Segmental zoster paresis of the upper extremity: a case report

Segmental zoster paresis, a rare complication of herpes zoster, is characterized by focal, asymmetric motor weakness in the myotome that corresponds to the dermatome of the rash. The pathogenesis of segmental zoster paresis is inflammation caused by the spread of the herpes virus. Motor damage may affect the root, plexus, or peripheral nerve. A woman in her early seventies with right shoulder pain and shoulder girdle muscle weakness was diagnosed with involvement of the C5-7 motor roots and upper truncus of the brachial plexus as a complication of herpes zoster. Recognition of herpes zoster as a cause of acute motor weakness is important in avoiding unnecessary interventions as well as in determining the treatment and outcome of the patient. This case is presented to emphasize that herpes zoster infection may be complicated by segmental paresis, which should be considered in the differential diagnosis of acute painful motor weakness of the upper extremity.     

Acute pain in herpes zoster: the famciclovir database project

The results of a considerable number of recent prospective studies have demonstrated that greater acute pain severity in herpes zoster patients is associated with a significantly greater risk of developing postherpetic neuralgia (PHN). Only a few studies have examined the relationships between acute pain severity and demographic characteristics and clinical features of patients with herpes zoster, however, and the results of these studies have been inconsistent. To clarify these relationships, data from 1778 herpes zoster patients studied within 72 h of rash onset in four clinical trials of the antiviral agent famciclovir were examined. Univariate and multivariate analyses indicated that greater acute pain severity was significantly associated with greater age, female sex, greater rash severity, the presence of a prodrome, and primary involvement of non-trigeminal dermatomes. These results demonstrate that three of the established risk factors for PHN - older age, greater rash severity, and the presence of a prodrome - are also associated with more severe acute pain assessed soon after rash onset in patients with herpes zoster. The results of this study are consistent with the recommendation that herpes zoster patients who are older, who have had a prodrome, or who have severe rash or severe acute pain should be targeted for interventions designed to prevent PHN.     

Epidemiology and impact on quality of life of postherpetic neuralgia and painful diabetic neuropathy

OBJECTIVE: This article reviews the prevalence, risk factors, natural history, and impact on quality of life of painful diabetic neuropathy (PDN) and postherpetic neuralgia (PHN). DISCUSSION: Diabetes mellitus afflicts more than 14 million persons in the U.S. An estimated 20% to 24% of these persons experience PDN. Data on risk factors for PDN are limited, but duration of diabetes mellitus and poor glycemic control are probably important factors. Painful diabetic neuropathy may interfere with general activity, mood, mobility, work, social relations, sleep, leisure activities, and enjoyment of life. Herpes zoster strikes an estimated 800,000 persons each year in the U.S., most of whom are elderly or immunosuppressed. Using pain at 3 months after rash onset as a definition of PHN, between 25% and 50% of adults older than 50 years develop PHN, depending on early antiviral therapy for herpes zoster. Increasing age, greater pain and rash severity, greater degree of sensory impairment, and psychological distress are risk factors for PHN. Postherpetic neuralgia may cause fatigue, insomnia, depression, anxiety, interference with social roles and leisure activity, and impaired basic and instrumental activities of daily living. CONCLUSIONS: Both conditions are common complications of their underlying disorders and can profoundly diminish the quality of life of affected persons.     

Postherpetic Neuralgia: The Never-Ending Challenge

Abstract: Postherpetic neuralgia (PHN) is defined as pain that persists 1 to 3 months following the rash of herpes zoster (HZ). PHN affects about 50% of patients over 60 years of age and 15% of all HZ patients. Patients with PHN may experience two types of pain: a steady, aching, boring pain and a paroxysmal lancinating pain, usually exacerbated by contact with the involved skin. Herpes zoster is initially a clinical diagnosis, based on the observation of a typical dermatomal distribution of rash and radicular pain. HZ is pathologically characterized by inflammatory necrosis of dorsal root ganglia, occasionally associated with evidence of neuritis, leptomeningitis, and segmental unilateral degeneration of related motor and sensory roots. Although acyclovir has been used successfully as standard therapy for varicella zoster virus (VZV) infection in the past decade, resistant strains of VZV are often recognized in immunocompromised patients. Therapy with acyclovir and the use of corticosteroids have been reported to prevent PHN in up to 60% of HZ patients. Management of chronic pain in PHN is more problematic. The only therapy proven effective for PHN in controlled study is the use of tricyclic antidepressants, including amitriptyline and desipramine. There is good evidence of efficacy from randomized trials that gabapentin and pregabalin (new anticonvulsant drugs) are of benefit in the reduction of pain from PHN. As alternative therapies, topical agents such as capsaicin, lidocaine or opioid analgesic treatment may give satisfactory results. Interventions with low risk, such as transcutaneous electrical nerve stimulation (TENS), are appropriate. Evidence is scant for the value of surgical and procedural interventions in general, although there are numerous, small studies supporting the use of specific interventions such as nerve blocks, neurosurgical procedures, and neuroaugmentation. Although antiviral agents are appropriate for acute HZ, and the use of neural blockade and sympathetic blockade may be helpful in reducing pain in selected patients with HZ, there is little evidence that these interventions will reduce the likelihood of developing PHN. Postherpetic neuralgia remains a difficult pain problem. This review describes the epidemiology and pathophysiology of PHN and discusses proposed mechanisms of pain generation with emphasis on the various pharmacological treatments and invasive modalities currently available.     

