Anteroposterior Diameter Of Dural Sac Research Articles

Effectiveness of caudal block in patients with spinal stenosis accompanied by redundant nerve root syndrome

Redundant nerve root syndrome (RNRS) is characterized by tortuous, elongated, and enlarged nerve roots in patients with lumbar spinal stenosis. This study was performed to evaluate the effects of caudal block in patients with RNRS and assess factors associated with RNRS. Patients with lumbar spinal stenosis who underwent caudal block were retrospectively analyzed. A comparative analysis of pain reduction was conducted between patients with RNRS (Group R) and those without RNRS (Group C). Generalized estimating equation analysis was used to identify factors related to the treatment response. RNRS-associated factors were analyzed using logistic regression analysis. In total, 54 patients were enrolled (Group R, n = 22; Group C, n = 32). Group R had older patients than Group C. The caudal block showed less pain reduction in Group R than in Group C, but the difference was not statistically significant. Generalized estimating equation analysis showed that RNRS was the factor significantly associated with the treatment response. The dural sac anteroposterior diameter and left ligamentum flavum thickness were associated with RNRS in the logistic regression analysis. Caudal block tended to be less effective in patients with than without RNRS, but the difference was not statistically significant.

Preoperative dorsal disc height is a predictor of indirect decompression effect through oblique lateral interbody fusion in lumbar degenerative stenosis.

The extent of indirect decompression after oblique lateral interbody fusion (OLIF) is one of the most important factors in deciding the strategy. To assess the radiographical predictors of the effect of indirect decompression in patients with lumbar degenerative spondylosis by OLIF. Thirty-two consecutive patients who underwent OLIF at 58 lumbar disc levels were enrolled in this study. The radiographic measurements included central disc height (cDH), dorsal disc height (dDH), right/left foraminal height in sagittal plane computed tomography (CT), and cross-sectional dural sac antero-posterior diameter (CDSD) in axial plane CT. All patients were followed up for 1 year after surgery. All CT parameters (cDH, dDH, CDSD, right foraminal height [RFH], and left foraminal height [LFH]) significantly increased after OLIF (P < .0001). The mean raised height difference was 4.3, 3.4, 3.4, and 2.6 mm for cDH, dDH, RFH, and LFH, respectively. The mean CDSD increase was 1.4 mm. The median values of post/pre-operation (change rates) were 1.5 times in cDH, 1.9 times in dDH, and 1.2 times in CDSD, RFH, and LFH. RFH and LFH change rates were related with both cDH and dDH change rates, while the CDSD change rate was only associated with the dDH change rate (P = .0206*) but not with cDH (P = .2061). There was a significant negative relationship between the CDSD change rate and preoperative dDH (P = .0311*, R2 = 0.0817) but not with preoperative cDH (P = .4864). OLIF should be avoided for patients with preserved high dDH.

Influence of Lumbar Spinal Canal Dimensions on Neurological Claudication Symptomatology - A Case Control Study

Lumbar spinal stenosis (LSS) is abnormal narrowing of spinal canal of lumbar vertebrae causing compression of neural tissue which leads to a neurologic deficit. LSS is diagnosed based on clinical symptoms of patient and it is confirmed using MRI (Magnetic Resonance Imaging). The aim of the study is to determine the association between MRI lumbar spinal canal and foraminal dimensions in on neurological claudication symptomology. A total of 89 patients (45 males ,44 females, age range: 20-60 years) referred for MRI Lumbar spine were included in this prospective study. Patients were categorized into symptomatic (49 cases) and asymptomatic (40 controls) based on Edinburgh claudication questionnaire (ECQ). The Antero-posterior diameter of dural sac, Transverse diameter of dural sac, Cross sectional area of dural sac, Cross sectional area of lateral recess, Lateral recess depth, Angle of lateral recess, Ligamentous interfacet distance was measured from L3 to S1 on Axial T2 weighted MRI images. The strength of association between MRI measurements and clinical symptoms were assessed using logistic regression analysis and Cramer’s V test. The Phi coefficient value for the lumbar spinal canal, foraminal dimensions with neurogenic claudication symptomology based on ECQ was 0.108 &amp; 0.207 respectively, which showed weak positive correlation. Our study concludes that MRI measurements of lumbar spinal canal and foraminal dimensions denoting LSS were found to show weak positive correlation with clinical symptoms assessed based on Edinburgh claudication questionnaire.

