Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Artículo en Inglés | MEDLINE | ID: mdl-39146215

RESUMEN

STUDY DESIGN: A prospective, comparative study on clinical, radiographic, and health-related quality of life (HRQoL) outcomes in adolescents with acute spondylolysis treated with a rigid thoracolumbar orthosis (Boston brace) or with a placebo (elastic lumbar support) with a 2-year follow-up time. OBJECTIVE: To compare outcomes of acute adolescent spondylolysis treated with a rigid thoracolumbar orthosis or a placebo with a 2-year follow-up time. SUMMARY OF BACKGROUND DATA: The benefits of the use of rigid orthosis for treatment of spondylolysis and achieving bony union of spondylolysis remains unclear. METHODS: Sixty consecutive patients with acute spondylolysis were prospectively enrolled. Three patients were excluded from analysis as they did not fulfill inclusion criteria. First 14 patients were randomized and the remaining 46 chose treatment method themselves. Treatment time was four months and follow-up time was two years. HRQoL was measured using Scoliosis Research Society-24 (SRS-24) outcome questionnaire. The primary outcome was the HRQoL at 24 months and whether treatment type, bony union of the spondylolysis or development of spondylolisthesis affected it. RESULTS: Thirty (30/57) patients were treated with a Boston brace and twenty-seven (27/57) patients with a placebo. The bony union rate of spondylolysis did not differ between study groups (20/30 vs 17/27, respectively, P=0.789). The HRQoL did not differ between treatment groups in the SRS-24 domains through follow-up (P>0.05 for all). Five patients (5/57) developed spondylolisthesis (mean slip 4.2 mm) during two-year follow-up time. Non-union of the spondylolysis predicted development of spondylolisthesis (P=0.005), but treatment type did not affect it (P>0.05). Two years after treatment patients who had bony union had higher SRS-24 total (P=0.005) and satisfaction domain (P<0.001) compared to patients with non-union. CONCLUSION: A rigid brace is not necessary for treatment of acute spondylolysis. Achieving bony union of adolescent spondylolysis is desirable as their HRQoL is higher at two years. LEVEL OF EVIDENCE: II.

2.
Spine (Phila Pa 1976) ; 48(2): 89-96, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-35834380

RESUMEN

STUDY DESIGN: A prospective study on clinical, radiographic, and health-related quality of life (HRQoL) outcomes in children with acute spondylolysis treated with a rigid thoracolumbar orthosis or with an elastic lumbar support. OBJECTIVE: To compare outcomes of pediatric spondylosysis treated with a hard brace or an elastic lumbar support. SUMMARY OF BACKGROUND DATA: The benefits of the use of a rigid orthosis in treatment of spondylolysis are not clear. MATERIALS AND METHODS: Fifty-seven consecutive children with acute spondylolysis (mean age: 14.1 yr, range: 9-17 yr) were prospectively enrolled. Patients were treated with a rigid thoracolumbar orthosis (Boston brace) or with a low-profile, elastic lumbar support. First 14 patients were randomized the remaining 43 chose brace type themselves. Treatment period was four months. Treatment outcomes included bony union of the spondylolysis assessed with a computed tomography at four months and HRQoL using the Scoliosis Research Society-24 outcome questionnaire filled out before and after the treatment. RESULTS: Of the 57 patients, 54 completed the treatment protocol. Twenty-nine patients were treated using the Boston brace and 25 patients the elastic lumbar support. Bony union was obtained in 69.0% (20/29) of the Boston brace and in 60.0% (15/25) of the elastic lumbar support group patients. Difference in union rates was not significant (relative risk=1.14, 95% confidence interval: 0.44-2.98, P =0.785). There was no difference in the Scoliosis Research Society-24 total or domain scores at the end of follow-up between the treatment groups ( P >0.159 for all comparisons). In the whole cohort, the bony union did not predict better HRQoL in the end of the treatment ( P =0.869), although the pain domain improved significantly in the whole cohort ( P <0.001). CONCLUSIONS: A rigid thoracolumbar orthosis did not provide any benefits over an elastic lumbar support in terms of bony union or HRQoL outcomes in children with acute spondylolysis. LEVEL OF EVIDEN: 2.


