Imaging Findings in Patients with Zoster-Associated Plexopathy

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.

Risk factors and nomogram-based prediction of the risk of limb weakness in herpes zoster

Background

Limb weakness is a less common complication of herpes zoster (HZ). There has been comparatively little study of limb weakness. The aim of this study is to develop a risk nomogram for limb weakness in HZ patients.

Methods

Limb weakness was diagnosed using the Medical Research Council (MRC) muscle power scale. The entire cohort was assigned to a training set (from January 1, 2018 to December 30, 2019, n = 169) and a validation set (from October 1, 2020 to December 30, 2021, n = 145). The least absolute shrinkage and selection operator (LASSO) regression analysis method and multivariable logistic regression analysis were used to identify the risk factors of limb weakness. A nomogram was established based on the training set. The discriminative ability and calibration of the nomogram to predict limb weakness were tested using the receiver operating characteristic (ROC) curve, calibration plots, and decision curve analysis (DCA). A validation set was used to further assess the model by external validation.

Results

Three hundred and fourteen patients with HZ of the extremities were included in the study. Three significant risk factors: age (OR = 1.058, 95% CI: 1.021–1.100, P = 0.003), VAS (OR = 2.013, 95% CI: 1.101–3.790, P = 0.024), involving C6 or C7 nerve roots (OR = 3.218, 95% CI: 1.180–9.450, P = 0.027) were selected by the LASSO regression analysis and the multivariable logistic regression analysis. The nomogram to predict limb weakness was constructed based on the three predictors. The area under the ROC was 0.751 (95% CI: 0.673–0.829) in the training set and 0.705 (95% CI: 0.619–0.791) in the validation set. The DCA indicated that using the nomogram to predict the risk of limb weakness would be more accurate when the risk threshold probability was 10–68% in the training set and 15–57% in the validation set.

Conclusion

Age, VAS, and involving C6 or C7 nerve roots are potential risk factors for limb weakness in patients with HZ. Based on these three indicators, our model predicted the probability of limb weakness in patients with HZ with good accuracy.

ACR Appropriateness Criteria® Plexopathy: 2021 Update

Plexopathy may be caused by diverse pathologies, including trauma, nerve entrapment, neoplasm, inflammation, infection, autoimmune disease, hereditary disease, and idiopathic etiologies. For patients presenting with brachial or lumbosacral plexopathy, dedicated plexus MRI is the most appropriate initial imaging modality for all clinical scenarios and can identify processes both intrinsic and extrinsic to the nerves. Other imaging tests may be appropriate for initial imaging depending on the clinical scenario. This document addresses initial imaging strategies for brachial and lumbosacral plexopathy in the following clinical situations: nontraumatic plexopathy with no known malignancy, traumatic plexopathy (not perinatal), and plexopathy occurring in the context of a known malignancy or posttreatment syndrome. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Approach to Neurologic Complications in the Immunocompromised Patient

Neurologic complications are common in immunocompromised patients, including those with advanced human immunodeficiency virus, transplant recipients, and patients on immunomodulatory medications. In addition to the standard differential diagnosis, specific pathogens and other conditions unique to the immunocompromised state should be considered in the evaluation of neurologic complaints in this patient population. A thorough understanding of these considerations is critical to the inpatient neurologist in contemporary practice, as increasing numbers of patients are exposed to immunomodulatory therapies. In this review, we provide a chief complaint-based approach to the clinical presentations and diagnosis of both infectious and noninfectious complications particular to immunocompromised patients.

Zoster-associated limb paralysis mimicking acute stroke: a case report

Background

Varicella zoster virus is a Deoxyribonucleic acid (DNA) virus exclusively affecting humans. Reactivation of varicella zoster virus causes herpes zoster with vesicular eruptions in a restricted dermatomal distribution. Peripheral motor neuropathy is a very rare complication of varicella zoster virus.

Case presentation

A 57-year-old previously well Sri Lankan female presented with acute onset painful weakness of the left upper limb with a preceding history of a febrile illness. Subsequently she developed vesicular eruptions in the dermatomal distribution of cervical 5, 6, and 7. Electromyography was suggestive of acute denervation of cervical 5, 6, and 7 myotomes. Diagnosis of zoster-associated brachial plexopathy was made, and the patient was treated with acyclovir, steroids, and analgesics. She made a good recovery.

