sex using Chi-square tests and geographic variations using Kruskal-Wallis tests. Spondylosis was frequently present (89.7%) and was commonly accompanied by enlargement of the ligamentum flavum (LF) (59.9%). Single-level disc pathology, ossification of posterior longitudinal ligament (OPLL), and spondylolisthesis had a prevalence of ∼10% each. OPLL was accompanied by spondylosis in 91.7%. Klippel-Feil syndrome was observed in 2.0%. The Asia-Pacific region had more OPLL (29%, P = 3 × 10) and less spondylolisthesis (1.9%, P = 0.002). Females presented more commonly with single-level disc pathology (13.9% vs. 6.7%; P = 0.013), and males with spondylosis (92.3% vs. 85.6%; P = 0.02) and enlargement of LF (61.4% vs. 49.1%; P = 0.01). C5 to C6 was the most frequent maximum compressed site (39.5%) and region for T2WI hyperintensity (38.9%). T2WI hyperintensity more commonly presented in males (82.4% vs. 66.7%; P < 0.001). This is the largest report on the prevalence and spectrum of pathology in patients with DCM. Herein, it has been demonstrated that degenerative features are highly interrelated, that females presented with milder MRI evidence of DCM, and that variations exist in the prevalence of pathologies between geographical regions. 2.

Association Between Paraspinal Muscle Morphology, Clinical Symptoms, and Functional Status in Patients With Degenerative Cervical Myelopathy.

A cross-sectional study. The aim of this study was to assess fatty infiltration and asymmetry of the multifidus (MF), semispinalis cervicis (SCer), semispinalis capitis (SCap), and splenius capitis (SPL) muscles in patients with degenerative cervical myelopathy (DCM), and evaluate their correlations with clinical symptoms and functional scores. Cervical muscle alterations have been reported in patients with chronic neck pain, but the assessment of cervical muscle morphology has been overlooked in patients with DCM. Thirty-eight patients diagnosed with DCM and spinal cord compression at C4-C5 or C5-C6 (first level of compression) were included. Cervical muscle measurements of cross-sectional area (CSA) and ratio of functional CSA (fat-free area, FCSA) to total CSA were obtained from T2-weighted axial images at the level above, same, and level below the most cranial level of spinal cord compression. Muscle fatty infiltration and asymmetry was assessed at every level and their associations with respect to clinical signs and symptoms and functional scores were investigated. There was a significant increase in fatty infiltration (decrease in FCSA/CSA ratio) of the MF (P = 0.001) and SPL (P < 0.001) muscles at the level below the spinal cord compression. A significant increase in MF CSA asymmetry was also observed at the level below the compression. Lower MF FCSA/CSA ratio was associated with longer 30-m walking test time. Lower SCer FCSA/CSA was associated with corticospinal distribution motor deficits and atrophy of the hands. Greater asymmetry in SCap CSA was associated with higher Neck Disability Index (NDI) scores, whereas lower asymmetry in MF CSA was associated with a positive Hoffman sign and weakness. A significant increase in muscle fatty infiltration and CSA asymmetry at the level below the compression was observed in patients with DCM. Our results also suggest an association between cervical muscle morphology and DCM clinical symptoms and functional status. 2.

96 - Association between Paraspinal Muscle Morphology, Clinical Symptoms and Functional Status in Patients with Degenerative Cervical Myelopathy

STUDY DESIGN A cross-sectional study. OBJECTIVE The aim of this study was to assess fatty infiltration and asymmetry of the multifidus (MF), semispinalis cervicis (SCer), semispinalis capitis (SCap), and splenius capitis (SPL) muscles in patients with degenerative cervical myelopathy (DCM), and evaluate their correlations with clinical symptoms and functional scores. SUMMARY OF BACKGROUND DATA Cervical muscle alterations have been reported in patients with chronic neck pain, but the assessment of cervical muscle morphology has been overlooked in patients with DCM. METHODS Thirty-eight patients diagnosed with DCM and spinal cord compression at C4-C5 or C5-C6 (first level of compression) were included. Cervical muscle measurements of cross-sectional area (CSA) and ratio of functional CSA (fat-free area, FCSA) to total CSA were obtained from T2-weighted axial images at the level above, same, and level below the most cranial level of spinal cord compression. Muscle fatty infiltration and asymmetry was assessed at every level and their associations with respect to clinical signs and symptoms and functional scores were investigated. RESULTS There was a significant increase in fatty infiltration (decrease in FCSA/CSA ratio) of the MF (P = 0.001) and SPL (P < 0.001) muscles at the level below the spinal cord compression. A significant increase in MF CSA asymmetry was also observed at the level below the compression. Lower MF FCSA/CSA ratio was associated with longer 30-m walking test time. Lower SCer FCSA/CSA was associated with corticospinal distribution motor deficits and atrophy of the hands. Greater asymmetry in SCap CSA was associated with higher Neck Disability Index (NDI) scores, whereas lower asymmetry in MF CSA was associated with a positive Hoffman sign and weakness. CONCLUSION A significant increase in muscle fatty infiltration and CSA asymmetry at the level below the compression was observed in patients with DCM. Our results also suggest an association between cervical muscle morphology and DCM clinical symptoms and functional status. LEVEL OF EVIDENCE 2.

