2024 Workshop Handout Bundle-W46AS Electrodiagnostic and Clinical Approach to Lumbosacral Plexopathies

W46AS Electrodiagnostic and Clinical Approach to Lumbosacral Plexopathies

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The document by Rocio Vazquez Do Campo, MD, from the University of Alabama at Birmingham, focuses on the electrodiagnostic and clinical approach to diagnosing and treating lumbosacral plexopathies. Lumbosacral plexopathies are complex nerve disorders that can be challenging to diagnose due to overlaps with other lower limb nerve conditions like radiculopathies or mononeuropathies. The pelvis-bound lumbosacral plexus, originating primarily from L1 through S4 nerve roots, is divided into the upper lumbar (L1-L4) and lower lumbosacral (L5-S4) plexi, and provides both sensory and motor innervation to the lower limbs.<br /><br />Key diagnostic clues for lumbosacral plexopathies include leg weakness, hyporeflexia, and sensory disruptions that do not align with single nerve root or peripheral nerve patterns. These disorders can be unilateral or bilateral and typically cause pain described as aching, throbbing, or burning. Specific muscle weaknesses can suggest whether the upper lumbar or lower lumbosacral plexus is affected.<br /><br />Electrodiagnostic (EDX) evaluation is crucial, requiring abnormalities in multiple muscles innervated by different peripheral nerves and nerve roots, along with abnormal sensory responses. Routine and non-routine nerve conduction studies (NCS) and needle electromyography (EMG) should be thoroughly conducted on both legs and include the paraspinal muscles to effectively identify the location and extent of the plexopathy.<br /><br />Clinical signs of LRPN (Lumbosacral Radiculoplexus Neuropathy), often related to diabetes and other metabolic or inflammatory conditions, can include neuropathic pain radiating from the back, leg weakness, and muscle atrophy. Critical EDX criteria to distinguish plexopathies from isolated nerve root or peripheral nerve disorders involve detecting abnormal sensory nerve action potentials (SNAPs), nonconsecutive myotome involvements on EMG, and normal paraspinal muscle EMG in the absence of increased radiographic findings.<br /><br />The document advises comprehensive EDX testing, including less routine NCS and judicious interpretation of sensory responses, especially in older or obese individuals. Muscle needle EMG should encompass various proximal and distal leg muscles to enhance diagnostic precision. Early recognition of these patterns and tailored EDX approaches can aid in effectively diagnosing and managing lumbosacral plexopathies.

Keywords

lumbosacral plexopathies

electrodiagnostic evaluation

nerve conduction studies

ncs

needle electromyography

sensory disruptions

leg weakness

hyporeflexia

neuropathic pain

muscle atrophy

diagnostic precision

nerve conduction studies

nerve conduction study

ncs