[Radiation-Induced Radiculopathy with Paresis of the Neck and Autochthonous Back Muscles with Additional Myopathy]. / Parese der Nacken- und autochthonen Rückenmuskulatur durch strahleninduzierte zervikale Radikulopathie mit Begleitmyopathie.

Radiation-induced tissue damage is caused by ionizing radiation mainly affecting the skin, vascular, neuronal or muscle tissue. Early damages occur within weeks and months while late damages may occur months or even decades after radiation.Radiation-induced paresis of the spine or the trunk muscles with camptocormia or dropped-head syndrome are rare but have already been described as long-term sequelae after treatment of Hodgkin's lymphoma. The differential diagnosis includes limb-girdle muscular dystrophy, fascioscapulohumeral muscular dystrophy (FSHD) or lysosomal storage diseases (e. g. Acid Maltase Deficiency). We present the case of a patient with long lasting diagnostics over many months due to different inconclusive results.

Estimulación eléctrica del nervio pudendo: una opción para el tratamiento de la hiperactividad neurogénica del detrusor / Electrical stimulation of pudendal nerve: an option for the treatment of the neurogenic detrusor overactivity

Objetivo: Introducir la estimulación eléctrica del nervio pudendo como un procedimiento capaz de tratar la hiperactividad neurogénica del detrusor en un contexto hospitalario y domiciliario. Pacientes y Métodos: Para el primer estudio (Programa de autoestimulación en ambiente domiciliario) se reclutaron 11 pacientes. La duración del protocolo fue de una semana e incluía dos urodinámicas, una al principio y otra al final del proceso. En el segundo protocolo se incluyeron doce pacientes (Estimulación eléctrica mediante EMG del nervio dorsal del pene/clítoris) donde se realizaron dos urodinámicas sucesivas, la primera sin y la segunda con estimulación. En los dos estudios se valoró la capacidad cistométrica. En el primer estudio, a los pacientes se les pedía que rellenaran un diario miccional. Resultados: Tanto para el primero como para el segundo estudio, los pacientes mostraron un aumento significativo de las capacidades cistométricas en las urodinámicas posteriores comparadas con las iniciales (p=0,045) (p=0,002). El volumen medio de micción diaria se incrementó conforme avanza la estimulación (p=0,035). Conclusión: La viabilidad y los resultados globalmente positivos de los estudios prueban que la estimulación eléctrica del nervio pudendo puede ser una opción para el tratamiento de la hiperactividad neurogénica del detrusor (AU)

Objetive: To introduce the electrical stimulation of the pudendal nerve as an effective procedure to treat neurogenic detrusor overactivity in both hospital and home settings. Patients and Methods: For this purpose, two studies were designed and performed. Eleven patients were recruited in the first study (Autostimulation program in home setting). The duration of the protocol was one week and it included two urodynamics, first at baseline and the second at the end of the study. In the second study (EMG electrical stimulation of the dorsal penile/clitoral nerve), twelve patients were included. Patients underwent two successive urodynamics, first without and second with electrical stimulation. In both studies, cystometric capacities were used to assess objectively the outcome of the treatment. In the first study, patients were asked to fill a bladder diary. Results: In both first and second studies, patients show an statistically significant improvement of the cystometric capacities in posterior urodynamics compared to baseline urodynamics (p=0.045 and p=0.002, respectively). Mean micturition volume per day increased significantly as long as stimulation days advanced (p=0.035). Conclusion: The feasibility and the globally positive outcomes of t both studies show that the stimulation of the pudendal nerve can be an option to the treatment of the neurogenic detrusor overactivity (AU)

Repeat gamma knife radiosurgery for trigeminal neuralgia.

