• The Korean Journal of Pain
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• v.27 no.1
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• pp.54-62
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• 2014

Background: The recently known analgesic action mechanisms of nefopam (NFP) are similar to those of anticonvulsants and antidepressants in neuropathic pain treatment. It is difficult to prescribe high doses of oral neuropathic drugs without titration due to adverse effects. Unfortunately, there are few available intravenous analgesics for the immediate management of acute flare-ups of the chronic neuropathic pain. The aim of this study was to determine the additional analgesic effects for neuropathic pain of NFP and its adverse effects during the titration of oral medications for neuropathic pain among inpatients with postherpetic neuralgia (PHN). Methods: Eighty inpatients with PHN were randomly divided into either the NFP or normal saline (NS) groups. Each patient received a 3-day intravenous continuous infusion of either NFP with a consecutive dose reduction of 60, 40, and 20 mg/d, or NS simultaneously while dose titrations of oral medications for neuropathic pain gradually increased every 3 days. The efficacy of additional NFP was evaluated by using the neuropathic pain symptom inventory (NPSI) score for 12 days. Adverse effects were also recorded. Results: The median NPSI score was significantly lower in the NFP group from days 1 to 6 of hospitalization. The representative alleviating symptoms of pain after using NFP were both spontaneous and evoked neuropathic pain. Reported common adverse effects were nausea, dizziness, and somnolence, in order of frequency. Conclusions: An intravenous continuous infusion of NFP reduces spontaneous and evoked neuropathic pain with tolerable adverse effects during the titration of oral medications in inpatients with PHN.

• The Korean Journal of Pain
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• v.10 no.1
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• pp.127-130
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• 1997

A 67-year old man with a history of cardiac disease underwent epidural catheterization for pain control of postherpetic neuralgia. Patient had severe back pain and pus discharge at catheter insertion site after dischange from medical part. Patient received anticoagulant therapy with $Aspirin^{(R)}$ and $Coumadin^{(R)}$ prescribed for 15 days in medical part. Magnetic resonance imaging(MRI) showed a diffuse $T_{4-7}$ anterior epidural mass compressing the spinal cord. Emergency surgical exploration revealed a thoracic epidural hematoma without abcess formation. Operation was successful and patient recovered satisfactory without any sequelae.

• The Korean Journal of Pain
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• v.26 no.1
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• pp.72-75
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• 2013

Zoster sine herpete (ZSH) is difficult to diagnosis during an acute period due to the absence of the characteristic zosteriform dermatomal rash; therefore, progression to postherpetic neuralgia is more common than typical zoster. In addition, misdiagnosis of other neuropathic pain as ZSH is common in clinical situations. Here, we report a case of spinal arteriovenous malformation that mimics ZSH. This is a rare condition; therefore, high clinical suspicion for a correct diagnosis and proper examination are not easy. However, early diagnosis and definitive treatment are essential to prevent neurologic deficit and mortality.

• The Korean Journal of Pain
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• v.24 no.3
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• pp.154-157
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• 2011

Background: Postherpetic neuralgia (PHN) is usually managed pharmacologically. It is not uncommon for patients with chronic kidney disease (CKD) to suffer from PHN. It is difficult to prescribe a sufficient dose of anticonvulsants for intractable pain because of the decreased glomerular filtration rate. If the neural blockade and pulsed radiofrequency ablation provide only short-term amelioration of pain, spinal cord stimulation (SCS) with a low level of evidence may be used only as a last resort. This study was done to evaluate the efficacy of spinal cord stimulation in the treatment of PHN in patients with CKD. Methods: PHN patients with CKD who needed hemo-dialysis who received insufficient relief of pain over a VAS of 8 regardless of the neuropathic medications were eligible for SCS trial. The follow-up period was at least 2 years after permanent implantation. Results: Eleven patients received percutaneous SCS test trial from Jan 2003 to Dec 2007. Four patients had successfully received a permanent SCS implant with their pain being tolerable at a VAS score of less than 3 along with small doses of neuropathic medications. Conclusions: SCS was helpful in managing tolerable pain levels in some PHN patients with CKD along with tolerable neuropathic medications for over 2 years.

