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1.
Clin Otolaryngol ; 41(6): 634-639, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26493548

RESUMEN

OBJECTIVE: To evaluate the efficacy of bilateral selective neck dissection of levels II-IV in elective and therapeutic management of the neck as a part of primary surgical treatment of patients with supraglottic laryngeal cancer and clinically negative cervical findings (N0). DESIGN: Institutional, observational, case-control study with historic control of patients who underwent primary supraglottic tumour surgery, and a prospective cohort of patient, who underwent, besides the operation of primary tumour, bilateral selective neck dissection (level II-IV). SETTING: University, tertiary level hospital, national referral centre. PARTICIPANTS: The study included 193 patients with supraglottic cancer and without palpable or ultrasound positive cervical findings who were surgically treated from 1988 to 2005. Besides the operation of primary tumour, all patients in the study group underwent bilateral selective neck dissection (level II-IV). Patients in the control group (N = 51) underwent primary tumour operation only and were followed up regularly. In cases with postoperative regional recurrences, the radical neck dissection was performed. All patients with histopathological confirmation of occult metastases were administered radiotherapy treatment (60 Gy) in the postoperative period. MAIN OUTCOME MEASURES: Five-year overall survival rate. RESULTS: Occult cervical metastases were found in 18% of patients. They were present in level II in 77.5%, in level III in 20% of cases and in one patient in level IV (2.5%); the extracapsular spread was observed in 20% of cases. Postoperative regional metastases were found in 4.15% of cases in the study group, and in 11.8% in the control group, which proved to be significantly higher. The five-year overall survival rate showed no significant difference between the study group and the control group. CONCLUSION: The incidence of postoperative regional recurrences could be reduced by performing bilateral selective neck dissection simultaneously with primary tumour operation, but with no influence on the survival rate.


Asunto(s)
Carcinoma/patología , Carcinoma/cirugía , Neoplasias Laríngeas/patología , Neoplasias Laríngeas/cirugía , Disección del Cuello , Adulto , Anciano , Carcinoma/mortalidad , Estudios de Casos y Controles , Femenino , Humanos , Neoplasias Laríngeas/mortalidad , Laringectomía , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Tasa de Supervivencia , Resultado del Tratamiento
2.
J Environ Monit ; 14(3): 866-77, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22314513

RESUMEN

In this study concentrations of metals in the native plants and soils surrounding the old flotation tailings pond of the copper mine were determined. It has been established that the soil is heavily contaminated with copper, iron and arsenic, the mean concentrations being 1585.6, 29,462.5 and 171.7 mg kg(-1) respectively. All the plants, except manganese, accumulated metallic elements in concentrations which were either in the range of critical and phytotoxic values (Pb and As) or higher (Zn), and even much higher (Cu and Fe) than these values. Otherwise, the accumulation of Mn, Pb and As was considerably lower than that of Cu, Fe and Zn. In most plants the accumulation of target metals was highest in the root. Several plant species showed high bioaccumulation and translocation factor values, which classify them into species for potential use in phytoextraction. The BCF and TF values determined in Prunus persica were 1.20 and 3.95 for Cu, 1.5 and 6.0 for Zn and 1.96 and 5.44 for Pb. In Saponaria officinalis these values were 2.53 and 1.27 for Zn, and in Juglans regia L. they were 8.76 and 17.75 for Zn. The translocation factor in most plants, for most metals, was higher than one, whereas the highest value was determined in Populus nigra for Zn, amounting to 17.8. Among several tolerant species, the most suitable ones for phytostabilization proved to be Robinia pseudoacacia L. for Zn and Verbascum phlomoides L., Saponaria officinalis and Centaurea jacea L. for Mn, Pb and As.


