Central poststroke pain (CPSP), formerly known as thalamic pain syndrome of Déjerine and Roussy, is a central neuropathic pain occurring in patients affected by stroke. It is one manifestation of central pain, which is broadly defined as central neuropathic pain caused by lesions or dysfunction in the central nervous system. Thalamic pain was first described 100 years ago by Déjerine and Roussy and has been described as “among the most spectacular, distressing, and intractable of pain syndromes”. CPSP is characterized by constant or intermittent pain and is associated with sensory abnormalities, particularly of thermal sensation. While the pain is frequently described as burning, scalding, or burning and freezing, other symptoms are usually vague and hard to characterize, making an early diagnosis particularly difficult. In fact, those who develop CPSP may no longer be under the care of health care professionals when their symptoms begin to manifest, resulting in misdiagnosis or a significant delay before treatment begins. Diagnosis is further complicated by cognitive and speech limitations that may occur following stroke, as well as by depression, anxiety and sleep disturbances. Patients may also exhibit spontaneous dysesthesia and the stimulus-evoked sensory disturbances of dysesthesia, allodynia and hyperalgesia. The present study offers a historical reference point for future clinical and basic research into this elusive type of debilitating pain.
Allodynia; Central neuropathic pain; Hypersensitivity; Poststroke pain; Stroke; Thalamic syndrome
To determine if an oral, tapered methylprednisolone regimen is superior to other commonly used pharmacologic interventions for the treatment of central post-stroke pain (CPSP).
Patients and methods
In this study, the charts of 146 stroke patients admitted to acute inpatient rehabilitation were retrospectively reviewed. Patients diagnosed with CPSP underwent further chart review to assess numerical rating scale for pain scores and as-needed pain medication usage at different time points comparing CPSP patients treated with methylprednisolone to those treated with other pharmacologic interventions.
In the sample, 8.2% were diagnosed with CPSP during acute care or inpatient rehabilitation. Mean numerical rating scale for pain scores day of symptom onset did not differ between those patients treated with methylprednisolone versus those treated with other pharmacologic interventions (mean ± standard deviation; 6.1 ± 2.3 versus 5.7 ± 1.6, P = 0.77). However, mean numerical rating scale for pain scores differed significantly 1-day after treatment initiation (1.7 ± 2.1 versus 5.0 ± 1.9, P = 0.03) and 1-day prior to rehabilitation discharge (0.3 ± 0.9 versus 4.1 ± 3.2, P = 0.01) between the two groups. Compared to day of symptom onset, as-needed pain medication usage within the methylprednisolone group was marginally less 1-day after treatment initiation (Z = −1.73, P = 0.08) and 1-day prior to rehabilitation discharge (Z = −1.89, P = 0.06). No difference in as-needed pain medication usage existed within the non-steroid group at the same time points.
Methylprednisolone is a potential therapeutic option for CPSP. The findings herein warrant study in prospective trials.
stroke; pain; central post-stroke pain; complex regional pain syndromes; therapeutics; neuralgia
Central post-stroke pain (CPSP) used to be known as 'thalamic syndrome'. Early post-mortem studies showed that many cases had extrathalamic lesions, and modern imaging methods have confirmed and extended these findings. CPSP affects between 2 and 6% of stroke patients, ie, there is an annual incidence in the UK of between 2000 and 6000. Most patients with CPSP appear to be younger than the general stroke population, and usually to have relatively mild motor affliction; thus they may live for many years, giving a prevalence perhaps as high as 20,000. True CPSP, characterised by a partial or total deficit for thermal and/or sharpness sensations, is best treated initially with adrenergically active antidepressants. If these do not work, mexiletine may be added in suitable cases. Recent studies suggest that stimulation of the motor cortex or spinal cord by implanted electrodes may help patients resistant to medical treatment. Positive relaxation, as an adjuvant therapy, should be used in nearly all cases. Considerable or even total relief can be achieved in almost two thirds of patients. There is evidence that the sooner antidepressant treatment is begun, the more likely the patient is to respond; time should not be wasted trying conventional analgesics, which rarely have any significant effect.
