Lumbar spinal canal MRI diameter is smaller in herniated disc cauda equina syndrome patients

Abstract

IntroductionCorrelation between magnetic resonance imaging (MRI) and clinical features in cauda equina syndrome (CES) is unknown; nor is known whether there are differences in MRI spinal canal size between lumbar herniated disc patients with CES versus lumbar herniated discs patients without CES, operated for sciatica. The aims of this study are 1) evaluating the association of MRI features with clinical presentation and outcome of CES and 2) comparing lumbar spinal canal diameters of lumbar herniated disc patients with CES versus lumbar herniated disc patients without CES, operated because of sciatica.MethodsMRIs of CES patients were assessed for the following features: level of disc lesion, type (uni- or bilateral) and severity of caudal compression. Pre- and postoperative clinical features (micturition dysfunction, defecation dysfunction, altered sensation of the saddle area) were retrieved from the medical files. In addition, anteroposterior (AP) lumbar spinal canal diameters of CES patients were measured at MRI. AP diameters of lumbar herniated disc patients without CES, operated for sciatica, were measured for comparison.Results48 CES patients were included. At MRI, bilateral compression was seen in 82%; complete caudal compression in 29%. MRI features were not associated with clinical presentation nor outcome. AP diameter was measured for 26 CES patients and for 31 lumbar herniated disc patients without CES, operated for sciatica. Comparison displayed a significant smaller AP diameter of the lumbar spinal canal in CES patients (largest p = 0.002). Compared to average diameters in literature, diameters of CES patients were significantly more often below average than that of the sciatica patients (largest p = 0.021).ConclusionThis is the first study demonstrating differences in lumbar spinal canal size between lumbar herniated disc patients with CES and lumbar herniated disc patients without CES, operated for sciatica. This finding might imply that lumbar herniated disc patients with a relative small lumbar spinal canal might need to be approached differently in managing complaints of herniated disc. Since the number of studied patients is relatively small, further research should be conducted before clinical consequences are considered.

Magnetic resonance imaging findings in intervertebral disc herniation: Comparison of canal compromise and canal size in patients with and without cauda equina syndrome

“…[7] Korse et al also reported statistically significant differences in the normal spinal canal diameters between patients with versus those without CES. [6] However, we found greater canal narrowing form Group B versus Group A patients at the L4-L5 and L5-S1 levels; the lesser canal sizes in Group B patients at L4-L5 and L5-S1 explained the occurrence of CES despite a lesser mean percentage of compression due to IDH versus the higher lumbar levels.…”

Usefulness of the Inferior Articular Process’s Cross-Sectional Area as a Morphological Parameter for Predicting Central Lumbar Spinal Stenosis

“…Kim et al have demonstrated that a longer walking distance is associated with a larger dural sac CSA [9]. Korse et al have found that patients with cauda equina syndrome due to lumbar disc herniation have significant smaller anteroposterior spinal canal diameters in the lumbar lesion than patients with lumbar disc herniation without cauda equina syndrome [17]. Yoshiiwa et al have reported that hypertrophy of ligamentum flavum development is associated with severe disc degeneration, segmental instability, and severe facet joint osteoarthritis [18].…”

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“…Further, patients with sciatica and a CES due to a lumbar herniated disc have a significantly smaller epidural space than sciatica patients without CES [24]. Since 1-10% of patients with a known lumbar herniated disc develop CES [24], the chances that an interventional procedure is performed during the time-frame of this natural neurological progression is realistic, thereby obscuring the causal relation with the epidural corticosteroid injection. In patients with spinal stenosis, injection of a small volume is recommended to minimize a possible pressure increase in the epidural space.…”