Asunto(s)
Metales/análisis , Plantas/química , Contaminantes del Suelo/análisis , Ciudades , Cobre , Monitoreo del Ambiente , Metalurgia , Minería , Serbia , Suelo/química
3.
J Hazard Mater ; 158(1): 23-34, 2008 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-18329798

RESUMEN

The flotation tailings pond of the Bor Copper Mine poses a great ecological problem not only for the town of Bor but also for the surrounding soils and watercourses. Since the old flotation tailings contain about 0.2% of copper on the average, we investigated their leaching with sulphuric acid in the absence and presence of an oxidant. The aim was to determine the leaching kinetics of copper and iron as affected by various factors such as: the pH value of the leach solution, stirring speed, pulp density, particle size, concentration of ferric ions, temperature and time for leaching. The average copper and iron recovery obtained was from 60% to 70% and from 2% to 3%, respectively. These results indicate that the old flotation tailings pond represents an important source of secondary raw material for the extraction of copper and that it should be valorized rather than land reclamation. At the end of the paper, a mechanism of dissolution of copper and iron minerals from the tailings was described.


Asunto(s)
Ácidos/química , Cobre/aislamiento & purificación , Residuos Industriales , Minería , Ecosistema , Compuestos Férricos/química , Concentración de Iones de Hidrógeno , Hierro/química , Cinética , Tamaño de la Partícula , Serbia , Ácidos Sulfúricos/química , Temperatura
4.
Eur J Pharmacol ; 577(1-3): 170-82, 2007 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-17854797

RESUMEN

As glucocorticoids influence both catecholamine synthesis and adrenoceptor expression by immune cells, the current study was undertaken to distinguish their direct effects on the development of experimental allergic encephalomyelitis from those induced by alteration of catecholamine signaling. We examined the influence of 16-day-long beta-adrenoceptor blockade with propranolol (0.40 mg/100 g body weight/day, s.c.) beginning 3 days before immunization on the development of experimental allergic encephalomyelitis in adrenalectomized (7 days before immunization) and in non-operated male Dark Agouti rats. Adrenalectomy aggravated the clinical course of experimental allergic encephalomyelitis. In contrast, propranolol attenuated both the clinical signs of the disease and decreased the number of lesions in the spinal cord. Furthermore, propranolol prevented adrenalectomy-induced aggravation of the disease course without affecting mortality. We also found that the percentage of CD4(+)CD25(+) T lymphocytes (recently activated or regulatory cells) was increased in peripheral blood of experimental allergic encephalomyelitis rats over that in the corresponding non-immunized and bovine serum albumin immunized rats. However, the percentage of these cells was reduced in adrenalectomized and/or propranolol-treated experimental allergic encephalomyelitis rats compared to control experimental allergic encephalomyelitis rats. Our findings, coupled with the clinical course of the disease and the underlying pathomorphological changes, clearly suggest that differential mechanisms were responsible for the changes in the percentage of CD4(+)CD25(+) T lymphocytes in propranolol-treated adrenalectomized rats and only propranolol-treated rats with experimental allergic encephalomyelitis. Our results, when viewed globally, indicate that: i) beta-adrenoceptor-dependent mechanisms are involved in the immunopathogenesis of experimental allergic encephalomyelitis, ii) experimental allergic encephalomyelitis has a more severe course in adrenalectomized rats and iii) beta-adrenoceptor-mediated mechanisms operate in adrenalectomy-induced aggravation of the disease.


Asunto(s)
Adrenalectomía , Antagonistas Adrenérgicos beta/uso terapéutico , Encefalomielitis Autoinmune Experimental/tratamiento farmacológico , Animales , Encéfalo/patología , Corticosterona/sangre , Encefalomielitis Autoinmune Experimental/patología , Encefalomielitis Autoinmune Experimental/fisiopatología , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Glucocorticoides/fisiología , Glucocorticoides/uso terapéutico , Técnicas para Inmunoenzimas , Linfocitos/inmunología , Linfocitos/fisiología , Masculino , Fenotipo , Propranolol/uso terapéutico , Ratas , Albúmina Sérica Bovina/inmunología
5.
Int Immunopharmacol ; 7(2): 167-74, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17178383