The profile of the spinal column in subjects with lumbar developmental spinal stenosis.

The aim of this study was to determine the differences in spinal imaging characteristics between subjects with or without lumbar developmental spinal stenosis (DSS) in a population-based cohort. This was a radiological analysis of 2,387 participants who underwent L1-S1 MRI. Means and ranges were calculated for age, sex, BMI, and MRI measurements. Anteroposterior (AP) vertebral canal diameters were used to differentiate those with DSS from controls. Other imaging parameters included vertebral body dimensions, spinal canal dimensions, disc degeneration scores, and facet joint orientation. Mann-Whitney U and chi-squared tests were conducted to search for measurement differences between those with DSS and controls. In order to identify possible associations between DSS and MRI parameters, those who were statistically significant in the univariate binary logistic regression were included in a multivariate stepwise logistic regression after adjusting for demographics. Odds ratios (ORs) and 95% confidence intervals (CIs) were reported where appropriate. Axial AP vertebral canal diameter (p < 0.001), interpedicular distance (p < 0.001), AP dural sac diameter (p < 0.001), lamina angle (p < 0.001), and sagittal mid-vertebral body height (p < 0.001) were significantly different between those identified as having DSS and controls. Narrower interpedicular distance (OR 0.745 (95% CI 0.618 to 0.900); p = 0.002) and AP dural sac diameter (OR 0.506 (95% CI 0.400 to 0.641); p < 0.001) were associated with DSS. Lamina angle (OR 1.127 (95% CI 1.045 to 1.214); p = 0.002) and right facet joint angulation (OR 0.022 (95% CI 0.002 to 0.247); p = 0.002) were also associated with DSS. No association was observed between disc parameters and DSS. From this large-scale cohort, the canal size is found to be independent of body stature. Other than spinal canal dimensions, abnormal orientations of lamina angle and facet joint angulation may also be a result of developmental variations, leading to increased likelihood of DSS. Other skeletal parameters are spared. There was no relationship between DSS and soft tissue changes of the spinal column, which suggests that DSS is a unique result of bony maldevelopment. These findings require validation in other ethnicities and populations. Level of Evidence: I (diagnostic study) Cite this article: Bone Joint J2021;103-B(4):725-733.

A New Posterior Extensor Attachment-Point Reconstruction Technique for Cervical Spondylotic Myelopathy Involving C2 Segment: Clinical Outcome and Safety.

Cervical spondylotic myelopathy (CSM) is a common degenerative disease that mainly occurs in elder patients, leading to different degrees of neurological dysfunction. Spinal cord involvement is mainly distributed at the C3-C7 segments, but it may also involve up to the C2 level. This study aimed to assess the clinical efficacy and safety of open-door laminoplasty using a new extensor attachment-point reconstruction technique for treating CSM involving the C2 segment. Fifty-nine patients with CSM involving the C2 segment and undergoing open-door laminoplasty were included in this retrospective study. Based on the titanium plate used in the operation, patients were divided into two groups, a reconstructed titanium plate fixation (RPF) group (n = 28) and a conventional titanium plate fixation (CPF) group (n = 31). Improvements in neurological function, cervical range of motion (ROM), cervical curvature index (CCI), preservation of posterior cervical muscle mass, and axial symptoms were compared between the two groups. There were no significant differences in operative time and intraoperative blood loss between the groups (p > 0.05). The Japanese Orthopaedic Association (JOA) score significantly increased in both groups postsurgery (p < 0.05); the neurological recovery rate was similar between the two groups (64.1 ± 13.3% vs. 65.9 ± 14.7%, p > 0.05). There was no significant loss of cervical ROM in either group (p > 0.05). The anteroposterior dural sac diameter at the C2 level was significantly enlarged in both groups (p < 0.05). Alternatively, CCI was significantly reduced in the CRP group (p < 0.05) but unchanged in the RPF group (p > 0.05). The cross-sectional area of the posterior cervical muscles was also significantly reduced in the CPF group (p < 0.05) but maintained in the RPF group (p > 0.05). Finally, axial symptoms were more severe in the CPF group than in the RPF group (p < 0.05). Laminoplasty is an effective surgical procedure for CSM involving the C2 segment. The reconstructed titanium plate achieved superior maintenance of cervical curvature and reduced both muscle atrophy and severity of axial symptoms compared with titanium conventional plates.

