A Rare Complication of Herpes Zoster: Segmental Zoster Paresis

Abstract

Segmental zoster paresis (SZP) is a rare complication of herpes zoster (HZ) that results in focal weakness of the extremity in the myotome that corresponds to dermatomal involvement. We present a case of an 80year-old female with a resolving HZ rash on her left leg and buttocks that presented with left leg weakness for two weeks. The patient's rash preceded the left leg weakness by two weeks. The exam revealed erythematous macular and crusting lesions in the left L3/L4 distribution. The left thigh was flaccid with 1/5 knee extension strength with an absent patellar reflex. Lumbar spine magnetic resonance imaging (MRI) revealed enhancement of the left L4 roots, suggestive of inflammation or neuropathy. The patient was discharged on gabapentin, amitriptyline, and a two-week prednisone taper. In this case study, we present SZP, a rare complication that occurs in approximately 3% of HZ patients. The majority of SZP cases occur on the face or upper extremity, whereas our patient had SZP of the lower extremity. This case emphasizes the importance of maintaining a comprehensive differential diagnosis and highlights that SZP should be considered in patients who present with acute weakness in an extremity.

Segmental Zoster Paresis of the Unilateral Lower Extremity With Neuritis MRI Findings: A Case Report and Literature Review

“…Weakness usually occurs a few days to weeks after the appearance of the herpetic rash and in the proximal muscle groups (C5, C6, C7 or L2, L3, L4 innervated muscles) [ 6 ]. Nerve enlargement and T2 hyperintensity consistent with clinical symptoms are rarely seen in MRI examinations of patients with SZP [ 1 , 2 ]. SZP management including antiviral treatment and symptomatic treatments has a good prognosis.…”

“…It is a rare form of SZP with MRI enhancement of the L5 nerve root resulting in focal weakness in the right lower extremity in its myotome (L5) and accompanied by a corresponding dermatomal (L5) rash. In the literature, only two cases of lower extremity SZP have been reported as having MRI enhancement of the affected nerve root (Table 1 ) [ 1 , 2 ].…”

“…However, laboratory data for VZV can be obtained by direct fluorescent antibody (DFA), polymerase chain reaction (PCR), and Tzanck smear [ 9 ]. Low amplitude of compound muscle action potentials (CMAP) and sensory nerve action potentials (SNAP) suggesting motor and sensory axonopathy may be seen in EMG of patients with SZP [ 1 ]. Although EMG and PCR were not performed on our patient the diagnosis is set by clinical evaluation.…”

“…We performed a literature search with these findings. Only two cases of patients with acute onset HZ rash presenting with radiculopathy of the lower extremity with dermatomal rash and lumbar nerve enhancement on MRI have been described in the literature [ 1 , 2 ]. We performed a consultation with our neuroradiologist team and concluded by suggesting the lesion may be associated with HZ.…”

“…Herpes zoster (HZ) is associated with numerous complications, including postherpetic neuralgia, encephalitis, aseptic meningitis, and segmental zoster paresis (SZP) [ 1 ]. However, SZP, which results in unilateral motor impairment in the extremity, is a rare complication of HZ.…”