RESUMEN

Pentoxifylline (PTX) is a drug used for the treatment of vascular disorders, but it also has a positive therapeutic effect in experimental models of some autoimmune diseases. In this work, we studied the effect of PTX on human monocyte-derived dendritic cells (MDDCs). Immature MDDCs were generated in vitro from monocytes in the presence of recombinant human granulocyte macrophage-colony stimulating factor (rhGM-CSF) and recombinant human interleukin-4 (rhIL-4), while mature MDDCs were obtained by cultivation of immature MDDCs with lipopolysaccharide (LPS). PTX (200 micro g/ml) was added at the beginning of cell cultivation. We found that PTX significantly impaired differentiation and function of immature MDDCs, as judged by the reduced allostimulatory activity of these cells on allogeneic T cells and down-regulation of costimulatory and adhesion molecules, such as CD86, CD40 and CD54. The maturation of MDDCs in the presence of PTX and LPS was characterized by the decreased expression of maturation marker CD83 and costimulatory molecule CD86, as well as lower stimulation of alloreactive T cells compared to the control MDDCs cultivated with LPS alone. PTX-treated MDDCs which were induced to mature with LPS produced lower levels of TNF-alpha, IL-12 and IL-18 and higher levels of IL-10 than corresponding control MDDCs. PTX did not significantly alter endocytosis of dextran by both immature and mature MDDCs. Cumulatively, our results show for the first time that PTX might impair differentiation, maturation and function of human MDDCs in vitro, suggesting an additional mechanism of its immunomodulatory activity.


Asunto(s)
Células Dendríticas/efectos de los fármacos , Factores Inmunológicos/farmacología , Pentoxifilina/farmacología , Antígenos CD/inmunología , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Citocinas/inmunología , Células Dendríticas/citología , Células Dendríticas/inmunología , Endocitosis/efectos de los fármacos , Humanos , Lectinas Tipo C/inmunología , Receptor de Manosa , Lectinas de Unión a Manosa/inmunología , Monocitos/citología , Receptores de Superficie Celular/inmunología , Linfocitos T/efectos de los fármacos , Linfocitos T/inmunología
6.
Hum Mov Sci ; 26(2): 275-95, 2007 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-17343947

RESUMEN

We have demonstrated that non-patterned electrical stimulation of the lumbar cord can induce stepping-like activity in the lower limbs of complete spinal cord injured individuals. This result suggested the existence of a human lumbar locomotor pattern generator, which can convert a tonic input to a rhythmic motor output. We have studied the human lumbar cord in isolation from supraspinal input but under extrinsic tonic input delivered by spinal cord stimulation. Large-diameter afferents within the posterior roots are directly depolarized by the electrical stimulation. These afferents project to motoneurons as well as to lumbar interneurons involved in the motor control of lower limbs. Stimulation at 25-50 Hz can elicit rhythmic alternating flexion/extension movements of the lower limbs in supine individuals. Reducing the tonic input frequency to 5-15 Hz initiates lower limb extension. Epidural stimulation applied during manually assisted treadmill stepping in complete spinal cord injured persons immediately increases the central state of excitability of lumbar cord networks and enhances stepping-like functional motor outputs. Sustained, non-patterned tonic input via the posterior roots can activate human lumbar cord networks. Pattern generating configurations of these multifunctional circuitries can be set-up depending on the stimulation parameters and particularly on the input frequency.


Asunto(s)
Estimulación Eléctrica/métodos , Locomoción/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/terapia , Biorretroalimentación Psicológica/fisiología , Electrodos Implantados , Electromiografía , Humanos , Región Lumbosacra , Periodicidad
7.
J Food Prot ; 69(5): 1061-5, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16715805