Correlation Between Dural Sac Size in Dynamic Magnetic Resonance Imaging and Clinical Symptoms in Patients with Lumbar Spinal Stenosis

To assess the dynamic change of the dural sac size in patients with lumbar spinal stenosis (LSS) from supine to standing position and their correlation with clinical symptoms. A total of 110 patients with LSS were prospectively enrolled to undergo both supine (0°) and standing (78°) magnetic resonance imaging (MRI). Dural sac cross-sectional area (DCSA) and dural sac anteroposterior diameter (DAPD) at the most constricted spinal level in supine and standing MRI were measured and compared. Clinical symptoms were assessed by duration of disease, claudication distance, visual analog scale (VAS) score of leg pain, and Chinese Oswestry Disability Index score of low back pain. The correlation between the parameters and clinical symptoms was analyzed by Pearson correlation coefficient (r). Mean minimum DCSA and DAPD in the standing position were significantly smaller (both P < 0.01) than in the supine position. DCSA and DAPD in standing MRI and their changes had better correlation with the intermittent claudication distance and VAS score of leg pain than in the supine position. A more than 15 mm2 reduction of DSCA was observed in patients with shorter claudication distance and more severe VAS score of leg pain (both P < 0.01). Dural sac size on MRI was reduced significantly from supine to standing position. Standing MRI and the changes of DCSA significantly correlated with claudication distance and VAS score of leg pain in patients with LSS. Therefore, standing MRI provides more radiologic information correlating with clinical symptoms in patients with LSS than supine MRI.

Is there a Correlation Between Degree of Radiologic Lumbar Spinal Stenosis and its Clinical Manifestation?

This was an observational cross-sectional study. The purpose of this study was to evaluate whether the degree of stenosis on magnetic resonance imaging (MRI) relates to the severity of clinical symptoms, disability, or neurological deficit in patients with symptomatic central lumbar spinal stenosis (LSS). The relationship between radiologic findings and the clinical manifestations of LSS remains unclear. A total of 84 patients (42 men, median age 70 y) with neurogenic claudication and central degenerative LSS were included in the study. The MRI parameters describing severity (anteroposterior diameter of dural sac, cross-sectional area of the dural sac, stenosis ratio, and Schizas qualitative morphologic classification were evaluated at maximum stenotic level) and the extent of stenosis (the number of central stenotic levels) were correlated to symptoms (pain intensity, walking capacity), functional disability (measured in terms of the Oswestry Disability Index), and neurological signs of LSS (neurological status was evaluated and scored by Neurological Impairment Score in LSS). A statistically significant correlation emerged only between the Neurological Impairment Score in LSS and Schizas morphologic classification (P=0.006). Pain intensity, walking capacity, and functional disability displayed no correlation with the MRI parameters of LSS. LSS is a clinicoradiologic syndrome with complex relationships between degree of radiologic stenosis disclosed by MRI and clinical manifestations. Neurological impairment in the lower extremities reflects the degree of morphologic LSS on MRI. This study did not identify any association between the degree of stenosis and functional disability, pain intensity, or walking capacity. Level II.

Spinal imaging features in Japanese patients with Marfan syndrome: a case-control study

The purpose of our study was to evaluate the morphology of the lumbosacral spine, i.e. the dura and vertebral body shape, of Japanese patients with Marfan syndrome (MFS) by comparing it with sex- and age-matched controls. Spinal MR or CT images of 32 MFS patients and 32 controls were retrospectively reviewed. The anteroposterior dural sac diameter (DSD), anteroposterior vertebral body diameter (VBD), and vertebral body height (VBH) were measured from L1 to S1 levels and the dural sac ratio [DSR = (DSD/VBD)] and vertebral body aspect ratio [VAR = (VBH/VBD)] were calculated. At each level, mean DSD and DSR were significantly higher in MFS patients; VBD was not. The cutoff values for DSR to differentiate between MFS patients and the controls were 0.59, 0.46, 0.42, 0.45, 0.47, and 0.47 from the level of L1 to S1. At a sensitivity of 93.8 % and a specificity of 84.4 % the cutoff value at S1 was most diagnostic. In MFS patients VAR was significantly higher at L3 and L4. Our cutoff value for DSR >0.47 at S1 may help to identify MFS in the Japanese population. A square-like appearance of the L3 and L4 vertebral bodies is a supplementary finding in MFS patients.

Lumbar spine MRI in upright position for diagnosing acute and chronic low back pain: statistical analysis of morphological changes

BackgroundPatients with low back pain frequently demonstrate recumbent magnetic resonance imaging (MRI) alterations not always related to homogeneous clinical symptoms. The purpose of this study was to evaluate and quantify the statistical significance of variations of some anatomical parameters of the lumbosacral spine and reveal occult disc pathologies from recumbent to upright position in patients with acute and chronic low back pain.Materials and methodsFifty-seven patients complaining of low back pain (27 women, 30 men) underwent dynamic lumbosacral MRI with a 0.25-T tilting system (G-scan Esaote). We settled five parameters for which variations have been evaluated: lumbosacral angle, lordosis angle, L3–L4 intersomatic disc height, L3–L4 interspinous processes distance, and widest anteroposterior dural sac diameter. Images were obtained in both recumbent and upright positions.ResultsStatistically significant differences [one-way analysis of variance (ANOVA), p = 0.0043] were found between each pair of values of parameters sampled in recumbent and upright positions. In 70 % of patients, on visual qualitative analysis only, an increment of disc protrusions and/or spondylolisthesis was found in the upright position; in three cases, in the upright position only, an interarticular pseudocyst was found.ConclusionsDynamic MRI with an open-configuration, low-field tilting MRI system is a feasible and promising tool to study degenerative pathology of the spine. Moreover, in cases of low back pain with negative MRI in the recumbent position or in patients with pain in the upright position only, tilting MRI permits visualization of occult spine and disc pathologies in patients with acute or chronic low back pain.

Application of intraoperative spinal ultrasonography in thoracic spinal decompressive operations

To investigate the feasibility and clinical value of intraoperative ultrasonography (IOUS) in thoracic spinal decompression surgery. Ten patients with confirmed thoracic spinal stenosis underwent thoracic spinal decompression in our center from August 2009 to December 2010. The appearance of the compressed section of spinal cord was observed with IOUS. Before and after the decompression operation, the diameters of dural sac and the spinal cord were recorded respectively. The location and nature of the compression-causing mass were confirmed. IOUS clearly showed the shape of the normal and the compressed sections of dural sac and spinal cord. In the 14 thoracic spinal cord sections of these 10 patients, the anteroposterior diameter, horizontal diameter, and their ratio were bigger than those before decompression. The values of anteroposterior diameter and anteroposterior/horizontal diameter ratio showed significant differences(the P value of dural sac anteroposterior diameter comparison was 0.008, which of spinal cord was 0.007; the P values of these two structures ratio comparison were both 0.002 before and after decompression), while the horizontal diameter presented no significant differences (the P values of both structures were 0.270 and 0.195 respectively before and after decompression). IOUS can clearly show the morphological changes of the dural sac and spinal cord before and after the decompression. In addition, it helps surgeons to locate and specify the nature of the compression-causing mass on the ventral side of dural sac. Furthermore, IOUS can suggest whether the decompression is sufficient in a real-time manner.

The Evaluation of Bladder Symptoms in Patients With Lumbar Compression Disorders Who Have Undergone Decompressive Surgery

Prospective cohort study. We study the relationship between the degree of dural sac compression, the prevalence of lower urinary tract symptoms, and the effect of surgical decompression in patients with lumbar spinal canal compression using the American Urological Association Symptom Score (AUAss). Patients with lumbar spinal canal compression not only experienced leg neuropathy but also lower urinary tract symptoms. There are few reports concerning the prevalence of bladder symptoms and the effect of decompression on urinary symptoms. We enrolled 245 patients, who were admitted for decompression of lumbar spinal canal compression, using the AUAss) On the basis of the score, patients were divided into 2 groups: those with significant neurologic bladder symptoms (high AUAss), and those without significant symptoms (low AUAss). The narrowest anteroposterior diameter of the dural sac at the corresponding level of decompression on axial magnetic resonance imaging (MRI) was measured for both groups. The Oswestry Disability Index and AUAss were compared before and after decompressive surgery. The urodynamic change in the group of high AUAss after surgery was analyzed. A total of 67 patients (27%) had significant lower urinary tract symptoms in our study group. The mean/median number of levels decompressed was 1.5/1 in high AUAss and 1.8/2 in low AUAss group. Decompressive surgery had beneficial effect on both the AUAss and Oswestry Disability Index in both groups. The postvoid residual urine volume was significantly reduced after surgical decompression. The narrowest diameter of dural sac on MRI has correlation with AUAss. We found that 27% patients with lumbar spinal compression disorders had lower urinary tract symptoms; the anteroposterior diameter of dural sac measured on axial MRI is correlated with the lower urinary tract symptoms. After the decompressive surgery, the most sensitive indicator of bladder dysfunction was subjective symptoms and postvoid residual voiding volume.

Dynamic Effects of Axial Loading on the Lumbar Spine During Magnetic Resonance Imaging in Patients with Suspected Spinal Stenosis

Previous studies have shown that axial compression in extension (ACE) of the spine during magnetic resonance imaging (MRI) has revealed unexpected pathological features compared with the conventional psoas-relaxed position (PRP) used in imaging. The purpose of this study was to evaluate the dynamic effect of axial loading on lumbar spinal stenosis using MRI in patients with spinal stenosis. A total of 14 women and 11 men with lumbar spinal stenosis were examined in both PRP and ACE positions. We calculated the dural-sac cross-sectional area (DCSA) to evaluate severity of spinal canal stenosis. DCSA, as well as the dural-sac anteroposterior diameter (DAPD) and dural-sac transverse diameter (DTD) in both positions were measured using a digital image view station. A paired t test determined the differences in DCSA, DAPD and DTD between the two positions at each intervertebral disc level. Axial loading increased severity of lumbar spinal stenosis during MRI, as demonstrated by a decrease in DCSA from 20.5% to 6.3% (mean, 11.40 +/- 3.66%) between the PRP and ACE positions (p less than 0.01). Significant differences were also noted in DAPD and DTD between the PRP and ACE positions (p less than 0.01). A significant correlation was found between the decrease in mean DCSA and that in DAPD and DTD. The decrease in mean DCSA, DAPD and DTD following axial compression was greatest at the L4/5 and L5/S1 levels. Axial loading increases severity of lumbar canal stenosis and the effect of axial loading on MRI examination is greatest at the L4/5 and L5/S1 levels.

The antero-posterior diameter of the lumbar dural sac does not predict sensory levels of spinal anesthesia for Cesarean delivery

The lumbosacral cerebrospinal fluid (CSF) volume, as assessed by magnetic resonance imaging, is a major determinant of the intrathecal spread of local anesthetics. Ultrasound imaging of the lumbar spine allows measurement of dural sac dimensions, which we hypothesize can be used to estimate CSF volume. The purpose of this study was to investigate whether the dural sac antero-posterior diameter correlates with sensory levels of spinal anesthesia during elective Cesarean delivery (CD). After Research Ethics Board approval and informed consent, a prospective observational study enrolled 41 patients scheduled for elective CD under spinal anesthesia. With ultrasound imaging (transverse approach, 2-5 MHz curved array probe), we measured the antero-posterior diameter of the lumbar dural sac (dural sac diameter, DSD). Spinal anesthesia was administered with 0.75% hyperbaric bupivacaine 1.6 mL, fentanyl 10 microg and morphine 100 microg, with the patient in the sitting position. Sensory block levels were assessed with ice and pinprick every five minutes until peak sensory levels (PSL) were attained. Spearman's rank correlation was used to correlate DSD with PSL and time to attain PSL. There were no significant correlations between DSD and PSL assessed with ice (P = 0.474) or pinprick (P = 0.583). Similarly, there was no significant correlation between DSD and time to reach PSL, and between DSD and patient demographics. The lumbar DSD, as determined by ultrasound, is not a predictor of spinal anesthesia spread. Further research is necessary to understand if ultrasound findings can be used to predict intrathecal spread of local anesthetics.

Postural Changes of the Dural Sac in the Lumbar Spines of Asymptomatic Individuals Using Positional Stand-Up Magnetic Resonance Imaging

Positional magnetic resonance imaging (MRI) study of control subjects. To determine dimensional changes in the lumbar dural sac as a function of posture, and to establish changes between the supine, erect and seated positions. Studies using computerized tomography and MRI were done to determine the mechanical effects on the lumbar spinal canal in the different positions. There has been no consecutive study, however, in which normal individuals were investigated for positional changes of the dural sac, including true standing position. Thirty-two male asymptomatic volunteers were recruited. The examination was performed using a new MRI system. All subjects were examined with sagittal T2 and axial T1-weighted spin-echo images. The subjects were studied in the supine, standing, and sitting positions. The measurements were made using OSIRIS software (Digital Imaging Unit University Hospital of Geneva, Geneva, Switzerland). On axial images, dural sac cross-sectional area and anteroposterior (AP) dural sac diameter were measured at the level of the L3/4, L4/5, and L5/S1 discs. On midsagittal images, AP dural sac diameter and the upper-endplate angles of L1 and S1 were measured. We found a disc degeneration or disc protrusion in 41% (12/29) of the subjects, but there was no obvious compression of the dural sac. Depending on the postures, the mean dural sac cross-sectional area and AP dural sac diameter changed. At all levels, mean dural sac cross-sectional area in the supine position was significantly smaller than in other postures. The dural area decreased most at the L5/S1 level due to positional change from standing to supine. The largest dural area at the L5/S1 level was in sitting extended. AP dural sac diameter on axial and midsagittal images showed a similar tendency. A significant posture-dependent difference of the dural sac cross-sectional area at the level of intervertebral disc in asymptomatic volunteers has been demonstrated. When the posture changed from supine to standing position, lumbar dural sac volume expanded by the increased pressure of cerebrospinal fluid, and the dural sac cross-sectional area increased. The smallest values were found in the supine position.

Degenerative Lumbar Scoliosis

A radiographic review of 78 consecutive patients with degenerative rotatory lumbar scoliosis. To assess the correlation between rotary olisthesis and neural canal dimensions using radiographic indexes and to establish a gradation system of lateral rotatory olisthesis. Degenerative scoliosis is a three-dimensional deformity often associated with spinal stenosis, although the association is not well defined. A total of 78 consecutive patients (average age, 69 years) with de novo degenerative scoliosis (79% lumbar, 21% thoracolumbar; average curve, 25 degrees) were studied with plain radiographs and MRI at presentation. Radiographic measurements included lateral translation, anteroposterior olisthesis, Cobb angle, and intervertebral rotation (Nash-Moe grade difference). Computerized measurements of MRI included dural sac cross-sectional area and anteroposterior diameter, minimum subarticular height, and foramen cross-sectional area bilaterally (convexity and concavity). Measurements were conducted twice on each lumbar level (total, 312) and the average was recorded. Lateral translation 5 mm or less (Grade I) was associated with Nash-Moe change 0 (23%) or I (77%), lateral translation 6-10 mm (Grade II) was coupled with Nash-Moe change 0 (20%) or I (80%) and lateral deviation more than 11 mm (Grade III) was associated with I (76%) or II (24%) Nash-Moe change. Maximum intervertebral rotation tended to be at either L2-L3 (48%) or L3-L4 (39%). Increased lateral translation was associated with increased intervertebral rotation (r = 0.37, P < 0.001). Increased anteroposterior olisthesis was associated with decreased anteroposterior diameter (r = -0.18, P < 0.001) and cross-sectional area (r = -0.11, P < 0.05) of the dural sac. Larger segmental Cobb angles were associated with greater foraminal cross-sectional area in the convexity (r = 0.12, P < 0.05). In the concavity, there was no significant correlation (P > 0.05) between indexes of rotary olisthesis and foraminal area or subarticular height. Cross-sectional foraminal area and subarticular height were significantly larger in the convexity than in the concavity of the scoliotic levels. In degenerative scoliotic curves, lateral translation is associated with rotation. Increased rotary olisthesis does not lead to decreased dural sac area. Anteroposterior olisthesis is inversely correlated to the dural sac anteroposterior diameter and cross-sectional area. With increased segmental Cobb angle, foraminal cross-sectional area enlarges in the convexity and does not decrease in the concavity. Presence of intervertebral rotation alone does not appear to be associated with reduced neural canal dimensions. Ligamentum flavum hypertrophy, posterior disc bulging, and bony overgrowth are more likely to contribute to stenosis irrespective of scoliosis.