Asunto(s)
Escoliosis , Espondilólisis , Niño , Humanos , Adolescente , Estudios Prospectivos , Escoliosis/diagnóstico por imagen , Escoliosis/terapia , Calidad de Vida , Espondilólisis/diagnóstico por imagen , Espondilólisis/terapia , Aparatos Ortopédicos , Resultado del Tratamiento , Vértebras Lumbares/diagnóstico por imagen
3.
J Bone Joint Surg Am ; 2021 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-34424869

RESUMEN

BACKGROUND: Surgical correction of spinal deformity requires major surgical intervention with extensive manipulation of the spine and neural elements. Persistent postoperative pain affects patient quality of life and can also cause financial burden for patient families and for society. We aimed to investigate the effect of perioperative pregabalin on the incidence of persistent pain following instrumented spinal fusion. METHODS: We conducted a randomized, double-blinded, and placebo-controlled single-center clinical trial. Adolescents and children 10 to 21 years old with a spinal deformity who were scheduled for pedicle screw instrumentation and fusion were randomized into either the pregabalin or placebo group. Patients received 2 mg/kg of pregabalin or a placebo twice daily preoperatively and for 5 days postoperatively. The duration of follow-up was 2 years. The primary outcomes were cumulative opioid consumption during the first 48 hours postoperatively and the incidence of persistent postoperative pain over the course of the 2-year follow-up. RESULTS: Sixty-four of 77 eligible patients were enrolled in the study, with all patients completing the 2-year follow-up. Thirty-three patients were randomized into the pregabalin group and 31 into the placebo group. There was no significant difference in cumulative 48-hour opioid consumption between the study groups. The Scoliosis Research Society 24-Item Questionnaire pain domain score improved significantly, from a mean value of 3.8 in both groups to 4.3 in the pregabalin and 4.0 in the placebo group at 2 years postoperatively, with no differences between the study groups at any time point (p = 0.317). The Scoliosis Research Society total scores of the study groups were similar (p = 0.678). Back pain, as measured with use of a visual analogue scale, improved significantly (p = 0.001) with no significant differences at any time point (preoperatively and 6 months, 1 year, and 2 years postoperatively). CONCLUSIONS: Perioperative pregabalin does not reduce postoperative opioid consumption or the incidence of persistent postoperative pain following instrumented posterior spinal fusion for spinal deformities in an adolescent population. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

4.
Spine (Phila Pa 1976) ; 45(23): E1572-E1579, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32925683

RESUMEN

STUDY DESIGN: A prospective study on the clinical, radiographic, and the health-related quality of life (HRQOL) outcomes in adolescents with spondylolisthesis undergoing instrumented circumferential spinal fusion compared with age and sex matched controls. OBJECTIVE: To determine the outcomes of pediatric spondylolisthesis patients minimum 2 years after surgery and to compare their HRQOL with age and sex matched controls. SUMMARY OF BACKGROUND DATA: There is limited evidence of the HRQOL of adolescent spondylolisthesis patients after surgery and no studies comparing it with healthy controls. METHODS: Twenty-six consecutive adolescents (mean age 14.7 yr, range 10-18 yr) undergoing instrumented reduction with intercorporeal spinal fusion for spondylolisthesis (11 low-grade, 15 high-grade) by a single orthopedic surgeon were included to this study cohort and matched by age and sex with two controls. The HRQOL was measured with Scoliosis Research Society-24 (SRS-24) questionnaire before surgery, 6 months and 2 years after the surgery. RESULTS: The mean (SD) vertebral slip in the low-grade patients was 25% (13%) and 67% (15%) in the high-grade patients and 6% (7%) and 21% (25%) postoperatively, respectively (P ≤ 0.041 for both comparisons). Three (12%) patients developed a non-union during follow-up. None of the patients developed a persistent neurologic deficit, but two (8%) patients presented with chronic postsurgical pain persisting 24 months. Seven (27%) of the patients had reoperations for any reason during the follow-up. Pain and activity domains of the SRS-24 improved significantly from preoperative to 2-year follow-up (P ≤ 0.007 for both). SRS pain, self-image, function domains, and total score were significantly worse as compared with the 52 controls (P ≤ 0.020 for all comparisons). CONCLUSION: Risk of non-union is relatively low after instrumented spinal reduction in adolescents with spondylolisthesis. HRQOL improves significantly after instrumented reduction and circumferential spinal fusion in adolescents with spondylolisthesis, but remains at statistically lower level than in the controls. LEVEL OF EVIDENCE: 2.


