Elbert Joosten - Academia.edu (original) (raw)

Papers by Elbert Joosten

Research paper thumbnail of Grafting cultured macrophages or fibroblasts in a contusion model of adult rat spinal cord : a combined morphological and biochemical study of neuronal and non-neuronal actors in repair processes

Research paper thumbnail of Prevalence and Predictive Factors of Chronic Postsurgical Pain and Global Surgical Recovery 1 Year After Outpatient Knee Arthroscopy

Medicine, 2015

Outpatient knee arthroscopy is one of the most commonly performed surgical procedures. Previous r... more Outpatient knee arthroscopy is one of the most commonly performed surgical procedures. Previous research has demonstrated that chronic postsurgical pain (CPSP) after outpatient surgery is prevalent. Our objective was to determine the prevalence and predictive factors of CPSP and Global Surgical Recovery (GSR) 1 year after knee arthroscopy.A prospective longitudinal cohort study was performed. Patients were included during an 18-month period. Data were collected by using 3 questionnaires: at 1 week preoperatively, 4 days postoperatively, and 1 year postoperatively. A value of >3 on an 11-point numeric rating scale (NRS) was defined as moderate to severe pain. A score of ≤80% on the Global Surgical Recovery Index was defined as poor GSR. Stepwise logistic regression analysis was performed to determine which variables were predictors for CPSP and poor GSR.The prevalence of moderate to severe preoperative pain in patients undergoing knee arthroscopy (n = 104) was 71.2%, of acute postsurgical pain 37.5%, and of CPSP 32.7%. Risk factors for CPSP were the presence of preoperative pain and preoperative analgesic use, with odds ratios of 6.31 (1.25-31.74) and 4.36 (1.58-12.07), respectively. The prevalence of poor GSR 1 year after outpatient knee arthrosocpy was 50.0%. Poor GSR 4 days after the surgery was a risk factor with an odds ratio of 8.38 (0.92-76.58) and quality of life 4 days after surgery was a protective factor with and odds ratio of 0.10 (0.02-0.64).Both CPSP and poor GSR are common 1 year after knee arthroscopy. Patients at risk for CPSP can be identified during the preoperative phase. Prediction of poor GSR 1 year after surgery is mainly related to early postoperative recovery.

Research paper thumbnail of Repairing injured peripheral nerves: Bridging the gap

Progress in Neurobiology, 2010

Research paper thumbnail of Locomotor Dysfunction and Pain: The Scylla and Charybdis of Fiber Sprouting After Spinal Cord Injury

Molecular Neurobiology, 2008

Research paper thumbnail of Basic Fibroblast Growth Factor Promotes Neuronal Survival but Not Behavioral Recovery in the Transected and Schwann Cell Implanted Rat Thoracic Spinal Cord

Journal of Neurotrauma, 2004

Research paper thumbnail of Oxidant treatment causes a dose-dependent phenotype of apoptosis in cultured motoneurons

Journal of Neuroscience Research, 1998

Evidence is growing that reactive oxygen species (ROS), by-products of (normal) cellular aerobic ... more Evidence is growing that reactive oxygen species (ROS), by-products of (normal) cellular aerobic metabolism, are involved in the pathogenesis of neurodegenerative diseases. One of these diseases is amyotrophic lateral sclerosis (ALS), in which motoneurons die, leading to paralysis and death. It remains uncertain whether ROS are the cause of (apoptotic) motoneuron death in ALS. To further understand the role of ROS in motoneuron death, we investigated the effects of ROS on isolated spinal rat motoneurons in culture. ROS were generated with a combination of iron(III) and ascorbate, or with hydrogen peroxide. Both toxic treatments resulted in a dose-dependent motoneuron death. Iron(III)/ascorbate toxicity was completely prevented with the hydrogen peroxide detoxifying enzyme catalase and partially prevented with the antioxidant vitamin E. SOD1, the enzyme that removes superoxide, did not protect against iron(III)/ascorbate toxicity. ROS treatment caused apoptotic motoneuron death: low doses of iron(III)/ ascorbate or hydrogen peroxide resulted in complete apoptosis ending in nuclear fragmentation, while high doses of ROS resulted in incomplete apoptosis (nuclear condensation). Thus, depending on the dose of ROS, the motoneurons complete the apoptotic pathway (low dose) or are stopped somewhere during this route (high dose).

