Neurogenic lower urinary tract dysfunction (NLUTD) affects the majority of individuals with spinal cord injury or disease (SCI/D). The main concern in NLUTD is renal damage as a result of excessive storage detrusor pressures due to low bladder compliance or detrusor overactivity with detrusor sphincter dyssynergia. In order to detect possible threats for renal health, NLUTD needs to be evaluated using (video)urodynamic studies (V)UDS). Regular (V)UDS are usually established in the subacute to chronic phase of SCI/D and not during the acute phase. Thus, there is a lack of data regarding the course of NLUTD during the acute and subacute phase after SCI/D. We have therefore investigated the course of NLUTD during and after primary rehabilitation in individuals with SCI/D.

Individuals completing primary rehabilitation for SCI/D in a specialized rehabilitation center between 2015 and 2017 were evaluated. Personal information and bladder management, medication and urodynamic data were collected at three time points: first urodynamic examination, last examination during primary rehabilitation and first examination after primary rehabilitation. Urodynamic data were analyzed for four lesion categories: cervical, high-thoracic (from T6), low-thoracic and lumbo-sacral. The changes in the urodynamic parameters over time and the differences between the lesion categories were evaluated using non-parametric analysis of variance and post-hoc analysis with the Wilcoxon signed-rank test. Furthermore, the number of individuals with detrusor overactivity within the first 40 days after SCI/D was determined. The statistical analyses were performed using the SPSS software (version 25, IBM, Somers, NY, USA). A p-value of ≤ 0.05 was considered significant.

The data of 207 men (75.8%) and 66 women (24.2%) with a mean age of 55±19 years were analyzed. The first urodynamic examination took place a median 63 days (50 / 83 days) after SCI/D. Median bladder capacity, maximum detrusor pressure and compliance were 460ml (390 / 500ml), 10cmH2O (5 / 30cmH2O), and 70ml/cmH2O (40 / 100ml/cmH2O), respectively. There was a significant (p=0.002) increase in maximum detrusor pressure in individuals with cervical or thoracic lesions, and values were significantly (p= 0.02) greater compared to individuals with a lumbo-sacral lesion. At the last examination during primary rehabilitation (24.5, 20.3 / 30.3 weeks after SCI/D), median bladder capacity, maximum detrusor pressure and compliance were 450ml (350 / 480ml), 17cmH2O (6 / 40cmH2O) and 61ml/cmH2O (32 / 110ml/cmH2O), respectively. In the first examination after primary rehabilitation (10.6, 9.2 / 12.8 months after SCI/D), maximum detrusor pressure increased to 20cmH2O (8 / 40cmH2O) whereas bladder capacity and compliance decreased to 430ml (330 / 493ml) and 65ml/cmH2O (32 / 106ml/cmH2O), respectively. The proportion of individuals who required detrusor relaxation increased from 5.6% at the initial assessment to 31% at the after-rehabilitation assessment. The need was greater in individuals with cervical or thoracic lesions (35.3%) compared to the ones with lumbo-sacral lesions (15.4%). Detrusor overactivity was observed in 11 of 24 individuals (45.8%, 25.6-67.2%) with an initial (V)UDS within the first 40 days after SCI/D.

There is a gradual deterioration of lower urinary tract function after SCI/D which is reflected in the decrease in bladder volume and compliance and the increase in maximum detrusor pressure during the storage phase and the need for detrusor relaxation. Almost half of the evaluated individuals showed detrusor overactivity during the first 40 days after SCI/D. This is in contrast to the common concept of an acontractile detrusor during spinal shock after SCI/D.

The present data support the need for regular urodynamic examinations during and after primary rehabilitation to detect relevant events such as an increase in detrusor pressure. The first urodynamic examination should be performed early after SCI/D.