RESUMEN

We report the effects of 2-nitro-1-propanol (2NPOH), 2-nitroethanol (2NEOH), and nitroethane (NE) on growth and survivability of Listeria monocytogenes. In all cases, inhibition was greatest with 2NPOH and least with NE. For example, specific growth rates of L. monocytogenes strain 18 declined (P < 0.05) 76, 60, and 29% from controls during aerobic culture at 37 degrees C in brain heart infusion broth containing 10 mM 2NPOH, 2NEOH, or NE, respectively. Mean specific growth rate for the controls incubated likewise without added nitrocompound was 0.62 +/- 0.02 h(-1). Specific growth rates of L. monocytogenes Scott A decreased (P < 0.05) 67, 45, and 11%, respectively, from controls (0.67 +/- 0.02 h(-1)) when cultured similarly. Specific growth rates for L. monocytogenes strain 18 incubated similarly except at 30 degrees C were reduced (P < 0.05) 76, 60, and 30%, respectively, and were reduced (P < 0.05) 78, 23, and 23% during anaerobic culture at 30 degrees C in brain heart infusion broth containing 15 mM 2NPOH, 2NEOH, or NE (control rates ranged from 0.37 +/- 0.07 to 0.74 +/- 0.05 h(-1)). Survivability of L. monocytogenes strain 18 was reduced (P < 0.05) during aerobic storage (4 months at 4 degrees C) in brain heart infusion broth containing 2NPOH or 2NEOH (by 7.8 and 1.9 log units, respectively) but not NE. The inhibitory effect of 2NPOH was approximately 20% greater during growth at pH 7.0 than at pH 5.6 or 8.0. These results demonstrate the differential inhibitory activity of 2NPOH, 2NEOH, and NE against L. monocytogenes in vitro.


Asunto(s)
Microbiología de Alimentos , Conservación de Alimentos/métodos , Listeria monocytogenes/efectos de los fármacos , Nitrocompuestos/farmacología , Recuento de Colonia Microbiana , Relación Dosis-Respuesta a Droga , Etano/análogos & derivados , Etano/farmacología , Manipulación de Alimentos/métodos , Concentración de Iones de Hidrógeno , Técnicas In Vitro , Cinética , Listeria monocytogenes/crecimiento & desarrollo , Nitroparafinas/farmacología , Propanoles/farmacología , Temperatura
8.
Environ Sci Process Impacts ; 18(6): 768, 2016 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-27173003

RESUMEN

Correction for 'Impact of metallurgical activities on the content of trace elements in the spatial soil and plant parts of Rubus fruticosus L.' by M. M. Nujkicet al., Environ. Sci.: Processes Impacts, 2016, 18, 350-360.

9.
Environ Sci Process Impacts ; 18(3): 350-60, 2016 03.
Artículo en Inglés | MEDLINE | ID: mdl-26982885

RESUMEN

The concentrations of the trace elements (TEs), Cu, Zn, Pb, As, Cd, Ni, were determined in parts of Rubus fruticosus L. and in topsoil, collected from eight different locations around the copper smelter in Bor, Serbia. Extremely high concentrations of Cu were determined in the soil and in R. fruticosus L., and for arsenic at some locations. The enrichment factors for TEs in soil showed enrichment with Cu, Zn, Pb, and As among which extremely high values were determined for Cu (EFsoil = 8.5-126.1) and As (EFsoil = 6.6-44.4). The enrichment factors for the parts of R. fruticosus L. showed enrichment with all TEs, except for nickel. The most extreme enrichment was found to occur in roots and stems for Cu (EFplant = 56.2 and 51.1) and leaves for Pb (EFplant = 45.68). The mean values of the three ratios of concentrations between plant parts for all TEs indicated pollution via the atmosphere while leaves appeared to be the best indicators for this kind of pollution. Numerous and very strong Pearson's correlations between TEs in the R. fruticosus L. parts confirmed these results. Principal Component Analysis showed that the major pollution source is the copper smelter that contaminates vegetation through soil and air.


Asunto(s)
Arsénico/análisis , Metales Pesados/análisis , Rubus , Contaminantes del Suelo/análisis , Monitoreo del Ambiente , Metalurgia , Hojas de la Planta/química , Raíces de Plantas/química , Tallos de la Planta/química , Serbia
10.
Curr Pharm Des ; 11(11): 1429-39, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15853673