Analysis of C5 Palsy After Cervical Open-door Laminoplasty

A retrospective study. To determine the clinical and imaging characteristics of postoperative C5 palsy after cervical open-door laminoplasty. Postoperative C5 palsy is a common complication of cervical laminoplasty, and although there are several hypotheses regarding its etiology, the pathogenesis and preventive measures remain unidentified and many controversies remain. A total of 141 consecutive patients (100 men and 41 women) who had undergone open-door laminoplasty for cervical myelopathy between 2006 and 2009 were included in this study. Postoperative C5 palsy was defined as deltoid muscle weakness of a grade <3 in manual muscle test. The patients were divided into 2 groups: 1 that had experienced C5 palsy (PG; the palsy group) and the other that had not (NPG; the nonpalsy group). The parameters evaluated were the incidence of C5 palsy, the level at which spinal cord compression appeared preoperatively, the spinal cord level showing a T2 high-signal intensity lesion on magnetic resonance imaging, T2 high-signal intensity lesions newly appearing postoperatively, and the diameters of the C4/5 and C5/6 foramens. The incidence of C5 palsy was 6.4% (9/141 cases). There were no significant differences between the 2 groups in sex, age, diagnosis, operation time, blood loss, level of spinal cord compression, level of T2 high-signal lesion, or new T2 high-signal lesions. The average diameter of the C4/5 foramen was 1.99 mm in the PG and 2.76 mm in the NPG (P<0.005). In contrast, the average diameter of the C5/6 foramen was 2.35 mm in PG and 2.50 mm in the NPG. There was a significant difference in the diameter of the C4/5 foramen between the PG and the NPG. The results suggest that the main etiology of C5 palsy is impairment of the C5 nerve root induced by preexisting C4/5 foraminal stenosis.

Use sagittal reconstruction CT for making decisions regarding the surgical strategy for cervical ossification of the posterior longitudinal ligament

Use sagittal reconstruction CT to verify the surgical strategy for cervical ossification of the posterior longitudinal ligament (OPLL). A retrospective study of 161 patients (106 males and 55 females) who had undergone surgery for OPLL from July 2007 to November 2010 was performed. The mean age at surgery was 54.5 years (range from 26 to 77 years). The mean follow-up period was 28 months (12 - 54 months). There were 40 patients accept anterior approach surgeries (anterior group) which include 14 cases of anterior cervical corpectomy and fusion and 26 cases of anterior cervical discectomy and fusion. There were 120 patients accept posterior approach surgeries (posterior group) which was spinous process-splitting laminoplasty for cervical myelopathy using coralline hydroxyapatite. One patient accepted combined anterior and posterior approach. According to the sagittal reconstruction CT, the main reason for spinal cord compression was cervical disc herniation in anterior group, and OPLL in posterior group. The level of spinal cord compression was 1 to 2 levels in anterior group, and 1 to 5 levels in posterior group with a major of 2 to 4 levels. As the classification of OPLL, segmental type and circumscribed type were major of segmental type in anterior group and all of the four types were in posterior group, the distribution of each type was average. The patients of posterior group were classified into two groups according to the modified K-line classification, and clinical results were compared between the two groups. The modified K-line was defined as a line that connects the midpoints of the spinal canal at C(2) and C(7) on sagittal CT myelography. Compression to the spinal cord did not exceed the K-line in the modified K-line(+) group and did exceed it in the modified K-line(-) group. Clinical data were compared using t-test or χ(2) test. Correlation analysis was used to determine the relationships of C(2)-C(7) angulation between sagittal reconstruction CT and neutral position X-ray. The patient of anterior group had better recovery rate of the JOA score (72% ± 27%) than the posterior group (59% ± 35%) at the latest follow-up (t = 2.238, P = 0.027). In posterior group, the patients of modified K-line(+) group had better recovery rate of the JOA score (63% ± 37%) than the K-line(-) group (49% ± 30%) at the latest follow up (t = 2.150, P = 0.034). The C(2)-C(7) angulation on sagittal reconstruction CT was 11° ± 9° which has significantly correlated with the C(2)-C(7) angulation on neutral position X-ray which was 10° ± 10° (r = 0.947, P < 0.01). Considering the selection of surgical approach, it should be combined with the main clinical diagnosis for spinal cord compression, the level of compression, the classification of OPLL and the kyphotic alignment of the cervical spine. The modified K-line is a simple and practical tool for making decisions regarding the surgical strategy for cervical OPLL patients.

