Lumbar nerve root biopsy with fascicle dissection and functional mapping: how I do it.

BACKGROUND: Lumbosacral plexopathies with unclear etiology are a rare entity. In certain cases, if workup unrevealing and medical management is suboptimal, an open lumbar nerve root biopsy may be considered.

METHOD: A standard lumbar laminectomy is performed for access to the intradural contents. The dura is opened at midline in a standard fashion. Single nerve roots are selected and stimulated for an EMG response. A nerve fascicle is then dissected and stimulated before excision.

CONCLUSION: Lumbar nerve root biopsy is feasible and safe. All non-invasive workup needs to be completed and negative before performing this procedure.