Effects of Acyclovir on Sensory Axonal Neuropathy, Segmental Motor Paresis and Postherpetic Neuralgia in Herpes zoster Patients

Abstract

The effect of oral treatment with acyclovir (ACV) on sensory axonal neuropathy, segmental motor paresis and postherpetic neuralgia (PHN) was studied in 105 patients with herpes zoster. Forty-seven patients were treated with ACV at a dose of 4 g/day in 5 doses for at least a week; the others did not undergo any kind of treatment. Electrodiagnostic examination of the nerves and muscles corresponding to the dermatomeric lesions was performed, including sensory and motor nerve conduction studies, blink reflex and electromyography (EMG). The patients treated with ACV showed a significant reduction in the number of cases in which there was electrophysiological evidence of axonal damage in afferent fibres of nerves arising from roots corresponding to affected dermatomes. The treated group also showed a smaller incidence of segmental motor neuritis, clinically evident or only detectable by EMG as denervation. However, there was no significant difference between groups as far as the incidence of PHN was concerned. Oral treatment with ACV therefore reduces peripheral sensory axonopathy due to ganglion damage and prevents the possibility of spread to anterior roots and spinal motoneurones. In this way it reduces the incidence of segmental motor neuritis, but does not reduce the incidence of PHN.

Post Herpetic C8 Myotomal Paresis

“…Involvement of limbs through spinal nerve involvement is uncommon. In the literature, Mondelli, Haanpaa and Akiyama (8,9,10) reported similar cases in series and there are a few reports from India (11,12). Myotomal paresis usually develops in the first few weeks after the onset of rash.…”

Motor Paresis in Herpes Zoster- a Rare Complication

“…Prompt antiviral therapy may prevent occurrence of motor paresis but there was not enough evidence to support whether it speeds the recovery. Although this reduces the zoster associated pain, fast recovery of skin lesions and reduces chances of getting PHN (10) .…”

Motor radiculopathy

“…On the basis of the findings of herpes simplex virus reactivation within the geniculate ganglion patients with idiopathic facial nerve palsy have been treated with antiviral agents with better outcomes than patients not treated with antivirals 6 7. In patients with herpes zoster radiculopathy the incidence of zoster paresis and the progression and severity of electrophysiological changes have been found to decrease in patients with antiviral therapy 8 9. However, there is limited data on the use of steroids for patients with herpes zoster radiculopathy but case reports are available to suggest marked improvement in symptoms following fluoroscopically guided nerve root block with steroid and local anaesthetic 10.…”