Complete recovery of herpes zoster radiculopathy based on electrodiagnostic study: A case report

BACKGROUNDHerpes zoster is a painful infectious disease caused by the varicella zoster virus. Herpes zoster radiculopathy, which is a type of segmental zoster paresis, can complicate the disease and cause motor weakness. This complication should be considered when a patient with a rash complains of acute-onset motor weakness, and the diagnosis can be verified via electrodiagnostic study. CASE SUMMARYA 64-year-old female with a history of asthma presented to the emergency department with stabbing pain, an itching sensation, and a rash on the right anterior shoulder that had begun 5 d prior. Physical examination revealed multiple erythematous grouped vesicles in the right C4-5 and T1 dermatome regions. Because herpes zoster was suspected, the patient immediately received intravenous acyclovir. On the third hospital day, she complained of motor weakness in the right upper extremity. Magnetic resonance imaging of the cervical spine revealed mild intervertebral disc herniation at C4-C5 without evidence of nerve root compression. On the 12^th hospital day, electrodiagnostic study revealed right cervical radiculopathy, mainly in the C5/6 roots. Six months later, monoparesis resolved, and follow-up electrodiagnostic study was normal. CONCLUSIONThis case emphasizes that clinicians should consider the possibility of post-herpetic paresis, such as herpes zoster radiculopathy, and that electrodiagnostic study is useful for diagnosis and follow-up.     

Natural history of sensory function after herpes zoster

The natural history of sensory function in the first 6 months after herpes zoster (HZ) was determined in a cohort of 94 subjects at elevated risk for developing post-herpetic neuralgia (PHN). All four visits included ratings of pain and sensory symptoms, mapping areas of altered sensation and allodynia, and quantitative thermal and mechanical sensory testing. The last three visits included the capsaicin response test. Sensory thresholds in distant control skin were stable. Mirror-image skin was persistently hyperesthetic to warming and mechanical stimuli and hyperalgesic to heat compared to distant control skin. HZ skin showed deficits in all thermal modalities. Sensory recovery was limited and selective. Allodynia area and severity, hyperalgesia to von Frey hair, and cold detection threshold improved, but deficits to warmth and heat pain did not. Capsaicin on HZ skin significantly aggravated pain and allodynia in the majority of subjects at 6–8 weeks after HZ onset. At study entry, eventual PHN subjects had significantly more impairment in detecting warmth and cold, a larger area of altered sensation, a larger area of allodynia, and more severe allodynia. The results support the study hypothesis that severity of initial injury predicts PHN, especially impaired cold sensation in HZ skin. The hypothesis that PHN develops because of a failure to recover normal neural function was not supported. Sensory recovery proceeded at the same rate in eventual pain-free and eventual PHN subjects and is not a requirement for pain resolution. Early interventions that reduce neural injury or enhance recovery should be of benefit.     

Psychosocial Risk Factors for Postherpetic Neuralgia: A Prospective Study of Patients With Herpes Zoster

The results of previous studies using retrospective methods or small samples have suggested that there may be psychosocial risk factors for postherpetic neuralgia (PHN). We conducted a prospective study in which 110 patients with herpes zoster were assessed within the first month after rash onset with measures of acute pain and five broad domains of psychosocial functioning-physical, role, social, and emotional functioning, and stress and social support. Twenty of the 102 patients with follow-up data were diagnosed with PHN, defined as pain that had persisted for 4 months after rash onset. Measures of role functioning, personality disorder symptoms, and disease conviction during herpes zoster each made independent contributions to predicting either presence or intensity of PHN in logistic and linear regression analyses that controlled for relevant demographic and clinical variables, including age and acute pain intensity. These findings indicate that psychosocial variables are risk factors for the development of PHN. PERSPECTIVE: The results of this prospective study of patients with herpes zoster suggest that future research on the mechanisms and prevention of PHN should consider psychosocial as well as neurobiologic processes.     