Asunto(s)
Calidad de Vida , Fusión Vertebral , Espondilolistesis/cirugía , Adolescente , Niño , Femenino , Humanos , Vértebras Lumbares/cirugía , Masculino , Estudios Prospectivos , Reoperación , Escoliosis/cirugía , Encuestas y Cuestionarios , Resultado del Tratamiento
5.
J Bone Joint Surg Am ; 102(3): 205-212, 2020 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-31770296

RESUMEN

BACKGROUND: Pregabalin as part of a multimodal pain-management regimen has been shown to reduce opioid consumption after spinal surgery in adults but it is unclear whether this is also true in adolescents. Pregabalin has been found to have neuroprotective effects and therefore could have a positive impact on pain after spinal deformity surgery. We conducted a randomized, double-blinded, placebo-controlled clinical trial of adolescent patients undergoing spinal fusion to evaluate the short-term effects of pregabalin on postoperative pain and opioid consumption. METHODS: Adolescents with adolescent idiopathic scoliosis, Scheuermann kyphosis, or spondylolisthesis who were scheduled for posterior spinal fusion with all-pedicle-screw instrumentation were randomized to receive either pregabalin (2 mg/kg twice daily) or placebo preoperatively and for 5 days after surgery. The patients ranged from 10 to 21 years of age. The primary outcome was total opioid consumption as measured with use of patient-controlled analgesia. Postoperative pain scores and opioid-related adverse effects were evaluated. RESULTS: Sixty-three of 77 eligible patients were included and analyzed. Cumulative oxycodone consumption per kilogram did not differ between the study groups during the first 48 hours postoperatively, with a median of 1.44 mg/kg (95% confidence interval [CI],1.32 to 1.67 mg/kg) in the pregabalin group and 1.50 mg/kg (95% CI, 1.39 to 1.79 mg/kg) in the placebo group (p = 0.433). A subgroup analysis of 51 patients with adolescent idiopathic scoliosis showed the same result, with a mean of 1.45 mg/kg (95% CI, 1.24 to 1.65 mg/kg) in the pregabalin group and 1.59 mg/kg (95% CI, 1.37 to 1.82 mg/kg) in the placebo group (p = 0.289). Total oxycodone consumption per hour (mg/kg/hr) was not different between the groups over the time points (p = 0.752). The postoperative pain scores did not differ significantly between the groups (p = 0.196). CONCLUSIONS: The use of perioperative pregabalin does not reduce the postoperative opioid consumption or pain scores in adolescents after posterior spinal fusion surgery. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.


Asunto(s)
Analgésicos/uso terapéutico , Pregabalina/uso terapéutico , Fusión Vertebral , Adolescente , Adulto , Analgésicos Opioides/uso terapéutico , Niño , Método Doble Ciego , Femenino , Humanos , Masculino , Dimensión del Dolor , Dolor Postoperatorio/tratamiento farmacológico , Adulto Joven
6.
J Bone Joint Surg Am ; 101(16): 1460-1466, 2019 08 21.
Artículo en Inglés | MEDLINE | ID: mdl-31436653