RESUMEN

In this review we describe clinical and neurophysiological features of motor control in human spinal cord injury based on two models. First, motor control is considered in subjects with injury-induced complete division of the spinal cord from brain and brainstem structures, and second, in those in which the division is partial. We describe motor control in terms of segmental and plurisegmental reflex activity that dominates motor unit output to the muscles following complete separation from the brain motor structures by accidental injury. With incomplete separation of the spinal cord from brain structures, motor control is defined as the voluntary manipulation of reflex and automatic activity integrated with internal and external feedback signals. We review here motor control found after complete spinal cord injury with paradigm of single and regular-repeating stimuli applied to elicit cutaneous and muscle stretch reflex responses. We argue, that isolated spinal cord neural circuitry is capable of organizing characteristic reflex events that depend on the characteristics of the stimulus. Also, the profile of residual brain and brainstem, modified by the reduction in descending long spinal tract fibers arriving at their targets in the spinal gray matter, produces characteristic changes in motor output to the muscles that leads to the development of new neural strategies for control of segmental and plurisegmental neural circuitry. In the second part of this review, we discuss available treatment modalities for impaired cord function and briefly outline neurobiological interventions under development for repair of spinal cord injury.


Asunto(s)
Neuronas Motoras/fisiología , Músculos/inervación , Traumatismos de la Médula Espinal/terapia , Humanos , Espasticidad Muscular/fisiopatología , Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/fisiopatología
11.
Neurology ; 27(11): 1078-86, 1977 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-563004

RESUMEN

The vibration reflex was studied in 49 patients with traumatic spinal cord lesions. It was elicited in all patients, even after presumably complete division of the cord. The vibration relfex consisted of a short-latency, brief outburst of phasic activity of motor units, followed by rapidly decreasing phasic component and a later slowly declining tonic component. When periods of vibration were repeated at short intervals of 2 to 10 seconds, the responses showed an approximately exponential decline, although the beginning of each subsequent response was always larger than the end of the preceding response. A large part of this decline can be characterized as a habituation of the vibration reflex. In comparison with the vibration reflex in normal subjects, the phasic component was increased and the tonic one reduced. The tonic component was especially susceptible to potentiation and dishabituation by voluntary effort to contract the vibrated muscle, even in some patients with no other evidence that the lesion was incomplete. We suggest that the tonic component of the human vibration reflex depends, at least in part, on segmental interneurons and their descending spinal pathways, while the phasic component depends mainly on the excitability level of spinal motoneurons.


Asunto(s)
Reflejo , Traumatismos de la Médula Espinal/fisiopatología , Vibración , Potenciales Evocados , Humanos , Interneuronas/fisiología , Neuronas Motoras/fisiología , Contracción Muscular , Tono Muscular , Músculos/inervación , Tiempo de Reacción
12.
Neurology ; 30(7 Pt 2): 19-27, 1980 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-6993992

RESUMEN

Electromyographic (EMG) recordings from multiple muscle groups with surface electrodes during systematic evaluation of phasic and tonic stretch reflexes, cutaneomuscular reflexes, long loop reflexes, postural reflexes, and volitional activation have been used to provide a neurophysiologic basis for selection of the appropriate treatment for spasticity, and to gain further insights into the general mechanisms of spasticity. Pharmacologic methods are useful as a temporary measure. Hypertonia of a single muscle can be effectively treated with 40% alcohol injections to the motor points and hypertonia of a muscle group with partial denervation through 6% phenol in water injected into the nerve trunk. Hypertonia of several muscle groups can be treated by chemical or surgical rhizotomy or myelotomy. Generalized hypertonia involving limb and trunk muscles can be modified through chronic epidural stimulation of the spinal cord. Modification of reciprocal antagonistic muscle activity may be achieved through electrical stimulation of the involved nerve trunks.


Asunto(s)
Espasticidad Muscular/terapia , Atención Ambulatoria , Ataxia/terapia , Baclofeno/uso terapéutico , Dantroleno/uso terapéutico , Diazepam/uso terapéutico , Estimulación Eléctrica , Electrodos , Electroencefalografía , Electromiografía , Humanos , Esclerosis Múltiple/complicaciones , Espasticidad Muscular/tratamiento farmacológico , Espasticidad Muscular/cirugía , Bloqueo Nervioso , Enfermedades Neuromusculares/complicaciones , Paresia/terapia , Médula Espinal/fisiopatología
13.
J Neuroimmunol ; 58(1): 43-50, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7537279

RESUMEN

Immunization of female rats with encephalitogen before gestation, during gestation, and during lactation differentially decreased susceptibility to experimental allergic encephalomyelitis (EAE) in their offspring. The most pronounced suppression, revealed by lowered incidence and weaker clinical signs of the disease, was observed in offspring of mothers immunized before gestation and during lactation in both Dark August (EAE-susceptible), and Wistar (EAE-relatively resistant) rat strains. Induction of EAE in mothers during pregnancy only delayed the onset of the disease in DA progeny. The overall effect on EAE in offspring did not depend on the disease intensity in mothers. Our results suggest that anti-myelin basic protein (MBP) antibodies passively transferred from mothers are not responsible for the observed protection in offspring.