Risk and prognostic factors of postherpetic neuralgia and focal sensory denervation: a prospective evaluation in acute herpes zoster ophthalmicus

OBJECTIVES: To determine the general risk and the prognostic factors of postherpetic neuralgia and focal sensory denervation in ophthalmic zoster disease. STUDY DESIGN: A prospective clinical study. SETTING: An ophthalmic practice participating in an eye-care network. PATIENTS: A cohort of 81 immunocompetent adult patients with herpes zoster ophthalmicus and referred by their general practitioner during the acute phase of the disease. METHODS: Various acute phase clinical parameters were determined via patient history and regular ophthalmic examinations. At a 2-month follow-up, the intensity of postherpetic neuralgia, rated on a 4-point verbal scale, and focal sensory denervation was determined. Skin tactile sensation within the ophthalmic dermatomes was tested with use of a cotton-wool tip, and corneal sensitivity was measured with use of a Cochet-Bonnet esthesiometer by comparing each eye. Statistical analysis was performed via chi2 analysis or Fisher exact test to identify prognostic factors of postherpetic neuralgia and focal sensory denervation at a 2-month follow-up. RESULTS: At a 2-month follow-up, pain of varying intensity was reported by 38 participants (47%). Of these patients, 25 patients (31%) rated their pain as mild, 8 patients (10%) rated their pain as moderate pain, and 5 patients (6%) rated their pain as severe. At that time, focal loss of normal skin or corneal sensation was detected in 49 patients (60%). Patient age, acute neuralgia score, manifestation and extent of acute skin rash, signs of ocular inflammation, and nontrigeminal cranial nerve involvement were all associated with prolonged pain and tactile sensory loss. CONCLUSIONS: The severity of acute skin rash, based on a specific manifestation of cutaneous herpes zoster eruptions, and the extent of infection to other neural pathways were clearly associated with postherpetic neuralgia and focal sensory denervation at a 2-month follow-up. These findings suggest that the inability of the immune system to control the spread of replicating varicella-zoster virus in the initial phase of the disease is an important factor in the pathogenesis of chronic zoster-related neuropathy.     

Postherpetic neuralgia in the elderly

Postherpetic neuralgia (PHN) is the most common complication of herpes zoster (HZ) or ‘shingles’ and affects a significant proportion of HZ patients with the disease, with the elderly being most frequently and seriously affected. Characterised by various types of pain (constant, intermittent and stimulus evoked) that persist between 3 months and many years after the resolution of the HZ rash, PHN can have a severe impact on the patient’s quality of life and functional ability. PHN remains highly resistant to current treatments. In this review, we discuss the epidemiology, clinical features and management of PHN in the elderly and the potential of vaccination against varicella zoster virus as a means to prevent HZ, and thus decrease the incidence and severity of PHN.     

The role of sympathetic nerve blocks in herpes zoster and postherpetic neuralgia

The most common complication of herpes zoster in immunocompetent patients is postherpetic neuralgia (PHN). Sympathetic blocks have been traditionally used for patients with herpes zoster and PHN with three different therapeutic goals: pain relief during acute herpes zoster, pain relief during PHN, and prevention of PHN by treating patients with acute zoster. The role of sympathetic blocks in herpes zoster and PHN remains controversial due to methodologic shortcomings in published studies and the limited current understanding of the role of the sympathetic nervous system in mediating pain. Current theories of the pathophysiology of PHN, the role of the sympathetic nervous system in herpes zoster and PHN, and published studies investigating use of sympathetic nerve blocks in herpes zoster and PHN are reviewed.     

