Article Text

Download PDFPDF
Individual motor unit analysis in the diagnosis of disorders of urethral sphincter innervation.
  1. C J Fowler,
  2. R S Kirby,
  3. M J Harrison,
  4. E J Milroy,
  5. R Turner-Warwick


    A technique is described for recording the electromyographic activity of striated muscle in the urethral sphincter. Using a concentric needle electrode and an oscilloscope with a delay line and trigger, individual motor units were isolated and measured. To validate the method as a means of detecting pathology, the results are presented of analysis of the motor units of a group of patients with disturbances of micturition, known to have either cauda equina lesions or pelvic nerve injury. These results are compared with those from a group of controls. In the control group 93% of the motor units were less than 6 ms in duration and 2.0 mv in amplitude. Of motor units recorded from patients with cauda equina or pelvic nerve injury 59% exceeded the control ranges for amplitude or duration. It is concluded that quantitative analysis of individual motor units may be a helpful technique in the investigation of patients with disorders of micturition.

    Statistics from

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.