PURPOSE: Repeat gamma knife stereotactic radiosurgery (GKRS) for recurrent or persistent trigeminal neuralgia induces an additional response but at the expense of an increased incidence of facial numbness. The present series summarized the results of a repeat treatment series at Wake Forest University Baptist Medical Center, including a multivariate analysis of the data to identify the prognostic factors for treatment success and toxicity. METHODS AND MATERIALS: Between January 1999 and December 2007, 37 patients underwent a second GKRS application because of treatment failure after a first GKRS treatment. The mean initial dose in the series was 87.3 Gy (range, 80-90). The mean retreatment dose was 84.4 Gy (range, 60-90). The dosimetric variables recorded included the dorsal root entry zone dose, pons surface dose, and dose to the distal nerve. RESULTS: Of the 37 patients, 81% achieved a >50% pain relief response to repeat GKRS, and 57% experienced some form of trigeminal dysfunction after repeat GKRS. Two patients (5%) experienced clinically significant toxicity: one with bothersome numbness and one with corneal dryness requiring tarsorraphy. A dorsal root entry zone dose at repeat treatment of >26.6 Gy predicted for treatment success (61% vs. 32%, p = .0716). A cumulative dorsal root entry zone dose of >84.3 Gy (72% vs. 44%, p = .091) and a cumulative pons surface dose of >108.5 Gy (78% vs. 44%, p = .018) predicted for post-GKRS numbness. The presence of any post-GKRS numbness predicted for a >50% decrease in pain intensity (100% vs. 60%, p = .0015). CONCLUSION: Repeat GKRS is a viable treatment option for recurrent trigeminal neuralgia, although the patient assumes a greater risk of nerve dysfunction to achieve maximal pain relief.

Application of pulsed radio frequency to the dorsal horn and dorsal roots.

In the world of neuromodulation for pain management, the new multifunctional electrode presented in this article, together with the associated procedure described, considerably extends the range of therapeutic options in the hands of pain physicians. Besides the definite therapeutic effect, the lower rate of complications and side effects, further factors also make this new procedure and device appear an attractive diagnostic and therapeutic modality.

Postradiation lumbosacral radiculopathy with spinal root cavernomas mimicking carcinomatous meningitis.

Lumbosacral radiculopathy is a rare complication of radiotherapy and may be challenging to differentiate from diagnosis of a tumor recurrence. We reviewed the records of three patients with a past history of cancer and radiotherapy who were referred for suspicion of carcinomatous meningitis on lumbar MRI, but whose final diagnosis was radiation-induced lumbosacral radiculopathy. The three patients developed a progressive lumbosacral radiculopathy at 20, 13, and 47 years after lumbar radiotherapy delivered for renal cancer, Hodgkin's disease, and a seminoma, respectively. MRI showed a diffuse, nodular enhancement of the cauda equina nerve roots on T1 sequences, suggestive of leptomeningeal metastasis. A slowly progressive clinical course over several years and negative cerebrospinal fluid cytologic analysis ruled out the diagnosis of carcinomatous meningitis. Because of the radiologic findings, a biopsy was performed in two patients. In the first, a biopsy limited to the arachnoid excluded a malignant infiltration. In the second, a biopsy of the enhancing lesions demonstrated spinal root cavernomas. These observations, together with three recent case reports in the literature, delineate a syndrome of "radiationinduced lumbosacral radiculopathy with multiple spinal root cavernomas" that mimics carcinomatous meningitis on MRI. Its diagnosis is important in order to avoid inappropriate treatment and useless or dangerous spinal root biopsies.

omega-Conotoxin inhibition of excitatory synaptic transmission evoked by dorsal root stimulation in rat superficial dorsal horn.

A number of omega-conotoxins are potent and selective antagonists of N-type voltage-gated calcium channels (VGCCs) and are potentially effective as analgesic agents. omega-Conotoxins CVID and CVIB, venom peptides from Conus catus, inhibit N-type and N/P/Q-type VGCCs, respectively, in rat dorsal root ganglion sensory neurons. In the present study, we tested the effects of five different omega-conotoxins, CVID, CVIB, MVIIA, MVIIC and GVIA, on excitatory synaptic transmission between primary afferents and dorsal horn superficial lamina neurons of rat spinal cord. The N-type VGCC antagonists CVID (200nM) and MVIIA (500nM) completely and irreversibly inhibited excitatory postsynaptic currents (EPSCs) in the dorsal horn superficial lamina. The N- and P/Q-type VGCC antagonist CVIB (200nM) reversibly reduced evoked EPSC amplitude an average of 34+/-8%, whereas MVIIC (200nM) had no effect on excitatory synaptic transmission. In neurons receiving polysynaptic input, CVIB reduced both the EPSC amplitude and the "success rate" calculated as the relative number of primary afferent stimulations that resulted in postsynaptic responses. These results indicate that (i) the analgesic action of omega-conotoxins that antagonise N-type VGCCs may be attributed to inhibition of neurotransmission between primary afferents and superficial dorsal horn neurons, (ii) nociceptive synaptic transmission between primary afferents and superficial lamina neurons is mediated predominantly by N-type VGCCs, and (iii) in contrast to the irreversible inhibition by CVID, MVIIA and GVIA, the inhibition of excitatory monosynaptic transmission by CVIB is reversible.

