title: Management of tight filum terminale syndrome with special emphasis on normal level conus medullaris (NLCM).
abstract: BACKGROUND
  Tethered cord syndrome is classically defined as having the tip of the conus medullaris below the body of L2, instead of at the normal L1-2 disc space level. The syndrome presents most commonly with urinary incontinence. In a patient with urinary incontinence and a low-lying conus medullaris, tethered cord syndrome can be diagnosed without difficulty. However, in a patient with urinary incontinence and a hyperreflexive type of neurogenic bladder, in whom the conus medullaris is found to be at the normal level on magnetic resonance imaging, diagnosing a tethered cord can be challenging. We hypothesized that patients with hyperreflexive neurogenic bladders have a neurologic basis for their bladder dysfunction, probably secondary to tethering by a tight filum terminale, despite having a normally positioned conus medullaris.
  
  
  METHODS
  We investigated 13 patients with tethered cord syndrome with urinary incontinence. All patients underwent urodynamic tests, somatosensory-evoked potentials (SSEPs), and magnetic resonance imaging. All had normal neurologic exams including lower extremity motor, sensory, and reflex functions. To minimize disturbance of the normal anatomy, we used a flavotomy approach and transected the tight filum terminale to release the tethered conus medullaris.
  
  
  RESULTS
  We show that urodynamic studies appear to be more predictive of a tight filum terminale than SSEPs. However, pathological SSEP results seem to correlate with poor surgical outcomes. Ninety-three percent of operated patients were continent by the first post-surgical day. However, disappointingly, almost half lost continence within the first month after surgery.
  
  
  CONCLUSIONS
  In cases of incontinence with a normal level conus medullaris, but urodynamic studies showing a hyperreflexic neurogenic bladder, we believe that sectioning of the filum terminale often improves continence.
authors.affiliation: University of Ankara, School of Medicine, Department of Neurosurgery, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Selçuki
authors.forename: K
authors.initials: K
authors.lastname: Coşkun
mesh_terms: D000293:Adolescent; D002420:Cauda Equina / Q000601:surgery*; D002648:Child; D002675:Child, Preschool; D004576:Electromyography; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D016136:Spina Bifida Occulta / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D014549:Urinary Incontinence / Q000150:complications / Q000175:diagnosis / Q000601:surgery; D014563:Urodynamics