Intervention Effect of Ruyi Zhenbao Pills on Mice with Central Pain After Thalamic Stroke / 中国实验方剂学杂志

ObjectiveTo observe the intervention effect of Ruyi Zhenbao pills （RYZBP） on central pain after thalamic stroke in mice and explore the underlying mechanism. MethodThe central post-stroke pain syndrome （CPSP） model was induced by stereotactic injection of type Ⅳ collagenase into the hypothalamus in mice. The mice were divided into a sham group， a model group， low-， medium-， and high-dose RYZBP groups （0.65， 1.3， 2.6 g·kg-1）， and a pregabalin group （0.075 g·kg-1）. Seven days after modeling， the mice in the groups with drug intervention were administered with corresponding drugs by gavage according to the body mass， once per day for 25 days， while those in the sham group and the model group received an equal volume of normal saline. During this period， mechanical pain and cold pain were detected at different time points， and the apoptotic state of brain tissue cells was detected by in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling （TUNEL）. The 36 classical broad-spectrum inflammatory factors were quantitatively analyzed by liquid-phase chip technology， and differential molecules were screened out and verified by Western blot and enzyme-linked immunosorbent assay （ELISA）. ResultCompared with sham operation group, mechanical pain threshold and cold sensitive pain threshold in model group were significantly changed （P<0.01）. TUNEL results showed that apoptosis of brain cells was obvious. Western blot and ELISA results showed that the expressions of interleukin-1α (IL-1α) and chemokine ligand 5 (CCL5) increased in hypothalamus tissue and serum， while the expressions of Ang-2, granulocyte-colony-stimulating factor (G-CSF) and IL-4 decreased significantly （P<0.01）. Compared with model group， RYZBW dose groups significantly increased mechanical pain threshold， decreased cold sensitivity pain threshold， decreased hypothalamus cell apoptosis ratio （P<0.01）， decreased the expression of IL-1α and CCL5 in hypothalamus tissue and serum， while the expression of ANG-2， G-CSF and IL-4 were significantly increased （P<0.05）. ConclusionRYZBP can relieve hyperalgesia in CPSP mice， and its mechanism is related to the regulation of the expression of pro-/anti-inflammatory factors IL-1α， CCL5， IL-4， G-CSF， and Ang-2.

Clinical Observation of Pregabalin Combined with Gabapentin in the Treatment of Central Pain after Cerebral Infarction / 中国药房

OBJECTVE:To investigate the clinical effect and safety of pregabalin combined with gabapentin in the treatment of central pain after cerebral infarction.METHODS:One hundred and fifty patients with central pain after cerebral infarction in our hospital from Jan.2010 to Dec.2015 in our department were randomly divided into group A,B,C,with 50 cases in each group.Group A was given Pregabalin capsule 75 mg,bid combined with Gabapentin capsule 0.1 g,tid;group B was given Pregabalin capsule 75 mg,bid;group C was given Gabapentin capsule 0.1 g,tid;3 groups were treated for 4 weeks.VAS score,NRS score,PSQI and SF-36 score were observed among 3 groups before and after treatment to evaluate clinical efficacies of 3 groups;the occurrence of ADR were recorded in 3 groups.RESULTS:The clinical total response rate of group A,B,C were separately 94.00％,74.00％,70.00％.The clinical total response rate of group A was significantly better than that of group B and C,with statistical significance (P＜0.05).After treatment,VAS score of group A,B,C were separately(3.87 ± 0.74),(5.10 ± 1.26),(5.03 ± 1.23);NRS score were separately (3.91 ± 0.88),(5.29 ± 1.25),(5.37 ± 1.30);VAS score and NRS score of group A were signifi cantly lower than group B,C and before treatment,with statistical significance (P＜0.05);PSQI score of group A,B,C were separately(4.03 ± 0.85),(5.92 ± 1.16),(5.83 ± 1.11);SF-36 score were separately (372.84 ± 73.25),(348.07 ± 60.54),(345.67 ± 59.72);PSQI score and SF-36 score of group A were significantly better than group B,C and before treatment,with statistical sig nificance (P＜0.05).There was no statistical significance in the incidence of ADR among 3 groups (P＞0.05).CONCLUSIONS:Compared with pregabalin and gabapentin alone,pregabalin combined with gabapentin in the treatment of central pain after cerebral infarction can efficiently relieve the perceived pain,improve sleep quality and daily life quality and not increase the risk of ADR;therefore,drug combination plan is recommended for patient with central pain after cerebral infarction,especially with poor effect of two single drug.

