Transdermal buprenorphine in the treatment of chronic pain

The transdermal matrix patch formulation of buprenorphine has been shown to be effective in managing moderate-to-severe cancer pain and severe pain unresponsive to nonopioid analgesics. Clinical trials have revealed that it is possible to switch from weak opioids or low doses of step III opioids to transdermal buprenorphine without any problems. With buprenorphine patches, the sublingual buprenorphine intake was dose-dependently reduced and was superior to placebo in this respect. The proportion of responders increased with the buprenorphine dose, and a higher proportion of patients receiving buprenorphine patches reported uninterrupted sleep for longer than 6 h compared with those receiving placebo. In a long-term, open, follow-up study in which the mean duration of treatment was 7.5 months, analgesia was rated as at least satisfactory by 90% of patients. Almost 60% of patients could manage their pain with one patch alone or with one additional sublingual tablet a day during the whole period of treatment, indicating a low incidence of tolerance development. The buprenorphine transdermal patch was assessed as user friendly by 94.6% of patients. In a postmarketing surveillance study, pain relief with transdermal buprenorphine was rated as good or very good by 70% of the responders. Postmarketing surveillance studies have shown that transdermal buprenorphine is also effective in the management of nociceptive and neuropathic pain, which some studies have shown to be relatively insensitive to mu-opioid analgesics, such as morphine. Transdermal buprenorphine was well tolerated. Most adverse events were either local reactions to the patch that generally subsided within 24 h or systemic events typical of treatment with opioid analgesics, such as nausea, vomiting and constipation.     

Behavioral covariation in the treatment of chronic pain

The successful use of operant procedures to alter behaviors associated with various medical conditions suggests that such behaviors may be learned and that the principles of learning may be applied not only to treatment but also to the study of the pathogenesis of illness behavior. The present study, conducted within an ongoing neuromuscular research project, assessed the covariation of behaviors associated with chronic pain within and across behavioral and drug approaches to treatment. Problems of screaming and five other behaviors (including self-reports of pain) were measured across conditions of varying behavioral contingencies (noncontingent reinforcement vs the removal of reinforcement contingent upon screaming) and varying administration (time since medication and dosage) of Parsidol during attempts to treat the muscle pain of a 24-year-old male with a severe, chronic neuromuscular disorder diagnosed as dystonia musculorum deformans (DMD). Results indicated that: (a) pain behaviors covaried during behavioral and drug conditions even though the behavioral intervention only targeted screaming; (b) effects were greater on nontargeted behaviors during periods that followed rather than preceded drug administration; (c) in contrast to behavioral observation data, physiological measures of neuromuscular activity (EMG) did not differ across conditions. These results suggest that functional response-response relationships exist in patients as the result of their illness experience.     

Interdisciplinary treatment of chronic pain

Interdisciplinary treatment care must address more than the physical pathology. Chronic pain comprises a range of interdependent variables including biologic, cognitive, affective, behavioral, and social factors. This article discusses these psychosocial issues, as well as the four levels of pain management programs, and the characteristics and goals of interdisciplinary treatment. Finally, recent clinical studies demonstrating the efficacy and cost benefits of interdisciplinary pain management programs are reviewed.     

Factors in the diagnosis and treatment of chronic pain

Symptoms are the verbal and nonverbal communicative expressions of experience. At any one time, the symptom is dependent on structural changes, genetic variations, metabolic abnormalities, immunopathic and other disorders, and the totality of social, economic, and situational experience. Complaints of pain may vary with time depending on the interaction of these features in a manner not directly related to the intensity of a noxious stimulus.     

Voltage-gated calcium channels in the etiopathogenesis and treatment of absence epilepsy

Voltage-gated calcium channels are key elements in regulating neuronal excitability and are thus of central importance in the pathogenesis of various forms of epilepsies. Among these, absence epilepsies represent about 10% of epileptic seizures in humans. They are electroencephalographically characterized by bilateral synchronous spike-wave discharge activity associated with loss or severe impairment of consciousness. Extensive studies during the last decades revealed that pathophysiologically increased oscillatory activity, i.e., hyperoscillation within the reticulothalamocortical circuitry, is the electrophysiological correlate of absence epilepsy, with extrathalamocortical structures, e.g., brainstem and cerebellum, projecting to the thalamocortical circuitry, thereby modulating its activity. Voltage-gated calcium channels are one of the central players regulating the transition from tonic to rebound burst-firing modes in both thalamic relay and reticular thalamic nucleus neurons, the burst-firing mode being the substrate of the thalamocortical oscillation. Thus, pharmacological interference with these channels enables effective control of spike-wave discharge activity in patients suffering from absence seizures. In this review, we summarize the medical history of absence epilepsies, their classification and terminology, the diagnostic armamentarium available today and the etiopathogenesis of absences. Finally, various antiepileptic drugs that have been proven to or are supposed to exert anti-absence effects are discussed with respect to their pharmacodynamics and pharmacokinetics.     

