title: Accidental subdural spinal cord stimulator lead placement and stimulation.
abstract: OBJECTIVE
  Neuromodulation with spinal cord stimulation has become an increasingly employed intervention for treatment of a variety of neuropathic pain states. As prevalence increases, so does the incidence of complications. Currently, there is sparse literature describing spinal cord stimulation lead placement and stimulation characteristics in the subdural space. In this case report we describe subdural lead placement and the associated stimulation parameters, and provide evidence-based support to initiate a dialog to further reduce procedural morbidity and mortality.
  
  
  METHODS
  This study is a case report following lead placement during permanent percutaneous spinal cord stimulator placement and stimulation testing. The lead placement and stimulation characteristics were suggestive of extra-epidural lead placement.
  
  
  RESULTS
  Using the same cathode/anode configuration (1:anode, 3:cathode, 5:anode), frequency of 40 Hz and pulse width of 650 microseconds, sequential stimulation was performed. Summarizing, the testing demonstrated similar impedance for the left and right leads (within 30 ohms) of approximately 300 ohms, and a large discrepancy in current of 3.2 mA for the left and 0.9 mA for the right. The patient reported "painful intense" stimulation with right lead stimulation.
  
  
  CONCLUSIONS
  Evidence suggesting subdural lead placement include the lack of cerebrospinal-fluid despite lavage, the absence of post-dural puncture headache, the recent evidence of intentional and reproducible subdural anesthesia, and the conductive properties of the dural spinal elements. It can be argued that subdural lead placement may occur unrecognized more frequently than originally anticipated.
authors: Division of Anesthesiology, Department of Pain Management, Cleveland Clinic, Cleveland, OH 44195, USA. popeje@me.com
authors: Jason E
authors: JE
authors: Pope
authors: Michael
authors: M
authors: Stanton-Hicks
mesh_terms: D004599:Electric Stimulation Therapy / Q000295:instrumentation; D004567:Electrodes, Implanted / Q000009:adverse effects*; D006801:Humans; D013116:Spinal Cord / Q000033:anatomy & histology* / Q000502:physiology; D013355:Subdural Space; D013904:Thoracic Vertebrae / Q000033:anatomy & histology