Orofacial antinociceptive effect of Mimosa tenuiflora (Willd.) Poiret.

Mimosa tenuiflora (Willd.) Poiret, popularly known in Brazil as "jurema-preta" is widely used against bronchitis, fever, headache and inflammation. Its antioxidant, anti-inflammatory and antinociceptive potential has already been reported. To assess the orofacial antinociceptive effect of M. tenuiflora, ethanolic extracts of M. tenuiflora (leaves, twigs, barks and roots) were submitted to in vitro tests of antioxidant activity. The extract with the highest antioxidant potential was partitioned and subjected to preliminary chemical prospecting, GC-MS, measurement of phenolic content and cytotoxicity tests of the fraction with the highest antioxidant activity. The nontoxic fraction with the highest antioxidant activity (FATEM) was subjected to tests of acute and chronic orofacial nociception and locomotor activity. The possible mechanisms of neuromodulation were also assessed. The EtOAc fraction, obtained from the ethanolic extract of M. tenuiflora barks, was the one with the highest antioxidant potential and nontoxic (FATEM), and Benzyloxyamine was the major constituent (34.27%). FATEM did not alter the locomotor system of mice and reduced significantly the orofacial nociceptive behavior induced by formalin, glutamate, capsaicin, cinnamaldehyde or acidic saline compared to the control group. FATEM also inhibited formalin- or mustard oil-induced temporomandibular nociception. In addition, it also reduced mustard oil-induced orofacial muscle nociception. However, FATEM did not alter hypertonic saline-induced corneal nociception. Neuropathic nociception was reversed by treatment with FATEM. The antinociceptive effect of FATEM was inhibited by naloxone, L-NAME and glibenclamide. FATEM has pharmacological potential for the treatment of acute and neuropathic orofacial pain and this effect is modulated by the opioid system, nitric oxide and ATP-sensitive potassium channels. These results lead us to studies of isolation and characterization of bioactive principles.

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.

Changes in osteoprotegerin/RANKL system, bone mineral density, and bone biochemicals markers in patients with recent spinal cord injury.

This study analyzed the temporal and regional variations in bone loss and explored bone cell activities via biochemical markers during an extended follow-up in patients with spinal cord injury (SCI). In parallel, the possible role of the osteoprotegerin (OPG)/RANKL system in disuse osteoporosis was investigated. Seven male patients with acute and complete SCI (31.3 +/- 9.5 years) and 12 able-bodied (AB) men (26.9 +/- 4.2 years) participated in the study. Measurements were performed 16, 24, 36, 48, and 71 weeks after injury. At week 16, marked calcium homeostasis disturbance and a concomitant increase in bone resorption markers were observed, reflecting an intense bone degradation process. Resorption activity decreased continuously with time. Contrasting with the great rise in the resorption markers, the bone formation markers showed little variation. During the period of investigation, a loss in bone mineral density (BMD) was demonstrated for the total body (-4.3%), pelvis (-15.7%) and lower limbs (-15.2%), whereas BMD did not change at the lumbar spine, upper limbs, or skull. At all stages, SCI patients had lower serum RANKL levels and higher serum OPG levels than did AB controls, but no significant variation with time was observed for either cytokine. These findings suggest that bone resorption persisted long after SCI and specifically affected BMD at sublesional sites. The marked modification of serum OPG/RANKL levels in SCI patients suggests that this system is affected, in disuse osteoporosis. However, the precise biologic role of the OPG/RANKL system in the bone tissue of SCI patients has yet to be determined.

[Neurosurgical treatment of hyperactive bladder in spinal cord injury patients]. / Traitement neurochirurgical de la vessie hyperactive chez le blessé médullaire.

OBJECTIVES: We report long-term results of posterior sacral root rhizotomies in combination with Finetech-Brindley anterior sacral root stimulators implanted intradurally in 20 spinal cord injury patients. MATERIAL: and methods: The 14 female and 6 male patients included 14 paraplegics and 6 tetraplegics. All of them initially presented hyperactive bladder, detrusor-sphincter dyssynergia, recurrent urinary tract infection and performed (self) intermittent catheterization. Prior to implantation, an intrathecal test using bupivacaine was performed to confirm the compliances of the bladder. The main indication for implantation was persistent urinary incontinence refractory to medical therapy. RESULTS: After implantation the mean follow-up was 4,5 years. In all, 18 patients used the stimulator alone for bladder emptying and 18 patients were completely continent. The mean bladder capacity increased from 190 ml preoperatively to 460 ml after the operation. The mean residual urinary volume was reduced from 90 ml to 25 ml. No changes were noted by renal isotopic scanning in upper urinary tracts of patients. In 1 patient, a second extradural implant was performed. DISCUSSION: This article also include an overview of a) the different available sites where application of electrical stimulation results in a detrusor contraction, b) the benefits and disadvantages of the sacral posterior rhizotomy, c) selective stimulation techniques that allow selective detrusor activation by sacral root stimulation. CONCLUSION: Sacral anterior root stimulation combined with sacral posterior rhizotomy is a valuable method to restore bladder functions in spinal cord injured patients suffering from hyperactive bladder refractory to medical therapy.