Central post-stroke pain (CPSP) is still an underestimated complication of stroke, resulting in impaired quality of life and, in addition to the functional and cognitive consequences of stroke, the presence of CPSP may be associated with mood disorders, such as depression, anxiety, and sleep disturbances. This type of pain may also impair activities of daily living and further worsen quality of life, negatively influencing the rehabilitation process. The prevalence of CSPS in the literature is highly variable (1%–12%) according to different studies, and this variability could be influenced by selection criteria and the different ethnic populations being investigated. With this scenario in mind, we performed a population-based study to assess the prevalence of CPSP and its main features in a homogeneous health district (Rimini, Italy), including five hospitals for a total population of 329,970 inhabitants. From 2008 to 2010, we selected 1,494 post-stroke patients and were able to interview 660 patients, 66 (11%) of whom reported pain with related tactile and thermal hyperesthesia, accompanied by needle puncture, tingling, swelling, and pressure sensations. Patients reported motor impairment and disability, which influenced their working ability, rehabilitation, and social life. Despite this severe pain state, there was a high percentage of patients who did not receive adequate treatment for pain.
stroke; central post-stroke pain; disability
Although deep brain stimulation (DBS) has been found to be efficacious for some chronic pain syndromes, its usefulness in patients with central poststroke pain (CPSP) has been disappointing. The most common DBS targets for pain are the periventricular gray region (PVG) and the ventralis caudalis of the thalamus. Despite the limited success of DBS for CPSP, few alternative targets have been explored. The nucleus accumbens (NAC), a limbic structure within the ventral striatum that is involved in reward and pain processing, has emerged as an effective target for psychiatric disease. There is also evidence that it may be an effective target for pain. We describe a 72-year-old woman with a large right hemisphere infarct who subsequently experienced refractory left hemibody pain. She underwent placement of 3 electrodes in the right PVG, ventralis caudalis of the thalamus, and NAC. Individual stimulation of the NAC and PVG provided substantial improvement in pain rating. The patient underwent implantation of permanent electrodes in both targets, and combined stimulation has provided sustained pain relief at nearly 1 year after the procedure. These results suggest that the NAC may be an effective DBS target for CPSP.
CPSP, central poststroke pain; DBS, deep brain stimulation; ECT, electroconvulive therapy; ICL, intercommissural line; MCS, motor cortex stimulation; NAC, nucleus accumbens; PFC, prefrontal cortex; PVG, periventricular gray region; VC, ventralis caudalis of the thalamus
In the elderly, pain of a widespread nature can often be debilitating. It is not uncommon to attribute this widespread pain to osteoarthritis within the spinal column structures and peripheral joints or to other musculoskeletal etiology. However, chiropractors should remain wary regarding pain experienced by the elderly, especially if pain is widespread and exhibits neuropathic features. Common features of neuropathic pain involve the presence of allodynia, hyperpathia and hyperalgesia. This characteristic widespread pain can sometimes be the sequelae of a central nervous system lesion such as a “Thalamic Pain Syndrome”, or “Central Post-Stroke Pain”, which are terms commonly used to describe pain that originates in the central nervous system.
Following is the case of a 90-year-old patient presenting with widespread pain attributed to Thalamic Pain Syndrome or Central Post-Stroke Pain. Discussion of the characteristics of neuropathic pain and bedside testing techniques are presented to help the chiropractor identify a patient who may be presenting with Central Post-Stroke Pain.
thalamic diseases; cerebrovascular disorders/complications; chiropractic; osteoarthritis; hyperalgesia; neuralgia
The aetiology of central post-stroke pain (CPSP) is poorly understood and such pains are often refractory to treatment. We report the case of a 56-year-old man, who, following a temporo-parietal infarct, suffered from debilitating and refractory hemi-body cold dysaesthesia and severe tactile allodynia. This was associated with thermal and tactile hypoaesthesia and hypoalgesia on his affected side. Implantation of a deep brain stimulating electrode in his periventricular gray (PVG) region produced an improvement in his pain that was associated with a striking normalisation of his deficits in somatosensory perception. This improvement in pain and thermal sensibility was reversed as stimulation became less effective, because of increased electrode impedance. Therefore, we postulate that the analgesic benefit may have occurred as a consequence of the normalisation of somatosensory function and we discuss these findings in relation to the theories of central pain generation and the potential to engage useful plasticity in central circuits.
