Pitfalls in the electrodiagnostic studies of sacral plexopathies

Abstract

This retrospective review characterizes the electrodiagnostic (EDX) features and etiologies of sacral plexopathies (SPs) and discusses difficulties in their identification. The EDX findings of 171 clinically suspected SPs were reviewed using the following criteria: reduced/absent sensory nerve action potentials (SNAPs) of the sural or superficial peroneal nerve, denervation of plexus-innervated muscles, and the absence of paraspinal denervation. Sixty cases localized unequivocally to the sacral plexus. The majority were cancer-related, followed by traumatic, idiopathic, and iatrogenic causes. Final diagnoses in the remaining 111 cases were indeterminate. Lesions localized to either the plexus or L4-5, S1 roots in 52 cases, the plexus or sciatic nerve in 32 cases, and were equally compatible with an SP, sciatic neuropathy, or radiculopathy in 27 cases. Findings in the EDX evaluation of SPs are often complex and difficult to localize to a specific site due to multiple complicating factors. Frequently, SPs cannot be diagnosed definitively by EDX assessment alone.

Unusual Etiology of Lumbar Radiculoplexopathy

“…None of the clinicians involved in her care—a physiatrist, oncologist, and neurosurgeon—believed a pelvic MRI was necessary when making a management decision in this particular case, but in general pelvic MRI is a reasonable part of the workup. Lumbosacral plexopathies are difficult to accurately diagnose [3]. Technology has yet to advance to consistently yield reliable results with MRI imaging of the pelvis.…”

Lower Extremity Weakness After Childbirth: A Case of Preserved Nerve Conduction Studies, Axonal Involvement, and Good Recovery

“…The challenges in localizing the pathology in suspected lumbosacral plexopathy have been documented [6]. This case is certainly an example of that uncertainty.…”

MRI imaging and clinical features of sciatic nerve injection injury

“…Electrodiagnostic recordings showed absent right superficial peroneal nerve and reduced sural nerve response, absence of right common peroneal nerve compound muscle action potential and evidence for denervation in right tibialis anterior, gluteus maximus and gluteus medius muscles. These features suggested a chronic axonal damage in the posterior division of the sacral plexus [1], including common peroneal division of the sciatic nerve, superior and inferior gluteal nerves (video 1).…”