Central Sensitization In Chronic Low Back Pain: A Narrative Review.

Objective: The aim of this narrative review is to examine the available literature related to central sensitization (CS) and altered central pain processing in chronic low back pain (CLBP) patients. Methodology: Literature was searched using many electronic databases. Additionally, reference list of most prominent articles were searched to increase the search accuracy, as much as possible. Studies which are evaluating the concept of CS in conservatively treated CLBP patients were included. Results: Results of studies evaluating the responsiveness to various types of stimuli in CLBP patients are contradictory. Some studies in CLBP patients have showed increased pain responses after sensory stimulation of body parts outside the painful region, when some other studies report no differences between patients and healthy controls. Studies evaluating the integrity of the endogenous pain inhibitory systems describe unchanged activity of this descending inhibitory system. Conversely, studies examining brain structure and function in connection with experimentally induced pain provide initial proof for changed central pain processing in CLBP patients. Also inappropriate beliefs about pain, depression and/or pain catastrophizing, may lead to the development of CS. Conclusion: Most of the literatures suggest that the CNS becomes centrally sensitized in a subgroup of patients with CLBP. However, the significance of this involvement is just starting to become clearer. This could be an active topic of future research. More studies are necessary for providing definite evidence for the clinical importance of CS.

Central neuropathic pain / Dores neuropáticas centrais

ABSTRACT BACKGROUND AND OBJECTIVES: Central pain, classified as neuropathic, is defined as a painful syndrome caused by injury to central nervous system structures. This is one of the most complexes, intriguing and difficult to treat syndromes. This study aimed at promoting a narrative review including the concept of central pain, its intercurrent symptoms which are important for the diagnosis, and different available treatments, indications, results and complications. CONTENTS: Relevant articles available in Medline, Scielo, Cochrane Library and Pubmed databases in the last 10 years were selected by means of keywords: chronic neuropathic pain, central neuropathic pain, central pain. CONCLUSION: Central painful syndrome is diagnosed by means of neurological clinical evaluation. It is often refractory to clinical and neuromodulatory treatment, its management should be multimodal and allow for rehabilitation.

RESUMO JUSTIFICATIVA E OBJETIVOS: A dor central, classificada como neuropática, é definida como uma síndrome dolorosa que decorre da lesão de estruturas no sistema nervoso central. Trata-se de uma das síndromes dolorosas mais complexas, intrigantes e de difícil tratamento. O objetivo deste estudo foi promover uma revisão narrativa que inclui desde o conceito de dor central, seus sintomas intercorrentes importantes no diagnóstico; e diversos tratamentos disponíveis, indicações, resultados e complicações. CONTEÚDO: Foi realizada uma seleção de artigos relevantes disponíveis nas plataformas Medline, Scielo, Biblioteca Cochrane e Pubmed nos últimos 10 anos, por meio dos descritores: dor crônica neuropática, dor neuropática central, dor central. CONCLUSÃO: A síndrome dolorosa central tem seu diagnóstico realizado por meio do exame clínico neurológico. É frequentemente refratária ao tratamento clínico e neuromodulatório e, portanto, deve ser multimodal e permitir a reabilitação.

Central pain due to stroke: cognitive representation and coping according to gender / Dor central em acidente vascular encefálico: representação cognitiva e enfrentamento conforme o gênero

OBJECTIVE: To identify and compare perceptions of pain and how it is faced between men and women with central post-stroke pain. METHODS: The participants were 25 men and 25 women of minimum age 30 years-old and minimum schooling level of four years, presenting central post-stroke pain for at least three months. The instruments used were: Mini-Mental State Examination; structured interview for the Brief Psychiatric Scale; Survey of Sociodemographic and Clinical Data; Visual Analogue Scale (VAS); Ways of Coping with Problems Scale (WCPS) in Scale; Revised Illness Perception Questionnaire (IPQ-R); and Beck Depression Inventory (BDI). RESULTS: A significantly greater number of women used the coping strategy "Turn to spiritual and religious activities" in WCPS. They associated their emotional state with the cause of pain in IPQ-R. "Distraction of attention" was the strategy most used by the subjects. CONCLUSION: Women used spiritual and religious activities more as a coping strategy and perceived their emotional state as the cause of pain.