Deep brain stimulation; Central post-stroke pain; Thalamic dysrhythmia; Allodynia
Background and Purpose
Elucidating the factors that predict the quality of life (QOL) in stroke patients is important. However, the residual sensory symptoms that are common in stroke patients have not usually been included as factors that influence the QOL. The purpose of the present study was to elucidate the factors that predict the QOL of chronic-stage patients with special attention to residual sensory symptoms.
We examined 214 patients who had experienced a first-time stroke during the subacute (i.e., approximately 3 months poststroke) stage; 151 patients from this group were followed up by telephone interview during the chronic (i.e., approximately 3 years poststroke) stage. Physical disabilities, including motor dysfunction, sensory symptoms that included central poststroke pain (CPSP, described using a standardized questionnaire with a visual analogue scale), activities of daily living (ADL, measured by the Barthel index score), as well as the presence of depression (using the DSM IV criteria), were assessed during both the subacute and chronic stages. Economic and job statuses during the chronic stage were also assessed. QOL ratings were determined by the World Health Organization QOL scale.
The following factors at 3 months poststroke were related to low QOL at 3 years poststroke: dependency in ADL, motor dysfunction, depression, and CPSP. At 3 years poststroke, dependency in ADL, depression, CPSP, poor economic status, and unemployment were all factors that were related to low QOL. Multiple regression analysis showed that dependency in ADL (19%), presence of CPSP (12%), and poor economic status (10%) were important explanatory factors for overall QOL. In the analysis of QOL subdomains, the most important explanatory factors were CPSP for both physical and psychological domains, dependency in ADL for both independence and social-relationships domains, economic status for the environmental domain, and female sex for the spiritual domain.
We conclude that dependency in ADL, depression, low socioeconomic status, and the presence of CPSP either at 3 months or 3 years poststroke are factors that are related to a low QOL at 3 years poststroke. The recognition of these factors may allow strategies to be developed to improve the QOL for stroke patients.
Depression; Central poststroke pain; Cerebrovascular disease; Quality of life
Myofascial pain is a regional pain syndrome characterized in part by a trigger point in a taut band of skeletal muscle and its associated referred pain. We examined a series of 172 patients presenting to a university primary care general internal medicine practice. Of 54 patients whose reason for a visit included pain, 16 (30%) satisfied criteria for a clinical diagnosis of myofascial pain. These patients were similar in age and sex to other patients with pain, and the frequency of pain as a primary complaint was similar for myofascial pain as compared with other reasons for pain. The usual intensity of myofascial pain as assessed by a visual analog scale was high, comparable to or possibly greater than pain due to other causes. Patients with upper body pain were more likely to have myofascial pain than patients with pain located elsewhere. Physicians rarely recognized the myofascial pain syndrome. Commonly applied therapies for myofascial pain provided substantial abrupt reduction in pain intensity. The prevalence and severity of myofascial pain in this university internal medicine setting suggest that regional myofascial pain may be an important cause of pain complaints in the practice of general internal medicine.
Purpose: Chronic post-surgical pain (CPSP) is a frequent outcome of musculoskeletal surgery. Physiotherapists often treat patients with pain before and after musculoskeletal surgery. The purposes of this paper are (1) to raise awareness of the nature, mechanisms, and significance of CPSP; and (2) to highlight the necessity for an inter-professional team to understand and address its complexity. Using total joint replacement surgeries as a model, we provide a review of pain mechanisms and pain management strategies.
Summary of Key Points: By understanding the mechanisms by which pain alters the body's normal physiological responses to surgery, clinicians selectively target pain in post-surgical patients through the use of multi-modal management strategies. Clinicians should not assume that patients receiving multiple medications have a problem with pain. Rather, the modern-day approach is to manage pain using preventive strategies, with the aims of reducing the intensity of acute postoperative pain and minimizing the development of CPSP.
Conclusions: The roles of biological, surgical, psychosocial, and patient-related risk factors in the transition to pain chronicity require further investigation if we are to better understand their relationships with pain. Measuring pain intensity and analgesic use is not sufficient. Proper evaluation and management of risk factors for CPSP require inter-professional teams to characterize a patient's experience of postoperative pain and to examine pain arising during functional activities.
chronic post-surgical pain; inter-professional teams; multi-modal analgesia; preventive analgesia; total joint replacement; analgésie multimodale; analgésie préventive; douleur chronique postopératoire; équipes interprofessionnelles; remplacement total d'une articulation
Background and objective: A single session of repetitive transcranial magnetic stimulation (rTMS) over motor cortex had been reported to produce short term relief of some types of chronic pain. The present study investigated whether five consecutive days of rTMS would lead to longer lasting pain relief in unilateral chronic intractable neuropathic pain.