Predictors of Postherpetic Neuralgia Among Patients With Herpes Zoster: A Prospective Study

Postherpetic neuralgia (PHN) is the most common complication of herpes zoster (HZ). The main objectives of this study were to: 1) estimate the severity and duration of PHN; and 2) identify the predictors of PHN. From October, 2005 to July, 2006, 261 outpatients with HZ, aged ≥50, were recruited within 14 days of rash onset during the routine clinical practice of 83 physicians across Canada. Physicians documented HZ characteristics, treatments, general health, functional, and immune status. HZ pain was measured at recruitment and on days 7, 14, 21, 30, 60, 90, 120, 150, and 180 following recruitment. PHN was defined as a worst pain ≥3 persisting or appearing more than 90 days after rash onset. Predictors of PHN were obtained by hierarchical log-binomial regression. Twenty-two percent of 249 immunocompetent subjects with HZ developed PHN. Median duration of PHN was 77 days. Independent predictors of PHN included: older age, limitation in performing usual activities prior to HZ, and pain severity at recruitment. This study confirms that older age and greater acute pain severity are predictors of PHN, while functional status emerges as a novel independent predictor of PHN that deserves further exploration. These findings will contribute to optimal use of the HZ vaccine and testing of new therapies that might prevent PHN.     

Intractable postherpetic itch and cutaneous deafferentation after facial shingles

Some patients develop chronic itch from neurological injuries, and shingles may be a common cause. Neuropathic itch can lead to self-injury from scratching desensate skin. A 39-year-old woman experienced severe postherpetic itch, but no postherpetic neuralgia, after ophthalmic zoster. Within 1 year, she had painlessly scratched through her frontal skull into her brain. Sensory testing and skin biopsies were performed on itchy and normal scalp to generate preliminary hypotheses about mechanisms of neuropathic itch. Quantitation of epidermal neurites in PGP9.5-immunolabeled skin biopsies demonstrated loss of 96% of epidermal innervation in the itchy area. Quantitative sensory testing indicated severe damage to most sensory modalities except itch. These data indicate that in this patient, severe postherpetic itch was associated with loss of peripheral sensory neurons. Possible mechanisms include electrical hyperactivity of hypo-afferented central itch-specific neurons, selective preservation of peripheral itch-fibers from neighboring unaffected dermatomes, and/or imbalance between excitation and inhibition of second-order sensory neurons.     

Predicting and preventing post-herpetic neuralgia: Are current risk factors useful in clinical practice?

Post-herpetic neuralgia (PHN) following acute herpes zoster remains a significant cause of neuropathic pain especially in the elderly. Early treatment of the zoster rash with antiviral agents, such as aciclovir remains one of the few measures proven to reduce the incidence and duration of PHN albeit only in a subset of patients. It is therefore crucial that the physician who first sees a case of zoster identifies those patients who are most likely to develop long-term pain and treats them accordingly. In particular, prodrugs such as famciclovir and valaciclvoir may be more beneficial in reducing PHN than the shorter acting aciclovir, but can be more expensive. Measures that could be used to predict patients likely to develop PHN would also facilitate the evaluation of early use of antiepileptic, anti-inflammatory and analgesic agents in the prevention of PHN. In a prospective study of 280 herpes zoster (HZ) cases seen by the general practitioner (GP) we evaluated the predictive value of five clinical factors identified in clinical trials as associated with a higher likelihood of PHN. A visual analogue score (VAS) over 5 and/or age over 50 correctly identified all subjects with PHN at 3 and 6 months, respectively. However, the specificity of this prediction was low because as many as 81% and 85% of those aged over 50 recovered within 3 and 6 months, respectively. Better methods are needed to identify patients over 50 at most risk of PHN that enable GPs to better allocate their resources with respect to HZ treatment.     

The change in zoster-associated pain treated with oral valaciclovir in immunocompetent patients with acute herpes zoster

We have analysed zoster-associated pain treated with valaciclovir (VCV) in immunocompetent patients with acute herpes zoster over 6 months, and evaluated the safety of VCV. We know of no reports that evaluate postherpetic neuralgia (PHN) treated with VCV for 6 months. Predisposing factors that influence PHN were age (over 60 years), clustered vesicles, severity of eruption, sleep disturbance, and hypesthesia. Timing of the administration of VCV before or after the onset of rash did not influence the incidence of PHN. No serious adverse reactions were observed during the administration of VCV.     

Neurology (65)

Herpes zoster and postherpetic neuralgia in the elderly. (University of Virginia, Charlottesville, VA) Geriatr Nurs 2000;21:132–136.
This article described herpes zoster (HZ), its causes, diagnosis, treatment, and associated complications. Postherpetic neuralgia (PHN), the most common complication of HZ, is the primary focus of the discussion. PHN is defined broadly as chronic pain that persists after the characteristic vesicular rash of HZ has resolved.     

