Varicella zoster lumbosacral plexopathy: a rare cause of lower limb weakness

Magnetic Resonance Imaging-Negative Varicella Zoster Virus Plexopathy in a Young Patient: A Case Report

Varicella zoster virus (VZV)-associated plexopathy mainly occurs in patients over 60 years old. Postherpetic neuralgia is a well-known complication of herpes zoster (HZ); however, segmental zoster paresis secondary to HZ was reported in 1-20% of cases in the literature. Magnetic resonance imaging (MRI) findings may be positive in up to 70% of the patients. We describe a 43-year-old male patient with a history of grade two left frontal oligodendroglioma, which was treated with two partial resections, radiation treatment and procarbazine/lomustine, who presented with left upper extremity pain and developed a blistering rash in a dermatomal pattern in the left proximal upper extremity two weeks after the initial symptoms. He was diagnosed with shingles and treated with steroids and acyclovir with minimal improvement. Six weeks after the initial symptoms, a physical exam revealed left deltoid, supraspinatus and infraspinatus weakness with normal muscle stretch reflexes and decreased sensation on the C5 dermatome. Electromyography (EMG) revealed absent left lateral antebrachial cutaneous sensory nerve action potentials (SNAP) amplitude and a small left radial SNAP amplitude compared to the right side. Evidence of ongoing denervation with reinnervation was seen in the left upper trunk-supplied muscles. MRI of the brachial plexus was negative for any abnormalities. The patient was diagnosed with VZV-associated plexopathy, which improved with pregabalin and physical therapy. Our patient was significantly younger than expected in the HZ group. MRI usually shows T2 hyperintensities and thickening of the nerve roots in patients with VZV-associated plexopathy. However, the presentation, onset of symptoms, characteristics of the rash, and clinical course were diagnostic of HZ, and the weakness pattern, supported by the EMG findings, was diagnostic of VZV-associated plexopathy.

Acute Herpes Zoster Radiculopathy of the Lower Extremity With Dermatomal Rash and Lumbar Nerve Enhancement on MRI

Herpes zoster is a frequent cause of neuralgia and dermatomal vesicular rash secondary to reactivation of latent varicella zoster virus. However, it rarely presents with acute lumbar radiculopathy and the diagnosis can be quite challenging in such cases. Nerve signal abnormalities on magnetic resonance imaging are well recognized in herpes zoster neuropathy or plexopathy affecting the extremities, although gadolinium enhancement is characteristically absent. In this article, we describe a case of acute herpes zoster lumbosacral radiculopathy with characteristic vesicular dermatomal rash and second ever reported finding of gadolinium enhancement of the lumbar nerve on magnetic resonance imaging.

Disseminated herpes zoster with cauda equina symptoms

Herpes zoster is a common infection resulting from the reactivation of dormant varicella zoster virus in a posterior dorsal root ganglion. The typical dermatomal involvement includes the thoracic region, followed by the face and the cervical and lumbosacral regions, with 1% having disseminated disease. We present a rare case of an immunocompetent 85-year-old man presenting with herpes zoster at the L3-S2 dermatomes, that evolved to disseminated varicella zoster virus (dVZV), with radiologically and laboratory-confirmed lumbosacral plexopathy manifesting with cauda equina syndrome. Here we also discuss the diagnosis and complications of dVZV as well as treatment strategy. By maintaining a high degree of clinical suspicion and initiating early treatment, high-quality patient care and good outcomes are able to be achieved in cases like this.