Somatostatin inhibits activation of dorsal cutaneous primary afferents induced by antidromic stimulation of primary afferents from an adjacent thoracic segment in the rat.

To investigate the effect of somatostatin on the cross-excitation between adjacent primary afferent terminals in the rats, we recorded single unit activity from distal cut ends of dorsal cutaneous branches of the T10 and T12 spinal nerves in response to antidromic stimulation of the distal cut end of the T11 dorsal root in the presence and absence of somatostatin and its receptor antagonist applied to the receptive field of the recorded nerve. Afferent fibers were classified based upon their conduction velocity. Mean mechanical thresholds decreased and spontaneous discharge rates increased significantly in C and Adelta but not Abeta fibers of the T10 and T12 spinal nerves in both male and female rats following antidromic electrical stimulation (ADES) of the dorsal root from adjacent spinal segment (DRASS) indicating cross-excitation of thin fiber afferents. The cross-excitation was not significantly different between male and female rats. Microinjection of somatostatin into the receptive field of recorded units inhibited the cross-excitation. This inhibitory effect, in turn, was reversed by the somatostation receptor antagonist cyclo-somatostatin (c-SOM). Application of c-SOM alone followed by ADES of DRASS significantly decreased the mechanical thresholds and increased the discharge rates of C and Adelta fibers, indicating that endogenous release of somatostatin plays a tonic inhibitory role on the cross-excitation between peripheral nerves. These results suggest that somatostatin could inhibit the cross-excitation involved in peripheral hyperalgesia and have a peripheral analgesic effect.

Peripheral repetitive magnetic stimulation induces intracortical inhibition in healthy subjects.

OBJECTIVE: Repetitive magnetic stimulation (rMS) is mainly used in transcranial applications. Only a few works have described its potential peripheral use. The aim of this investigation was to determine if conditioning peripheral (paravertebral) rMS of the cervical nerve roots in a group of healthy subjects induces changes in motor cortical excitability. METHODS: This was measured by means of motor evoked potentials (MEP), motor recruitment curves (RC), intracortical inhibition (ICI) and facilitation, as well as the cortical silent period (CSP) before and after repetitive stimulation. rMS was carried out by applying ten series of stimulation at 120% of resting motor threshold, each lasting 10 seconds with a frequency of 20 Hz. The nerve roots (C7/C8) of the right hand innervating the target muscles (the first dorsal interosseous) were systematically stimulated. RESULTS: This conditioning rMS caused a significantly longer CSP (p=0.001), increased MEP amplitudes (with a tendency to significance of p=0.06) and raised ICI (p<0.05). These changes were absent on the contralateral side, as well as in the course of RC. In conclusion, previously published results that described a prolonged CSP and increased MEP amplitudes led us to speculate that conditioning peripheral rMS is, like electrical stimulation, capable of influencing motor cortical excitability. SIGNIFICANCE: rMS might therefore be used in rehabilitative strategies for spasticity, pain or central paresis.

Dorsal rhizotomy combined with anterior sacral root stimulation for neurogenic bladder.

A spinal cord lesion (traumatic or not) above the sacral micturition center may induce hyperreflexia of the detrusor, spasticity of the sphincter and vesico-sphincter dyssynergia. Eventually, alterations in the upper urinary tract can be associated with increased mortality in this patient population. Sacral rhizotomies combined with implantation of an anterior sacral root stimulator appear to be an effective method not only for the treatment of voiding dysfunction but also for defecation and sexual disorders. The clinical and electrophysiological checks and the surgical technique are described. In most series, the results show a constant improvement in the patient's functional status. Ninety percent of patients gain satisfactory continence and no longer require an incontinence appliance. Bladder capacity and compliance increase dramatically. As a consequence, urinary infection rate decreases. The majority of patients remain dry, and more than 80% have a complete voiding or a post-void residue of less than 50ml and do not require any catheterization. Anterior sacral root stimulation combined with sacral posterior rhizotomy is a valuable method to restore bladder function in spinal cord-injured patients suffering from hyperactive bladder.