Research paper thumbnail of Effects of macrophage transplantation in the injured adult rat spinal cord: A combined immunocytochemical and biochemical study

Journal of Neuroscience Research, 1998

Early and robust invasion by macrophages may be one of the reasons why axonal regeneration is mor... more Early and robust invasion by macrophages may be one of the reasons why axonal regeneration is more effective in the PNS than in the CNS. Therefore, we have grafted autologous peritoneal macrophages labeled with fluorescent latex microspheres into spinal cord compression lesions. At various survival times, we have studied their effect on the expression of neuronal (neurofilaments [NF], calcitonin gene-related peptide [CGRP], 5-hydroxytryptamine [5-HT]) and nonneuronal markers (myelin-associated glycoprotein [MAG], glial fibrillary acidic protein [GFAP], laminin) by using semiquantitative Western blot and immunohistochemical techniques. After 1 month, we observed a significant decrease of the expression of MAG as well as an important invasion of the lesion site by neurites, chiefly peptidergic axons of presumed dorsal root origin, in macrophage-grafted animals compared with controls. In addition, angiogenesis and Schwann cell infiltration were more pronounced after macrophage grafts, providing an increase in laminin, a favorable substrate for axonal regrowth. By using reverse transcription-polymerase chain reaction (RT-PCR), mRNAs for tumor necrosis factor-alpha (TNF-alpha) were detected in the transplanted cells, whereas results were negative for nerve growth factor (NGF), neurotrophin-3 (NT-3), brain-derived neurotrophic factor (BDNF), or acidic fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF). Thus, macrophage grafts may represent an interesting strategy to promote axonal regeneration in the CNS. Our study suggests that they may exert their beneficial effects by degrading myelin products, which inhibit axonal regrowth, and by promoting a permissive extracellular matrix containing notably laminin. No evidence for a direct synthesis of neurotrophic factors by the transplanted macrophages was found in this study, but resident glial cells could secrete such factors as a result of stimulation by macrophage-released cytokines.

Research paper thumbnail of CatWalk gait analysis in assessment of functional recovery after sciatic nerve injury

Journal of Neuroscience Methods, 2008

Research paper thumbnail of 378 Effects of Early Vegf Treatment on Evoked Pain Behavior in a Rat Model of Central Neuropathic Pain

European Journal of Pain Supplements, 2010

Research paper thumbnail of An anterograde tracer study on the development of corticospinal projections from the medial prefrontal cortex in the rat

Developmental Brain Research, 1989

The aim of the present study is to investigate, both qualitatively and quantitatively, the develo... more The aim of the present study is to investigate, both qualitatively and quantitatively, the development of corticospinal (CS) projections from the medial prefrontal cortex of the rat. This study was carried out with the use of anterogradely transported wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) after iontophoretic injections in the medial prefrontal cortex. For comparison similar injections are made in the sensorimotor cortex. The CS axons of neurons situated in the medial prefrontal cortex have reached the first thoracic segment (T1) at postnatal day 3 (P3) and reach their most caudal extension in the spinal cord sixth thoracic segment (T6) at postnatal day 7 (P7) and then gradually disappear during the second postnatal week. Quantitative results revealed that after labelling of the medial prefrontal cortex no peaks in labelling density, neither at the cervical nor at the lumbar intumescence, were present. Furthermore, the CS axons of medial prefrontal neurons never showed any outgrowth into the spinal grey matter at any age studied. Concludingly, the extension and subsequent elimination of CS axons originating in the medial prefrontal cortex follow a similar time course as those from the occipital cortex (Dev. Brain Res., 36 (1987) 121-130).

