Background and Objective. Spinal cord stimulation is the most commonly used implantable neurostimulation modality for management of pain syndromes. For treatment of lower extremity pain, the spinal cord stimulator lead is typically placed in the thoracic epidural space, at the T10–T12 levels. Typically, satisfactory stimulation can be obtained relatively easily. Anatomical variability in the epidural space, such as epidural scarring, has been reported to prevent successful implantation of spinal cord stimulators. Spinal epidural lipomatosis describes an abnormal overgrowth of adipose tissue in the extradural space. Cases have documented spinal epidural lipomatosis complicating intrathecal baclofen pump implantation or causing repeated failure of epidural analgesia. However, so far, there is no published literature describing how spinal epidural lipomatosis affects spinal cord stimulation.
Case Report. We report a case of spinal cord stimulation in a patient with spinal epidural lipomatosis. Very high impedance was encountered during the trial spinal cord stimulator lead placement. Satisfactory stimulation was only obtained after repeated repositioning of the spinal cord stimulator trial lead. Post-procedure thoracic spine magnetic resonance imaging revealed marked thoracic epidural lipomatosis. At the level where satisfactory stimulation was obtained, the thickness of the epidural fat was within normal limits. The patient eventually underwent placement of a laminotomy lead with good coverage and pain relief.
Conclusion. Spinal epidural lipomatosis significantly increases the impedance in the epidural space, making effective neurostimulation very difficult to obtain. Physicians should consider the possibility of spinal epidural lipomatosis when very high impedances are encountered during lead placement.