RESUMEN

BACKGROUND: Posterior spinal fusion with pedicle screws is the gold-standard treatment for adolescent idiopathic scoliosis (AIS); however, it is unclear whether this procedure results in improved long-term back pain and health-related quality of life compared with patients not surgically treated for AIS. The aim of the present study was to evaluate back pain and quality of life in surgically managed patients with a minimum follow-up of 5 years compared with patients with untreated AIS and a healthy control group. METHODS: Fifty-five consecutive adolescent patients who underwent posterior pedicle screw instrumentation for AIS by a single orthopaedic surgeon were prospectively enrolled. At a minimum of 5 years postoperatively, 49 patients completed Scoliosis Research Society (SRS)-24 questionnaires, and data on reoperation were collected. Pain and quality-of-life parameters were compared with those of 49 age and sex-matched patients with untreated AIS and 49 healthy controls. RESULTS: The major curve averaged 53° preoperatively and 12° at 2 years postoperatively. One reoperation (pedicle screw removal) was needed because of a new neurological deficit (transient). The SRS-24 pain, function, and total scores improved significantly from preoperatively to 5 years postoperatively (all p ≤ 0.016), with pain scores improving from 4.0 to 4.3 (p = 0.003). There was no association between pain scores and the preoperative major curve, instrumentation below L1, or postoperative rib hump. The surgical treatment group had significantly better pain, activity, and self-image domain scores at 5 years postoperatively compared with the untreated AIS group (all p ≤ 0.014), and similar pain, self-image, and activity domain scores compared with the healthy control group; however, function scores were significantly lower among patients in the surgical treatment group (p < 0.001). CONCLUSIONS: Patients who underwent posterior spinal fusion with pedicle screws experienced improved back pain and health-related quality of life compared with patients with untreated AIS. Patients in the surgical treatment group had similar health-related quality of life to that of the healthy control group, except for function, which was significantly lower. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.


Asunto(s)
Dolor de Espalda/etiología , Dolor Postoperatorio/fisiopatología , Calidad de Vida , Escoliosis/cirugía , Fusión Vertebral/efectos adversos , Adolescente , Análisis de Varianza , Dolor de Espalda/fisiopatología , Dolor de Espalda/psicología , Niño , Estudios de Cohortes , Femenino , Humanos , Fijadores Internos , Masculino , Análisis Multivariante , Dimensión del Dolor , Pronóstico , Valores de Referencia , Estudios Retrospectivos , Escoliosis/complicaciones , Escoliosis/psicología , Índice de Severidad de la Enfermedad , Fusión Vertebral/métodos , Resultado del Tratamiento , Adulto Joven
7.
World Neurosurg ; 127: e1020-e1025, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30995548

RESUMEN

OBJECTIVE: Pedicle screw instrumentation is widely used for spinal deformity correction and fusion in adolescents for idiopathic scoliosis. The goal is to achieve and sustain good alignment in all 3 planes. We compared 2 different cobalt-chromium (CoCr) rod designs with different stiffnesses with regard to the restoration of coronal and sagittal balance in adolescents operated on for idiopathic scoliosis. MATERIAL AND METHODS: A prospective comparative study was made of 90 consecutive adolescents, mean age (standard deviation) 15.6 years (2.1 years), with idiopathic scoliosis who underwent posterior spinal fusion by the use of bilateral segmental pedicle screw instrumentation (PSI) with 6.0 Co-Cr rods. Fifty-four adolescents (43 girls) were operated on by the use of circular rods and 36 (27 girls) by the use of sagittal reinforced rods, with a 2-year follow-up. RESULTS: Preoperative major coronal curves were similar and at 2 years: 11° (5.0) and 17° (7.2) with correction percentages of 78% (10) and 69% (12) in the circular and reinforced rod groups (P < 0.01). Thoracic kyphosis at 2 years measured 16° (7) and 21° (6) in the circular and reinforced rod groups (P < 0.01). The number of patients with hypokyphosis was lower in the reinforced rod group at 2 years (P = 0.02). In the reinforced rod group, there was a negative correlation between coronal correction and thoracic kyphosis (r = -0.52, P < 0.01). CONCLUSIONS: Both circular and sagittal reinforced 6.0-mm CoCr rods provide adequate coronal correction for adolescents with idiopathic scoliosis. The use of sagittal reinforced rods provided better thoracic kyphosis restoration and a lower risk for postoperative hypokyphosis.