Patients and methods: Forty eight patients with therapy resistant chronic unilateral pain syndromes (24 each with trigeminal neuralgia (TGN) and post-stroke pain syndrome (PSP)) participated. Fourteen from each group received 10 minutes real rTMS over the hand area of motor cortex (20 Hz, 10x10 s trains, intensity 80% of motor threshold) every day for five consecutive days. The remaining patients received sham stimulation. Pain was assessed using a visual analogue scale (VAS) and the Leeds assessment of neuropathic symptoms and signs (LANSS) scale, before, after the first, fourth, and fifth sessions, and two weeks after the last session.
Results: No significant differences were found in basal pain ratings between patients receiving real- and sham-rTMS. However, a two factor ANOVA revealed a significant "± TMS" x "time" interaction indicating that real and sham rTMS had different effects on the VAS and LANSS scales. Post hoc testing showed that in both groups of patients, real-rTMS led to a greater improvement in scales than sham-rTMS, evident even two weeks after the end of the treatment. No patient experienced adverse effects.
Conclusion: These results confirm that five daily sessions of rTMS over motor cortex can produce longlasting pain relief in patients with TGN or PSP.
Scalene myofascial pain syndrome is a regional pain syndrome wherein pain originates over the neck area and radiates down to the arm. This condition may present as primary or secondary to underlying cervical pathology. Although scalene myofascial pain syndrome is a well known medical entity, it is often misdiagnosed as being some other neck pain associated with radiculopathy, such as cervical disc prolapse, cervical spinal stenosis and thoracic outlet syndrome. Because scalene myofascial pain syndrome mimics cervical radiculopathy, this condition often leads to mismanagement, which can, in turn, result in persistent pain and suffering. In the worst-case scenarios, patients may be subjected to unjustifiable surgical intervention. Because the clinical findings in scalene myofascial pain syndrome are “pathognomonic”, clinicians should be aware of ways to recognize this disorder and be able to differentiate it from other conditions that present with neck pain and rediculopathy. We present two cases of unilateral scalene myofascial pain syndrome that significantly impaired the patients’ functioning and quality of life. This case report serves to create awareness about the existence of the syndrome and to highlight the potential morbidity due to clinical misdiagnosis.
cervical radiculopathy; myofascial pain syndrome; pain radiation; Scalene muscle; trigger point; neurosciences
Due to the lack of a specific diagnostic tool for neuropathic pain, a grading system to categorize pain as ‘definite’, ‘probable’, ‘possible’ and ‘unlikely’ neuropathic was proposed. Somatosensory abnormalities are common in neuropathic pain and it has been suggested that a greater number of abnormalities would be present in patients with ‘probable’ and ‘definite’ grades. To test this hypothesis, we investigated the presence of somatosensory abnormalities by means of Quantitative Sensory Testing (QST) in patients with a clinical diagnosis of neuropathic pain and correlated the number of sensory abnormalities and sensory profiles to the different grades. Of patients who were clinically diagnosed with neuropathic pain, only 60% were graded as ‘definite’ or ‘probable’, while 40% were graded as ‘possible’ or ‘unlikely’ neuropathic pain. Apparently, there is a mismatch between a clinical neuropathic pain diagnosis and neuropathic pain grading. Contrary to the expectation, patients with ‘probable’ and ‘definite’ grades did not have a greater number of abnormalities. Instead, similar numbers of somatosensory abnormalities were identified for each grade. The profiles of sensory signs in ‘definite’ and ‘probable’ neuropathic pain were not significantly different, but different from the ‘unlikely’ grade. This latter difference could be attributed to differences in the prevalence of patients with a mixture of sensory gain and loss and with sensory loss only. The grading system allows a separation of neuropathic and non-neuropathic pain based on profiles but not on the total number of sensory abnormalities. Our findings indicate that patient selection based on grading of neuropathic pain may provide advantages in selecting homogenous groups for clinical research.
