Hypothesis / aims of study
Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disease involving the optic nerves, spinal cord, and cerebral white matter. The incidence of lower urinary tract symptoms (LUTS) and lower urinary tract dysfunctions (LUTD) in NMOSD is approximately 80% [1]. The severity of LUTS / LUTD is associated with widespread transverse myelitis and central spinal cord injury. The purpose of this study is to investigate whether brain/spinal magnetic resonance imaging (MRI) findings and urodynamic study (UDS) findings make a difference in the management of bladder dysfunction in patients with NMOSD.
Study design, materials and methods
Between October 2010 and March 2023, 35 patients (27 females and eight males) were diagnosed with NMOSD. The patients were first treated for NMOSD at each specialized neurological hospital and subsequently admitted to our hospital for rehabilitation. Urologists intervened for bladder management in 20 (57%) patients. We retrospectively evaluated MRI and UDS findings and bladder management in these 20 patients based on medical records.
Results
This study included 20 patients (16 females and four males) with a mean age was 53.3±16.9 years. Twelve (60%) patients had a first episode of NMOSD, whereas eight (40%) patients had been diagnosed with recurrent. Aquaporin 4 antibody immunoglobulin G seropositivity was found in 18 (90%) patients. UDS was performed in 18 of 20 patients, and the other two patients were evaluated with measurement of post-void residual urine only.
1) MRI findings
Five (25%) patients had extensive cerebral white matter lesions, all of which had extensive spinal cord involvement. Twelve (60%) patients had cervical spinal cord lesions and scattered cerebral white matter lesions. Three (15%) patients had thoracic spinal cord lesions and scattered cerebral white matter lesions.
2) UDS findings
UDS was performed on 18 patients. Three patients had low-compliance bladder (LCB), one patient had detrusor overactivity (DO), and six patients had both LCB and DO. Two patients had detrusor underactivity (DU), and one patient had both DO and DU. Five patients had normal UDS findings.
3) Bladder management
The initial urinary management method was urethral catheterization in 13 patients, clean intermittent catheterization (CIC) in three patients, and spontaneous voiding in four patients. Urologist intervention led to urethral catheterization in three patients, CIC in seven patients, and spontaneous voiding in 10 patients on their discharge.
Interpretation of results
According to the previous paper, during the initial phase, the patients have the inability to void, with urinary retention as a predominant complaint. As with other myelopathies, UDS performed after 4 to 6 weeks of insult would give a more accurate status of bladder dysfunction and help in managing bladder better in the longer term [2]. In our study, approximately 40% of first-episode cases did not show significant findings in UDS, but recurrent cases showed some findings, such as LCB, DO, or DU. Additionally, three of five patients with extensive cerebral white matter lesions were recurrent cases. Two of these three patients required indwelling catheters and one patient required CIC. All three patients with DU were recurrent cases. On the other hand, all five patients with normal UDS findings were first-episode cases.
There are some research limitations in this study. First, the UDS data are from the convalescent period only at our rehabilitation hospital, and the results of the study may be biased. Furthermore, there are no randomized controlled trials available for bladder management in patients with NMOSD. Therefore, existing recommendations for bladder management are mostly based on empirical and retrospective studies.