Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Oral Maxillofac Surg ; 28(3): 1287-1294, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38698248

RESUMEN

PURPOSE: PEMF (pulsed electromagnetic fields) founds application in several medical fields to accelerate bone wounds healing and to reduce inflammation. The aim of our study was to evaluate the effectiveness of PEMF in reducing postoperative swelling and pain in patients undergoing orthognathic surgery. METHODS: A prospective observational monocentric study was conducted on a sample of 30 patients undergone to orthognathic surgery in Maxillofacial Surgery Unit of University of Naples Federico II. The patients who followed these inclusion criteria were enrolled in the study: age ≥ 18 years, Class III malocclusion, Surgical procedure of Le Fort I osteotomy + Bilateral Sagittal Split Osteotomy (BSSO), Written informed consent. Patients were divided into two groups: Group SD) postoperative standard treatment with medical therapy and cryotherapy, Group SD + PEMF) postoperative standard therapy + PEMF. Each patient underwent a 3D facial scan, at one (1d) and four (4d) days after surgery to compare the swelling reduction. The pain score was assessed through VAS score and analgesics administration amount. RESULTS: In SD + PEMF group, the facial volume reduction between 1d and 4d scan was on average 56.2 ml (6.23%), while in SD group, it was 23.6 ml (2.63%). The difference between the two groups was 3.6% (p = 0.0168). VAS pain values were significantly higher in SD group compared to SD + PEMF group in the second day after surgery (P = 0.021) and in the total 4 days (P = 0.008). CONCLUSIONS: Our data suggest that PEMF is valid tool to promote faster postoperative swelling and pain reduction in patients undergoing orthognathic surgery.


Asunto(s)
Edema , Procedimientos Quirúrgicos Ortognáticos , Dolor Postoperatorio , Humanos , Dolor Postoperatorio/prevención & control , Estudios Prospectivos , Edema/prevención & control , Femenino , Masculino , Adulto , Osteotomía Le Fort , Adulto Joven , Magnetoterapia/métodos , Dimensión del Dolor , Maloclusión de Angle Clase III/cirugía , Maloclusión de Angle Clase III/terapia , Osteotomía Sagital de Rama Mandibular/métodos , Adolescente , Crioterapia/métodos , Complicaciones Posoperatorias/prevención & control , Campos Electromagnéticos
2.
PLoS One ; 18(7): e0288312, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37450545

RESUMEN

Microwave imaging is a safe and promising new technology in breast radiology, avoiding discomfort of breast compression and usage of ionizing radiation. This paper presents the first prospective microwave breast imaging study during which both symptomatic and asymptomatic subjects were recruited. Specifically, a prospective multicentre international clinical trial was performed in 2020-2021, to investigate the capability of a microwave imaging device (MammoWave) in allowing distinction between breasts with no radiological finding (NF) and breasts with radiological findings (WF), i.e., with benign or malignant lesions. Each breast scan was performed with the volunteers lying on a dedicated examination table in a comfortable prone position. MammoWave output was compared to reference standard (i.e., radiologic study obtained within the last month and integrated with histological one if available and deemed necessary by responsible investigator) to classify breasts into NF/WF categories. MammoWave output consists of a selection of microwave images' features (determined prior to trials' start), which allow distinction between NF and WF breasts (using statistical significance p<0.05). 353 women were enrolled in the study (mean age 51 years ± 12 [SD], minimum age 19, maximum age 78); MammoWave data from the first 15 women of each site, all with NF breasts, were used for calibration. Following central assessor evaluation, 111 NF (48 dense) and 272 WF (136 dense) breasts were used for comparison with MammoWave output. 272 WF comprised 182 benign findings and 90 malignant histology-confirmed cancer. A sensitivity of 82.3% was achieved (95%CI: 0.78-0.87); sensitivity is maintained when limiting the investigation to histology-confirmed breasts cancer only (90 histology-confirmed breasts cancer have been included in this analysis, having sizes ranging from 3 mm to 60 mm). Specificity value of approximately 50% was achieved as expected, since thresholds were calculated (for each feature) using median value obtained after recruiting the first 15 women (of each site), all NF. This prospective trial may represent another step for introducing microwave imaging into clinical practice, for helping in breast lesion identification in asymptomatic women.


