Division of Pain Medicine, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA.
Pain Med. 2011 Mar;12(3):377-81. doi: 10.1111/j.1526-4637.2011.01057.x. Epub 2011 Feb 18.
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.
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.
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.
脊髓刺激是治疗疼痛综合征最常用的植入式神经刺激方式。对于下肢疼痛的治疗,脊髓刺激器的导联通常放置在胸段硬膜外腔,T10-T12 水平。通常,相对容易获得满意的刺激。硬膜外腔的解剖变异,如硬膜外瘢痕形成,已被报道会导致脊髓刺激器植入失败。脊髓硬膜外脂肪增多症描述了硬脊膜外腔脂肪组织的异常过度生长。有病例记录脊髓硬膜外脂肪增多症使鞘内巴氯芬泵植入复杂化或导致硬膜外镇痛反复失败。然而,迄今为止,尚无文献描述脊髓硬膜外脂肪增多症如何影响脊髓刺激。
我们报告了一例脊髓硬膜外脂肪增多症患者的脊髓刺激病例。在试验性脊髓刺激器导联放置过程中遇到了非常高的阻抗。仅在反复重新定位脊髓刺激试验导联后才获得满意的刺激。术后胸椎磁共振成像显示明显的胸椎硬膜外脂肪增多症。在获得满意刺激的水平,硬膜外脂肪的厚度在正常范围内。患者最终接受了椎板切开术导联的放置,覆盖范围和疼痛缓解良好。
脊髓硬膜外脂肪增多症显著增加了硬膜外腔的阻抗,使得有效的神经刺激非常难以获得。当在导联放置过程中遇到非常高的阻抗时,医生应考虑脊髓硬膜外脂肪增多症的可能性。