Diabetic and non-diabetic lumbosacral radiculoplexus neuropathy

Background: Lumbosacral radiculoplexus neuropathy (LRPN) originally described in diabetic patients is a distinct clinical condition characterized by debilitating pain, weakness and atrophy most commonly affecting the proximal thigh muscles asymmetrically. The syndrome is usually monophasic and preceded by significant weight loss (at least more than 10 lbs). Though a self-limited condition, recovery is gradual with some residual weakness. Recent advances and research has provided new insights in the pathogenesis and thereby management of this syndrome. In this paper, we review the clinical and diagnostic features as well as discuss recent insights and treatment strategies along with our experience in the management of patients with diabetic and non-diabetic LRPN. Materials and Methods: Literature in English published between 1953 and 2008 was searched in the MEDLINE and Pubmed database, maintained by the US National library of medicine and National institutes of health, using key words of diabetic amyotrophy, lumbosacral radiculoplexus neuropathy, diabetic proximal neuropathy, diabetic radiculopathy and diabetic lumbosacral plexopathy. In addition, literature reported in various textbooks on peripheral neuropathy was reviewed as well. Observation: The diagnosis relies mostly on clinical suspicion and characteristic electromyographic findings. The exact pathogenesis of the illness remains unknown, but there seems to be a component of immune-mediated inflammatory microvasculitis which causes secondary ischemia of the lumbosacral plexus. This has prompted a trial of immunosuppressive agents (like steroids) with an attempt to alter the course of the illness. A few reports have noted that immunosuppression when instituted early in the course of the illness (within three months of symptom onset) may hasten the recovery and improve symptoms. Conclusion: Though the exact mechanism of LRPN in diabetic and non-diabetic patients remains unknown, new evidence alludes to an underlying inflammatory vasculitic process. Early treatment with immunosuppressants may be beneficial in some cases, although the data available at this time is limited to a small cohort of patients. The decision is individualized weighing the risks and benefits in a given patient. Future research in this direction with double-blinded case-controlled studies is required to investigate this further.

Keywords
Diabetic amyotrophy, diagnosis and treatment, lumbosacral plexopathy, lumbosacral radiculoplexus neuropathy, non-diabetic amyotrophy.