Conclusion

Brachial plexus neuritis due to varicella zoster infection should be considered in an acute monoparesis of a limb as it is a treatable and reversible condition

Complete recovery of herpes zoster radiculopathy based on electrodiagnostic study: A case report

BACKGROUND

Herpes zoster is a painful infectious disease caused by the varicella zoster virus. Herpes zoster radiculopathy, which is a type of segmental zoster paresis, can complicate the disease and cause motor weakness. This complication should be considered when a patient with a rash complains of acute-onset motor weakness, and the diagnosis can be verified via electrodiagnostic study.

CASE SUMMARY

A 64-year-old female with a history of asthma presented to the emergency department with stabbing pain, an itching sensation, and a rash on the right anterior shoulder that had begun 5 d prior. Physical examination revealed multiple erythematous grouped vesicles in the right C4-5 and T1 dermatome regions. Because herpes zoster was suspected, the patient immediately received intravenous acyclovir. On the third hospital day, she complained of motor weakness in the right upper extremity. Magnetic resonance imaging of the cervical spine revealed mild intervertebral disc herniation at C4-C5 without evidence of nerve root compression. On the 12^th hospital day, electrodiagnostic study revealed right cervical radiculopathy, mainly in the C5/6 roots. Six months later, monoparesis resolved, and follow-up electrodiagnostic study was normal.

CONCLUSION

This case emphasizes that clinicians should consider the possibility of post-herpetic paresis, such as herpes zoster radiculopathy, and that electrodiagnostic study is useful for diagnosis and follow-up.

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.

Post-Herpetic Brachial Plexopathy: A Rare Case Report With a Side Note on Localizing Brachial Plexopathies and a Literature Review of Post-Herpetic Segmental Paresis

We present the case of a 77-year-old man who developed shingles over the cervical C8 dermatome followed by post-herpetic medial cord brachial plexopathy, with hand weakness and difficulty performing the pinch " O " sign. This is the very first case, to our knowledge, of a detailed presentation of a medial cord plexopathy following shingles. We review the literature of post-herpetic brachial plexopathies and discuss the magnetic resonance imaging (MRI) findings of the brachial plexus in this group of patients. We also speculate on the intriguing finding that despite frequent abnormalities on MRI such as T2 signal hyperintensity and nerve hypertrophy, contrast enhancement of nerves is exceedingly rare. Furthermore, we adumbrate on the localization of brachial plexus lesions by proposing a user-friendly diagram and table, which simplifies the diagnostic algorithm.

Segmental zoster paresis of unilateral upper extremity: A case report and literature review

RATIONALE

Segmental zoster paresis (SZP) is a relatively rare neurologic complication of herpes zoster (HZ), and is characterized by focal asymmetric motor weakness in the myotome that corresponds to skin lesions of the dermatome. The upper extremities are the second most commonly involved regions after the face, and predominantly involve proximal muscles. The pathogenesis of SZP remains unclear; however, most of the reports indicate that it is the inflammation because of the spread of the herpes virus.

PATIENT CONCERNS

A 72-year-old man without trauma history of the left shoulder joint developed weakness of the left proximal upper extremity 10 days after vesicular eruption of HZ.

DIAGNOSES

His left shoulder girdle paresis was diagnosed with the upper truncus of the brachial plexus as a HZ complication according to a series of tests, including cervical magnetic resonance imaging (MRI), cerebral fluid analysis, sonography, and electrophysiological studies.

INTERVENTIONS

Acyclovir and prednisolone were administered during hospitalization to treat SZP. Meanwhile, analgesics and gabapentin were administered to control the patient's neuralgic pain. He also received inpatient (daily) and outpatient (3 times per week) physical therapy along with range of motion and strengthening exercises.

OUTCOMES

Partial improvement of the strength of the left shoulder girdle, and no improvement of the left deltoid muscle was observed 2 months after the interventions.

LESSONS

This case emphasizes that HZ infections may be complicated by segmental paresis and they should be considered in the differential diagnosis of acute paresis in the upper limb. Awareness of this disorder is important because it avoids unnecessary invasive investigations and interventions, leading to suitable treatments with favorable prognosis.

