Detrusor overactivity in patients with cauda equina syndrome.
METHODS
Retrospective cross-sectional study.


OBJECTIVE
To delineate the neurogenic bladder type in patients with cauda equina syndrome (CES) and to suggest, in light of the clinical, radiological, and electrophysiological findings, a possible cause of bladder dysfunction.


BACKGROUND
Many patients with CES experience bladder dysfunction, although the type of neurogenic bladder is quite variable in the clinical setting. Bladder dysfunction in patients with CES is usually areflexic or acontractile detrusor. However, detrusor overactivity (DOA) also reported the cases that cannot be explained by pure root injuries in the cauda equina region.


METHODS
Patients with CES with neurogenic bladder were studied, all of whom (n = 61; mean age ± SD, 48.0 ± 15.9 yr) underwent urodynamic analysis, magnetic resonance imaging (MRI), and electrophysiology. According to the urodynamic findings, the neurogenic bladder was classified into 2 types: DOA and detrusor underactivity or acontractility. The highest level of injury (HLI) or level of injury was determined and analyzed on the basis of the clinical-urodynamic and electrophysiological findings, respectively.


RESULTS
Twenty patients with CES (32.8%) showed DOA; in most of them (85.0%, 17/20 patients), the HLI on electrophysiological assessment was L2 or above. Forty-one patients with CES showed detrusor underactivity or acontractility; and most of the patients with CES whose HLI was L3 or below showed detrusor underactivity or acontractility (91.2%, 31/34 patients). None of the HLI or level of injury from the clinical or magnetic resonance imaging findings correlated with neurogenic bladder type. We also found that urodynamic findings including maximal detrusor pressure and bladder capacity was partially correlated with the HLI on electrophysiological assessment (r² = 0.244, P < 0.001 and r² = 0.330; P < 0.001, respectively).


CONCLUSIONS
DOA was seen most often in patients with CES whose HLI was L2 or above, and might be associated with combined conus medullaris lesion. Electrophysiology might be the most useful assessment tool for prediction of neurogenic bladder type in patients with CES.
*Department of Rehabilitation Medicine, Dankook University College of Medicine, Cheonan, Republic of Korea; and †Department of Nanobiomedical Science and BK21PLUS NBM Global Research Center for Regenerative Medicine, and ‡Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, Republic of Korea.
Seo-Young
SY
Kim
Hee Chung
HC
Kwon
Jung Keun
JK
Hyun
D000328:Adult; D002420:Cauda Equina / Q000473:pathology* / Q000503:physiopathology; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010523:Peripheral Nervous System Diseases / Q000150:complications* / Q000503:physiopathology; D012189:Retrospective Studies; D013577:Syndrome; D001750:Urinary Bladder, Neurogenic / Q000150:complications* / Q000503:physiopathology; D014563:Urodynamics