Neuroprotective effects of a novel NMDA antagonist, Gacyclidine, after experimental contusive spinal cord injury in adult rats.

The aim of this study was to analyze the optimal time-window for neuroprotection by a novel NMDA antagonist, Gacyclidine, after experimental spinal cord injury, in terms of its functional, histopathological and electrophysiological effects. This molecule has already demonstrated its capacity for reducing the extent of an ischemic lesion and is currently experimented in a clinical trial of spinal cord injury. In this study, the spinal cord of rats was damaged by a contusive method and the animals were treated by saline or 1 mg/kg of Gacyclidine i.v., 10, 30, 60 and 120 min after injury. The time-course of the motor score was evaluated on days 1, 7 and 18 after injury, and somatosensory evoked potentials were determined on day 20. The animals were then killed and the cross-sectional area of the spinal cord (at the epicenter of the injury, above and below the injury), was measured. Walking recovery was better (P<0.0125) in the group treated 10 min after injury than in the untreated injured animals after 18 days of injury. Motor performances were related to the preservation of a larger undamaged area of spinal cord at the level of the injury (P<0.0125). Somatosensory evoked potential amplitudes were also higher in this group. These results confirm that Gacyclidine attenuates spinal cord damage after an experimental spinal cord lesion. Recovery was better within the group treated 10 min after injury compared with the other groups, which certainly confirms that the acute time-course of glutamate release requires rapid pharmacological intervention to achieve good results.

Neuroprotective effects of gacyclidine after experimental photochemical spinal cord lesion in adult rats: dose-window and time-window effects.

The aim of this study was to evaluate the efficacy, optimal dose, and optimal time-window of gacyclidine, a novel N-methyl-D-aspartate (NMDA) receptor antagonist, in terms of its functional, histopathological, and electrophysiological effects after experimental spinal cord injury. The spinal cord of rats was damaged by a photochemical method and the animals were treated by saline or gacyclidine at doses of 1, 2.5, or 5 mg/kg 10 min after injury or gacyclidine 1 mg/kg 10, 30, 60, and 120 min after injury. The time-course of the motor score (walking and inclined-plane stability) was evaluated until day 18, and somatosensory evoked potentials were determined on day 18. The animals were then sacrificed, and the cross-sectional area of the spinal cord (at the epicenter of the injury, above and below the injury) was measured. Walking recovery was better in most of the groups treated after injury than in the untreated injured animals. Motor performances were related to preservation of a larger undamaged area of spinal cord at the level of the injury and, interestingly, with prevention of extension of the anatomical lesion above the level of the injury. Somatosensory evoked potential amplitudes were often higher in treated groups. These results confirm that gacyclidine induces dose-dependent and time-dependent attenuation of spinal cord damage after an experimental vascular lesion. Although all three doses induced neuroprotective effects, recovery was greater and very homogeneous in the group treated with 1 mg/kg. Moreover, recovery was slightly better and more homogeneous within the groups treated 10 and 30 min after injury compared to the other groups. It appears that, according to the existing evidence, NMDA antagonists are an essential component in the elaboration of a neuroprotective strategy after spinal cord trauma.

Variability of the fatigue response of paralyzed skeletal muscle in relation to the time after spinal cord injury: mechanical and electrophysiological characteristics.

The aim of this study was to determine the effect of the time after spinal cord injury (less than and greater than 10 months) on the mechanical and electrophysiological characteristics of muscle fatigue of the paralyzed electrically stimulated quadriceps muscle. Morphologically and histochemically, a relationship was observed between muscle fatigue and the delay from injury, revealing a critical period of enzymatic turning and a maximum peak of atrophy around the 10th month after the injury, followed by a long-term stabilization. Knee-torque output and M-wave variables (amplitude, latency, duration, and root mean square, RMS) of two muscular heads of the quadriceps were recorded in 19 paraplegic patients during a 120-s isometric contraction. The fatiguing muscle contraction was elicited by supramaximal continuous 20-Hz electrical stimulation. Compared to the chronic group, the acutely paralyzed group showed a greater resistance to fatigue (amount and rate of force decline, P < or = 0.01), smaller alterations of the M-wave amplitude and RMS, and a limited decrease of the muscle fiber conduction velocity (P < 0.05). Mechanical and electrophysiological changes during fatigue provided a clear functional support of the transformation of skeletal muscle under the lesion and of the existence of a critical period of muscular turn. In conclusion, when considering the artificial restoration of motor function, the evolution of the endurance and force-generating capabilities of the muscle actuator must be taken into account, particularly when tasks require important safety conditions (e.g., standing and walking).