OBJETIVO: Identificar e comparar a percepção e o enfrentamento da dor entre homens e mulheres com dor central por acidente vascular cerebral (AVC). MÉTODOS: Participaram do estudo 25 homens e 25 mulheres com dor central por AVC há pelo menos três meses, maiores de 30 anos, escolaridade mínima de 4ª série. Os instrumentos utilizados foram: Mini-exame do Estado Mental; Entrevista Estruturada para Escala Psiquiátrica Breve; Inquérito de Dados Sociodemográficos e Clínicos; Escala Visual Analógica (EVA); Escala dos Modos de Enfrentamento de Problemas (EMEP); Questionário de Percepção da Doença Revisado (QPD-R) e Inventário de Depressão de Beck (IDB). RESULTADOS: Um número significativamente maior de mulheres revelou usar a estratégia de enfrentamento "Realizar atividades espirituais e religiosas" na EMEP e associou o estado emocional à causa de suas dores no QPD-R. "Distração da atenção" foi a estratégia mais utilizada pelos sujeitos. CONCLUSÃO: As mulheres utilizaram mais atividades espirituais e religiosas como estratégia de enfrentamento e perceberam mais o estado emocional como causa da dor.

Comparing the effects of transcuataneous electrical nerve stimulation and fluoxetine on central pain in patients with spinal cord injury / 中华物理医学与康复杂志

Objective To compare the effects of fluoxetine and transcuataneous electrical nerve stimulation (TENS) on central pain after spinal cord injury (SCI) using a sham-controlled crossover method.Methods Ele-ven patients with central pain after SCI were randomly divided into two groups which were then subject to 2 phases of treatment.Patients in group 1 were treated by oral intake of fluoexetine for 4 weeks followed by TENS treatment for 4 weeks.Those in group 2 were treated in the reverse sequence.A fifteen day washout period was arranged between the two phases of treatment.The short-form McGill pain questionnaire (SF-MPQ) and the Beck depression inventory (BDI) were used to assess all patients pre-and post-treatment.Results SF-MPQ scores were reduced significantly after either fluoexetine or TENS treatment.After each phase of treatment there was no significant difference between the two groups.Significant improvement in terms of BDI scores was found with fluoxetin treatment in both phases of the trial,but not with TENS treatment.Conclusions Both fluoxetine and TENS can alleviate central pain after SCI,and fluoxetine can relief patients' depression at the same time.

Motor cortex electric stimulation for the treatment of neuropathic pain / Estimulação elétrica do córtex motor no tratamento da dor neuropática

OBJECTIVE: Motor cortex stimulation (MCS) is considered to be an effective treatment for chronic neuropathic pain. The aim of the present study was to assess the efficacy of MCS for treating neuropathic pain. METHOD: 27 patients with chronic neuropathic pain were operated. Electrodes were implanted with the use of an stereotactic frame. Electrophysiological evaluations (motor stimulation and somatosensory evoked potentials) were performed, with guidance by means of three-dimensional reconstruction of magnetic resonance images of the brain. 10 patients (37 percent) presented central neuropathic pain (post-stroke pain) and 17 others (63 percent) presented peripheral neuropathic pain (brachial plexus avulsion, phantom limb pain or trigeminal pain). RESULTS: In 15 patients (57.7 percent) the pain relief was 50 percent or more; while in ten patients (38.5 percent), more than 60 percent of the original pain was relieved. No differences were found in relation to central and peripheral neuropathic pain (p=0.90), pain location (p=0.81), presence of motor deficit (p=0.28) and pain duration (p=0.72). No major complications were observed. CONCLUSION: MCS was efficient for treating patients presenting chronic central or peripheral neuropathic pain.