Research paper thumbnail of Beneficial Effects of the Melanocortin ??-Melanocyte-stimulating Hormone on Clinical and Neurophysiological Recovery after Experimental Spinal Cord Injury

Research paper thumbnail of Copolymers from unsaturated macrolactones : toward the design of cross-linked biodegradable polyesters

Biomacromolecules, Feb 1, 2011

Research paper thumbnail of Limitations in transplantation of astroglia-biomatrix bridges to stimulate corticospinal axon regrowth across large spinal lesion gaps

Neuroscience Letters, Jun 12, 2006

Research paper thumbnail of Differential GABAergic disinhibition during the development of painful peripheral neuropathy

Neuroscience, 2011

An impaired spinal GABAergic inhibitory function is known to be pivotal in neuropathic pain (NPP)... more An impaired spinal GABAergic inhibitory function is known to be pivotal in neuropathic pain (NPP). At present, data concerning time-dependent alterations within the GABAergic system itself and post-synaptic GABAA receptor-mediated inhibitory transmission are highly controversial, likely related to the experimental NPP model used. Furthermore, it is unknown whether the severity of NPP is determined by the degree of these GABAergic disturbances. In the present study we therefore examined in one experimental animal model whether anatomical changes within the spinal GABAergic system and its GABAA receptor-mediated inhibitory function are gradually aggravated during the development of partial sciatic nerve injury (PSNL)-induced NPP and are related to the severity of PSNL-induced hypersensitivity. Three and 16 days after a unilateral PSNL (early and late NPP, respectively), GABA-immunoreactivity (GABA-IR) and the number of GABA-IR neuronal profiles were determined in Rexed laminae 1–3 of lumbar spinal cord cryosections. Additionally, the efficiency of dorsal horn GABAA receptor-induced inhibition was examined by cation chloride cotransporter 2 (KCC2) immunoblotting. NPP-induced hypersensitivity was only observed at the ipsilateral side, both at early and late time points. During early NPP, a decrease in ipsilateral dorsal horn GABA-IR was observed without alterations in the number of GABA-IR neuronal profiles or KCC2 protein levels. In contrast, bilateral increases in spinal GABA-IR accompanied by an unchanged number of GABA-IR interneurons were observed during late NPP. This was furthermore attended with decreased ipsilateral KCC2 levels. Moreover, the degree of hypersensitivity was not related to disturbances within the spinal GABAergic system at all time points examined. In conclusion, our anatomical data suggest that a dysfunctional GABA production is likely to be involved in early NPP whereas late NPP is characterized by a combined dysfunctional GABA release and decreased KCC2 levels, the latter suggesting an impaired GABAA receptor-mediated inhibition.▶GABA production is dysfunctional during early neuropathic pain. ▶GABAA receptor-mediated inhibition is normal during early neuropathic pain. ▶GABA release is dysfunctional during late neuropathic pain. ▶GABAA receptor-mediated inhibition is impaired during late neuropathic pain. ▶The degree of neuropathic pain is not related to alterations in the GABAergic system.

Research paper thumbnail of Strain and locomotor speed affect over-ground locomotion in intact rats

Physiology Behavior, May 12, 2007

A variety of animal models for neurological disease and injury exist and locomotor performance is... more A variety of animal models for neurological disease and injury exist and locomotor performance is an important outcome parameter in studies employing these models. The CatWalk, an automated quantitative gait analysis method is a method to study over-ground locomotor performance in large groups of animals. In the present study, we used the CatWalk which allowed us to investigate strain differences in over-ground locomotion in three commonly used strains of laboratory rat (i.e. Lewis, Wistar and Sprague-Dawley rats) based on objective data-analysis in a large number of animals. The present results revealed marked strain differences on the static paw parameters; base-of-support, and the relative paw position. Furthermore, strain differences were noted on the static parameter stride length and the dynamic parameters stance-, swing- and stepcycle duration, which are due logically to morphological differences between strains. The parameters related to coordination did not reveal any differences between the strains. Furthermore, the swing duration and the cruciate and alternate patterns i.e. regular step patterns Ca ("cruciate" pattern type a) and Ab ("alternate" pattern type b) were shown to be differentially affected by the locomotor speed. We conclude that differences in gait traits exist between the three laboratory rat strains investigated and several of the examined gait parameters showed strain dependent interdependency with locomotor speed.

Research paper thumbnail of 149 Workshop Summary: Pulsed Radiofrequency Adjacent to the DRG for Radicular Pain: Does It Work and How?

