Study On The Plasticity Of The Lower Urinary Tract In Patients With Spinal Cord Injury

First study:Remodeling of the lower urinary tract in patients with neurogenic bladder after spinal cord injury(SCI).Objective:The aim of this study was to determine the relationship between detrusor wall thickness(DWT) and lower urinary tract function and investigate the remodeling of the lower urethral tissue by the ultrasonic measurement of DWT in patients with neurogenic bladder after SCI.Methods:Seventy-nine adults with urinary tract dysfunction due to SCI were selected as the experimental group, and another 41 healthy adults formed the control group. The experimental group underwent evaluation of lower urethral function by means of urinary dynamic examination.The DWT of all subjects was measured using 8-13MHz linear ultrasound probe in different bladder capacity(BC).Results:With the increase of bladder capacity, DWT decreased. At maximum bladder capacity(MBC), the DWT in experimental group was (0.96±0.38) mm and (0.59±0.07) mm in control group, demonstrating a significant difference in DWT between patients with SCI and normal adults (p<0.05).The DWT in patients with the combination of a hyperreflexive detrusor and sphincter(type A) increased most significantly. At MBC, DWT was significantly correlated with maximum detrusor pressure in the filling phase(MDP) (r=0.619, p<0.01) and bladder compliance(C) in experimental group (r=-0.27,p<0.05). There was no significant correlation between DWT and the maximum urethral pressure(MUP). A DWT of 0.89mm could be used as a critical value to predict type A high-risk patients(MDP≥40cmH2O).Conclusions:There were remodeling changes of bladder wall in patients with neurogenic bladder due to SCI.Patients with SCI exhibited significantly increased DWT, which was positively correlated with MDP. Additionally, DWT could be uesd to predict type A high-risk patients.Second study:The plasticity of the sacral spinal cord in patients with neurogenic bladder due to spinal cord injuryObjective:The purpose of this study was to observe the changes of sacral cord imaging, and to analyze the relationship between the index of diffusion tensor imaging(DTI) and the function of the lower urinary tract, and to investigate the changes of sacral nerve remodeling after spinal cord injury by DTI in patients with cervical SCI.Methods:Twenty adults with urinary tract dysfunction due to cervical SCI were recruited for the experimental group(10 patients with complete spinal cord injury,10 patients with incomplete spinal cord injury), and another 15 healthy adults formed the control group. The experimental group underwent evaluation of lower urethral function by means of urinary dynamic examination. Fractional anisotropy (FA) and apparent diffusion coefficient ADC) of sacral cord lateral horn and anterior horn in all objects were determined using magnetic resonance imaging instrument(3T signa HDxt GE/MR).Results:The FA values of sacral dorsal horn and anterior horn in the experimental group, which were (0.21+0.03) and (0.22+0.03), were significantly different compared with the control group (p<0.05). The ADC values of sacral dorsal horn and anterior horn in the experimental group, which were (2.44±0.53)×10-9mm2/s and (2.29±0.31)×10-9mm2/s, were significantly different compared with the control group (p<0.05). The FA values of sacral dorsal horn in the experimental group was positively correlated with maximum detrusor pressure during voiding (r=0.737, p<0.01). The ADC values of sacral dorsal horn in the experimental group was negatively correlated with maximum detrusor pressure during voiding (r=-0.578, p<0.01). Compared with the patients with incomplete cervical cord injury, the FA values of sacral dorsal horn and anterior horn in the patients with complete cervical cord injury were significantly lower (p<0.05). The value of ADC in patients with complete cervical cord injury was significantly increased than that in patients with incomplete spinal cord injury.Conclusions:Descending neural plasticity occurred in the dorsal horn and anterior horn of the sacral spinal cord after cervical spinal cord injury. This nerve remodeling was related to the severity of cervical spinal cord injury. The plasticity in the dorsal horn of the sacral spinal cord was positively correlated with maximum detrusor pressure during voiding.