Painful radiculopathies (RAD) and classical neuropathic pain syndromes (painful diabetic polyneuropathy, postherpetic neuralgia) show differences how the patients express their sensory perceptions. Furthermore, several clinical trials with neuropathic pain medications failed in painful radiculopathy. Epidemiological and clinical data of 2094 patients with painful radiculopathy were collected within a cross sectional survey (painDETECT) to describe demographic data and co-morbidities and to detect characteristic sensory abnormalities in patients with RAD and compare them with other neuropathic pain syndromes. Common co-morbidities in neuropathic pain (depression, sleep disturbance, anxiety) do not differ considerably between the three conditions. Compared to other neuropathic pain syndromes touch-evoked allodynia and thermal hyperalgesia are relatively uncommon in RAD. One distinct sensory symptom pattern (sensory profile), i.e., severe painful attacks and pressure induced pain in combination with mild spontaneous pain, mild mechanical allodynia and thermal hyperalgesia, was found to be characteristic for RAD. Despite similarities in sensory symptoms there are two important differences between RAD and other neuropathic pain disorders: (1) The paucity of mechanical allodynia and thermal hyperalgesia might be explained by the fact that the site of the nerve lesion in RAD is often located proximal to the dorsal root ganglion. (2) The distinct sensory profile found in RAD might be explained by compression-induced ectopic discharges from a dorsal root and not necessarily by nerve damage. These differences in pathogenesis might explain why medications effective in DPN and PHN failed to demonstrate efficacy in RAD.
In order to study the efficacy of linear-polarized near-infrared light irradiation (LPNIR) on relieving chronic pain in conjunction with nerve block (NB) or local block (LB), a 3-week prospective, randomized, double-blind, controlled study was conducted to evaluate the pre- and post-therapy pain intensity. Visual analogue scales (VASs) were measured in all patients before and 6 months after therapy visiting the pain clinic during the period of August 2007 to January 2008. A total of 52 patients with either shoulder periarthritis or myofascial pain syndrome or lateral epicondylitis were randomly assigned into two groups by drawing lots. Patients in Group I were treated with NB or LB plus LPNIR; Group II patients, for their part, were treated with the same procedures as in Group I, but not using LPNIR. In both groups, the pain intensity (VAS score) decreased significantly immediately after therapy as compared to therapy. There was a significant difference between the test and control groups immediately after therapy (P < 0.05), while no effect 6 months later. No side effects were observed. It is concluded that LPNIR is an effective and safe modality to treat various chronic pains, which has synergic effects with NB or LB.
Repetitive transcranial magnetic stimulation (rTMS) modulates central neuropathic pain in some patients after stroke, but the mechanisms of action are uncertain.
The authors used diffusion tensor imaging (DTI) and functional MRI (fMRI) to evaluate the integrity of the thalamocortical tract (TCT) and the activation pattern of the pain network in 22 patients with poststroke central pain.
Each patient underwent daily 10-Hz rTMS sessions for 1000 pulses on 5 consecutive days over the hotspot for the first dorsal interosseus muscle. Pain severity was monitored using the Visual Analogue Scale (VAS). Mood was assessed by the Hamilton Depression Rating Scale.
Clinical data from all participants along with the DTI and fMRI findings from 10 patients were analyzed. VAS scores decreased significantly, if modestly, following administration of rTMS in 14 responders, which lasted for 2 weeks after the intervention. Regression analysis showed a significant correlation between less initial depression and higher antalgic effect of rTMS. Integrity of the superior TCT in the ipsilesional hemisphere showed significant correlation with change of VAS score after rTMS. fMRI showed significantly decreased activity in the secondary somatosensory cortex, insula, prefrontal cortex, and putamen in rTMS responders, whereas no change was noted in nonresponders.
Mood may affect the modest antinociceptive effects of rTMS that we found, which may be mediated by the superior TCT through modulation of a distributed pain network.
poststroke central pain; transcranial magnetic stimulation; diffusion tensor imaging; thalamocortical tract; functional MRI; stroke rehabilitation
it has been established that chronic neck pain following whiplash is associated with the phenomenon of central sensitization, in which injured and uninjured parts of the body exhibit lowered pain thresholds due to an alteration in central pain processing. it has furthermore been hypothesized that peripheral sources of nociception in the muscles may perpetuate central sensitization in chronic whiplash. the hypothesis explored in the present study was whether myofascial trigger points serve as a modulator of central sensitization in subjects with chronic neck pain.
controlled case series.
outpatient chronic pain clinic.
seventeen patients with chronic and intractable neck pain and 10 healthy controls without complaints of neck pain.
symptomatic subjects received anesthetic infiltration of myofascial trigger points in the upper trapezius muscles and controls received the anesthetic in the thigh.