Compound motor action potentials and mechanical failure during sustained contractions by electrical stimulation in paraplegic patients.

In nine paraplegic patients we recorded the torque output and compound motor action potentials (CMAPs) produced by the quadriceps muscle during an isometric contraction elicited by electrical stimulation. The torque, the peak to peak amplitude, the latency, the peak to peak duration and the total surface of the rectified CMAPs were computed over a period of 126 s. After a brief increase the mechanical output rapidly decreased and reached a stable minimum level by the end of 126 s. The final torque output values ranged from 7.1 to 54% of initial values. This torque decrease was related neither to length of time between injury and testing, nor to the thoracic level of the spinal cord injury. The peak to peak amplitude of the CMAPs changed over the course of stimulation. It was noted to increase over a period of time after which it decreased to a minimum level. The latency from the onset of stimulation to the onset of the CMAP varied to a relatively small extent compared to the peak to peak duration. Therefore, the conduction velocity along the muscle fibres appeared to be more affected by the test than by the conduction velocity along the nerve fibres and the transmission across the neuromuscular junction. The mechanisms involved in the changes in CMAPs and the change in torque output over the time course of stimulation are discussed.

The management of upper urinary tract calculi by piezoelectric extracorporeal shock wave lithotripsy in spinal cord injury patients.

From May 1988 to September 1994, 15 spinal cord injury patients were treated by piezoelectric extracorporeal shock wave lithotripsy. Aged from 23 to 71 years (mean = 39), they presented with a total of 23 stones, of which 18 were located in the calyces, three in the renal pelvis and two in the proximal ureter. The maximum dimensions of calculi varied from 5 to 35 mm (mean = 11). Patients were placed in a dorsal decubitus position during the sessions, three being sedated with diazepam, while the other 12 remained unsedated. All were treated routinely with systemic antibiotics. Auxiliary procedures consisted of two pyelocalyceal flushings, three double J ureteral stenting and three ureteroscopies with fragment removal with a Dormia basket. No episode of autonomic dysreflexia was observed. Short term side effects were limited to a few cases of gross haematuria which regressed spontaneously. Overall, eight successes (53%), and seven failures (47%), were registered. Of the failures, one was the result of a partial fragmentation, while six were related to intrarenal retention of residual fragments resulting in four cases in rapid recurrences. Extracorporeal shock wave lithotripsy can be easily applied to spinal cord injury patients. Its usefulness and limitations need to be well understood and a global consideration must be applied to the prevention and early detection of the upper urinary calculi in this exposed population of patients.

[Surgical classification of the upper limb in tetraplegic patients]. / Classification chirurgicale du membre supérieur du tétraplégique.

The authors report the classification which they use in functional surgery of the upper limb in tetraplegics. They have adopted an international surgical classification and have added minor modifications which they justify. High, intermediate and low tetraplegias must be distinguished. They form homogeneous groups requiring different surgical modalities. They authors emphasise the schematic nature of this classification which can only be used as a guide for surgical indications, as each case must be assessed individually.

Thienylphencyclidine protection for the spinal cord of adult rats against extension of lesions secondary to a photochemical injury.

The purpose of this study was to evaluate treatment with the N-methyl-D-aspartate antagonist thienyl-phencyclidine (TCP) after spinal cord injury for its behavioral, electrophysiological, morphological, and immunohistochemical effects. Five minutes after a photochemical lesion was produced in rats at the T-8 level, the animals received TCP (1 mg/kg, intravenously) or TCP vehicle (saline). The animals were evaluated on Day 18 for neurological recovery by testing motor and sensory functions. The TCP-treated group showed less neurological impairment than the untreated group (p < 0.05 for inclined-plane stability and withdrawal reflex to extension). Somatosensory evoked potential testing was performed on Days 21 to 23 and the wave amplitude between the onset and P1 in the TCP-treated group was higher than in the untreated group (p < 0.05). Mean arterial blood pressure was not significantly modified after TCP injection. Morphometric studies of the lesion area in cross section revealed a significantly reduced spinal cord infarction in the TCP-treated group (p < 0.05). Immunohistochemical evaluation of the spinal cord in lumbar area showed an increased level of serotonin immunoreactivity in the dorsal horn of animals treated by TCP. These results demonstrate the efficacy of TCP in reducing secondary lesions after spinal cord injury in rats.

Effects of functional electrical stimulation (FES) on evoked muscular output in paraplegic quadriceps muscle.

