Objective: Neurogenic bladder refers to morphofunctional alterations of the bladder-sphincter complex secondary to central or peripheral neurological lesions. Discal etiology can be suggested by clinical observation in patients complaining of classical lower back pain, but not excluded even without musculoskeletal pain. This review provides a brief overview of associations between neurogenic bladder and disc disease, analyzing neuroanatomy, pathophysiology, clinical and urodynamic findings. Therapy is reviewed focusing on etiological treatments.
Methods: The literature search was performed on PubMed, Medline and Google scholar using the following keywords: 'neurogenic bladder', 'disc herniation', 'disc prolapse', 'disc protrusion', 'cauda equina syndrome', 'treatment', 'surgery', 'urodynamic', either alone or in combination using 'AND' or 'OR'. The reference lists of articles retrieved were examined to capture other potentially relevant articles. The search was restricted to articles published between 1970 and 2012. Seventy-nine papers were found, but only 42 were reviewed and summarized.
Findings: The literature reviewed confirmed correlations between neurogenic bladder and disc disease. Approximately 40% of patients with lumbar disc disease have abnormal urodynamic testing, and an even larger proportion complain of voiding symptoms. The most common urodynamic finding is detrusor areflexia, but underactive or overactive detrusor can also be observed. Electromyography can show perineal floor muscle innervation abnormalities. Chronic nervous damage induces reduction of bladder sensitivity and detrusor atrophy. An overdistension of the bladder follows, with global and circumferential thinning of the bladder wall. Overactive detrusor is related to early nerve roots stretching causing an irritative state responsible for overstimulation and neurogenic overactivity. Detrusor hypertrophy is the anatomical deformation correlated.
Conclusions: Benefits for neurogenic bladder obtained through disc disease treatment should be studied in more detail, especially conservative therapies, not yet discussed in literature. Spine surgery effectiveness on voiding function should be valued in the light of the latest surgical techniques, considering the controversial results reported after laminectomy.