MR Spectroscopy of Cervical Spinal Cord in Patients with Clinical and/or Electrophysiologic Signs of Spinal Cord Compression

We evaluated the efficiency of MR spectroscopy compared with conventional MR imaging in 14 patients with clinical and/or electrophysiologic signs of spinal cord compression. Cervical spinal cord was evaluated for the presence of abnormal signal intensity on T1 and T2 weighted images. MR spectroscopy was performed at the level of spinal cord compression seen on conventional MR images. Clinical and/or electrophysiological studies were also obtained to confirm the presence of a suspected spinal cord compression for these areas. MR spectroscopy was also performed at a normal site of spinal cord without any clinical and/or electrophysiological finding of compression and without any sign of compression on conventional MR images. MR spectroscopy findings of suspected areas were compared with the normal areas for each patient. Twenty levels of cervical spinal cord with both clinical and/or electrophysiological and conventional MR signs of compression were evaluated with MR spectroscopy. MR spectroscopy was also performed at the normal areas of the cervical spinal cord selected adjacent to the level of compression as vascularity and metabolism of cervical spinal cord significantly change between different levels. All patients except one had a decrease in N-acetylaspartate level at the suspected areas compared to the normal areas without any sign or suspicion of compression. Creatine levels were increased in 14 suspected area but decreased in six. Choline levels were decreased in 12 and increased in eight levels. Lactate levels were increased at eight levels and decreased in 12 levels. MR spectroscopy of the spinal cord can yield results supporting both clinical and electrophysiological evaluation. MR spectroscopy of the spinal cord at the level of compression observed on conventional MR images can support neuronal loss and disruption of axonal integrity.

Imaging modalities for cervical myelopathy: Medical decision making and surgical outcomes

Cervical myelopathy describes the pathologic condition of spinal cord compression within the cervical spine resulting in dysfunction of spinal cord functions. This may manifest as an alteration of gait, loss offine motor skills of the hands and arms, or in more advanced cases, with alteration of normal bowel and bladder control. 1 The most common clinical scenario occurs in a patient with spondylotic changes with multilevel disc degeneration of the cervical spine (cervical spondylotic myelopathy, CSM). Other pathologic processes may include large cervical disc herniations, ossification of the posterior longitudinal ligament (OPLL), ossification of the yellow ligament (OYL), or primary or malignant tumors of the spine. Diagnostic imaging tests include plain radiographs (typically AP, lateral, flexion, and extension views), computed tomography (CT), magnetic resonance imaging (MRI), and myelography with and without CT. Each type of imaging modality offers unique information, thus frequently mandating the use of several tests to gather the necessary clinical information to make appropriate treatment decisions. Three-dimensional imaging techniques such as CT scans and MRI have greatly expanded our understanding of cervicalmyelopathy.Theuseofthesediagnostictoolscontinuesto enhance our understanding of the pathoanatomy. Positive and negative prognostic indicators are emerging from the increasing detail seen with current imaging techniques. Nurick’s natural history study has demonstrated the stepwise decline in function which is seen in untreated cervical spondylotic myelopathy. 2 Identification of risk factors which impact surgical and nonoperative treatment will give the clinician the ability to best counsel and advise patients with cervical myelopathy. Advanced age at the time of diagnosis, longer duration of myelopathy symptoms, multiple levels of spinal cord compression, and severity of spinal cord compression are all associated with diminished recovery potential following spinal cord decompression. 3-7 Each type of imaging study provides a component of information which is then combined with the patient’s history and physical examination to determine the treatment plan. Plain radiographs along with at least one form of three-dimensional imaging (CT, CT myelogram, or MRI) represent the essential basic information that is required before consideration of surgical intervention.

Adaptive signal enhancement of somatosensory evoked potential for spinal cord compression detection: an experimental study

The objective of this study was to assess the efficacy of adaptive signal enhancement (ASE) as a means of indicating intraoperative spinal cord impingement. ASE technique was used to determine the changes in the somatosensory evoked potential (SEP) elicited from eighteen rats with varying levels of spinal cord compression. ASE technique was found to be able to effectively extract SEP signals for the detection of spinal cord injury. Furthermore, while the traditional ensemble averaging (EA) technique requires more than 500 trials for meaningful signal processing in severe noisy SEP recordings, the ASE method required only 50 trials to provide similar information. Because of its fast and reliable SEP detection, the ASE method is ideal for spinal cord monitoring in the clinical setting.