Outcome measures: pre and post injection cervical range of motion, pressure pain thresholds (ppt) over the infraspinatus, wrist extensor, and tibialis anterior muscles. sensitivity to light (photophobia) and subjects' perception of pain using a visual analog scale (vas) were also evaluated before and after injections. only the ppt was evaluated in the asymptomatic controls.
immediate (within 1 minute) alterations in cervical range of motion and pressure pain thresholds were observed following an average of 3.8 injections with 1–2 cc of 1% lidocaine into carefully identified trigger points. cervical range of motion increased by an average of 49% (p = 0.000) in flexion and 44% (p = 0.001) in extension, 47% (p = 0.000) and 28% (p < 0.016) in right and left lateral flexion, and a 27% (p = 0.002) and 45% (p = 0.000) in right and left rotation. ppt were found increased by 68% over the infraspinatus (p = 0.000), by 78% over the wrist extensors (p = 0.000), and by 64% over the tibialis anterior (p = 0.002). among 11 subjects with photophobia, only 2 remained sensitive to light after the trigger point injections (p = 0.033). average vas dropped by 57%, from 6.1 to 2.6 (p = 0.000). no significant changes in ppt were observed in the control group following lidocaine infiltration of the thigh.
the present data suggest that myofascial trigger points serve to perpetuate lowered pain thresholds in uninjured tissues. additionally, it appears that lowered pain thresholds associated with central sensitization can be immediately reversed, even when associated with long standing chronic neck pain. although the effects resulting from anesthesia of trigger points in the present study were temporary, it is possible that surgical excision or ablation of the same trigger points may offer more permanent solutions for chronic neck pain patients. further study is needed to evaluate these and other options for such patients.
Neuropathic pain remains a major clinical problem and a therapeutic challenge because existing analgesics are often ineffective and can cause serious side effects. Increased N-methyl-D-aspartate receptor (NMDAR) activity contributes to central sensitization in certain types of neuropathic pain. NMDAR antagonists can reduce hyperalgesia and allodynia in animal models of neuropathic pain induced by nerve injury and diabetic neuropathy. Clinically used NMDAR antagonists, such as ketamine and dextromethorphan, are generally effective in patients with neuropathic pain, such as complex regional pain syndrome and painful diabetic neuropathy. However, patients with postherpetic neuralgia respond poorly to NMDAR antagonists. Recent studies on identifying NMDAR-interacting proteins and molecular mechanisms of increased NMDAR activity in neuropathic pain could facilitate the development of new drugs to attenuate abnormal NMDAR activity with minimal impairment of the physiological function of NMDARs. Combining NMDAR antagonists with other analgesics could also lead to better management of neuropathic pain without causing serious side effects.
complex regional pain syndrome; diabetic neuropathy; neuropathic pain; NMDA receptors; spinal cord; synaptic plasticity; synaptic transmission
Diabetic peripheral neuropathy is a common complication of diabetes. It presents as a variety of syndromes for which there is no universally accepted unique classification. Sensorimotor polyneuropathy is the most common type, affecting about 30% of diabetic patients in hospital care and 25% of those in the community. Pain is the reason for 40% of patient visits in a primary care setting, and about 20% of these have had pain for greater than 6 months. Chronic pain may be nociceptive, which occurs as a result of disease or damage to tissue with no abnormality in the nervous system. In contrast, neuropathic pain is defined as “pain arising as a direct consequence of a lesion or disease affecting the somatosensory system.” Persistent neuropathic pain interferes significantly with quality of life, impairing sleep and recreation; it also significantly impacts emotional well-being, and is associated with depression, anxiety, and noncompliance with treatment. Painful diabetic peripheral neuropathy is a difficult-to-manage clinical problem, and patients with this condition are more apt to seek medical attention than those with other types of diabetic neuropathy. Early recognition of psychological problems is critical to the management of pain, and physicians need to go beyond the management of pain per se if they are to achieve success. This evidence-based review of the assessment of the patient with pain in diabetes addresses the state-of-the-art management of pain, recognizing all the conditions that produce pain in diabetes and the evidence in support of a variety of treatments currently available. A search of the full Medline database for the last 10 years was conducted in August 2012 using the terms painful diabetic peripheral neuropathy, painful diabetic peripheral polyneuropathy, painful diabetic neuropathy and pain in diabetes. In addition, recent reviews addressing this issue were adopted as necessary. In particular, reports from the American Academy of Neurology and the Toronto Consensus Panel on Diabetic Neuropathy were included. Unfortunately, the results of evidence-based studies do not necessarily take into account the presence of comorbidities, the cost of treatment, or the role of third-party payers in decision-making. Thus, this review attempts to give a more balanced view of the management of pain in the diabetic patient with neuropathy and in particular the role of pregabalin.