European Journal of Pain Supplements, 2010

Research paper thumbnail of Pathofysiologie van de traumatische ruggenmergslaesie

Research paper thumbnail of Sustained Treatment Effect of Spinal Cord Stimulation in Painful Diabetic Peripheral Neuropathy: 24-Month Follow-up of a Prospective Two-Center Randomized Controlled Trial

Research paper thumbnail of Spinal cord stimulation and pain relief in painful diabetic peripheral neuropathy: a prospective two-center randomized controlled trial

Diabetes care, 2014

Painful diabetic peripheral neuropathy (PDPN) is a common complication of diabetes mellitus. Unfo... more Painful diabetic peripheral neuropathy (PDPN) is a common complication of diabetes mellitus. Unfortunately, pharmacological treatment is often partially effective or accompanied by unacceptable side effects, and new treatments are urgently needed. Small observational studies suggested that spinal cord stimulation (SCS) may have positive effects. We performed a multicenter randomized clinical trial in 36 PDPN patients with severe lower limb pain not responding to conventional therapy. Twenty-two patients were randomly assigned to SCS in combination with the best medical treatment (BMT) (SCS group) and 14 to BMT only (BMT group). The SCS system was implanted only if trial stimulation was successful. Treatment success was defined as ≥50% pain relief during daytime or nighttime or "(very) much improved" for pain and sleep on the patient global impression of change (PGIC) scale at 6 months. Trial stimulation was successful in 77% of the SCS patients. Treatment success was obser...

Research paper thumbnail of Pulsed radiofrequency: a review of the basic science as applied to the pathophysiology of radicular pain: a call for clinical translation

Regional anesthesia and pain medicine

Radicular pain is an important health care problem, with only limited evidence-based treatments a... more Radicular pain is an important health care problem, with only limited evidence-based treatments available. Treatment selection should ideally target documented pathophysiological pathways. In herniated discs, a sequence in the inflammatory cascade can be observed that initiates and maintains increased nociceptive signal input. Inflammatory mediators including tumor necrosis factor α are released from the nucleus pulposus and the degenerating peripheral nerve, which, in turn, induces production of neurotrophins like nerve growth factor and brain-derived neurotrophic factor. Neurotrophins interfere not only with the generation of ectopic firing of nociceptive neurons in the dorsal root ganglion but also with the excitability and sensitization of neuronal transmission in the dorsal spinal horn. Radicular pain is further characterized by the electrophysiological spreading of the afferent nociceptive input over different spinal nerve roots. Both the complex pathophysiological pathways in...

Research paper thumbnail of Grafting cultured macrophages or fibroblasts in a contusion model of adult rat spinal cord : a combined morphological and biochemical study of neuronal and non-neuronal actors in repair processes

Research paper thumbnail of Prevalence and Predictive Factors of Chronic Postsurgical Pain and Global Surgical Recovery 1 Year After Outpatient Knee Arthroscopy

Medicine, 2015

Outpatient knee arthroscopy is one of the most commonly performed surgical procedures. Previous r... more Outpatient knee arthroscopy is one of the most commonly performed surgical procedures. Previous research has demonstrated that chronic postsurgical pain (CPSP) after outpatient surgery is prevalent. Our objective was to determine the prevalence and predictive factors of CPSP and Global Surgical Recovery (GSR) 1 year after knee arthroscopy.A prospective longitudinal cohort study was performed. Patients were included during an 18-month period. Data were collected by using 3 questionnaires: at 1 week preoperatively, 4 days postoperatively, and 1 year postoperatively. A value of >3 on an 11-point numeric rating scale (NRS) was defined as moderate to severe pain. A score of ≤80% on the Global Surgical Recovery Index was defined as poor GSR. Stepwise logistic regression analysis was performed to determine which variables were predictors for CPSP and poor GSR.The prevalence of moderate to severe preoperative pain in patients undergoing knee arthroscopy (n = 104) was 71.2%, of acute postsurgical pain 37.5%, and of CPSP 32.7%. Risk factors for CPSP were the presence of preoperative pain and preoperative analgesic use, with odds ratios of 6.31 (1.25-31.74) and 4.36 (1.58-12.07), respectively. The prevalence of poor GSR 1 year after outpatient knee arthrosocpy was 50.0%. Poor GSR 4 days after the surgery was a risk factor with an odds ratio of 8.38 (0.92-76.58) and quality of life 4 days after surgery was a protective factor with and odds ratio of 0.10 (0.02-0.64).Both CPSP and poor GSR are common 1 year after knee arthroscopy. Patients at risk for CPSP can be identified during the preoperative phase. Prediction of poor GSR 1 year after surgery is mainly related to early postoperative recovery.