Asunto(s)
Neoplasias de la Mama , Neoplasias , Femenino , Humanos , Persona de Mediana Edad , Adulto Joven , Adulto , Anciano , Mamografía/métodos , Estudios Prospectivos , Sensibilidad y Especificidad , Mama/diagnóstico por imagen , Neoplasias de la Mama/diagnóstico por imagen
3.
J Craniofac Surg ; 34(1): 145-152, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36217228

RESUMEN

Titanium plates and screws are essential devices in maxillofacial surgery since late 1980s, but despite their wide use there is no consensus in titanium internal fixators removal after bone healing. A systematic literature review and meta-analysis were conducted on seventeen retrospective studies. Effect size and 95% confidence intervals were calculated for plate removal (per plate and per patient) and for removal causes (infection, pain, screws complications, exposition, palpability). Odds ratio, 95% confidence intervals, and χ 2 test were measured for sex, smoking, and implant site. Heterogeneity was evaluated with Cochran and Inconstancy test. Obtained data were used to design Forest and Funnel plots. The aim of the study is to identify and clarify reasons and risk factors for plates and screws removal. Infection is the most frequent reason; the habit of tobacco usage and implant site (mandibula) are the main risk factors. The administration of antibiotic prophylaxis is essential, and patients must quit smoking before and after surgery. In conclusion there is no scientific evidence supporting the removal of internal devices as mandatory step of the postoperative procedure.


Asunto(s)
Cirugía Bucal , Titanio , Humanos , Estudios Retrospectivos , Placas Óseas , Mandíbula/cirugía , Remoción de Dispositivos , Fijación Interna de Fracturas/métodos
4.
Indian J Otolaryngol Head Neck Surg ; 74(Suppl 2): 1510-1513, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36452793

RESUMEN

Sinonasal inverting papilloma is a rare benign, locally aggressive tumour, arising from sinus and/or nasal fossa mucosa, with high recurrence rate, and risk of malignant transformation. This is a case of orbital invasive, lateral extending inverting papilloma approached via combined external and endoscopic surgery.

5.
Indian J Otolaryngol Head Neck Surg ; 74(4): 547-554, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36514430

RESUMEN

Purpose: Orbital floor Fractures are the most common fractures involving the facial skeleton and usually occurs after traumatic events. The reconstruction of the orbital floor can be performed with different biocompatible materials. The aim of our retrospective study is to analyze the short- and long-term outcomes of surgically treated patients based on the material used to repair the orbital floor. Methods: We enrolled 146 patients hospitalized for orbital floor fractures in the Maxillofacial Surgery Unit of the Federico II University of Naples from 1 to 2010 to July 2020. All the fractured orbital floors were reconstructed with non-resorbable (Titanium Mesh, SynPor, SuPor and MedPor implants) or resorbable (collagen membrane, bovinum pericardium membrane, autologous bone graft) materials. Results: We utilized non-resorbable materials in 56% (82 cases) and resorbable implants in 44% (64 cases). An improvement of the preoperative symptomatology and an aesthetical good outcome was achieved in most cases. Conclusions: Data obtained supports that both resorbable and non-resorbable materials for orbital floor reconstruction are a safe and effective alternatives and offer satisfactory results in functional and aesthetic evaluations.

6.
PLoS One ; 17(7): e0271377, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35862368

RESUMEN

MammoWave is a microwave imaging device for breast lesion detection, employing two antennas which rotate azimuthally (horizontally) around the breast. The antennas operate in the 1-9 GHz band and are set in free space, i.e., pivotally, no matching liquid is required. Microwave images, subsequently obtained through the application of Huygens Principle, are intensity maps, representing the homogeneity of the dielectric properties of the breast tissues under test. In this paper, MammoWave is used to realise tissues dielectric differences and localise lesions by segmenting microwave images adaptively employing pulse coupled neural network (PCNN). Subsequently, a non-parametric thresholding technique is modelled to differentiate between breasts having no radiological finding (NF) or benign (BF) and breasts with malignant finding (MF). Resultant findings verify that automated breast lesion localization with microwave imaging matches the gold standard achieving 81.82% sensitivity in MF detection. The proposed method is tested on microwave images acquired from a feasibility study performed in Foligno Hospital, Italy. This study is based on 61 breasts from 35 patients; performance may vary with larger number of datasets and will be subsequently investigated.