Late appearance of dropped head syndrome after radiotherapy for Hodgkin's disease.

We present three cases of dropped head syndrome that occurred as a complication of mantle field (i.e., lymph nodes of the neck, axillae, and mediastinum) or whole-body radiation therapy for Hodgkin's disease. These cases are characterized by a late onset (2-27 years after radiation treatment), fibrosis, and contraction of the anterior cervical muscles, and atrophy of the posterior neck and shoulder girdle. This report adds to the increasing literature about the late neurological complications of radiation therapy and describes a previously unrecognized cause of dropped head syndrome.

Pulsed radiofrequency of lumbar nerve roots for treatment of chronic inguinal herniorraphy pain.

BACKGROUND: Inguinal hernia repairs are commonly performed and although not seen in a majority of patients, chronic inguinal pain can be a debilitating state resulting after inguinal hernia repairs. Treatment options exist, including pharmacological and surgical management, but with associated risks and side effects. METHODS: In this case series report, five patients with chronic inguinal pain were selected. After initial positive response to T12, L1 and L2 nerve root blocks, pulse radiofrequency (PRF) was performed. RESULTS: All patients reported 75% to 100% pain relief lasting from six to nine months. DISCUSSION: Several hypotheses have been proposed, including selective delta and c-nerve fiber destruction, upregulation of intermediate early gene expression (IEG) and increase in c-fos protein that modulated pain transmission. CONCLUSION: The mechanism of action of pulsed radiofrequency remains unclear. This case study demonstrates the effectiveness of minimally invasive neurodestruction of T12, L1 and L2 nerve roots utilizing Pulse Radiofrequency fields.

Cervical nerve root stimulation. Part I: technical aspects and normal data.

OBJECTIVE: Cervical nerve root stimulation (CRS) is a technique of assessing the proximal segments of motor axons destined to upper extremity muscles. Few studies report normal values. The objective was to determine CMAP onset-latencies and CMAP amplitude, area, and duration changes in healthy controls for the abductor pollicis brevis (APB), abductor digiti minimi (ADM), biceps, and riceps muscles. In addition, to determine the tolerability of CRS, as measured by the visual analog scale (VAS). METHODS: We studied 21 healthy volunteers prospectively with CRS using four target muscles (APB, ADM, biceps, and triceps) bilaterally. Collision studies were used in all APB recordings. VAS was obtained in all subjects. RESULTS: Mean CMAP onset-latencies were: APB 14 +/- 1.5 ms; ADM 14.2 +/- 1.5 ms; biceps 5.4 +/- 0.6 ms; triceps 5.4 +/- 1.0 ms. Onset-latency significantly correlated with height for all nerves. The mean change in CMAP amplitude and area (%) between most distal stimulation and CRS was: APB reduction of 15.1 +/- 11.6 and 4.9 +/- 3.6%; ADM reduction of 21.1 +/- 10.7 and 17.2 +/- 8.8; biceps reduction of 10 +/- 11.5 and reduction of 8.7 +/- 6.8; triceps increase of 3.3 +/- 5.2 and 11.0 +/- 9.9% respectively. Mean CMAP duration change between most distal stimulation and CRS was: APB, increase of 20.4 +/- 7.4%; ADM, increase of 14.4 +/- 8.5%; biceps, increase of 13.9 +/- 10.8%; triceps, increase of 7.7 +/- 6.7%. The mean VAS score was 3.8 +/- 1.2, and all subjects completed the study. CONCLUSIONS: The present study establishes normative data and indicates that CRS is a well-tolerated technique. SIGNIFICANCE: The normal values may be used as reference data for the needle CRS technique in the assessment of proximal conduction abnormalities.

Cervical nerve root stimulation. Part II: findings in primary demyelinating neuropathies and motor neuron disease.