Asunto(s)
Tornillos Pediculares , Equilibrio Postural/fisiología , Escoliosis/diagnóstico por imagen , Escoliosis/cirugía , Fusión Vertebral/instrumentación , Adolescente , Femenino , Estudios de Seguimiento , Humanos , Masculino , Tornillos Pediculares/normas , Estudios Prospectivos , Fusión Vertebral/normas , Vértebras Torácicas/diagnóstico por imagen , Vértebras Torácicas/cirugía
8.
Eur Spine J ; 27(2): 298-304, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29147795

RESUMEN

PURPOSE: This study was designed to evaluate the effect of preoperative pregabalin on intraoperative neurophysiological monitoring in adolescents undergoing surgery for spinal deformities. METHODS: Thirty-one adolescents undergoing posterior spinal fusion were randomized to receive preoperatively either pregabalin 2 mg/kg twice daily or placebo. The ability to make reliable intraoperative neurophysiological measurements, transcranial motor (MEPs) and sensory evoked potentials (SSEP) was evaluated. RESULTS: Two patients (pregabalin group) did not fulfil the inclusion criteria and one patient's (placebo group) spinal monitoring was technically incomplete and these were excluded from the final data. In the rest, spinal cord monitoring was successful. Anaesthesia prolonged the latency of MEPs and increased the threshold current of MEP. The current required to elicit MEPs did not differ between the study groups. There were no statistically significant differences between the study groups regarding the latency of bilateral SSEP (N32 and P37) and MEP latencies at any time point. CONCLUSIONS: Preoperative pregabalin does not interfere spinal cord monitoring in adolescents undergoing posterior spinal fusion. LEVEL OF EVIDENCE: I.


Asunto(s)
Analgésicos/administración & dosificación , Monitorización Neurofisiológica Intraoperatoria/métodos , Pregabalina/administración & dosificación , Curvaturas de la Columna Vertebral/cirugía , Fusión Vertebral/métodos , Adolescente , Analgésicos/efectos adversos , Método Doble Ciego , Potenciales Evocados Motores/efectos de los fármacos , Potenciales Evocados Motores/fisiología , Potenciales Evocados Somatosensoriales/efectos de los fármacos , Potenciales Evocados Somatosensoriales/fisiología , Femenino , Humanos , Masculino , Pregabalina/efectos adversos , Médula Espinal/fisiopatología , Médula Espinal/cirugía
9.
J Pediatr Surg ; 53(8): 1542-1546, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29153469

RESUMEN

BACKGROUND: Postoperative urinary retention has been reported to affect up to 27% of adults undergoing degenerative lumbar spine surgery and approximately one-third of children undergoing lower-extremity orthopedic surgery. No data exist on the incidence and risk factors of postoperative urinary tract retention/difficulties to empty the bladder in young patients undergoing instrumented posterior spinal fusion. We aimed to characterize incidence, risk factors and treatment of postoperative urinary retention (POUR) and difficulties to empty the bladder in young patients undergoing posterior spinal fusion (PSF) for idiopathic scoliosis. METHODS: One hundred and eleven consecutive patients (mean age 16years [range, 11-21years], 81 females and 30 males) undergoing PSF for adolescent idiopathic scoliosis were screened after removal of urinary catheter postoperatively for inability to void and residual volume of urinary bladder. The latter was measured using ultrasound on two separate occasions. POUR and the need for intermittent catheterization were defined as an inability to void after catheter removal and documented full bladder with ultrasound (a residual of 300mL or more) or a significant residual volume after voiding (>2mL/kg or >100mL). RESULTS: Fifty-one (46%) of the patients were either unable to void or had a clinically significant amount of residual volume after voiding. These fifty-one patients required intermittent catheterization for a mean of two days. Thirty patients (27%) had POUR, a residual volume of 300mL or more. Two (1.8%) patients experienced urinary tract infection postoperatively. Patients with urinary retention had a significantly higher mean intraoperative blood loss (mean 626mL vs. 464mL; p=0.020) and longer operation time (mean 3.3h vs. 2.8h; p=0.009) as compared with those not having urinary retention. In multivariate analyses the main risk factor for urinary retention was male gender (odds ratio 3.2 [95% confidence interval 1.1-9.2], p=0.028). CONCLUSIONS: Postoperative voiding difficulties affect almost half of the patients with age under 21years undergoing PSF for idiopathic scoliosis. The main risk factors were increased intraoperative blood loss, longer length of surgery and male gender. POUR should be actively screened and treated in this patient population. LEVEL OF EVIDENCE: Prospective Cohort Study II.