OBJETIVO: A estimulação do córtex motor (ECM) é método considerado eficaz no tratamento da dor neuropática crônica rebelde. O presente estudo avaliou a eficácia da ECM no tratamento de pacientes portadores de dor neuropática crônica. MÉTODO: 27 doentes foram avaliados; 10 (37,0 por cento) apresentavam dor neuropática de origem central, enquanto 17 (63,0 por cento), dor neuropática periférica. Avulsão de raízes do plexo braquial, dor no membro fantasma, dor decorrente de doença cerebrovascular isquêmica ou hemorrágica ou neuropatia trigeminal foram as causas mais freqüentes da dor. Os doentes foram operados com uso da técnica de localização estereotáctica do córtex motor associadamente a estudo eletroneurofisiológico (estimulação motora e potencial evocado somatossensitivo) ou ainda com uso de imagens de ressonância magnética do encéfalo reconstruídas tridimensionalmente. RESULTADOS: O alívio da dor foi igual ou superior a 50 por cento em 15 doentes (57,7 por cento), sendo em 10 (38,5 por cento), superior a 60 por cento. Não houve diferença nos resultados quanto a origem central ou periférica (p=0,90) da dor, localização da dor (p=0,81), ocorrência ou não de déficit motor (p=0,28) e duração da sintomatologia (p=0,72). Não foram observadas complicações graves. CONCLUSÃO: A estimulação do córtex motor foi útil no tratamento da dor neuropática crônica rebelde tanto de origem central como periférica.

Recomendaciones para el tratamiento del dolor neuropático / Recommendations for the treatment of neuropathic pain

Con la introducción y el desarrollo de nuevos productos que han demostrado ser eficaces en el dolor neuropático (DN), se ha generado una clara necesidad de tener un algoritmo basado en la evidencia para tratar las diferentes condiciones del DN. El objetivo de este artículo es elaborar unas recomendaciones para el tratamiento del DN que estén avaladas por la evidencia científica y que estén consensuadas por un grupo multidisciplinario de expertos en metodología y en tratamiento del dolor. La evidencia se ha obtenido de estudios de metanálisis que recogen la mayor información disponible para cada tipo de DN. La búsqueda bibliográfica se llevó a cabo por 5 revisores, que se centraron individualmente en las diferentes formas de presentación del DN. Las bases de datos consultadas fueron la Cochrane Library, EMBASE (año 2000 en adelante) y PUBMED(año 2000 en adelante), y se seleccionaron metaanálisis y ensayos clínicos aleatorizados y controlados. Finalmente, los autores, especialistas en dolor, evaluaron e hicieron las recomendaciones clínicas para el tratamiento del DN. En algunos tipos de DN, de los cuales no hay suficiente información, se han incluido recomendaciones basadas en publicaciones científicas sin evidencia, con el objetivo de que estas recomendaciones proporcionen la mayor información posible acerca de su tratamiento. Se han revisado estudios de eficacia y seguridad de neuralgia postherpética (NPH), neuropatía diabética dolorosa (NDD) y neuralgia del trigémino(NT) como paradigmas de DN periférico, y también se ha recogido la escasa información existente acerca del DN central(DNC) y el dolor simpático (DS). Con los resultados obtenidos con este estudio bibliográfico y las evidencias extraídas, se ha elaborado un algoritmo de decisión con los fármacos disponibles actualmente en la farmacopea española para la NPH y la NDD; por otro lado, y de forma independiente, para la NT y, finalmente, para el DNC y el DS.

The introduction and development of new products with demonstrated efficacy in neuropathic pain has generated a clear need for an evidence-based algorithm to treat the different types of neuropathic pain. The present article aims to provide recommendations on the treatment of neuropathic pain supported by the scientific evidence and agreed on by consensus by a multidisciplinary group of experts in methodology and pain management. The evidence was obtained from meta-analyses including the greatest amount of information available for each type of neuropathic pain. The literature search was performed by 5 reviewers, who focussed individually on the distinct forms of presentation of neuropathic pain. The databases consulted were the Cochrane Library, EMBASE (from 2000 onwards), and PUBMED (from 2000 onwards). Meta-analyses and randomized, controlled clinical trials were selected. Finally, retrieved articles were evaluated and clinical recommendations for the treatment of neuropathic pain were designed by the pain specialists. For some types of neuropathic pain, there is insufficient information. In these types of pain, recommendations based on scientific publications without evidence were included to provide the reatest possible amount of information on their treatment. Studies of safety and efficacy in postherpetic neuralgia (PHN), painful diabetic neuropathy (PDN), and trigeminal neuralgia (TN) were reviewed as paradigms of peripheral neuropathic pain. The scarce available information on central neuropathic pain (CNP) and sympathetic pain (SP) was also gathered. Based on the results obtained with this literature review and the evidence extracted, a decision algorithm was designed with the drugs currently available in the Spanish pharmacopeia for PHN and PDN, and separate decision algorithms were designed for TN and finally for CNP and S P.