diabetes mellitus; painful neuropathy; pain; treatment; pregabalin
Neuropathic pain is an apparently spontaneous experience triggered by abnormal physiology of the peripheral or central nervous system, which evolves with time. Neuropathic pain arising from peripheral nerve injury is characterized by a combination of spontaneous pain, hyperalgesia and allodynia. There is no evidence of this type of pain in human infants or rat pups; brachial plexus avulsion, which causes intense neuropathic pain in adults, is not painful when the injury is sustained at birth. Since infants are capable of nociception from before birth and display both acute and chronic inflammatory pain behaviour from an early neonatal age, it appears that the mechanisms underlying neuropathic pain are differentially regulated over a prolonged postnatal period.
We have performed a microarray analysis of the rat L4/L5 dorsal root ganglia (DRG), 7 days post spared nerve injury, a model of neuropathic pain. Genes that are regulated in adult rats displaying neuropathic behaviour were compared to those regulated in young rats (10 days old) that did not show the same neuropathic behaviour. The results show a set of genes, differentially regulated in the adult DRG, that are principally involved in immune system modulation. A functional consequence of this different immune response to injury is that resident macrophages cluster around the large A sensory neuron bodies in the adult DRG seven days post injury, whereas the macrophages in young DRG remain scattered evenly throughout the ganglion, as in controls.
The results show, for the first time, a major difference in the neuroimmune response to nerve injury in the dorsal root ganglion of young and adult rats. Differential analysis reveals a new set of immune related genes in the ganglia, that are differentially regulated in adult neuropathic pain, and that are consistent with the selective activation of macrophages around adult, but not young large A sensory neurons post injury. These differences may contribute to the reduced incidence of neuropathic pain in infants.
Post-herpetic neuralgia is a neuropathic pain syndrome resulting from an insult to the peripheral and central nervous systems caused by the varicella zoster virus. Spontaneous pain may result in the persistent sensation of burning, tingling, or aching and may be associated with thermally or mechanically provoked pain, resulting in hyperalgesia or allodynia. The majority of cases occur in patients over the age of 50 years. Gabapentin is a structural analog of gamma aminobutyric acid that binds to the α2-δ site of voltage-dependent calcium channels and modulates the influx of calcium, with a resulting reduction in excitatory neurotransmitter release. Gabapentin is effective in reducing neuropathic pain due to post-herpetic neuralgia when given at least three times per day, due to its short half-life, resulting in demonstrable fluctuations in plasma levels. Gabapentin has dose-limiting side effects that prevent some patients from achieving therapeutic plasma levels, such as somnolence (27.4%), dizziness (23.9%), and ataxia (7.1%). Gralise™ is a once-daily extended-release formulation of gabapentin that has been developed using AcuForm™ technology. AcuForm is a polymer-based drug delivery system that retains the tablet in the stomach and upper gastrointestinal tract for a sustained period of time. Once-daily dosing has been shown to provide comparable drug exposure with an identical daily dose of the immediate-release formulation when administered three times daily. Participants given Gralise 1800 mg daily had a statistically significant reduction in average daily pain intensity scores compared with placebo, reduced sleep interference due to pain, and a greater percent of participants reporting being much or very much improved on the patient global impression of change. An analysis comparing the efficacy and safety profiles in the aging population (≥65 years) with those younger than 65 years showed that Gralise is effective and well tolerated in both age groups.
gabapentin; gabapentin extended-release; post-herpetic neuralgia; neuropathic pain; aging population
Patients with carpal tunnel syndrome (CTS) often complain of prominent pain in shoulder and arm, also there are patients that have pain in their shoulder and arm which is due to myofascial trigger point (MTP) located in their upper trapezius muscle. Despite the frequency of this observation, few studies have previously sought to establish possible relationship between the CTS and MTP in shoulder area.
