Rationales for a urodynamic study in patients with cervical spondylotic myelopathy.

BACKGROUND: Detrusor sphincter dyssynergia (DSD), involuntary detrusor contractions (IDC) and poor bladder compliance (PC) are relatively common urodynamic findings in cervical myelopathy. However, there is little information regarding the role of a urodynamic study (UDS) after decompression surgery for cervical spondylotic myelopathy (CSM).

METHODS: The urodynamic study was performed before and 6 months after decompression of CSM. The Japanese Orthopaedic Association (JOA) scores for cervical myelopathy and the Neck Disability Index (NDI) functional score were used. For male patients, the International Prostate Symptom Score (IPSS) was used, whereas the Urinary Distress Inventory (UDI-6) was applied in female patients.

RESULTS: The mean age was 61.3 years. Among the 32 patients, 17 patients completed the final follow-up, where neurogenic bladder was confirmed in 11 (64.7%) patients, with 7 patients having PC, 3 patients having IDC, and 6 patients having DSD. Four of the 7 PCs were normalized, 2 (phasic) of the 3 IDCs disappeared and 1 (terminal) IDC remarkably improved. Four of the 6 DSDs markedly improved. Before and after the decompression surgery, bladder compliance in the 17 patients was 45.52 ± 23.71 and 77.07 ± 39.85, respectively (p=0.004). Both JOA scores and NDI scores improved (p=0.007 and p=0.001, respectively). However, the IPSS and UDI-6 were not changed 6 months after surgery.

CONCLUSIONS: The neurogenic bladder could be partially controlled in CSM patients after surgical decompression. However, the neurogenic component in the UDS findings varied, and depending on the findings, further proper urological treatments after neurological decompression surgery should be considered.