带状疱疹后遗神经痛风险因素的研究

目的:带状疱疹后遗神经痛(postherpetic neuralgia,PHN)是带状疱疹最常见的并发症之一,了解其发生的原因对指导临床治疗有重要的作用,本文旨在对可能引起带状疱疹发展为带状疱疹后神经痛的危险因素进行分析。方法:通过收集我科2009年1月至2011年3月共101例住院带状疱疹患者信息,定义PHN为出疹90天后仍有疼痛。将年龄、性别、早期治疗、疼痛程度、疱疹面积、高血压、糖尿病、免疫疾病等列为自变量,建立logistic回归模型,利用向前逐步法筛选出有统计学意义的变量。结果:研究数据的logistic回归分析显示,风险因素中年龄(P<0.0001,OR=1.125,95%CL1.062~1.191)、疼痛程度(P=0.0003,OR=5.598,95%CL)是带状疱疹后神经痛发生危险因素;疱疹位置(P=0.0069,OR=0.131,95%CL 0.030~0.573)、早期抗病毒治疗(P=0.0059,OR=0.019,95%CL 0.001~0.321)、抗病理神经痛治疗(P=0.0190,OR=0.136,95%CL 0.026~0.720)为有利因素。结论:重视高年龄、头面部带状疱疹的患者,早期进行抗病毒、抗病理神经痛治疗能有效预防疱疹后神经痛。     

Neuralgia and zovirax treatment of patients with herpes zoster

AIM: To estimate the occurrence of postherpetic neuralgia (PHN) arising after acute period of herpes zoster (HZ) and determination of zovirax efficiency in PHN prevention. MATERIALS AND METHODS: Of a total of 102 patients with HZ aged 17-89 years, 20 patients aged 26-83 years were given zovirax. RESULTS: Acute pain syndrome in PHN was observed in more that one-third of HZ patients. Patients over 60 years of age were more predisposed to PHN. Zovirax reduced the duration of acute rash and its healing, decreased the number of patients with zoster-associated pain and PHN patients. CONCLUSION: Zovirax is effective and safe in preventing PHN in HZ patients.     

Neurogenic bladder from occult herpes zoster

Active infection with herpes zoster may cause acute urinary retention, especially when it involves sacral dermatomes. Although frank retention usually develops days to weeks after eruption of the typical rash, bladder incompetence infrequently develops first, raising concern over other, more ominous etiologies. In the case presented, rash appearance was delayed until six weeks after the initial onset of urinary retention, a much longer interval than previously reported. Occult herpes zoster infection should be considered in patients presenting with an acute neurogenic bladder of obscure cause.     

Development of a measure of the burden of pain due to herpes zoster and postherpetic neuralgia for prevention trials: adaptation of the brief pain inventory.

In preparation for clinical trials of a vaccine against herpes zoster (HZ), we conducted a prospective, observational study to evaluate (1) the Zoster Brief Pain Inventory (ZBPI), an HZ-specific questionnaire to quantify HZ pain and discomfort, (2) an operational definition of postherpetic neuralgia (PHN), and (3) a severity-duration measure of the burden of illness caused by HZ. HZ patients aged 60 years or older (n = 121) were enrolled within 14 days of rash onset and completed ZBPI, McGill Pain Questionnaire Present Pain Intensity (PPI), quality of life (QoL), and activities of daily living (ADL) questionnaires on a predetermined schedule. Reliability, measured by intraclass correlation coefficients within 14 days of rash onset, ranged between 0.63 and 0.78. ZBPI pain scores were strongly correlated with other pain measures, interference with ADL, and worsening QoL. The operational definition of PHN, a ZBPI pain score of 3 or greater occurring 90 or more days after rash onset, had high agreement with pain worse than mild on the PPI (kappa = 0.72). The ZBPI pain severity-duration measure had high correlations with severity-duration measures of ADL interference, worsening QoL, and other pain scales. These findings support the validity and utility of the ZBPI, the definition of PHN, and the severity-duration measure of the burden of HZ illness. PERSPECTIVE: Herpes zoster pain, as measured by the ZBPI severity-duration measure, is associated with impairment in daily living activities and quality of life. The ZBPI measure appears useful for quantifying herpes zoster pain, postherpetic neuralgia, and impairment in daily living activities for clinical trials of herpes zoster prevention.