Samples were 160 patients (221 hands) consist of 130 females and 30 males, with suspected diagnosis of CTS, from March 2008 to October 2008. In this study after performing electrodiagnosis searches, another evaluation was performed to find out if there was any sign of myofascial trigger point. The correlation between these two was sought.
It was found that all of 36 hands with normal electrodiagnostic findings had myofascial trigger points in their upper trapezius muscle. Out of 185 hands, 130 hands (70%) with electrophysiological evidences of CTS showed myofascial trigger points in their trapezius muscles. Statistical analysis revealed significant (p < 0.001) reverse correlation between the severity of CTS and the presence of MTP.
The findings of this study imply the significant correlation between occurrence of CTS and MTP. It is suggested that clinicians consider the probability of existence of MTP in patients referred for diagnosis of CTS.
Carpal Tunnel Syndromes; Myofascial Trigger Point; Electrodiagnoses
Fibromyalgia is a chronic syndrome characterized by generalized pain, joint rigidity, intense fatigue, sleep alterations, headache, spastic colon, craniomandibular dysfunction, anxiety, and depression. The purpose of the present study was to determine whether massage-myofascial release therapy can improve pain, anxiety, quality of sleep, depression, and quality of life in patients with fibromyalgia. A randomized controlled clinical trial was performed. Seventy-four fibromyalgia patients were randomly assigned to experimental (massage-myofascial release therapy) and placebo (sham treatment with disconnected magnotherapy device) groups. The intervention period was 20 weeks. Pain, anxiety, quality of sleep, depression, and quality of life were determined at baseline, after the last treatment session, and at 1 month and 6 months. Immediately after treatment and at 1 month, anxiety levels, quality of sleep, pain, and quality of life were improved in the experimental group over the placebo group. However, at 6 months postintervention, there were only significant differences in the quality of sleep index. Myofascial release techniques improved pain and quality of life in patients with fibromyalgia.
A patient with traumatic rotator cuff tear of the left shoulder developed severe myofascial pain syndrome with reflex sympathetic dystrophy (RSD) involving the left upper extremity. He was unable to tolerate any type of manual therapy or needle treatment due to severe allodynia in the whole left upper limb. This patient presented for treatment approximately 6 months after the onset of trauma. Treatment consisting of specific myofascial trigger point (MTrP) therapy, beginning with desensitization and gentle massage on the MTrP of the first dorsal interosseous muscle, followed by treatment of MTrPs of the wrist-finger extensors and anterior deltoid muscles was commenced. Allodynia was remarkably reduced and further physical therapy with modalities was administered. After 2 weeks of daily MTrP therapy, he received local steroid injection to the left shoulder and continued MTrP therapy 2-3 times per week. Approximately 2 months after the injection the patient was almost pain free with nearly full range of motion in his left shoulder. The mechanism of MTrPs and their association with RSD is discussed in this paper.
Manual therapy; muscle pain; Myofascial Trigger Points; Reflex Sympathetic Dystrophy
Stroke is the leading cause of disability and one of the most common causes of death worldwide. Outside the setting of acute management, secondary prevention and stroke rehabilitation, little has been written to address the ongoing symptomatic and palliative needs of these patients and their families. In this literature review, we look beyond secondary prevention with the aim of providing evidence-informed management guidelines for the myriad and often under-recognized symptomatic and palliative care needs of stroke survivors. Some of the most common and disabling post-stroke symptoms that are reviewed here include central post-stroke pain, hemiplegic shoulder pain, painful spasticity, fatigue, incontinence, post-stroke seizures, sexual dysfunction, sleep-disordered breathing, depression and emotionalism. We review the role of caregivers and explore ways to support them and, lastly, remind the reader to be perceptive to the patient’s spiritual needs. The literature is most robust, including controlled trials, for central post-stroke pain and depression. Synthesis and discussion outside these areas are frequently limited to smaller studies, case reports and expert opinion. While some data exists to guide informed decision-making, there is an urgent need to document best practice and identify appropriate clinical standards for the full spectrum of symptoms experienced by stroke survivors. We present the current and established data to aid health care providers in symptomatic and palliative management of stroke survivors.
stroke; palliative care; symptom management