The usefulness of central motor conduction studies in the localization of cord involvement in cervical spondylytic myelopathy

Cervical spondylytic myelopathy (CSM) is common. Magnetic resonance imaging (MRI), although sensitive, often reveals extensive and sometimes clinically irrelevant findings. The purpose of this study was to investigate the usefulness of central motor conduction studies in localizing the rostral level of cord involvement in 6 patients with CSM. Central motor conduction was assessed using high-voltage stimulation for the spinal roots and magnetoelectrical stimulation for the motor cortex, recording from “marker muscles” innervated by successively higher cervical cord segments. Abnormal central motor conduction affected all subjects at C8–T1, 5 subjects at C7, but none at the C5–C6 levels. The MRI showed abnormalities at multiple levels as high as C4. Our results suggest that central motor conduction studies are helpful in localizing the clinically relevant levels of spinal cord compression in CSM and correlate well with motor abnormalities on clinical examination. © 1998 John Wiley & Sons, Inc. Muscle Nerve 21:1220–1223, 1998.

The usefulness of central motor conduction studies in the localization of cord involvement in cervical spondylytic myelopathy.

Cervical spondylytic myelopathy (CSM) is common. Magnetic resonance imaging (MRI), although sensitive, often reveals extensive and sometimes clinically irrelevant findings. The purpose of this study was to investigate the usefulness of central motor conduction studies in localizing the rostral level of cord involvement in 6 patients with CSM. Central motor conduction was assessed using high-voltage stimulation for the spinal roots and magnetoelectrical stimulation for the motor cortex, recording from "marker muscles" innervated by successively higher cervical cord segments. Abnormal central motor conduction affected all subjects at C8-T1, 5 subjects at C7, but none at the C5-C6 levels. The MRI showed abnormalities at multiple levels as high as C4. Our results suggest that central motor conduction studies are helpful in localizing the clinically relevant levels of spinal cord compression in CSM and correlate well with motor abnormalities on clinical examination.

Magnetic resonance imaging findings in ossification of the posterior longitudinal ligament of the cervical spine.

Because of the lack of magnetic resonance (MR) signal from cortical bones, MR imaging is inadequate for diagnosing ossified lesions in the spinal canal. However, MR imaging provides important information on spinal cord morphology and associated soft-tissue abnormality. The purpose of this study is to determine the role of MR imaging in the diagnosis and treatment of patients with ossification of the posterior longitudinal ligament (OPLL) of the cervical spine. The authors reviewed MR imaging findings in 42 patients with cervical OPLL who were examined with a superconducting MR imaging system. The types of OPLL reviewed included eight cases of continuous, 21 cases of segmental, and 13 cases of the mixed type. All patients were treated surgically either by anterior (26 cases) or posterior decompression (16 cases). The T1-weighted images clearly demonstrated the spinal cord deformity caused by OPLL. Associated disc protrusion was found to be present at the maximum compression level in 60% of the patients in this series. The highest incidence of disc protrusion (81%) was found in patients with segmental OPLL. Intramedullary hyperintensity on T2*-weighted imaging was noted in 18 patients (43%). The neurological deficits observed in these 18 patients were significantly more severe than those observed in the other 24 patients. Postoperative MR imaging revealed improvement in the spinal cord deformity, although the intramedullary hyperintensity was still observed in most cases. The present study demonstrates the importance of associated disc protrusion in the development of myelopathy in patients with cervical OPLL. Magnetic resonance imaging findings may be used to help determine the actual levels of spinal cord compression and to suggest the method of surgical treatment.

Chronic cervical compressive myelopathy in horses: clinical correlations with spinal cord alterations

Histological examination was performed on the cervical spinal cord from 13 horses with chronic cervical compressive myelopathy of 4 to 29 months duration. Structural alterations were correlated with clinical features. At the level of compression, the spinal cord was grossly deformed. Histological alterations included nerve fibre swelling and degeneration, occasional spheroids, astrocytic gliosis, increased macrophage activity and increased perivascular collagen. Myelin degeneration or loss at the level of the compressive lesion was greatest in the ventral and lateral funiculi and less consistently present in the dorsal funiculi. Asymmetry of lesions in the dorsal funiculi was associated with asymmetry of clinical signs in 5 horses. Histological alterations in areas of Wallerian degeneration were similar to that at the level of spinal cord compression, except that perivascular collagen was not increased. Wallerian degeneration was present cranial to the compressed site in the superficial portions of the lateral funiculi and in the middle of the dorsal funiculi. Caudal to the compressed site it was present in the ventral funiculi adjacent to the ventral median fissure and in the middle of the lateral funiculi. Deformation of the spinal cord did not correlate with the severity or duration of clinical signs but was positively correlated with the amount of perivascular collagen increase. The amount of nerve fibre swelling was not correlated with the severity of clinical signs but was negatively correlated with their duration. A rapid loss of nerve fibres apparently occurred early in the course of compression, since there was a marked decrease in the amount of nerve fibre swelling and Marchi stained degenerating myelin with increasing clinical duration.(ABSTRACT TRUNCATED AT 250 WORDS)