Research paper thumbnail of Repairing injured peripheral nerves: Bridging the gap

Progress in Neurobiology, 2010

Research paper thumbnail of Locomotor Dysfunction and Pain: The Scylla and Charybdis of Fiber Sprouting After Spinal Cord Injury

Molecular Neurobiology, 2008

Research paper thumbnail of Basic Fibroblast Growth Factor Promotes Neuronal Survival but Not Behavioral Recovery in the Transected and Schwann Cell Implanted Rat Thoracic Spinal Cord

Journal of Neurotrauma, 2004

Research paper thumbnail of Oxidant treatment causes a dose-dependent phenotype of apoptosis in cultured motoneurons

Journal of Neuroscience Research, 1998

Evidence is growing that reactive oxygen species (ROS), by-products of (normal) cellular aerobic ... more Evidence is growing that reactive oxygen species (ROS), by-products of (normal) cellular aerobic metabolism, are involved in the pathogenesis of neurodegenerative diseases. One of these diseases is amyotrophic lateral sclerosis (ALS), in which motoneurons die, leading to paralysis and death. It remains uncertain whether ROS are the cause of (apoptotic) motoneuron death in ALS. To further understand the role of ROS in motoneuron death, we investigated the effects of ROS on isolated spinal rat motoneurons in culture. ROS were generated with a combination of iron(III) and ascorbate, or with hydrogen peroxide. Both toxic treatments resulted in a dose-dependent motoneuron death. Iron(III)/ascorbate toxicity was completely prevented with the hydrogen peroxide detoxifying enzyme catalase and partially prevented with the antioxidant vitamin E. SOD1, the enzyme that removes superoxide, did not protect against iron(III)/ascorbate toxicity. ROS treatment caused apoptotic motoneuron death: low doses of iron(III)/ ascorbate or hydrogen peroxide resulted in complete apoptosis ending in nuclear fragmentation, while high doses of ROS resulted in incomplete apoptosis (nuclear condensation). Thus, depending on the dose of ROS, the motoneurons complete the apoptotic pathway (low dose) or are stopped somewhere during this route (high dose).

Research paper thumbnail of Effects of macrophage transplantation in the injured adult rat spinal cord: A combined immunocytochemical and biochemical study

Journal of Neuroscience Research, 1998

Early and robust invasion by macrophages may be one of the reasons why axonal regeneration is mor... more Early and robust invasion by macrophages may be one of the reasons why axonal regeneration is more effective in the PNS than in the CNS. Therefore, we have grafted autologous peritoneal macrophages labeled with fluorescent latex microspheres into spinal cord compression lesions. At various survival times, we have studied their effect on the expression of neuronal (neurofilaments [NF], calcitonin gene-related peptide [CGRP], 5-hydroxytryptamine [5-HT]) and nonneuronal markers (myelin-associated glycoprotein [MAG], glial fibrillary acidic protein [GFAP], laminin) by using semiquantitative Western blot and immunohistochemical techniques. After 1 month, we observed a significant decrease of the expression of MAG as well as an important invasion of the lesion site by neurites, chiefly peptidergic axons of presumed dorsal root origin, in macrophage-grafted animals compared with controls. In addition, angiogenesis and Schwann cell infiltration were more pronounced after macrophage grafts, providing an increase in laminin, a favorable substrate for axonal regrowth. By using reverse transcription-polymerase chain reaction (RT-PCR), mRNAs for tumor necrosis factor-alpha (TNF-alpha) were detected in the transplanted cells, whereas results were negative for nerve growth factor (NGF), neurotrophin-3 (NT-3), brain-derived neurotrophic factor (BDNF), or acidic fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF). Thus, macrophage grafts may represent an interesting strategy to promote axonal regeneration in the CNS. Our study suggests that they may exert their beneficial effects by degrading myelin products, which inhibit axonal regrowth, and by promoting a permissive extracellular matrix containing notably laminin. No evidence for a direct synthesis of neurotrophic factors by the transplanted macrophages was found in this study, but resident glial cells could secrete such factors as a result of stimulation by macrophage-released cytokines.

