Prediction of the Development of Neurogenic Bladder in Patients with Lumbar Disc Herniation / 대한정형외과학회잡지

PURPOSE: To predict the development of a neurogenic bladder based on an analysis of the clinical and radiological findings in patients with lumbar disc herniations. MATERIALS AND METHODS: Twenty-six patients, who were suspected of having neurogenic bladders, underwent urodynamic testing. The anteroposterior diameters and the cross-sectional areas of the dural sacs at the herniated disc levels were measured by magnetic resonance imaging. Clinically, we evaluated lower back pain, radiating pain, saddle anesthesia, bladder function, motor weakness of the lower limbs, and the Japanese Orthopaedic Association (JOA) score. RESULTS: Thirteen (50%) of the 26 patients were diagnosed with positive neurogenic bladders. The average anteroposterior diameters of the dural sacs in group I (13 cases) with positive neurogenic bladders and in group II (13 cases) with negative neurogenic bladders, were 6.8 (range, 4-9) mm and 9.0 (range, 8-10) mm, respectively (p<0.001). When an anteroposterior diameter of 7 mm was used as the threshold value for differentiation between the anteroposterior diameter of the dural sac and a neurogenic bladder, the sensitivity and specificity were 61.5% and 100%, respectively. The average cross-sectional areas of the dural sacs in group I and group II were 74.9 (range 50-96) mm(2) and 86.2 (range 60-103) mm(2), respectively (p=0.069). When a cross-sectional area of 77 mm2 was used as the threshold value for differentiation between the cross-sectional area of the dural sac and a neurogenic bladder, the sensitivity and specificity were 61.5% and 84.6%, respectively. All 9 patients who had saddle anesthesia were diagnosed with positive neurogenic bladders. However, there was no statistical significance between the preoperative JOA score and the development of a neurogenic bladder. CONCLUSION: The anteroposterior diameter of the dural sac and saddle anesthesia might be important factors in predicting the presence of a neurogenic bladder in patients with lumbar disc herniation.

Abnormal Spontaneous Activities According to Type of Herniated Lumbar Disc and Anteroposterior Diameter of Dural Sac in MRI

OBJECTIVE: To assess the abnormal spontaneous activities in needle electromyography (EMG) according to the type of herniated lumbar disc and anteroposterior the diameter of dural sac in magnetic resonance imaging (MRI). METHOD: We performed the MRI on 120 patients with low back pain (LBP) and measured the midline anteroposterior diameter of dural sac in a MRI axial view. Fifty patients with a disc protrusion or extrusion in MRI were reviewed for the clinical findings on physical examination and assessed for the abnormal spontaneous activities (ASA) in needle EMG. RESULTS: Seventy cases with a normal finding in MRI did not have differences in a dural sac diameter regardless their age or sex. Fifty cases with a protrusion or extrusion in MRI showed that the dural sac size decreased more in an extrusion than in a protrusion, and more in a paracentral type than in a central type. The incidence of ASA in a needle EMG increased more in an extrusion than in a protrusion, and more in a paracentral type than in a central type. The incidence also increased according to the decrement of a dural sac diameter. The incidence of ASA were 100% in a group with both motor and sensory signs, 94% in a group with a motor sign, 86% in a group with a sensory sign, 26% in a group without motor or sensory sign. CONCLUSION: We concluded that the abnormalities in needle EMG must be correlated with the direction of herniated lumbar disc and anteroposterior diameter of the dural sac in MRI as well as clinical findings.