Lumbosacral plexopathy

Purpose of Review: This article provides an up-to-date review of the clinical features and pathogenesis of different types of lumbosacral plexopathy and a clinical approach to their evaluation and management. Often, the pathologic involvement is not limited to the plexus and also involves the root and nerve levels. These conditions are called lumbosacral radiculoplexus neuropathies. Recent Findings: The pathophysiology of diabetic and nondiabetic lumbosacral radiculoplexus neuropathy has been elucidated; it is ischemic injury due to a perivascular inflammatory process and microvasculitis. The clinical and neurophysiologic features of these two entities have been found to be similar, consisting of acute or subacute onset of pain and paresthesia followed by profound motor weakness asymmetrically involving the lower limbs and associated with weight loss. A lower limb and motor predominant neuropathy without pain also occurs in diabetes mellitus and has been shown to be a form of diabetic lumbosacral radiculoplexus neuropathy and not diabetic chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). The pathophysiology of some cases of postsurgical lumbosacral plexopathies has recently been shown also to be inflammatory from microvasculitis, and treatment with immunotherapy in a timely fashion may be desirable. Summary: Many pathophysiologic processes, such as neoplastic, traumatic, infectious, radiation, and inflammatory/microvasculitic processes, can affect the lumbosacral plexus causing lumbosacral plexopathy. The clinical symptoms and signs depend on the part of the plexus involved and the temporal course. Management depends on the cause of the lumbosacral plexopathy. Many cases of lumbosacral plexopathy previously thought to be idiopathic have been shown to be caused by ischemic injury from microvasculitis; despite lack of evidence for efficacy in improving neurologic deficits, the authors of this article include immunotherapy in their management of patients with this condition.