Motor deficits after herpes zoster: a comparative analysis of patient characteristics and sensory changes

INTRODUCTION: Herpes zoster (HZ) predominantly affects sensory nerves and can lead to postherpetic neuralgia. A motor deficit in the corresponding myotome is a rare but severe complication. Objectives: The objective of this study was to further characterize patients with HZ-related motor deficits and to explore potential risk factors.

METHODS: This retrospective cohort study in the tertiary pain clinic of the University Medical Center Utrecht, includes a comparative analysis of patients presenting with and without motor deficit resulting from HZ. Patient characteristics including psychological distress were assessed using standardized questionnaires, and Quantitative Sensory Testing outcomes were analysed between the 2 groups.

RESULTS: The study population included 158 patients with postherpetic neuralgia, of whom 17 patients had motor paralysis. In the motor paralysis group, most were male (94.1%). The median pain intensity was NRS 7, similar in both groups. Anxiety, depression, Pain Catastrophizing Scale, and DN4 scores did not differ significantly between groups. Tampa Scale of Kinesiophobia, indicating kinesiophobia did significantly differ between both groups (P = 0.043). Patients with motor deficit showed distinct sensory profiles characterized by sensory loss in 70.6% of patients compared with 35.5% in the group without motor deficit (P = 0.017).

CONCLUSION: Motor deficit may be more common than we realize and is a serious complication of HZ. Patients who experienced motor deficit as a complication of herpes zoster demonstrated more severe nerve damage, with sensory loss being the most frequent sensory phenotype. More awareness is needed for this serious complication accompanied with research guiding treatment and rehabilitation protocols.