Redundant nerve roots of the cauda equina: review of the literature

Nogueira-Barbosa, Marcello Henrique; Savarese, Leonor Garbin; Herrero, Carlos Fernando Pereira da Silva; Defino, Helton Luíz Aparecido

doi:10.1590/s0100-39842012000300007

Cited by 13 publications

(27 citation statements)

References 13 publications

(27 reference statements)

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“…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).…”

Section: Introductionmentioning

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.

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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...

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Section: Introductionmentioning

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.

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“…5,16 Supine body positioning yields better depiction of RNR on myelography. 6 Currently, MRI has replaced myelography as the imaging modality of choice for RNR. 6 Diagnostic imaging requires multiplanar information to diagnose RNR.…”

Section: Discussionmentioning

confidence: 99%

“…6 Currently, MRI has replaced myelography as the imaging modality of choice for RNR. 6 Diagnostic imaging requires multiplanar information to diagnose RNR. Magnetic resonance imaging is the main diagnostic modality for RNR evaluation in the evaluation of CLDCS.…”

Section: Discussionmentioning

confidence: 99%

“…Last, some hereditary neuropathies, such as Charcot-Marie-Tooth type 1 (not type 2) and Dejerine-Sottas syndromes, are included in the differential diagnosis. 6 From the differential diagnosis, SDAVF is the most common spinal vascular malformation with a male gender predilection. 17 Spinal dural arteriovenous fistula creates serpentine and dilated intervertebral veins or perimedullary venous plexus, creating flow voids on T2-weighted images.…”

Section: Discussionmentioning

confidence: 99%

“…4,5 Myelography was first utilized in the diagnosis of RNR, but most recently, magnetic resonance imaging (MRI) has been employed. 6 Although the pathophysiological mechanism of RNR formation remains unclear, mechanical trapping above or below the level of degenerative stenosis is assumed to cause its serpiginous appearance. The reported prevalence of RNR varies, with some observing it in 33.8% to 42% of patients with CLDCS.…”

Section: Introductionmentioning

confidence: 99%

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Redundant Nerve Root in a Patient With Chronic Lumbar Degenerative Canal Stenosis

Villafañe

Harvey

Kettner

2017

Journal of Chiropractic Medicine

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Objective: The purpose of this case report is to describe the diagnostic imaging features of redundant nerve roots caused by chronic lumbar degenerative canal stenosis (CLDCS). Clinical Features: A 56-year-old male presented with severe low back pain. He experienced pain during minimal active lumbar range of motion. The patient demonstrated weakness of the right iliopsoas and hypoesthesia of the L-2 dermatome. A working diagnosis of CLDCS was established. The patient's worsening severe low back pain warranted magnetic resonance imaging of the lumbar spine, which was performed for further evaluation. Magnetic resonance imaging demonstrated disk protrusion and canal stenosis with tortuosity of the cauda equina consistent with redundant nerve root appearance. Intervention and Outcome: The patient was treated with chiropractic flexion distraction, which was followed by a course of acupuncture and spinal manipulation. The patient self-discharged following clinical improvement. Conclusions: This case demonstrated CLDCS with associated redundant nerve roots. Conservative treatment included chiropractic diversified lumbar spinal manipulation, acupuncture, and electrical stimulation. The patient selfdischarged following clinical improvement in 3 months. (J Chiropr Med 2017;16:236-241)

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Redundant nerve roots in lumbar spinal stenosis: inter- and intra-rater reliability of an MRI-based classification

et al. 2019

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Purpose Patients with central lumbar spinal stenosis (LSS) have a longer symptom history, more severe stenosis, and worse postoperative outcomes, when redundant nerve roots (RNRs) are evident in the preoperative MRI. The objective was to test the inter-and intra-rater reliability of an MRI-based classification for RNR. Methods This is a retrospective reliability study. A neuroradiologist, an orthopedic surgeon, a neurosurgeon, and three orthopedic surgeons in-training classified RNR on 126 preoperative MRIs of patients with LSS admitted for microsurgical decompression. On sagittal and axial T2-weighted images, the following four categories were classified: allocation (A) of the key stenotic level, shape (S), extension (E), and direction (D) of the RNR. A second read with cases ordered differently was performed 4 weeks later. Fleiss and Cohen's kappa procedures were used to determine reliability. Results The allocation, shape, extension, and direction (ASED) classification showed moderate to almost perfect inter-rater reliability, with kappa values (95% CI) of 0.86 (0.83, 0.90), 0.62 (0.57, 0.66), 0.56 (0.51, 0.60), and 0.66 (0.63, 0.70) for allocation, shape, extension, and direction, respectively. Intra-rater reliability was almost perfect, with kappa values of 0.90 (0.88, 0.92), 0.86 (0.84, 0.88), and 0.84 (0.81, 0.87) for shape, extension, and direction, respectively. Intra-rater kappa values were similar for junior and senior raters. Kappa values for inter-rater reliability were similar between the first and second reads (p = 0.06) among junior raters and improved among senior raters (p = 0.008). Conclusions The MRI-based classification of RNR showed moderate-to-almost perfect inter-rater and almost perfect intra-rater reliability.

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Redundant nerve roots of the cauda equina: review of the literature

Cited by 13 publications

References 13 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

Redundant Nerve Root in a Patient With Chronic Lumbar Degenerative Canal Stenosis

Redundant nerve roots in lumbar spinal stenosis: inter- and intra-rater reliability of an MRI-based classification

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