Research paper thumbnail of CatWalk gait analysis in assessment of functional recovery after sciatic nerve injury

Journal of Neuroscience Methods, 2008

Research paper thumbnail of 378 Effects of Early Vegf Treatment on Evoked Pain Behavior in a Rat Model of Central Neuropathic Pain

European Journal of Pain Supplements, 2010

Research paper thumbnail of An anterograde tracer study on the development of corticospinal projections from the medial prefrontal cortex in the rat

Developmental Brain Research, 1989

The aim of the present study is to investigate, both qualitatively and quantitatively, the develo... more The aim of the present study is to investigate, both qualitatively and quantitatively, the development of corticospinal (CS) projections from the medial prefrontal cortex of the rat. This study was carried out with the use of anterogradely transported wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) after iontophoretic injections in the medial prefrontal cortex. For comparison similar injections are made in the sensorimotor cortex. The CS axons of neurons situated in the medial prefrontal cortex have reached the first thoracic segment (T1) at postnatal day 3 (P3) and reach their most caudal extension in the spinal cord sixth thoracic segment (T6) at postnatal day 7 (P7) and then gradually disappear during the second postnatal week. Quantitative results revealed that after labelling of the medial prefrontal cortex no peaks in labelling density, neither at the cervical nor at the lumbar intumescence, were present. Furthermore, the CS axons of medial prefrontal neurons never showed any outgrowth into the spinal grey matter at any age studied. Concludingly, the extension and subsequent elimination of CS axons originating in the medial prefrontal cortex follow a similar time course as those from the occipital cortex (Dev. Brain Res., 36 (1987) 121-130).

Research paper thumbnail of Beneficial Effects of the Melanocortin ??-Melanocyte-stimulating Hormone on Clinical and Neurophysiological Recovery after Experimental Spinal Cord Injury

Research paper thumbnail of Copolymers from unsaturated macrolactones : toward the design of cross-linked biodegradable polyesters

Biomacromolecules, Feb 1, 2011

Research paper thumbnail of Limitations in transplantation of astroglia-biomatrix bridges to stimulate corticospinal axon regrowth across large spinal lesion gaps

Neuroscience Letters, Jun 12, 2006

Research paper thumbnail of Differential GABAergic disinhibition during the development of painful peripheral neuropathy

Neuroscience, 2011

An impaired spinal GABAergic inhibitory function is known to be pivotal in neuropathic pain (NPP)... more An impaired spinal GABAergic inhibitory function is known to be pivotal in neuropathic pain (NPP). At present, data concerning time-dependent alterations within the GABAergic system itself and post-synaptic GABAA receptor-mediated inhibitory transmission are highly controversial, likely related to the experimental NPP model used. Furthermore, it is unknown whether the severity of NPP is determined by the degree of these GABAergic disturbances. In the present study we therefore examined in one experimental animal model whether anatomical changes within the spinal GABAergic system and its GABAA receptor-mediated inhibitory function are gradually aggravated during the development of partial sciatic nerve injury (PSNL)-induced NPP and are related to the severity of PSNL-induced hypersensitivity. Three and 16 days after a unilateral PSNL (early and late NPP, respectively), GABA-immunoreactivity (GABA-IR) and the number of GABA-IR neuronal profiles were determined in Rexed laminae 1–3 of lumbar spinal cord cryosections. Additionally, the efficiency of dorsal horn GABAA receptor-induced inhibition was examined by cation chloride cotransporter 2 (KCC2) immunoblotting. NPP-induced hypersensitivity was only observed at the ipsilateral side, both at early and late time points. During early NPP, a decrease in ipsilateral dorsal horn GABA-IR was observed without alterations in the number of GABA-IR neuronal profiles or KCC2 protein levels. In contrast, bilateral increases in spinal GABA-IR accompanied by an unchanged number of GABA-IR interneurons were observed during late NPP. This was furthermore attended with decreased ipsilateral KCC2 levels. Moreover, the degree of hypersensitivity was not related to disturbances within the spinal GABAergic system at all time points examined. In conclusion, our anatomical data suggest that a dysfunctional GABA production is likely to be involved in early NPP whereas late NPP is characterized by a combined dysfunctional GABA release and decreased KCC2 levels, the latter suggesting an impaired GABAA receptor-mediated inhibition.▶GABA production is dysfunctional during early neuropathic pain. ▶GABAA receptor-mediated inhibition is normal during early neuropathic pain. ▶GABA release is dysfunctional during late neuropathic pain. ▶GABAA receptor-mediated inhibition is impaired during late neuropathic pain. ▶The degree of neuropathic pain is not related to alterations in the GABAergic system.