Preliminary Result of Olfactory Ensheathing Cell Transplantation in Intractable Neuropathic Pain Following Spinal Cord Injury: 17 Cases Report / 中国康复理论与实践

@#ObjectiveTo explore the feasibility and potential benefit of olfactory ensheathing cell (OEC) intraspinal transplantation in the treatment of intractable chronic neuropathic pain after spinal cord injury (SCI).Methods17 patients, 15 male and 2 female, with intractable chronic neuropathic pain after spinal cord injury was treated by OEC implant from November, 2004 to November, 2007. The age ranged from 18 to 68 (mean 40.4) years. The etiology of cord impairment included car accidents, falls, radiation damage, machine extrusion, gun-shot, and diving. The patients suffered severe persistent pain for 6 to 309 (mean 102.2) months, and the time points when cell therapy were administrated in the patients ranged from 6 to 312 (mean 105.9 months) after their injuries. Olfactory bulbs were harvested and trypsinized down to single fetal OECs. They were cultured for 12～14 days before implant. The fetal OECs were transplanted by injection into spinal cord at opposing ends of the injury site. The degree of pain was assessed and compared before operation and long-term follow-up according to the International Association of Neurorestoratology Spinal Cord Injury Functional Rating Scale (IANR-SCIFRS), i.e., 0 point means extreme pain, uncontrolled; 1 point, severe pain, narcotics required; 2 points, mild pain, ordinary pain killer effective; 3 points, no pain.ResultsThe follow-up and pain reevaluation were performed at 0.5 to 88 months with an average of 17.5 months after cell transplantation. The mean score of pain amelioration is 1.2 points.ConclusionThe OEC intraspinal transplantation appears to have a promising role in treatment of intractable chronic neuropathic pain after SCI.

Central Pain from Excitotoxic Spinal Cord Injury Induced by Intraspinal NMDA Injection: A Pilot Study

BACKGROUND: The pathophysiological and neurochemical changes following spinal injury are not yet elucidated. This study was designed to evaluate the morphological changes of the dorsal horn of the spinal cord and profiles of pain behaviors following intraspinal injection of NMDA in rats. METHODS: Rats were randomized into three groups: a sham-operated control group and groups where the rats received 10 mM or 100 mM N-methyl-D-aspatate (NMDA) injected into their spinal dorsal horn. Following injection, hypersensitivity to cold and mechanical stimuli and excessive grooming behaviors were assessed serially for four weeks. Morphological changes of the spinal cord were evaluated four weeks after intraspinal injection. RESULTS: Few animals in the NMDA groups developed hypersensitivity to cold and mechanical stimuli. The number of groomers and the severity of excessive grooming were significantly higher in the 100 mM NMDA group than those values of the control and 10 mM NMDA groups. The size of the neck region (lamina III-IV) was significantly smaller in the 100 mM NMDA group than in the control and 10 mM NMDA groups. CONCLUSIONS: In conclusion, intraspinal injection of NMDA in rats leads to the pathological sequela in the spinal cord and to excessive grooming behavior. These results support the use of NMDA and excessive grooming behavior after excitotoxic SCI as a model to study chronic pain after SCI.

Central Pain Following Spinal Cord Iinjury (review) / 中国康复理论与实践

@# Central pain (CP) following spinal cord injury (SCI) challenges the health care community. A number of pain syndromes associated with SCI are based on the nature of the lesion, neurological structure damage and secondary pathophysiological changes. The hyperresponsiveness of neurons following SCI is the key factor of the mechanisms of CP. And several treatments have received some effects. So it is very important to study the mechanisms and therapies of CP.

