A cross-sectional survey of health state impairment and treatment patterns in patients with postherpetic neuralgia.
BACKGROUND: Postherpetic neuralgia (PHN) develops in 8-24% of patients with herpes zoster. Few studies have evaluated the patient burden and treatment of PHN in general practice. OBJECTIVES: To determine the patient burden of PHN with respect to pain intensity and impact on patient functioning and to characterise treatment patterns and health resource utilisation in general practice. METHODS: Eighty-four patients with PHN were identified in general practice settings during an observational survey of neuropathic pain syndromes in six European countries. Patients answered a questionnaire that included: pain severity and interference items from the modified short form brief pain inventory (mBPI-SF); EuroQol (EQ-5D) survey; and questions related to current treatment, health status and resource utilisation. Physicians provided information on medications prescribed for PHN and pain-related co-morbidities (anxiety, depression and sleep disturbance). RESULTS: Mean patient age was 71.0 +/- 12.8 years, 76% were > or = 65 years and 45% of patients had PHN > or = 1 year. The mean pain severity index was 4.2, reflecting moderate pain despite 89% of patients taking prescription medications for PHN. Few medications with demonstrated efficacy against PHN (e.g. carbamazepine and gabapentin) were prescribed, often at suboptimal doses. Pain severity was associated with reduced EQ-5D health state valuation (P<0.001), greater pain interference on all domains (P<0.001) and increased health resource utilisation (P = 0.008). CONCLUSIONS: PHN causes substantial patient burden expressed as interference with daily functioning and reduced health status associated with pain severity. This burden may result in part from suboptimal management strategies and suggests a need for more effective pain management. (+info)
Repetitive paravertebral nerve block using a catheter technique for pain relief in post-herpetic neuralgia.
We described in this report a case of post-herpetic neuralgia refractory to medical therapy that was successfully treated with repetitive injections of local aesthetic mixture (bupivacaine 0.5% 19 ml and clonidine 150 microg ml(-1) 1 ml) every 48 h for 3 weeks using a paravertebral catheter inserted at T2-T3 level. (+info)
Basal heat pain thresholds predict opioid analgesia in patients with postherpetic neuralgia.
BACKGROUND: A variety of analgesics have been studied in the treatment of postherpetic neuralgia, with several medications demonstrating some degree of efficacy. However, existing trials have documented large individual differences in treatment responses, and it is important to identify patient characteristics that predict the analgesic effectiveness of particular interventions. Several animal studies have indicated that reduced basal nociceptive sensitivity, in the form of relatively high heat pain thresholds, is associated with greater opioid analgesia, but this finding has not been applied to human studies of opioid treatment for chronic pain. METHODS: Using data from a previously published crossover trial of opioids and tricyclics in postherpetic neuralgia, the authors evaluated baseline thermal pain thresholds, assessed at a body site contralateral to the affected area, as a predictor of treatment responses. RESULTS: During opioid treatment, a greater reduction in pain and higher ratings of pain relief were observed in patients with relatively higher heat pain thresholds at baseline. Baseline pain thresholds did not predict responses to tricyclics or placebo. Interestingly, other individual-difference variables such as age and baseline pain intensity also significantly predicted opioid responses (i.e., higher baseline pain and younger age were related to greater opioid-associated pain reduction, with nearly 20% of the variance in opioid analgesia explained by these two factors). CONCLUSIONS: These findings, which will require replication, suggest that pretreatment assessment of heat pain sensitivity might prove useful in identifying those patients most likely to respond to opioids. (+info)
New and emerging treatment options for neuropathic pain.
A large number of neuroanatomical, neurophysiologic, and neurochemical mechanisms are thought to contribute to the development and maintenance of neuropathic pain (NP). As a result, a corresponding wide range of treatments have been employed to treat patients with NP, including antiepileptic drugs, opioid analgesics, tricyclic antidepressants, selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, N-methyl-D-aspartate receptor antagonists, cholecystokinin receptor antagonists, adenosine, lipoic acid, cannabinoids, isosorbide dinitrate, dronabinol, capsaicin, protein kinase C inhibitors, aldose reductase inhibitors, and VR-1 receptor modulators. Many of these compounds are limited by marginal efficacy and clinically significant adverse events; few have been evaluated in well-controlled, large-scale clinical trials. At present, the only agents approved for the treatment of painful diabetic peripheral neuropathy and postherpetic neuralgia are lidocaine patches 5%, duloxetine, gabapentin, and pregabalin. Of these, only pregabalin is indicated for both conditions. (+info)
Herpes zoster and postherpetic neuralgia: diagnosis and therapeutic considerations.