Research paper thumbnail of Strain and locomotor speed affect over-ground locomotion in intact rats

Physiology Behavior, May 12, 2007

A variety of animal models for neurological disease and injury exist and locomotor performance is... more A variety of animal models for neurological disease and injury exist and locomotor performance is an important outcome parameter in studies employing these models. The CatWalk, an automated quantitative gait analysis method is a method to study over-ground locomotor performance in large groups of animals. In the present study, we used the CatWalk which allowed us to investigate strain differences in over-ground locomotion in three commonly used strains of laboratory rat (i.e. Lewis, Wistar and Sprague-Dawley rats) based on objective data-analysis in a large number of animals. The present results revealed marked strain differences on the static paw parameters; base-of-support, and the relative paw position. Furthermore, strain differences were noted on the static parameter stride length and the dynamic parameters stance-, swing- and stepcycle duration, which are due logically to morphological differences between strains. The parameters related to coordination did not reveal any differences between the strains. Furthermore, the swing duration and the cruciate and alternate patterns i.e. regular step patterns Ca ("cruciate" pattern type a) and Ab ("alternate" pattern type b) were shown to be differentially affected by the locomotor speed. We conclude that differences in gait traits exist between the three laboratory rat strains investigated and several of the examined gait parameters showed strain dependent interdependency with locomotor speed.

Research paper thumbnail of 149 Workshop Summary: Pulsed Radiofrequency Adjacent to the DRG for Radicular Pain: Does It Work and How?

European Journal of Pain Supplements, 2010

Research paper thumbnail of Pathofysiologie van de traumatische ruggenmergslaesie

Research paper thumbnail of Sustained Treatment Effect of Spinal Cord Stimulation in Painful Diabetic Peripheral Neuropathy: 24-Month Follow-up of a Prospective Two-Center Randomized Controlled Trial

Research paper thumbnail of Spinal cord stimulation and pain relief in painful diabetic peripheral neuropathy: a prospective two-center randomized controlled trial

Diabetes care, 2014

Painful diabetic peripheral neuropathy (PDPN) is a common complication of diabetes mellitus. Unfo... more Painful diabetic peripheral neuropathy (PDPN) is a common complication of diabetes mellitus. Unfortunately, pharmacological treatment is often partially effective or accompanied by unacceptable side effects, and new treatments are urgently needed. Small observational studies suggested that spinal cord stimulation (SCS) may have positive effects. We performed a multicenter randomized clinical trial in 36 PDPN patients with severe lower limb pain not responding to conventional therapy. Twenty-two patients were randomly assigned to SCS in combination with the best medical treatment (BMT) (SCS group) and 14 to BMT only (BMT group). The SCS system was implanted only if trial stimulation was successful. Treatment success was defined as ≥50% pain relief during daytime or nighttime or "(very) much improved" for pain and sleep on the patient global impression of change (PGIC) scale at 6 months. Trial stimulation was successful in 77% of the SCS patients. Treatment success was obser...

Research paper thumbnail of Pulsed radiofrequency: a review of the basic science as applied to the pathophysiology of radicular pain: a call for clinical translation

Regional anesthesia and pain medicine

Radicular pain is an important health care problem, with only limited evidence-based treatments a... more Radicular pain is an important health care problem, with only limited evidence-based treatments available. Treatment selection should ideally target documented pathophysiological pathways. In herniated discs, a sequence in the inflammatory cascade can be observed that initiates and maintains increased nociceptive signal input. Inflammatory mediators including tumor necrosis factor α are released from the nucleus pulposus and the degenerating peripheral nerve, which, in turn, induces production of neurotrophins like nerve growth factor and brain-derived neurotrophic factor. Neurotrophins interfere not only with the generation of ectopic firing of nociceptive neurons in the dorsal root ganglion but also with the excitability and sensitization of neuronal transmission in the dorsal spinal horn. Radicular pain is further characterized by the electrophysiological spreading of the afferent nociceptive input over different spinal nerve roots. Both the complex pathophysiological pathways in...