Multidisciplinary Therapy on Central Pain after Spinal Cord Injury: 32 Cases Report / 中国康复理论与实践

@#Objective To observe the effects of multidisciplinary therapy on central pain of patients with spinal cord injury.Methods 32 cases of spinal cord injury with central pain were treated with accupuncture, massage and drugs, and the effects were assessed by McGill Pain Questionnaire (MPQ), Visual Analogous Score (VAS) and Barthel Index (BI).Results The scores of pain of all patients significantly decreased and the scores of BI highly increased after treatment (P<0.01).Conclusion Multidisciplinary therapy is effective on central pain in patients with spinal cord injury.

Ketamine Infusion Therapy in a Patient of Posttraumatic Syringomyelia / 대한통증학회지

The clinical syndrome of posttraumatic syringomyelia can complicate major spinal trauma and develops many months after spinal injury. The 50-90% of patients experienced the pain and especially the component of central pain. In patients with central pain following spinal cord injury, ketamine has been shown to be an effective analgesic. We report a case of posttraumatic syringomyelia in a 30-year-old woman who complained of central pain, weakness of both legs and dysesthesia. She had not responded to pulsed radiofrequency, or lidocaine infusion therapy, but a continuous intravenous infusion of ketamine, an N-methyl-D-asparate receptor antagonist, reduced her severe central pain. In conclusion, a ketamine infusion therapy resulted in a significant reduction of central pain without decreasing of motor power and function.

The Relation of Somatosensory Evoked Potentials to Central Post-stroke Pain

OBJECTIVE: To find out the clinical features of central post- stroke pain (CPSP) and how somatosensory evoked potentials (SEPs) are affected in patients with CPSP. METHOD: One hundred and one patients with stroke who showed normal results in nerve conduction study, were enrolled. SEPs were evoked by electrical stimulation of the median and tibial nerves. The results of the SEPs in the CPSP group were compared with those in the non-CPSP group. Brain SPECT (single photon emission computed tomography) was examined and thalamic involvement in SPECT was compared between the groups. RESULTS: Seventeen patients met the diagnostic criteria of CPSP. Nine patients showed normal findings in SEP. Abnormal findings in SEP were not related to the development of CPSP, but those who showed no response in SEP had significantly higher chance of developing CPSP. Thalamic involvement in SPECT was found in thirteen patients with CPSP, but was not related to the development of CPSP. CONCLUSION: Stroke patients who showed severe abnormality in SEP seem to be more likely to have CPSP. Therefore, SEP is thought to be helpful in the prediction of CPSP.

Improvement of Spinal Central Pain by Brachial Plexus Block: A case report / 대한통증학회지

Central pain is defined as pain associated with lesions of the central nervous system, and is among the most intractable of chronic pain syndromes. A 47 year-old-female, who had right arm and shoulder pain, was diagnosed with syringomyelia of the Arnold Chiari malformation type I and received foramen magnum decompression and a syringo-subarachnoid shunt. After the operation, the evoked pain was improved, but she complained of a continuous burning pain, coupled with cold and tactile allodynia. This symptom failed to fully subside on administration of oral medicine; therefore, brachial plexus block was performed, which relieved her pain transiently. Through repeated trials, a gradual decrease in the pain intensity and frequency was found. However, the way in which brachial plexus block improves spinal central pain is not completely known.

Effect of comprehensive therapy on central pain after incomplete spinal cord injury / 中国康复理论与实践

@# ObjectiveTo observe the effects of comprehensive therapy on central pain after incomplete spinal cord injury. Methods12 patients with central pain after incomplete spinal cord injury who accepted comprehensive therapy were assessed with McGill pain questionnaire (MPQ) and visual analogue scale (VAS) before and after treating. ResultsThe scores of pain rating index sensory quality (PRI-S), pain rating index totality (PRI-T), the number of words chosen (NWC), pain rating index affective quality (PRI-A) and present pain intensity (PPI)max in MPQ and VAS were significantly decreased(P<0.01 or P<0.05).ConclusionThe comprehensive therapy is practical effective on central pain after incomplete spinal cord injury.