Prediction of response to treatment in chronic pain patients

A seven-item rating scale reported by researchers from the Mayo Clinic to have high validity in identifying chronic pain patients who would benefit from inpatient treatment was administered to an outpatient sample. Initial results did not replicate the previous findings; inclusion of four additional variables (disruption of a close relationship, altered body image, history of childhood illness, and history of abuse in childhood) produced results comparable to the Mayo study. This expanded screening test appears to be a useful method for selecting patients in a pain-management program and warrants further investigation.     

Surgical treatment of epilepsy with chronic cerebral granuloma caused by Schistosoma japonicum

PURPOSE: To study the surgical treatment of epilepsy with cerebral granuloma caused by Schistosoma japonicum. METHODS: Two hundred fifty cases of epilepsy caused by cerebral schistosomiasis from 1955 to 2004 were analyzed retrospectively. RESULTS: There were no deaths. Follow-up of 196 cases for 4-5 years after operation demonstrated that 180 cases (92%) were seizure-free or well-controlled. CONCLUSIONS: Surgical treatment should be considered when drug therapy fails to control epilepsy or the lesion shows mass effect. Intraoperative electrocorticography monitoring is helpful to define the extent of the resection of the lesion.     

A three-dimensional treatment programme for chronic pain

ABSTRACT – The treatment of chronic pain contains several problems such as ineffectiveness, side effects and drug dependence. The concepts of respondent and operant pain are introduced, together with a general operant learning model for analysis and treatment of psychological problems. To make a psychological analysis of pain, evidence for learned pain behaviour must be assessed, reinforcers for treatment revealed, goal behaviours set up, and support in the environment secured. In the further analysis, account must be taken to a) time pattern of pain, b) pain behaviour, c) reactions from the environment, d) pain activators, e) pain reducers, f) the effect of tension versus relaxation on pain, and g) changes in the family structure necessary because of the pain problem. A three-dimensional operant treatment programme for chronic pain is presented. It consists of 1) reduction of medication, 2) increase of activity, and 3) reduction of pain behaviour. Results, supporting the efficacy of the model, are presented.     

Epidemiologic perspective on chronic pain treatment.

OBJECTIVE: To review the epidemiologic literature concerning psychosocial mediators of outcome in chronic pain. These factors deserve attention in the assessment and treatment of chronic pain by mental health professionals. METHOD: We reviewed literature dealing with epidemiologic perspectives on abuse, depression, addiction, employment, coping skills, and psychosocial problems. Treatments considered include analgesics, psychological rehabilitation, and prevention of disability. RESULTS: Psychosocial factors such as abuse, mood disorder, employment handicap, poor coping skills, and other psychosocial problems are commonly found in chronic pain patients referred to clinics. CONCLUSION: Many psychosocial factors that can be identified in chronic pain sufferers are relevant to the professional skills of mental health professionals. These factors are determinants of prognosis, course, and outcome of chronic pain.     

Measurement of plasma levels of clomipramine in the treatment of chronic pain

The analgesic effect of clomipramine and the possible relationships between the antalgic action and the plasma levels of this tricyclic drug have been studied in 30 patients with chronic pain induced by nervous lesions determining a deafferentation. Twenty of 30 patients treated with clomipramine reported a significant improvement (up to 50%) observed as soon as the 4th day, with few side effects. The pharmacokinetic analysis shows the existence (r = 0.358; p less than 0.001) of a relationship between analgesia and plasma levels of clomipramine for each individual patient. This study also indicates a "therapeutic window" of plasma levels between 20 and 85 ng/ml. These results permit discussion of measurement of plasma levels of clomipramine in the treatment of chronic pain.     

Peripheral nerve stimulation for the treatment of chronic pain.

The aim of this retrospective study is to evaluate the role of the implanted peripheral nerve stimulator in patients with pain in a peripheral nerve distribution. The current study is the largest in the literature that examines the role of the implantable peripheral nerve stimulator in the chronic pain patient. Our patient sample included 38 patients (with 41 nerve stimulators), consisting of 19 males and 19 females with a mean age of 44 years (SD=11 years). Four groups of etiologic factors were identified; blunt or sharp nerve trauma (14/38), iatrogenic injuries from surgery (9/38), inadvertent injection of a nerve (9/38) and post surgery for entrapment or tumour (8/38). Stimulation was attempted in 45 patients, but an initial trial failed in 4. Mean follow-up time from implantation of the stimulator was 31 months (SD=19 months). Compensation benefit was an issue in 29 cases (76%). Outcome following implantation was assessed based on pain criteria, narcotic usage and return to normal function/ work. Relief from preoperative pain was judged as good (>50% relief) by 23/38 patients (61%). A total of 15 patients reported fair or poor results (39%). Six patients required removal of their stimulators (15%) due to infection or reduction of pain control after an initial good result. A statistically significant decrease in reported pain level was found postoperatively (p<0.05). Workers' compensation patients have equivalent outcomes to non-compensable patients (p>0.05). Eighteen of 38 (47%) patients reported a significant improvement in their activity levels following stimulator implant. In conclusion, over 60% of patients had a significant improvement in their pain and lifestyle following implantation of peripheral nerve stimulators. We therefore conclude that peripheral nerve stimulation can be useful in decreasing pain in well selected patients with severe pain in the distribution of a peripheral nerve.