Asunto(s)
Neoplasias de la Mama , Imágenes de Microonda , Algoritmos , Mama/diagnóstico por imagen , Mama/patología , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Diagnóstico por Imagen , Femenino , Humanos , Microondas , Redes Neurales de la Computación
7.
Diagnostics (Basel) ; 11(10)2021 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-34679628

RESUMEN

Recently, a novel microwave apparatus for breast lesion detection (MammoWave), uniquely able to function in air with 2 antennas rotating in the azimuth plane and operating within the band 1-9 GHz has been developed. Machine learning (ML) has been implemented to understand information from the frequency spectrum collected through MammoWave in response to the stimulus, segregating breasts with and without lesions. The study comprises 61 breasts (from 35 patients), each one with the correspondent output of the radiologist's conclusion (i.e., gold standard) obtained from echography and/or mammography and/or MRI, plus pathology or 1-year clinical follow-up when required. The MammoWave examinations are performed, recording the frequency spectrum, where the magnitudes show substantial discrepancy and reveals dissimilar behaviours when reflected from tissues with/without lesions. Principal component analysis is implemented to extract the unique quantitative response from the frequency response for automated breast lesion identification, engaging the support vector machine (SVM) with a radial basis function kernel. In-vivo feasibility validation (now ended) of MammoWave was approved in 2015 by the Ethical Committee of Umbria, Italy (N. 6845/15/AV/DM of 14 October 2015, N. 10352/17/NCAV of 16 March 2017, N 13203/18/NCAV of 17 April 2018). Here, we used a set of 35 patients. According to the radiologists conclusions, 25 breasts without lesions and 36 breasts with lesions underwent a MammoWave examination. The proposed SVM model achieved the accuracy, sensitivity, and specificity of 91%, 84.40%, and 97.20%. The proposed ML augmented MammoWave can identify breast lesions with high accuracy.

8.
PLoS One ; 16(4): e0250005, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33848318

RESUMEN

MammoWave is a microwave imaging device for breast lesions detection, which operates using two (azimuthally rotating) antennas without any matching liquid. Images, subsequently obtained by resorting to Huygens Principle, are intensity maps, representing the homogeneity of tissues' dielectric properties. In this paper, we propose to generate, for each breast, a set of conductivity weighted microwave images by using different values of conductivity in the Huygens Principle imaging algorithm. Next, microwave images' parameters, i.e. features, are introduced to quantify the non-homogenous behaviour of the image. We empirically verify on 103 breasts that a selection of these features may allow distinction between breasts with no radiological finding (NF) and breasts with radiological findings (WF), i.e. with lesions which may be benign or malignant. Statistical significance was set at p<0.05. We obtained single features Area Under the receiver operating characteristic Curves (AUCs) spanning from 0.65 to 0.69. In addition, an empirical rule-of-thumb allowing breast assessment is introduced using a binary score S operating on an appropriate combination of features. Performances of such rule-of-thumb are evaluated empirically, obtaining a sensitivity of 74%, which increases to 82% when considering dense breasts only.


Asunto(s)
Mama/diagnóstico por imagen , Mamografía/métodos , Adulto , Anciano , Algoritmos , Área Bajo la Curva , Neoplasias de la Mama/diagnóstico , Femenino , Humanos , Mamografía/instrumentación , Imágenes de Microonda , Persona de Mediana Edad , Curva ROC , Sensibilidad y Especificidad , Adulto Joven
9.
J Craniofac Surg ; 32(2): e205-e208, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33705075