Avoiding a lumbar puncture may be a rash decision: a case report of varicella-zoster virus-associated radiculopathy in advanced HIV infection

A 34-year-old man recently diagnosed with advanced human immunodeficiency virus infection (CD4 cell count of 139 cells/mm3), not yet started on antiretroviral medications, presented to hospital with a ten-day history of left leg weakness and difficulty walking. He described a childhood history of chickenpox with previous shingles over his buttock over three years ago. Examination revealed reduced power in the left hip and knee flexors and absent knee and adductor reflexes. Lumbar punctures were performed and polymerase chain reaction (PCR) detected varicella-zoster virus (VZV) DNA. Concurrent serum samples for VZV PCR were negative. The patient was diagnosed with VZV radiculopathy and treated with high-dose intravenous acyclovir. Within two days, neurological signs improved. Previous case reports define VZV radiculopathy by a temporal and geographical relationship with a zoster rash. Our diagnosis was based on a clinical picture of radiculopathy with virological evidence in CSF and confirmed by a dramatic clinical response to treatment. We propose that lumbar puncture and detection of VZV DNA by PCR in the cerebrospinal fluid (CSF) is an invaluable investigation that should be considered in the workup of immunosuppressed patients presenting with a radiculopathy.

Indications for neuromuscular ultrasound: Expert opinion and review of the literature

Over the last two decades, dozens of applications have emerged for ultrasonography in neuromuscular disorders. We wanted to measure its impact on practice in laboratories where the technique is in frequent use. After identifying experts in neuromuscular ultrasound and electrodiagnosis, we assessed their use of ultrasonography for different indications and their expectations for its future evolution. We then identified the earliest papers to provide convincing evidence of the utility of ultrasound for particular indications and analyzed the relationship of their date of publication with expert usage. We found that experts use ultrasonography often for inflammatory, hereditary, traumatic, compressive and neoplastic neuropathies, and somewhat less often for neuronopathies and myopathies. Usage significantly correlated with the timing of key publications in the field. We review these findings and the extensive evidence supporting the value of neuromuscular ultrasound. Advancement of the field of clinical neurophysiology depends on widespread translation of these findings.

A retrospective case series of segmental zoster paresis of limbs: clinical, electrophysiological and imaging characteristics

BACKGROUND

Segmental zoster paresis (SZP) of limbs, characterized by focal weakness of extremity, is recognized as a rare complication of herpes zoster (HZ). The following study analyzes the clinical characteristics and data from electromyography and MRI scans in patients with motor weakness after zoster infection.

METHODS

One thousand three hundred ninety-three patients from our database (Shandong Provincial Qianfoshan Hospital) suffering from HZ were retrospectively reviewed from June 2015 to July 2017. Patients who fulfilled the diagnostic criteria for SZP were included in the analysis. The clinical characteristics, as well as electromyography findings and MRI scans were analyzed.

RESULTS

SZP was present in 0.57% of patients with HZ (8/1393). The average age of symptom onset in 8 SZP patients was 69 years old (SD: 13, range 47-87). The severity of muscle weakness ranged from mild to severe. The electrophysiological testing revealed the characteristics of axonopathy. Radiculopathy (2/8), plexopathy (2/8), radiculoplexopathy (3/8) and combined radiculopathy and mononeuropathy (1/8) were also identified. MRI revealed hyperintensity of the affected spinal dorsal horns, nerve roots or peripheral nerves.

CONCLUSIONS

SZP is associated with obvious limb weakness, nerve axons lesions and localization to nerve roots, plexus or peripheral nerves.

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

This is a rare case of Varicella zoster virus (VZV) lumbosacral plexopathy in an 84-year-old women presenting with lower limb weakness and rash. Contrast-enhanced MRI showed enhancement of the left L3-L5 descending nerves and left lumbosacral plexus consistent with inflammatory/infectious aetiology. Cerebrospinal fluid PCR confirmed VZV DNA and cerebrospinal fluid serological testing was positive for VZV immunoglobulin (Ig)M and IgG antibodies. The patient was treated with intravenous acyclovir but this was complicated by the development of acute renal failure attributed to acyclovir-induced nephropathy, requiring dose adjustment. After a prolonged course of oral acyclovir and inpatient rehabilitation, the patient made a partial neurological and functional recovery.