Asunto(s)
Encefalomielitis Autoinmune Experimental/prevención & control , Esquemas de Inmunización , Proteína Básica de Mielina/administración & dosificación , Animales , Anticuerpos Antiidiotipos/sangre , Susceptibilidad a Enfermedades/inmunología , Esquema de Medicación , Encefalomielitis Autoinmune Experimental/inmunología , Femenino , Inmunidad Innata/inmunología , Inmunidad Materno-Adquirida , Lactancia/inmunología , Masculino , Proteína Básica de Mielina/inmunología , Embarazo , Ratas , Ratas Endogámicas , Ratas Wistar , Especificidad de la Especie
14.
J Neurotrauma ; 6(1): 25-9, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2666675

RESUMEN

This article outlines the clinical characteristics of head injuries and describes their outcome. It emphasizes that some of the clinical characteristics and patterns of recovery can be explained by temporary or long-term failure in connection between different regions of the brain by specialized white matter pathways, which results in so-called dysconnection syndromes. It points out that the ability to assess these dysconnection syndromes leads to the prevention of disuse of the uninjured part of the brain and suppression of secondary brain dysfunctions. The second part of this article describes restorative neurology and then discusses how it is becoming possible to breach the existing gap between cellular and human holistic neurobiology. It concludes that restorative neurology research programs will be used routinely in the treatment of patients with acute and chronic head injury.


Asunto(s)
Traumatismos Craneocerebrales/rehabilitación , Traumatismos Craneocerebrales/fisiopatología , Traumatismos Craneocerebrales/terapia , Humanos , Neurofisiología
15.
J Neurotrauma ; 10(3): 315-26, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-8258844

RESUMEN

Nine patients were examined in the chronic stage of spinal cord injury (12 to 56 months postinjury). Surface lumbosacral spinal cord evoked potentials (LSEPs) were obtained using electrodes placed over the S1, L2, L4, and T12 vertebral levels, referenced to a T6 surface electrode. Epidural LSEPs were obtained using a multielectrode lead placed percutaneously into the epidural space for evaluation of the efficacy of spinal cord stimulation for modification of pain and spasticity. The LSEPs resulting from supramaximal stimulation of the tibial nerve at the popliteal fossa were composed of propagating and stationary action potential components. Based on the surface LSEP amplitudes and latencies established in healthy subjects, the data was divided into normal (less than 2 SD), marginal (between 2 and 2.5 SD), and abnormal (greater than 2.5 SD) categories. Comparison of surface and epidural LSEPs at the T12 vertebral level for the normal group (n = 6, 4 incomplete and 2 complete) revealed a mean epidural/surface amplitude ratio of 9.44 and a latency for the major negative component of 15.2 +/- 0.6 ms for the epidural versus 14.8 +/- 0.6 ms for the surface LSEP. In cases where the lead was progressively removed and LSEPs recorded (n = 4) the propagating components rapidly attenuated and increased in duration while the stationary components attenuated but did not change in duration. The LSEPs for the marginal group (n = 2, 1 incomplete and 1 complete) showed similar epidural/surface amplitude ratios. In the abnormal case (n = 1, complete) surface LSEPs were absent but epidural LSEPs were present but with stationary and propagating components of low amplitude. This study demonstrates the ability of the epidural LSEP to provide more information than the surface LSEP of the functional condition of the lumbosacral spinal cord, particularly regarding the character of the propagating action potentials and in cases when the surface LSEPs appear to be of very low amplitude or absent.