In order to assess the effects of FES on muscle output, chronic electrical stimulation of the quadriceps muscle was applied for half an hour twice a day for 2 months, in 10 thoracic level traumatic paraplegic patients. Results concerning torque (at 6 different muscle lengths) and fatigue were measured using a strain gauge transducer in isometric condition, and compared with the findings in 15 paraplegic patients who had not received electrical stimulation, and with 10 able bodied subjects with normal motor functions. With training, muscle strength was very significantly improved whilst fatigue resistance remained at a low level. The peak torque was not found to be of the same muscle length when comparing paraplegics and control subjects; it seemed to demonstrate that length-tension relationship of the muscular actuator was changing when it was electrically activated. Moreover, the force recorded in paraplegics remained markedly lower than in able bodied people.

[Vesico-sphincter dyssynergia in the central paraplegic patient. Physiopathological reflections]. / La dyssynergie vésico-sphinctérienne du paraplégique central. Réflexion physiopathologique.

The vesico-sphincter dyssynergia is generally observed in paraplegic patients with supra sacral lesions (40% of our cases). The neurophysiologic basis of the vesico-sphincter dyssynergia are the field of controversies. The animal experimentations have shown that a section below the ponts, induce a neural reorganization, enough to produce a normal micturation, rising sacral short loop reflexes. The reality of such mechanism is discussed by different authors who consider a normal micturation as a brain stem reflex rather than a simple sacral reflex. These factors allow the authors to undergo a neurophysiologic, neuropharmacologic and urodynamic investigation, with the intention of shedding light on the pathophysiology of the vesico-sphincter dyssynergia in 20 cases of paraplegic patients. On the basis of our data the following conclusions were made: the importance of the polysynaptic reflexes evoked by cutaneous or vesical stimulation (below the neurologic lesions) on the different degrees of vesico-sphincter dyssynergia; the quality of voiding depends on the equilibrium between extension and flexor reflexes in paraplegic patients; the presence of a neural reorganization using short loop reflexes who are the expression of a complex system rather than a simple sacral reflex; the effect of chronic intrathecal morphinic drugs on the reflex equilibrium and the quality of voiding and the eventual relation between opiate receptors and vesical sphincter dyssynergia.

Computed tomography of acute spinal epidural hematoma associated with cervical root avulsion.

A case of acute spinal epidural hematoma associated with post-traumatic cervical root avulsion is described. Surgical management of this condition depends to a large extent on its early recognition as well as accurate information about its site and extent. Computed tomography is the investigative procedure of choice to evaluate this entity.

[Biomechanical bases of dorsal and lumbar spinal osteosynthesis]. / Bases biomécaniques des ostéosynthèses rachidiennes dorsales et lombaires.

The authors report the results of their biomechanical experimental study on the fixation of various lesions of the spine, using Roy Camille metal plates, and the results of Fischer -- Gonon (using Harrington rods) and Kempf -- Jaeger (using Kempf rods). They conclude to: the efficiency of the posterior techniques of fixation, the necessity, in the thoraco-lumbar and lumbar segments to associate an anterior graft (fibula), in order to reinforce the late stability, the best functional results achieved by a "short" fixation in association with an anterior graft (double approach technique). According to their experience, the authors advocate for the use of Roy Camille metal plates screwed in the pedicles, the Harrington or Kempf rods helping in the per operative course to gain further reduction, namely in cases of disymetrical displacements.

[Value of preoperative investigations in the so-called "cervical myelopathy" (author's transl)]. / Valeurs du bilan préopératoire dans les myélopathies dites cervicarthrosiques.

The particular value of clinical, radiological and electromyographical features is compared in 42 patients with motor deficit related to cervicarthrosic myelopathy or amyotrophic lateral sclerosis. The initial onset of the disease was identical (motor deficit and long tracts pathways involvement). Three different groups were identifyed according to the evolution: -- Group I: (13 cases): true lateral amyotrophic sclerosis which were not operated on. -- Group II (10 cases): myelopathy called "cervicarthrosic" because of radiological findings which were operated on but had the same steady worsened course as a lateral amyotrophic sclerosis. -- Group III (19 cases): cervical myelopathy which had surgery. The operation brought about stabilization or fairly good recovery over the 18 months following at least. From a clinical aspect, the "Lhermitte sign" or objective sensitive deficit are strongly significant for cervical myelopathy. On the contrary, diffuse fasciculations specially in the tongue seem to be mostly found in lateral amyotrophic sclerosis, whereas they are restricted into the paralysed area in cervical myelopathy. Electromyographic examination is decisive: simple activity with high frequency motor units (increased amplitude and polyphasic waves) or "preponderant potentials" into a cranial nerve territory or three segments of the lower limbs are frequently found in lateral amyotrophic sclerosis. These electromyographic features are less significant in the upper limbs. The neuroradiological findings lonely cannot assert definitely the cervicarthrosic origin of the myelopathy but visualize the conflicting situation between the spinal cord and the cervical canal and allow to choose the surgical procedure.