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

Hassan Kesserwani

doi:10.7759/cureus.10747

Abstract

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.

Highlights

Herpes zoster-associated brachial plexitis has been referred to as zoster segmental paresis of the limbs
A magnetic resonance imaging (MRI) study performed in half the patients early during the disease process showed nerve hypertrophy and T2 signal hyperintensity in the afflicted peripheral nerves in two patients and T2 signal hyperintensity in the dorsal horns of the cervical C5 and C6 spinal cord [1]
We review the literature of herpetic segmental paresis, the radiologic findings on MRI, and speculate why these lesions rarely reveal contrast enhancement on MRI

Summary

Introduction

Herpes zoster-associated brachial plexitis has been referred to as zoster segmental paresis of the limbs. Careful examination and electrophysiology studies unequivocally localized the lesion to the medial cord of the brachial plexus We believe that his presentation is more likely a radiculo-plexopathy, as the dermatomal herpetic rash extended beyond the medial antebrachial cutaneous sensory and ulnar sensory nerves, all the way up into the shoulder. We present the case of a 77-year-old right-handed man who developed a shingles rash over the ulnar half of his left hand and forearm, posterior aspect of his left upper arm, all the way proximally to behind the left shoulder. The electromyography (EMG) study reveals acute and florid denervation of the left median and ulnar innervated muscles of the hand and forearm, with the preservation of radial, axillary, and musculocutaneous nerves (Table 2). First dorsal interosseus Abductor pollicis Flexor digitorum profundus (median) Flexor digitorum profundus (ulnar) Flexor pollicis longus Flexor digitorum superficialis Extensor carpi radialis longus Biceps brachii Triceps Deltoids Pronator teres Brachialis Supinator Lower cervical paraspinals

C8 T1 C8 T1 C6 C7 C5 C6 C6 C7 C8 C5 C6 C6 C7 C5 C6 C5 C6 C7

Discussion

Conclusions

Findings

Disclosures

Ferrante MA