Asunto(s)
Escoliosis/cirugía , Fusión Vertebral/efectos adversos , Retención Urinaria/etiología , Adolescente , Adulto , Niño , Estudios de Cohortes , Femenino , Humanos , Incidencia , Masculino , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/terapia , Estudios Prospectivos , Factores de Riesgo , Ultrasonografía/métodos , Vejiga Urinaria/fisiopatología , Cateterismo Urinario/estadística & datos numéricos , Retención Urinaria/epidemiología , Retención Urinaria/terapia , Adulto Joven
10.
Duodecim ; 131(19): 1785-91, 2015.
Artículo en Finés | MEDLINE | ID: mdl-26638663

RESUMEN

Untreated severe scoliosis results in a serious malposition of the back, restrictive lung disease and increases mortality compared with the normal population. Idiopathic scoliosis rarely reaches a severe degree. In the treatment of severe scoliosis, preoperative head traction of several weeks' duration has proven a safe and effective method of correcting the malposition, and will also make scoliosis surgery technically easier. Most cases of severe scoliosis can be treated with anterior pedicle screw instrumentation, and vertebrectomy is only seldom required.


Asunto(s)
Escoliosis/terapia , Tornillos Óseos , Humanos , Índice de Severidad de la Enfermedad , Fusión Vertebral/instrumentación , Tracción
11.
Duodecim ; 131(11): 1085-9, 2015.
Artículo en Finés | MEDLINE | ID: mdl-26245071

RESUMEN

Posterior cruciate ligament tear is a rare injury in the pediatric and adolescent population. Primary diagnosis of posterior cruciate ligament injury is based on careful attention to specific physical examination, but MRI is the mainstay for assessing the extent of ligamentous and possible associated injuries. In general, most of the posterior cruciate ligament tears in children and adolescents can be treated non-operatively with good functional outcome. Surgical treatment for these injuries should however be cautiously considered also for skeletally immature patients with a complete, intrasubstance ligament tear or dislocated avulsion fracture.


Asunto(s)
Traumatismos de la Rodilla/diagnóstico , Traumatismos de la Rodilla/terapia , Ligamento Cruzado Posterior/lesiones , Adolescente , Niño , Humanos , Imagen por Resonancia Magnética
12.
Eur J Pediatr Surg ; 23(4): 297-303, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23172567

RESUMEN

BACKGROUND: There are only few studies of Lisfranc injuries in children and adolescents. The aim of this study was to evaluate the mid-term results of the operatively treated injuries. METHODS: Seven Lisfranc injuries of adolescents were treated operatively in the Tampere University Hospital between 2004 and 2009. In four of the seven feet, the trauma comprised all the metatarsal bones. All patients were treated with open reduction and internal fixation. A questionnaire concerning the function and pain of the foot was sent to all the patients. RESULTS: In all but one case, the anatomical reduction was achieved and held during the follow-up. However, most patients claimed discomfort or constant harm in the injured foot at the end of the follow-up. Still, all the patients were able to run and no one needed to wear special shoes or any other kind of means. CONCLUSIONS: Lisfranc injuries in adolescents are likely to cause constant harm, even if the anatomical reduction is achieved.