OBJECTIVE: Cervical nerve root stimulation (CRS) allows the assessment of conduction in the proximal segments of motor fibers destined to the upper extremities, which are not evaluated by routine nerve conduction studies (NCS). Since many primary demyelinating polyneuropathies (PDP) are multifocal lesions may be confined to the proximal nerve segments. CRS may therefore increase the yield of neurophysiologic studies in diagnosing PDP. METHODS: We reviewed clinical and neurophysiologic data from 38 PDP patients and compared them to 35 patients with motor neuron disease (MND), and 21 healthy controls (HC). RESULTS: Mean onset-latency was significantly prolonged in PDP patients. The optimal onset-latency cutoff necessary to distinguish PDP from MND and controls was 17.5 ms for the abductor pollicis brevis (APB) and abductor digiti minimi (ADM), and 7 ms for Biceps and Triceps. Mean reduction in proximal to distal CMAP amplitude to APB and ADM was significantly greater in PDP patients, with an optimal cutoff in proximal to distal CMAP amplitude reduction necessary to distinguish PDP from MND and HC being 45%. CONCLUSIONS: CRS is effective in distinguishing PDP from MND and HC based on prolonged onset latency and conduction block criteria. SIGNIFICANCE: CRS may increase the diagnostic yield in cases where demyelinating lesions are confined to the proximal peripheral neuraxis.

A new approach to estimation of the number of central synapse(s) included in the H-reflex.

BACKGROUND: Among the main clinical applications of the H-reflex are the evaluation of the S1 nerve root conductivity such as radiculopathy and measurement of the excitability of the spinal motoneurons in neurological conditions. An attempt has been made to reduce the pathway over which H-reflex can be obtained in a hope to localize a lesion to the S1 nerve root, so the S1 central loop has been suggested. The main goal of this study is the estimation of the H-reflex number of synapse(s) for better understanding of the physiology of this practical reflex. METHODS: Forty healthy adult volunteers (22 males, 18 females) with the mean age of (37.7 +/- 10.2) years participated in this study. They were positioned comfortably in the prone position, with their feet off the edge of the plinth. Recording electrodes were positioned at the mid point of a line connecting the mid popliteal crease to the proximal flare of the medial malleolus. Stimulation was applied at the tibial nerve in the popliteal fossa and H, F and M waves were recorded. Without any change in the location of the recording electrodes, a monopolar needle was inserted as cathode at a point 1 cm medial to the posterior superior iliac spine, perpendicular to the frontal plane. The anode electrode was placed over the anterior superior iliac spine, and then M and H waves of the central loop were recorded. After processing the data, sacral cord conduction delay was determined by this formula: sacral cord conduction delay = central loop of H-reflex - (delays of the proximal motor and sensory fibers in the central loop). RESULTS: The central loop of H-reflex was (6.77 +/- 0.28) msec and the sacral cord conduction delay was (1.09 +/- 0.06) msec. CONCLUSION: The sacral cord conduction time was estimated to be about 1.09 msec in this study and because at least 1 msec is required to transmit the signal across the synapse between the sensory ending and the motor cell, so this estimated time was sufficient for only one central synapse in this reflex.

Dorsal root entry zone (DREZ) localization using direct spinal cord stimulation can improve results of the DREZ thermocoagulation procedure for intractable pain relief.

The dorsal root entry zone (DREZ) thermocoagulation for intractable pain after brachial plexus avulsion was performed in 21 patients. Good results in pain relief (relief of more than 75% of preoperative pain) were achieved in 62% of patients, whereby fair results (relief of 25-75% of preoperative pain) in 38% of patients. There was no patient with poor result (relief of less than 25% of preoperative pain). Complication rate was 14%. The whole patient population was subdivided into two groups (Group 1 and Group 2). Direct spinal cord bipolar stimulation and registration with the goal to localize DREZ was performed in the Group 2 consisting of 12 patients (n=12). The point on the spinal cord surface where no response after stimulus of low intensity was obtained was the site (the posterolateral sulcus) we identified as the most suitable point for the placement of radiofrequency thermocoagulation electrode. Comparing with the Group 1 consisting of nine patients (n=9), where the localization of DREZ by evoked potentials was not performed, significantly better effect of pain relief was recorded (P<0.05, odds ratio 10). There was no statistically significant difference (P>0.7) in complication rate in Group 1 and Group 2. Described electrophysiological technique is very helpful in identifying of DREZ and, in combination with microsurgical technique, can create DREZ thermocoagulation more effective.

The effect of laser irradiation for nucleus pulposus: an experimental study.