Asunto(s)
Traumatismos de la Médula Espinal/fisiopatología , Médula Espinal/fisiopatología , Adolescente , Adulto , Enfermedad Crónica , Estimulación Eléctrica , Espacio Epidural , Potenciales Evocados , Femenino , Humanos , Región Lumbosacra , Masculino , Persona de Mediana Edad , Tiempo de Reacción , Valores de Referencia , Piel , Tórax , Nervio Tibial/fisiopatología
16.
J Neurotrauma ; 6(4): 231-45, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2614851

RESUMEN

Six patients were examined in the acute stage of spinal cord injury, between 11 h and 12 days posttrauma. Quadripolar epidural electrodes were positioned either percutaneously using a Tuohy needle or directly into the epidural space during surgical intervention. These electrodes were combined with a common reference to obtain monopolar recordings of spinal cord evoked potentials resulting from either median nerve stimulation at the wrist or tibial nerve stimulation at the popliteal fossa. Spinal cord evoked injury potentials (SCEIPs), stationary potentials with positive polarity on the distal aspect of the lesion and negative polarity on the proximal aspect, were recorded in all cases. The average amplitude (n = 3) of the SCEIP resulting from tibial nerve stimulation as measured across the lesion was 13.5 microV with an average duration of 12.7 msec. For median nerve stimulation, the average amplitude (n = 3) of the SCEIP was 16.3 microV with an average duration of 6.7 msec. There was a change in polarity in all cases over a distance of less than 6 mm, the distance between the electrode contacts on the epidural electrode. In one case, recordings were performed initially at 11 h and repeated at 21 days posttrauma. In the latter recording, the SCEIP was still present but was five times smaller in amplitude. Coincidentally, the patient also showed clinical signs of improvement in sensory and motor spinal cord function. This study demonstrates the feasibility of recording the SCEIP in patients with acute spinal cord injury, describes the features of these SCEIPs, discusses their origins, and explores the utility of recording the SCEIP as an aid in determining the severity of the injury as well as a means of monitoring changes in spinal cord function.


Asunto(s)
Traumatismos de la Médula Espinal/fisiopatología , Potenciales de Acción , Adulto , Femenino , Humanos , Masculino
17.
J Neurotrauma ; 14(8): 539-48, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9300564

RESUMEN

Other than clinical examination, few methods exist for assessing the functional condition of descending long tracts of the spinal cord in humans. This review covers neurophysiological examination of the corticospinal system using transcranial electrical and magnetic motor cortex stimulation. The neurophysiological basis for the motor evoked potentials (MEPs) and the differences between the two methods are discussed followed by a review of their use in individuals with spinal cord injury (SCI). Transcranial motor cortex stimulation is used to monitor descending spinal cord tract condition during spinal surgeries and could be useful for assessing central nervous system trauma, especially in the unconscious multitrauma patient. In the chronic phase of SCI, recordings of MEPs have enabled the estimation of central conduction times that relate to the condition of axons passing through the injured segment of the spinal cord. They were found to correlate well with clinical examination scores but as predictors of outcome, the reports have been mixed. The use of transcranial motor cortex stimulation to modify segmental reflexes and in combination with volitional attempts have also provided evidence of conduction across the lesion in paralyzed SCI subjects. However, MEPs can be absent in some SCI individuals who may be able to volitionally activate muscles below the level of the spinal cord lesion. Such findings are useful in elucidating the neural mechanisms underlying the performance of a volitional movement and may serve to guide and monitor the effects of future treatments for paralysis in SCI and other neurological disorders.


Asunto(s)
Corteza Cerebral/fisiopatología , Corteza Motora/fisiopatología , Traumatismos de la Médula Espinal/fisiopatología , Animales , Estimulación Eléctrica , Humanos
18.
J Neurotrauma ; 9 Suppl 1: S293-300, 1992 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1588619

RESUMEN

Selected neurophysiologic studies can supplement clinical examination in assessing residual motor function after spinal cord or head injury. The ability of polyelectromyographic recording to detect subclinical suprasegmental control is illustrated in paraplegic patients after spinal cord injury. Excitatory or inhibitory modulation of segmental motor activity in a subpopulation of patients with clinically complete motor paralysis suggests residual connection across the lesion. This observation is consistent with the pathologic finding that complete transection of the spinal cord is rare after spinal cord injury. A preliminary study of motor-evoked potentials also indicates their potential value as an objective measure of the functional status of descending pathways. Neurophysiological assessment of subclinical residual motor function may be useful in understanding the role of suprasegmental input in the manifestation of spasticity, in objectively documenting recovery of function after injury, and may aid in the development of more specific restorative measures. Our limited experience in head-injured patients also suggests the potential usefulness of these tools in supplementing clinical evaluation.