Asunto(s)
Tornillos Óseos , Fijación Interna de Fracturas , Fracturas Óseas/cirugía , Huesos Metatarsianos/lesiones , Adolescente , Femenino , Estudios de Seguimiento , Fijación Interna de Fracturas/efectos adversos , Fijación Interna de Fracturas/métodos , Fracturas Óseas/diagnóstico por imagen , Humanos , Masculino , Dolor Postoperatorio/etiología , Radiografía , Estudios Retrospectivos , Encuestas y Cuestionarios , Resultado del Tratamiento
13.
J Clin Monit Comput ; 23(4): 237-42, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19565340

RESUMEN

OBJECTIVE: It was hypothesized that somato- sensory evoked potentials can be achieved faster by selective averaging during periods of low spontaneous electroen- cephalographic (EEG) activity. We analyzed the components of EEG that decrease the signal-to-noise ratio of somatosensory evoked potential (SEP) recordings during propofol anesthesia. METHODS: Patient EEGs were recorded with a high sampling frequency during deep anesthesia, when EEGs were in burst suppression. EEGs were segmented visually into bursts, spindles, suppressions, and artifacts. Tibial somatosensory evoked potentials (tSEPs) were averaged offline separately for burst, suppression, and spindle segments using a signal bandwidth of 30-200 Hz. Averages achieved with 2, 4, 8, 16, 64, 128, and 256 responses were compared both visually, and by calculating the signal-to-noise ratios. RESULTS: During bursts and spindles, the noise levels were similar and significantly higher than during suppressions. Four to eight times more responses had to be averaged during bursts and spindles than during suppressions in order to achieve a similar response quality. Averaging selectively during suppressions can therefore yield reliable tSEPs in approximately one-fifth of the time required during bursts. CONCLUSION: The major source of EEG noise in tSEP recordings is the mixed frequency activity of the slow waves of bursts that occur during propofol anesthesia. Spindles also have frequency components that increase noise levels, but these are less important, as the number of spindles is fewer. The fastest way to obtain reliable tSEPs is by averaging selectively during suppressions.


Asunto(s)
Anestesia , Electroencefalografía/métodos , Adolescente , Adulto , Anestésicos Intravenosos , Electromiografía/métodos , Potenciales Evocados Somatosensoriales/efectos de los fármacos , Potenciales Evocados Somatosensoriales/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Monitoreo Intraoperatorio , Monitoreo Fisiológico , Propofol/farmacología , Tibia/inervación
14.
J Endocrinol ; 177(2): 319-26, 2003 May.
Artículo en Inglés | MEDLINE | ID: mdl-12740020

RESUMEN

Sex steroids are required for a normal pubertal growth spurt and fusion of the human epiphyseal growth plate. However, the localization of sex steroid receptors in the human pubertal growth plate remains controversial. We have investigated the expression of estrogen receptor (ER) alpha, ERbeta and androgen receptor (AR) in biopsies of proximal tibial growth plates obtained during epiphyseal surgery in 16 boys and eight girls. All pubertal stages were represented (Tanner stages 1-5). ERalpha, ERbeta and AR were visualized with immunohistochemistry and the number of receptor-positive cells was counted using an image analysis system. Percent receptor-positive chondrocytes were assessed in the resting, proliferative and hypertrophic zones and evaluated for sex differences and pubertal trends. Both ERalpha- and ERbeta-positive cells were detected at a greater frequency in the resting and proliferative zones than in the hypertrophic zone (64+/-2%, 64+/-2% compared with 38+/-3% for ERalpha, and 63+/-3%, 66+/-3% compared with 53+/-3% for ERbeta), whereas AR was more abundant in the resting (65+/-3%) and hypertrophic zones (58+/-3%) than in the proliferative zone (41+/-3%). No sex difference in the patterns of expression was detected. For ERalpha and AR, the percentage of receptor-positive cells was similar at all Tanner pubertal stages, whereas ERbeta showed a slight decrease in the proliferative zone during pubertal development (P<0.05). In summary, our findings suggest that ERalpha, ERbeta and AR are expressed in the human growth plate throughout pubertal development, with no difference between the sexes.


Asunto(s)
Placa de Crecimiento/química , Receptores Androgénicos/análisis , Receptores de Estrógenos/análisis , Maduración Sexual/fisiología , Tibia , Adolescente , Determinación de la Edad por el Esqueleto , Análisis de Varianza , Niño , Receptor alfa de Estrógeno , Receptor beta de Estrógeno , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Inmunohistoquímica/métodos , Masculino , Análisis de Regresión
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA