Pressure Changes Within the Cauda Equina Following Constriction of the Dural Sac An In Vitro Experimental Study

Schönström, Nils; Bolender, Nicole; Spengler, Dan M.; Hansson, Tommy

doi:10.1097/00007632-198409000-00011

Cited by 64 publications

(31 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…First, related to the methodology, since the researchers measured stenosis via the anteroposterior diameter in the MRI and not via the dural sac CSA. The CSA measurements of the dural sac have previously been emphasised as the best option for studying spinal canal stenosis 18,19,20 . CSA measurements via MRI yield a high interobserver reproducibility 21 .…”

Section: Discussionmentioning

confidence: 99%

Cauda equina redundant nerve roots are associated to the degree of spinal stenosis and to spondylolisthesis

Savarese

Ferreira-Neto²,

Herrero

et al. 2014

Arq. Neuro-Psiquiatr.

View full text Add to dashboard Cite

To evaluate the association of redundant nerve roots of cauda equina (RNRCE) with the degree of lumbar spinal stenosis (LSS) and with spondylolisthesis. Method: After Institutional Board approval, 171 consecutive patients were retrospectively enrolled, 105 LSS patients and 66 patients without stenosis. The dural sac cross-sectional area (CSA) was measured on T2w axial MRI at the level of L2-3, L3-4 and L4-5 intervertebral discs. Two blinded radiologists classified cases as exhibiting or not RNRCE in MRI. Intra-and inter-observer reproducibility was assessed. Results: RNRCE were associated with LSS. RRNCE was more frequent when maximum stenosis,55 mm 2 . Substantial intra-observer agreement and moderate inter-observer agreement were obtained in the classification of RNRCE. Spondylolisthesis was identified in 27 patients and represented increased risk for RRNCE. Conclusion: LSS is a risk factor for RNRCE, especially for dural sac CSA,55 mm 2 . LSS and spondylolisthesis are independent risk factors for RNRCE.Keywords: magnetic resonance imaging, spinal nerve roots, cauda equina, spinal stenosis, spondylolisthesis. RESUMOAvaliar associação entre raízes nervosas redundantes da cauda eqüina (RNRCE) com grau de estenose do canal lombar (ECL) e espondilolistese. Método: Após aprovação do Comitê de Ética, 171 pacientes foram selecionados retrospectivamente, 105 com ECL e 66 sem estenose. Foram realizadas mensurações da área seccional do saco dural em imagens axiais de RM ponderadas em T2 em L2/L3, L3/L4 e L4/ L5. Presença ou não de RRNCE foi classificada de forma independente por dois radiologistas, às cegas. Concordância intra e inter-observador foi analisada. Resultados: RNRCE foi associada à ECL e foi mais freqüente quando a máxima estenose encontrada foi ,55mm 2. Houve grande concordância intra-observador e moderada inter-observador na classificação das RRNCE. Espondilolistese foi identificada em 27 pacientes e representou maior risco para desenvolvimento de RNRCE. Conclusão: ECL é fator de risco para RNRCE, especialmente com áreas seccionais ,55mm 2. ECL e espondilolistese representam fatores de risco independentes para desenvolvimento de RNRCE.Palavras-chave: ressonância magnética, raizes nervosas, cauda equina, estenose espinhal, espondilolistese.Redundant nerve roots of the cauda equina (RNRCE) are characterised in magnetic resonance images (MRIs) of the lumbosacral spinal cord by the presence of elongated and tortuous nerve roots with a serpiginous or coiled appearance and near an area of spinal canal stenosis 1,2,3,4,5,6,7,8 . The literature describes this entity in association with degenerative spinal canal stenosis (Figure 1). It is believed that the acquired elongation of the nerve roots is due to a chronic compression force at the level of the lumbar spinal stenosis (LSS) 9 . This condition is not a new or separate disease but may be part of the natural evolution of lumbar canal stenosis.The recognition of RNRCE in diagnostic imaging is especially important for avoiding the misdiagnosis of other dis...

show abstract

Section: Discussionmentioning

confidence: 99%

Cauda equina redundant nerve roots are associated to the degree of spinal stenosis and to spondylolisthesis

Savarese

Ferreira-Neto²,

Herrero

et al. 2014

Arq. Neuro-Psiquiatr.

View full text Add to dashboard Cite

show abstract

“…Schönstrom et al [13,14] in an in vitro study calculated the CSA at which a further constriction caused a pressure increase among the nerve roots and called this the critical size. The average corresponding critical size was 76.9 mm 2 at the level L2, 71.5 mm 2 at level L3 and 64.8 mm 2 at L4.…”

Section: Discussionmentioning

confidence: 99%

“…The average corresponding critical size was 76.9 mm 2 at the level L2, 71.5 mm 2 at level L3 and 64.8 mm 2 at L4. Measuring the CSA with CT or MR has been shown to be a reliable method to diagnose lumbar stenosis [13][14][15][16].…”