The inhibitory effects of peripheral electrical stimulation on chronic central pain after spinal cord injury / 中华物理医学与康复杂志

Objective To investigate the mechanisms of the inhibitory effects of peripheral electrical stimu- lation(PES)on chronic central pain(CCP)after spinal cord injury(SCI).Methods Twenty-four male Sprague- Dawley rats with CCP following SCI were randomly divided into three groups:a group without stainless steel needles implanted (NSSN group,n=8),a group with a stainless steel needle implanted but no peripheral electrical stimula- tion applied(NPES group,n=8)and a PES group(PES group,n=8).The rats' CCP was evaluated through ob- serving their response to nociceptive stimulation by means of the paw withdrawal pressure threshold(PWPT)and the paw withdrawal latency(PWL).Spontaneous pain behaviors including autophagia and scratching were observed at the same time.PES was applied via stainless steel needles inserted into standard acupoints on the hind limps and the back.The expression of the NMDA receptor 1(NR-1)subunit in the spinal cord horn was measured using immuno- chemical methods.Results Compared with the NSSN and NPES groups,CCP in the PES group was alleviated, PWPT and PWL were dramatically increased(P＜0.01)and the expression of NR-1 was obviously decreased (P＜0.01).Conclusion Peripheral electrical stimulation may alleviate chronic central pain after spinal cord injury in rats.

Relationship of chronic central pain and substance P in spinal dorsal horn after spinal cord injury / 中国康复理论与实践

@#Objective To approach the neurobiochemical mechanism of chronic central pain (CCP) after spinal cord injury (SCI). Methods 28 SD rats were divided into four groups, the normal group (group A), the pseudosurgery group (group B), and groups with CCP (group C) and without CCP (group D) after L1 spinal cord section injured with WADE method. T13 and L2 segments of rats' spinal cord were took and concentration changes of substance P (SP) in the spinal dorsal horn between two sections were examined by immunofluorescence histochemistry staining combined with confocal laser scanning microscope. Results Concentration of SP in the group D was decreased significantly compared with groups C,A and B (P<0.05-0.01), that of the group C was less than that of group A and B (P<0.05). Conclusion The rat model established by WADE method is proper to study CCP after SCI. SP in dorsal horn of spinal cord may inhibit the CCP after SCI in some degrees.

Loss of the Spinal GABAergic System Is Involved in Chronic Central Pain Following a Spinal Cord Injury; Behavioral and Electrophysiological Evidences / 대한마취과학회지

BACKGROUND: Allodynia, hyperalgesia, and spontaneous pain are symptoms characterized by chronic central pain which was frequently observed following a spinal cord injury (SCI). However, the underlying mechanism has not been fully understood. This study was conducted to investigate whether the loss of the GABAergic system in the spinal dorsal horn was involved in the development of central pain following a spinal cord injury. METHODS: SCI was induced by a hemisection of the spinal cord at T13 in adult male Sprague-Dawley rats. Mechanical allodynia was tested by measuring paw withdrawal frequency in response to repeated applications of a von Frey hair to the plantar surface of the hind-paw. Single neuronal activity of the dorsal horn neurons (L4 L6) was recorded extracellularly using a carbon filament-filled glass microelectrode (2 4 MOhm). The drugs were intrathecally or topically administrated on the spinal surface for behavioral and electrophysiological experiments, respectively. RESULTS: After a left spinal hemisection at T13, behavioral signs of mechanical allodynia developed on both hind-paws and responsiveness of spinal dorsal horn neurons increased on both sides of the spinal dorsal horn. GABA receptor agonists including GABAA and GABAB receptor subtypes suppressed mechanical allodynia on both sides of hind-paws and decreased responsiveness of spinal dorsal horn neurons on both sides of spinal cord. CONCLUSIONS: These results indicate that a loss of the GABAergic system within the spinal cord plays a key role on the development of central pain following a spinal cord injury.

Microsurgical DREZotomy for treatment of intractable central pain in patient with spinal cord injury / 영남의대학술지

The central pain in patient with spinal cord injury is a common and disabling sequelae. The microsurgical DREZ(Dorsal Root Entry Zone)otomy is a surgical procedure effective in the treatment of intractable pain and spasticity in spinal cord injured patients. It consists of a microsurgical lesions performed in the ventrolateral region of the dorsal root entry zone at the selected levels. This report presents one case with incomplete paraplegia patient, who had chronic central neuropathic pain ineffective to many conservative treatments in bilateral T10 and right T11 segments and both lower extremities, is relieved from the pain after microsurgical DREZotomy. In conclusion, microsurgical DREZotomy is one method of effective treatments for spinal cord injured patients with intractable central neuropathic pain.