• The Korean Journal of Pain
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• v.30 no.3
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• pp.214-219
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• 2017

Background: As herpes zoster progresses via postherpetic neuralgia (PHN) to well-established PHN, it presents its recalcitrant nature to the treatment. At this point, the well-established PHN is fixed as a non-treatable, but manageable chronic painful neuropathic disorder. This study evaluated the incidence of complete relief from PHN according to PHN duration at their first visit, and the other factors influencing it. Methods: A retrospective chart review was performed on patients with PHN at a university-based pain clinic over 7 years. The responders were defined as patients who had complete relief from pain after 1 year of active treatment. Age, sex, PHN duration at their first visit, dermatomal distribution, and underlying disorders were compared in the responder and non-responder groups. Responders were also compared according to these factors. Results: Among 117 PHN patients (M/F = 48/69), 35 patients (29.9%) had complete relief from PHN. Mean ages were $64.3{\pm}10.6$ and $66.9{\pm}10.7$ years, numbers of male to female patients were 11/24 and 37/45, and mean durations of PHN at their first visit were $8.5{\pm}6.3$ and $15.3{\pm}10.7$ months in the responder and non- responder groups, respectively. In addition, PHN patients who visited the clinic before 9 months showed a better result. Dermatomal distribution and underlying disorders did not show significant differences. Conclusions: Almost 30% of PHN patients received complete relief. Those who sought treatment in a pain clinic before 9 months received a better result.

• The Korean Journal of Pain
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• v.33 no.3
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• pp.208-215
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• 2020

Zoster sine herpete (ZSH) is one of the atypical clinical manifestations of herpes zoster (HZ), which stems from infection and reactivation of the varicella-zoster virus (VZV) in the cranial nerve, spinal nerve, viscera, or autonomic nerve. Patients with ZSH display variable symptoms, such as neuralgia, however, different from HZ, ZSH show no zoster, which makes clinical diagnosis difficult. ZSH not only causes initial symptoms, such as neuropathic pain in the affected nerve, Bell palsy, and Ramsay Hunt syndrome, but also postherpetic neuralgia and fatal complications such as VZV encephalitis and stroke. The misdiagnosis of ZSH and tardy antiviral treatment may lead to severe ZSH sequelae. We review the publications related to ZSH, especially its diagnosis with VZV DNA and/or anti-VZV immunoglobulin (IgG and IgM). More work about ZSH, especially ZSH epidemiological survey and guidelines for its diagnosis and treatment, are needed because most of the present studies are case reports.

• The Korean Journal of Pain
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• v.32 no.3
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• pp.215-222
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• 2019

Background: Several nerve blocks can reduce the incidence of postherpetic neuralgia (PHN) as well as relieve acute zoster-related pain, but the long-term outcome of PHN has not been clearly determined. This study investigated the efficacy of selective nerve root block (SNRB) for herpes zoster (HZ) on the long-term outcome of PHN. Methods: We prospectively conducted an interview of patients who had undergone an SNRB for HZ from January 2006 to December 2016 to evaluate their long-term PHN status. The relationship between the time from HZ onset to the first SNRB and the long-term outcome of PHN was investigated. Results: The data of 67 patients were collected. The patients were allocated to acute ($SNRB{\leq}14days$, n = 16) or subacute (SNRB > 14 days, n = 51) groups. The proportions of cured patients were 62.5% and 25.5% in the acute and subacute groups (P = 0.007), respectively. In logistic regression, an SNRB >14 days was the significant predictor of PHN (adjusted odd ratio, 3.89; 95% confidence interval, 1.02-14.93; P = 0.047). Kaplan-Meier analysis revealed that time from the SNRB to the cure of PHN was significantly shorter in the acute group ($2.4{\pm}0.7yr$) than in the subacute group ($5.0{\pm}0.4yr$; P = 0.003). Conclusions: An early SNRB during the acute stage of HZ (within 14 days) appears to decrease the incidence and shorten the duration of PHN, with a median of 5.0 years of follow-up.