Section: Discussionmentioning

confidence: 99%

Early postoperative MRI in detecting hematoma and dural compression after lumbar spinal decompression: prospective study of asymptomatic patients in comparison to patients requiring surgical revision

et al. 2010

View full text Add to dashboard Cite

Early postoperative MRI after spinal surgery is difficult to interpret because of confounding postoperative mass effects and frequent occurrence of epidural hematomas. Purpose of this prospective study is to evaluate prevalence, extent and significance of hematoma in the first postoperative week in asymptomatic patients after decompression for lumbar stenosis and to determine the degree of clinically significant dura compression by comparing with the patients with postoperative symptoms. MRI was performed in 30 asymptomatic patients (47 levels) in the first week after lumbar spine decompression for degenerative stenosis. Eleven patients requiring surgical revision (16 levels) for symptomatic early postoperative hematoma were used for comparison. In both groups the cross-sectional area of the maximum dural compression (bony stenosis and dural sac expansion) was measured preoperatively and postoperatively by an experienced radiologist. Epidural hematoma was seen in 42.5% in asymptomatic patients (20/47 levels). The median area of postoperative hematoma at the operated level was 176 mm 2 in asymptomatic patients and 365 mm 2 in symptomatic patients. The median cross-sectional area of the dural sac at the operated level was 128.5 and 0 mm 2 in asymptomatic and symptomatic patients, respectively, at the site of maximal compression. In the symptomatic group 75% of the patients had a maximal postoperative dural sac area of 58.5 mm 2 or less, whereas in the asymptomatic group 75% of patients with epidural hematoma had an area of 75 mm 2 or more. The size of hematoma and the degree of dural sac compression were significantly larger in patients with symptoms needing surgical revision. Dural sac area of less than 75 mm 2 in early postoperative MRI was found to be the threshold for clinical significance.

show abstract

“…Computed tomography, with its cross-sectional scan, not only provides the capability to visualize the impact of degenerative changes in the three-joint complex and the role of soft tissues in the stenosis, but also establishes measurement of the transverse area of the dural sac as the main criteria for central spinal stenosis [25][26][27], especially when myelography is employed. After studying several spinal measurements, Scho¨nstro¨m et al [26,27] noted that the dural sac cross-sectional area shows the highest correlation to the degree of spinal stenosis, clinically and experimentally.…”

Section: Abstract Lumbar Spinal Stenosis Quantitative Diagnosis mentioning

confidence: 99%

“…After studying several spinal measurements, Scho¨nstro¨m et al [26,27] noted that the dural sac cross-sectional area shows the highest correlation to the degree of spinal stenosis, clinically and experimentally. Patients with greater reduction in the compression of cauda equina were found to have better surgical outcomes [1,15].…”

Section: Abstract Lumbar Spinal Stenosis Quantitative Diagnosis mentioning

confidence: 99%

A Novel Method for the Quantitative Evaluation of Lumbar Spinal Stenosis

et al. 2006

View full text Add to dashboard Cite

Study design: A retrospective study of computed tomography (CT) myelographic images in patients with degenerative lumbar spinal stenosis (LSS). Objectives: To introduce a new technique for the quantitative evaluation of LSS. Background: Advances in hardware and software technology now permit inexpensive digitalization of radiological images, and enable methodologies for quantifying space available for neural elements in spinal canal. However, a valid method with quantitative evaluation of spinal stenosis in living patients has not been developed yet. Methods and materials: Preoperative CT myelographic scans of 50 patients with degenerative LSS were collected for retrospective investigation. The patients subsequently underwent lumbar decompressive surgery. They included scans from thoracic vertebra 12 (T12) to sacrum (S1), in which each segment was scanned through both the vertebral body and disk. All CT scan films were digitized using a high-resolution digital camera. ImageTool i software was used to measure three parameters: cross-sectional area of dural sac at disk level (A), crosssectional area of spinal canal at midpedicular level (B), and cross-sectional area of vertebral body (C). The dural sac canal ratio (DSCR) was calculated as A/BÂ100%. Low DSCR implied severe dural sac compression with a high degree of stenosis. The spinal canal vertebral ratio (CVR) was also calculated as B/CÂ100%. Low CVR implied a low baseline of canal capacity for neural elements. They were calculated from T12 to S1. Results: The study consisted of 26 male and 24 female patients, with an average age of 68.4 (35-97) years. A total of 295 segments were evaluated, of which 118 (40%) were surgically decompressed. There were wide ranges of canal crosssectional areas (140-475 mm 2 ) and dural sac crosssectional area (54-435 mm 2 ). Male patients had a slightly larger canal cross-sectional area than female patients at each level. The mean CVR was found decreased from T12 (26.1%) to L4 (18.3%). This was higher in female than in male patients, especially from T12 to L2 (P < 0.01). There were significant correlations between spinal canal and dural sac cross-sectional area (r = 0.55, P < 0.001), and also between CVR and DSCR (r = 0.31, P < 0.001). Of the levels decompressed, 82% was performed from the level L2 to L5, in which there was no significant difference in canal cross-sectional area and CVR between decompression and nondecompression (P > 0.05). There was a good correspondence between decreasing mean DSCR and increasing percentile of levels decompressed. Conclusion: DSCR represents a useful method for the quantitative diagnosis of lumbar spinal canal stenosis. ImageTool i software is a useful tool in measuring spinal morphometry.

show abstract

Pressure Changes Within the Cauda Equina Following Constriction of the Dural Sac An In Vitro Experimental Study

Cited by 64 publications

References 0 publications

Cauda equina redundant nerve roots are associated to the degree of spinal stenosis and to spondylolisthesis

Cauda equina redundant nerve roots are associated to the degree of spinal stenosis and to spondylolisthesis

Early postoperative MRI in detecting hematoma and dural compression after lumbar spinal decompression: prospective study of asymptomatic patients in comparison to patients requiring surgical revision

A Novel Method for the Quantitative Evaluation of Lumbar Spinal Stenosis

Contact Info

Product

Resources

About