Asunto(s)
Lesiones Encefálicas/fisiopatología , Traumatismos Craneocerebrales/fisiopatología , Traumatismos de la Médula Espinal/fisiopatología , Electromiografía , Potenciales Evocados , Humanos , Actividad Motora , Examen Neurológico
19.
Restor Neurol Neurosci ; 5(2): 119-29, 1993 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-21551705

RESUMEN

The tonic stretch reflex elicited by vibration of a muscle or tendon provides a means of studying segmental reflex activity in humans with impaired volitional motor activity due to spinal cord injury (SCI). Vibration applied to the achilles or patellar tendon in a group of 51 SCI subjects elicited motor unit activity different from that found in 12 healthy subjects. Four distinct features of motor unit responses to vibration of a single tendon (achilles or patellar) could be seen in the SCI subjects: (i) a rapid onset, tonic response, frequently beginning with a single burst analogous to a tendon jerk, in 72% of vibrated sites; (ii) repetitive, phasic bursts of activity or vibratory-induced clonus in 23% of the tonic responses; (iii) spread of activity to muscles distant from the vibration in 44% of the tonic responses; and vibratory-induced withdrawal reflexes (VWR) which occurred after vibration of 37% of the sites. Overall, 81% of stimulated sites responded to vibration in SCI subjects. In contrast, only 54% of vibrated sites responded in control subjects, always with a gradual onset tonic response, never accompanied by a VWR. The VWR in SCI subjects was typically of much larger amplitude than the tonic responses and involved a mean of 5 muscles (41% bilaterally). Features of these responses provide an insight into underlying neurocontrol mechanisms which may provide guidance in the selection of appropriate intervention or management strategies.

20.
Restor Neurol Neurosci ; 7(4): 225-34, 1995 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-21551793

RESUMEN

Introduction of transcranial magnetic stimulation (TMS) has provided means to study non-invasively corticospinal functions in humans. The purpose of the present study was to obtain an objective evaluation of spinal cord functions in spinal cord injury (SCI) subjects using TMS, multichannel surface EMG and somatosensory-evoked potentials (SSEP). Multichannel surface EMG recording was performed during reinforcement manoeuvres and during vibratory tonic reflex. Twenty-five post-traumatic clinically incomplete (ambulatory, AMB, and non-ambulatory, nAMB) SCI subjects were studied and compared to a control group of seven subjects. After preliminary analysis of neurophysiological studies they were divided into four groups according to presence or absence of motor-evoked potentials (MEP) in response to TMS in muscles below the level of the lesion and according to their ability to ambulate. TMS was delivered at vertex at 100% intensity and recorded from the large muscles of the upper and lower limbs. Surface EMG was recorded during reinforcement manoeuvres (RM) in the leg muscles and EMG activity was scored. SSEP were recorded at T12, L2, L4 and SI spinous processes and at Cz' on the scalp following tibial nerve stimulation at popliteal fossa. The prevalence of EMG responses during RM was higher in group with present MEPs (AMB/MEP+ and nAMB/MEP+) than in the group without MEPs. The group with present MEPs also showed better preserved functions of the ascending tracts compared to subjects without MEPs. Groups with present MEPs had 5/10 normal, 2/10 abnormal and 3/10 absent cortical SSEPs, whereas groups without MEPs showed 1/11 normal, 4/11 abnormal and 6/11 absent cortical SSEPs. Sustained function of ascending tracts was also positively correlated with preserved ability to ambulate. It was concluded that TMS in combination with multichannel surface EMG monitoring and sensory evoked potentials may prove feasible in assessing the functional capacity of the spinal cord after spinal cord lesion.

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