Zoster-associated neuralgia (ZAN) refers to neuropathic pain resulting from herpes zoster
(HZ) infection. Based on the duration of symptoms, ZAN is classified into three stages:
acute herpetic neuralgia (AHN, less than 1 month), subacute herpetic neuralgia (SHN, 1 to
3 months), and postherpetic neuralgia (PHN, more than 3 months).The global annual
incidence of HZ is approximately 3 to 5 per 1,000 individuals, with higher rates observed
among individuals aged 50 years and older, and among females. In China, the annual
incidence is approximately 4.89 per 1,000 individuals, with a notable increase observed
with advancing age.
Pain is the most common clinical symptom of HZ, and its severity correlates with age,
immune status, and initial pain intensity. Older adults and immunocompromised patients
are more prone to developing PHN . HZ may also lead to complications such as ocular
herpes zoster, meningitis, and motor nerve damage, particularly in immunocompromised
individuals, where the risk and severity of these complications are significantly
elevated . The pathogenesis of PHN remains incompletely understood and may involve
inflammatory responses, ion channel alterations, and peripheral/central sensitization .
Chronic pain severely impacts patients' quality of life and can lead to psychological
issues such as anxiety, depression, and sleep disturbances, imposing substantial burdens
on families and society .
ZAN is challenging to treat, with current approaches including pharmacotherapy, nerve
blocks, pulsed radiofrequency, and spinal cord stimulation (SCS) . SCS is a minimally
invasive neuromodulation technique widely used for chronic pain. It involves implanting
electrodes in the epidural space to deliver electrical pulses to the dorsal columns and
dorsal horn structures, thereby modulating pain signal transmission. Although the
analgesic mechanism of SCS is not fully elucidated, its theoretical basis dates back to
the 1965 "gate control theory" proposed by Melzack and Wall. This theory posits that
activating large-diameter Aβ afferent fibers inhibits nociceptive signals mediated by
small-diameter Aδ and C fibers, reducing spinal sensitization .
Recent studies suggest that SCS also regulates neurotransmitters, suppresses
neuroinflammation, and modulates autophagy . At the neurotransmitter level, SCS enhances
the release of γ-aminobutyric acid (GABA), reduces glutamate concentrations, amplifies
endogenous opioid signaling, and activates the endocannabinoid system, thereby
rebalancing dorsal horn activity and inhibiting pain transmission. In neuroinflammatory
regulation, SCS elevates anti-inflammatory resolvin D1, reduces pro-inflammatory
cytokines (IL-1β, TNF-α), suppresses microglial overactivation, and modulates the p38MAPK
pathway, thereby attenuating neuroinflammation and pain hypersensitivity . Additionally,
SCS promotes neuronal autophagy, accelerating the clearance of damaged cellular
components to restore function and mitigate neural injury, further alleviating pain .
These mechanisms collectively support SCS as a multimodal analgesic strategy, driving its
clinical adoption.
SCS has shown efficacy in ZAN treatment, particularly for patients refractory to
medications or other minimally invasive therapies. However, traditional low-frequency SCS
(30-100 Hz), which relies on high-intensity pulses to modulate spinal and ascending pain
pathways, often induces paresthesia (e.g., tingling) as a side effect. Clinical
limitations include incomplete pain coverage, diminishing efficacy over time, and
discomfort in non-target areas, necessitating novel SCS paradigms with improved efficacy
and tolerability .
High-frequency spinal cord stimulation (HF-SCS) is an emerging neuromodulation technique
that alleviates chronic neuropathic pain without paresthesia and may benefit patients
unresponsive to traditional SCS. In China, HF-SCS research remains exploratory, with no
clinical studies on ZAN. International studies, though advanced, lack systematic data on
ZAN, with heterogeneous parameters (indications, frequency, pulse width, etc.). This
study compares short-term 1 kHz HF-SCS with traditional low-frequency SCS in ZAN
treatment, evaluating pain relief, psychological status (anxiety/depression), sleep
quality, patient experience, and complication rates. The findings aim to establish the
safety and efficacy of short-term HF-SCS for ZAN, offering a novel therapeutic option for
this challenging condition.