Herpes zoster (HZ), also known as shingles, is a painful vesicular rash resulting from reactivation of the virus that also causes chickenpox - Varicella zoster virus (VZV). Typically, the rash runs its course in a matter of 4-5 weeks. The pain, however, may persist months, even years, after the skin heals. This phenomenon is known as postherpetic neuralgia (PHN). Often described as an intense burning, itching sensation, this pain can be significant to the point of being debilitating, and as such can greatly affect quality of life. Although shingles is generally regarded as a self-limited condition, the fact it can take several weeks to resolve and has the potential for development of complications such as PHN presents a challenge to clinicians. Many treatment options are available, each offering variable levels of efficacy. Conventional therapies include prescription antivirals, corticosteroids, and analgesics, both oral and topical. Other considerations include use of over-the-counter anti-inflammatory agents, physiotherapy, and nerve block injections. This article reviews herpes zoster and postherpetic neuralgia, and presents the most effective conventional treatment options currently available, as well as select botanical, nutritional, and other considerations that may be beneficial in the management of this condition. (+info)
Clinical approach to patients with neuropathic pain.
At long last, advances have been made in the field of neuropathic pain treatment, in large part due to a better understanding of the mechanisms underlying this type of pain. New antidepressants and anticonvulsants with novel mechanisms of action have spearheaded the way, and studies have finally shown that opioids are effective for treating chronic and breakthrough pain. (+info)
Brain activity for spontaneous pain of postherpetic neuralgia and its modulation by lidocaine patch therapy.
Postherpetic neuralgia (PHN) is a debilitating chronic pain condition, yet there is a lack of knowledge regarding underlying brain activity. Here we identify brain regions involved in spontaneous pain of PHN (n=11) and determine its modulation with Lidoderm therapy (patches of 5% lidocaine applied to the PHN affected body part). Continuous ratings of fluctuations of spontaneous pain during fMRI were contrasted to ratings of fluctuations of a bar observed during scanning, at three sessions: (1) pre-treatment baseline, (2) after 6h of Lidoderm treatment, and (3) after 2 weeks of Lidoderm use. Overall brain activity for spontaneous pain of PHN involved affective and sensory-discriminative areas: thalamus, primary and secondary somatosensory, insula and anterior cingulate cortices, as well as areas involved in emotion, hedonics, reward, and punishment: ventral striatum, amygdala, orbital frontal cortex, and ventral tegmental area. Generally, these activations decreased at sessions 2 and 3, except right anterior insular activity which increased with treatment. The sensory and affective activations only responded to the short-term treatment (6h of Lidoderm); while the ventral striatum and amygdala (reward-related regions) decreased mainly with longer-term treatment (2 weeks of Lidoderm). Pain properties: average magnitude of spontaneous pain, and responses on Neuropathic Pain Scale (NPS), decreased with treatment. The ventral striatal and amygdala activity best reflected changes in NPS, which was modulated only with longer-term treatment. The results show a specific brain activity pattern for PHN spontaneous pain, and implicate areas involved in emotions and reward as best reflecting changes in pain with treatment. (+info)
Natural history of pain following herpes zoster.
In a longitudinal observational study of 94 patients (39 M:55 F, mean age 69) at elevated risk for developing post herpetic neuralgia (PHN), the natural history of pain during the first 6 months after herpes zoster (HZ) rash onset was determined. Pain severity and impact were rated using pain-VAS, SF-MPQ, and MPI. Applying a definition of PHN of average daily pain >0/100 on the pain VAS during the last 48 h, 30 subjects had PHN at 6 months. These 30 subjects reported more pain and a higher SF-MPQ score (p<0.01) at study inclusion than the 64 subjects whose pain completely resolved by 6 months. At 6 months, mean daily pain in the PHN group was 11/100 (95% CI 5,16) and only nine of these subjects were still taking prescription medication for HZ pain. The rate of recovery (pain severity over time) was the same in the PHN and no-pain groups. At study inclusion, the SF-MPQ and MPI scores in our PHN group were similar to historical controls with chronic severe PHN enrolled in clinical trials, but by 6 months the scores in our PHN subjects were significantly lower than historic controls. Only two subjects met the more stringent criteria for 'clinically meaningful' PHN at 6 months (> or = 30/100 on the pain VAS). Defining PHN as average daily pain >0/100 at 6 months after rash onset appears to substantially overestimate the number of HZ patients negatively impacted by ongoing pain and disability. (+info)