Is Pain Ever “Normal”?

Patients' Perception of Chronic-Pain-Related Patient-Provider Communication in Relation to Sociodemographic and Pain-Related Variables: A Cross-Sectional Nationwide Study

Pain is a personal experience and patient-provider communication therefore an essential part of diagnosis and treatment where the patient's perspective needs to be central. The aim of this descriptive cross-sectional study was to investigate chronic-pain-related patient-provider communication in the context of sociodemographic variables, pain variables, perceived outcome of care, and satisfaction with health care providers. A postal questionnaire measuring socio-demographic variables, pain characteristics, pain-related health care utilization and patient-provider communication was sent to a sample of 4,500 individuals randomly drawn from the national population of Iceland. A subsample reporting chronic pain and having visited a health care provider for pain the previous six months (n = 401) was analyzed. Relationships between patient-provider communication and other measured variables were tested using bivariate and multivariate statistics. The more chronic pain impaired health-related quality of life, the more provider control the patients perceived in the patient-provider communication. There was also a strong negative relationship between patients' perception of providers' support and openness to discussing symptoms, and satisfaction with health care provider. Patients' perception of their own control in patient-provider communication and involvement in decisions regarding care was related to sociodemographic variables (specifically, education and residence) but not to pain related variables. This study highlights the importance of assessing chronic pain in a broad spectrum, listening, and giving patients time and support to communicate chronic pain and how it affects their life situation. The more interfering the pain is, the more important this is.

Quantitative sensory testing with Von Frey monofilaments in patients with allodynia: what are we quantifying?

The International Association for the Study of Pain defines allodynia as pain due to a stimulus that does not normally provoke pain and hyperalgesia as an increased response to a stimulus, which is normally painful. However, does "normally painful" mean "any stimulation of nociceptors" or "the subjective pain response?" We argue that "normally painful" should not mean "any stimulation of nociceptors," as Von Frey monofilaments may evoke a pricking sensation--which implies the involvement of nociceptors--without necessarily leading to a subjective pain perception. In this paper, we propose that the diagnosis of either allodynia or hyperalgesia should be based on the patient's report, that is, painful versus not painful, rather than on the (sub) type of afferent fiber involved.

Cortical correlates of perception and suppression of electrically induced pain

Two neuroimaging studies using fMRI were conducted in order to assess the cortical processes involved in the perception and suppression of pain. In the first study, 15 healthy subjects were stimulated with variable intensities of electrical pulses during a discrimination task. In the second study, the same subjects had to try to suppress the feeling of pain during tonic stimulation. The discrimination task resulted in cortical activation of contralateral SI, corresponding in extent to the intensity of the stimulus. Activation of contralateral operculum/posterior insula (SII) and non-dominant dorsolateral prefrontal cortex (DLPFC) with non-painful stimuli changed to activations of non-dominant anterior insula upon painful stimulation. In the second study, all subjects succeeded in suppressing the feeling of pain during previously painful levels of stimulation. During this suppression task, activations changed from anterior to posterior insula; also there was a suppression of activity in the anterior cingulated cortex (ACC) and caudate nucleus. Subjects seem to be able to suppress to a certain degree the feeling of pain under constant (and previously painful) stimulation. The cortical correlate seems to be a shift of cerebral activation from anterior to posterior right insula and a suppression of activity in the ACC and caudate nucleus.

What do the numbers mean? Normative data in chronic pain measures

Although self-reported measures play a central role in the assessment of pain and its treatment, it has long been recognized that interpretation of these measures is severely limited by the absence of normative data. Despite that, relatively few of the measures used in pain clinics or research studies have normative data for reference. Using a pain centre sample (n=6124), this paper describes the development of a normative dataset on a number of commonly used pain-related measures. The measures cover many of the key dimensions in pain assessment, including pain severity/quality, disability (physical functioning), and mood (emotional functioning). Measures of different cognitive and coping constructs are also included. Mean scores are reported for each measure according to age group, gender, pain site, as well as percentiles for different scores for patients with chronic low back pain. The potential uses for datasets of this type include the assessment and evaluation of individual cases, as well as the interpretation of published clinical trials. It is also argued that future systematic reviews of pain treatments should include consideration of such patient characteristics as pain levels, disability and mood in the studies reviewed rather than pain site and chronicity alone.

Overview on pathophysiology and newer approaches to treatment of peripheral neuropathies

Peripheral neuropathies are extremely heterogeneous nosological entities. One of the most common symptoms is pain, the underlying mechanisms of which are numerous and complex. Inflammation, reparative processes, and anatomical and gene expression alterations lead to chronic pain, the persistence of which is sustained by peripheral and central sensitisation mechanisms. Treatment of peripheral neuropathies is targeted to its symptomatic and aetiological features. For pain relief, several types of drugs may be used, notably antidepressants (e.g. tricyclic antidepressants, selective serotonin reuptake inhibitors, and both serotonin and noradrenaline [norepinephrine] reuptake inhibitors), antiepileptic drugs (e.g. carbamazepine, phenytoin, lamotrigine, valproic acid, gabapentin, topiramate and pregabalin), NSAIDs and opioid analgesics. Aetiological therapy is aimed at modifying the pathophysiological mechanisms underlying the neuropathy, some of which are common in different neuropathic conditions. Certain drugs are known to exert more than one action on different pathophysiological mechanisms. This is the case with acetyl-L-carnitine (ALC), which can be considered both a symptomatic therapy that can be used in any kind of painful neuropathy, and an aetiological therapy, at least in diabetic neuropathy and neuropathies induced by nucleoside reverse transcriptase inhibitors and cancer chemotherapeutic agents. ALC acts via several mechanisms, inducing regeneration of injured nerve fibres, reducing oxidative stress, supporting DNA synthesis in mitochondria, and enhancing nerve growth factor concentrations in neurons.