• The Korean Journal of Pain
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• v.35 no.1
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• pp.114-123
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• 2022

Background: Different views have been proposed on the radiofrequency treatment modes and parameters of radiofrequency thermocoagulation of the spinal dorsal root ganglion for the treatment of postherpetic neuralgia (PHN). It is urgent to identify a more effective therapy for patients with PHN. Methods: Patients who underwent radiofrequency thermocoagulation therapy for PHN were retrospectively reviewed and were divided into a radiofrequency thermocoagulation (CRF) and double neddles radiofrequency thermocoagulation (DCRF). The pain scores (numerical rating scale, NRS) were evaluated at the following time points: before the operation, 1 day, 3 months, 6 months, 1 year, and 2 years after operation. The incidence of complications and the degree of pain relief were evaluated. The in vitro ovalbumin experiment was used to indicate the effects of radiofrequency thermocoagulation. Results: Compared with the preoperative NRS scores, the postoperative NRS scores decreased significantly; the NRS scores of the DCRF group was lower than that of the CRF group at all time points from 6 months to 2 years following the operation. The total effective rate of the DCRF group was significantly higher than that of the CRF group at 2 years following the operation. The incidence of numbness in the DCRF group was higher than that noted in the CRF group. The ovalbumin experiments in vitro indicated that the effects of radiofrequency thermocoagulation were optimal when the distance between the two needles was 5 mm. Conclusions: DCRF with a 5 mm spacing exhibits a longer duration and higher effective rate in the treatment of PHN and is worth promoting.

• Journal of Oral Medicine and Pain
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• v.35 no.1
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• pp.93-99
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• 2010

Herpes zoster (HZ) is the secondary manifestation of an earlier infection with the varicella-zoster virus in one or more dermatomes. As reactivation of the virus is linked to an age-related diminished virus-specific and cell-mediated immunity, HZ develops mainly in elderly people. Acute zoster is painful, but does not incur lasting morbidity. Reactivation of the varicella-zoster virus in the trigeminal nerve (Herpes zoster) occur with severe pain and rash in the oro-facial region. The acute pain decreases as the rash begins to heal. Postherpetic neuralgia(PHN), the most frequent complication of herpes zoster, is usually defined as pain in the involved dermatome that is still present 3 month after rash onset. The clinical characteristics of PHN are, eposodic stabbing pain, burning pain and allodynia, with hypoesthesia and/or dysesthesia. $Neurometer^{(R)}$(neuroselective sensory nerve conduction threshold: sNCT, Automated current perception threshold: CPT, neurotron incorporated. Baltimore, Maryland. 21209 U.S.A.) is convenient, rapid and noninvasive, and allows objective assessment of sensory disturbance. This case is about the postherptic neuralgia patient assessed with $Neurometer^{(R)}$. From this case, we reviewed the pathophysiology and the treatment of PHN and recommend the assessment of pain intensity with $Neurometer^{(R)}$ as quantitative and objective method.

• The Korean Journal of Pain
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• v.34 no.4
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• pp.463-470
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• 2021

Background: Although neuropathic pain is a severe and common pain, its pathophysiology has not been elucidated yet. Studies in recent years have focused on the immune system's role in the pathogenesis of neuropathic pain. The aim of this study was to investigate the role of immunological mechanisms in neuropathic pain and the effect of pregabalin by measuring immunological marker levels in peripheral blood before and after pregabalin treatment in postherpetic neuralgia (PHN) patients with neuropathic pain. Methods: Forty patients diagnosed with PHN were included in the study. CD4, T follicular cells (Tfh: CD4⁺CXCR5⁺PD1⁺), Th17 (CD4⁺CCR6⁺ and CD4⁺IL17A⁺), regulatory T cells (Treg: CD4⁺ CD25⁺foxp3⁺), Th1 (CD4⁺ CXCR3⁺ and CD4⁺ IFN-γ⁺) and Th2 (CD4⁺ IL-4⁺) cell ratios were measured in peripheral blood samples before treatment and after 3 months of treatment. Results: When immunological marker and inflammation parameter levels were compared before and after treatment, the helper T cell ratio (CD3⁺, CD4⁺) was 30.28 ± 12.27% before treatment and 34.93 ± 11.70% after treatment, so there was a statistically significant increase (P = 0.028). Th17 was 4.75 ± 5.02% before treatment and 5.80 ± 3.13% after treatment, and there was a statistically significant increase (P = 0.036). Conclusions: Immunological mechanisms play an essential role in the pathogenesis of neuropathic pain, immunologically based treatment approach will be the critical point of treatment.