Clinical and radiologic features of lumbar spinal stenosis and disc herniation with neuropathic bladder.

Clinical and radiologic findings of patients with lumbar spinal stenosis and lumbar disc herniation presenting with neuropathic bladder were prospectively analyzed. To study the relationship between the degree of cauda equina compression and prevalence of neuropathic bladder in patients with lumbar spinal stenosis and lumbar disc herniation. Bladder dysfunction has frequently been noted in patients with lumbar spinal stenosis and lumbar disc herniation. However, there have been few studies that have demonstrated the correlation between bladder function and the degree of stenotic compression of the cauda equina seen on radiologic findings in patients with lumbar spinal stenosis and lumbar disc herniation. Thirty-four patients admitted for treatment for lumbar spinal stenosis or lumbar disc herniation underwent urodynamic studies, and computed tomographic scans after myelography were obtained to determine the degree of cauda equina compression. The cross-sectional area and anteroposterior diameter of the dural sac were measured at their smallest transverse area. Twenty (58.8%) of the 34 patients were diagnosed with positive neuropathic bladder. There was no significant difference in the cross-sectional area of dural sac between the patients with positive neuropathic bladder and with negative neuropathic bladder. However, the dural sac anteroposterior diameter in positive neuropathic bladder patients was significantly shorter than that in patients with negative neuropathic bladder. A critical size for the dural sac of patients with neuropathic bladder was revealed as 8 mm in this study. The prevalence of neuropathic bladder is more significantly associated with dural sac anteroposterior diameter than with the cross-sectional area of dural sac. Therefore, dural sac anteroposterior diameter might be an important factor predicting the existence of neuropathic bladder.

Lumbosacral epidural lipomatosis: MRI grading.

Lumbosacral epidural lipomatosis (LEL) is characterized by excessive deposition of epidural fat (EF). The purpose of our retrospective study was to quantify normal and pathologic amounts of EF in order to develop a reproducible MRI grading of LEL. In this study of 2528 patients (1095 men and 1433 women; age range 18-84 years, mean age 47.3 years) we performed a retrospective analysis of MRI exams. We obtained four linear measurements at the axial plane parallel and tangent to the superior end plate of S1 vertebral body: antero-posterior diameter of dural sac (A-Pd DuS), A-Pd of EF, located ventrally and dorsally to the DuS, and A-Pd of the spinal canal (Spi C). We calculated (a) DuS/EF index and (b) EF/Spi C index. We developed the following MRI grading of LEL: normal, grade 0: DuS/EF index >or=1.5, EF/Spi C index <or=40%; LEL grade I: DuS/EF index 1.49-1, EF/Spi C index 41-50% (mild EF overgrowth); LEL grade II: DuS/EF index 0.99-0.34, EF/Spi C index 51-74% (moderate EF overgrowth); LEL grade III: DuS/EF index <or=0.33, EF/Spi C index >or=75% (severe EF overgrowth). The MRI exams were evaluated independently by three readers. Intra- and interobserver reliabilities were obtained by calculating Kappa statistics. The MRI grading showed the following distribution: grade 0, 2003 patients (79.2%); LEL grade I, 308 patients (12.2%); LEL grade II, 165 patients (6.5%); and LEL grade III, 52 patients (2.1%). The kappa coefficients for intra- and interobserver agreement in a four-grade classification system were substantial to excellent: intraobserver, kappa range 0.79 [95% confidence interval (CI), 0.65-0.93] to 0.82 (95% CI, 0.70-0.95); interobserver, kappa range 0.76 (95% CI, 0.62-0.91) to 0.85 (95% CI, 0.73-0.97). In LEL grade I, there were no symptomatic cases due to fat hypertrophy. LEL grade II was symptomatic in only 24 cases (14.5%). In LEL grade III, all cases were symptomatic. A subgroup of 22 patients (42.3%) showed other substantial spinal pathologies (e.g., disk herniation). By means of simple reproducible measurements and indexes MRI grading enables a distinction between mild, moderate, and severe EF hypertrophy. Kappa statistics indicate that LEL can be reliably classified into a four-grade system by experienced observers.