BACKGROUND: The radicular pain caused by disc herniation can be explained by two mechanisms: the compression of the nerve root by the herniated disc or the irritation of the nerve root due to chemical factors. Percutaneous laser disc decompression (PLDD) was introduced for the treatment of lumbar disc hernias in the 1980s. Decompression of the nerve root is assumed to be an effective therapeutic mechanism for PLDD. However, laser irradiation might reduce the chemical factors that cause nerve root irritation by altering intra-disc proteins. We used nerve conduction velocities (NCV) and levels of two chemical factors to evaluate the differences between the two groups in this in vivo study. METHODS: All rabbits had the nerve root in contact with the leakage from the nucleus pulposus. One group underwent laser irradiation for the leaking nucleus pulposus including the incision site of the disc and nucleus pulposus itself. The levels of two chemical factors, prostaglandin E2 and phospholipase E2, in the intervertebral disc were measured before and after laser irradiation. RESULTS: NCV in the laser-irradiated group was significantly faster than in the non-laser-irradiated group. The levels of chemical factors were significantly reduced after laser irradiation. CONCLUSIONS: One of the mechanisms thought to be responsible for PLDD's effectiveness is a decrease in the chemical factors through protein alteration in the intervertebral disc by laser irradiation.

Inhibition by spinal mu- and delta-opioid agonists of afferent-evoked substance P release.

Opioid mu- and delta-receptors are present on the central terminals of primary afferents, where they are thought to inhibit neurotransmitter release. This mechanism may mediate analgesia produced by spinal opiates; however, when they used neurokinin 1 receptor (NK1R) internalization as an indicator of substance P release, Trafton et al. (1999) noted that this evoked internalization was altered only modestly by morphine delivered intrathecally at spinal cord segment S1-S2. We reexamined this issue by studying the effect of opiates on NK1R internalization in spinal cord slices and in vivo. In slices, NK1R internalization evoked by dorsal root stimulation at C-fiber intensity was abolished by the mu agonist [D-Ala2, N-Me-Phe4, Gly-ol5]-enkephalin (DAMGO) (1 microM) and decreased by the delta agonist [D-Phe2,5]-enkephalin (DPDPE) (1 microM). In vivo, hindpaw compression induced NK1R internalization in ipsilateral laminas I-II. This evoked internalization was significantly reduced by morphine (60 nmol), DAMGO (1 nmol), and DPDPE (100 nmol), but not by the kappa agonist trans-(1S,2S)-3,4-dichloro-N-mathyl-N-[2-(1-pyrrolidinyl)cyclohexyl]-benzeneacetamide hydrochloride (200 nmol), delivered at spinal cord segment L2 using intrathecal catheters. These doses of the mu and delta agonists were equi-analgesic as measured by a thermal escape test. Lower doses neither produced analgesia nor inhibited NK1R internalization. In contrast, morphine delivered by percutaneous injections at S1-S2 had only a modest effect on thermal escape, even at higher doses. Morphine decreased NK1R internalization after systemic delivery, but at a dose greater than that necessary to produce equivalent analgesia. All effects were reversed by naloxone. These results indicate that lumbar opiates inhibit noxious stimuli-induced neurotransmitter release from primary afferents at doses that are confirmed behaviorally as analgesic.

Motor root conduction block in traumatic brachial plexopathy.

A 31-year old man sustained severe left brachial plexus traction injury. Electrical stimulation demonstrated multilevel motor root conduction block, which reversed after a 4-month period. Motor root conduction studies are useful diagnostic and prognostic adjuncts in the management of brachial plexopathy.

NR2B receptors are involved in the mediation of spinal segmental reflex potentials but not in the cumulative motoneuronal depolarization in vitro.

Windup, the frequency dependent build-up of spinal neuronal responses is an electrophysiological model of the development of the central sensitization in the chronic pain states. NR2B subunit containing NMDA-type glutamate receptors are implicated in the windup of dorsal horn neurons, while their role at the motoneuronal level is controversial. The cumulative motoneuronal depolarization in hemisected rat spinal cord preparation is an in vitro model of windup. The role of NR2B receptors in this process, and in the mediation of dorsal root stimulation evoked ventral root reflex potentials was elucidated. Three selective NR2B antagonists; CP-101,606; CI-1041 and Co-101244 (1 microM) were used. They had only weak, but statistically significant inhibitory effect on the early part of ventral root response, and did not influence the cumulative depolarization. On the contrary, non-selective NMDA antagonist APV (40 microM) decreased both responses markedly. We conclude that the pharmacological sensitivities of windup at the sensory and motor levels are different. NR2B containing NMDA receptors have major role in the mediation of the windup of dorsal horn neurons, but their contribution to this phenomenon at the motor level is negligible.