RESUMEN

OBJECTIVE: The aim of our study was to analyze the aesthetic and functional outcome in the radial forearm free flap donor site using a simple split thickness skin grafting (STSG) closure compared with the use of dermal scaffold supporting the STSG closure. METHODS: The study analyzed 18 patients, divided in 2 groups based on the donor site closure modality. In STSG group, a simple STSG was used to cover the defect. In the DS + STSG group, the defect was covered by the use of dermal substitute (MatriDerm) supporting the STSG. Groups were compared on the following outcome variable: scar status; hand function; circumferences at most proximal and most distal point of the graft. All patients were followed up 1, 6, and 12 months post-operative. RESULTS: Nine patients from STSG group showed a difference in circumference between the operated and contralateral limbs respectively of 2.9 mm proximal and 1.2 mm distal; in the 9 patients of DS + STGS group the difference was respectively of 1.2 mm proximal and 1.3 mm distal. Welch unequal variances t-test demonstrated statistical significance of the values with P < 0.004 (P < 0.5). The average VSS was 1.82 ±â€Š0.2 for STSG group and 1.75 ±â€Š0.2 for DS + STGS group. The DASH score was 21.8% in STSG group and 19.4% in DS + STGS group. CONCLUSION: Our study shows that patients treated with Matriderm + STSG obtained a better result both in esthetic and functional outcomes.


Asunto(s)
Colgajos Tisulares Libres , Procedimientos de Cirugía Plástica , Estética Dental , Antebrazo/cirugía , Humanos , Trasplante de Piel
10.
J Craniofac Surg ; 31(6): e630-e633, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32649560

RESUMEN

The recent pandemic has led to an unprecedented overload of sanitary systems around the world. Despite that a maxillofacial department is not a frontline specialty in the treatment of coronavirus disease 2019 infections, our department has found itself faced with numerous problems in keeping the care system active and efficient while ensuring safety for patients and healthcare professionals. Massive redistribution of health personnel was needed to improve prevention and personal safety measures. The education and training system has been kept active, giving residents a decisive role in managing the state of emergency response. This article outlines new guidelines for infection prevention: from clinical control, treatment processes, clinical management, protection, and disinfection of healthcare professionals.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/prevención & control , Cabeza/cirugía , Maxilar/cirugía , Cuello/cirugía , Pandemias/prevención & control , Neumonía Viral/prevención & control , Guías de Práctica Clínica como Asunto , COVID-19 , Infecciones por Coronavirus/transmisión , Humanos , Neumonía Viral/transmisión , SARS-CoV-2
11.
Sci Rep ; 9(1): 10510, 2019 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-31324863

RESUMEN

Breast lesion detection employing state of the art microwave systems provide a safe, non-ionizing technique that can differentiate healthy and non-healthy tissues by exploiting their dielectric properties. In this paper, a microwave apparatus for breast lesion detection is used to accumulate clinical data from subjects undergoing breast examinations at the Department of Diagnostic Imaging, Perugia Hospital, Perugia, Italy. This paper presents the first ever clinical demonstration and comparison of a microwave ultra-wideband (UWB) device augmented by machine learning with subjects who are simultaneously undergoing conventional breast examinations. Non-ionizing microwave signals are transmitted through the breast tissue and the scattering parameters (S-parameter) are received via a dedicated moving transmitting and receiving antenna set-up. The output of a parallel radiologist study for the same subjects, performed using conventional techniques, is taken to pre-process microwave data and create suitable data for the machine intelligence system. These data are used to train and investigate several suitable supervised machine learning algorithms nearest neighbour (NN), multi-layer perceptron (MLP) neural network, and support vector machine (SVM) to create an intelligent classification system towards supporting clinicians to recognise breasts with lesions. The results are rigorously analysed, validated through statistical measurements, and found the quadratic kernel of SVM can classify the breast data with 98% accuracy.


Asunto(s)
Mama/diagnóstico por imagen , Imágenes de Microonda , Redes Neurales de la Computación , Máquina de Vectores de Soporte , Algoritmos , Neoplasias de la Mama/diagnóstico por imagen , Ensayos Clínicos como Asunto , Espectroscopía Dieléctrica/instrumentación , Espectroscopía Dieléctrica/métodos , Diseño de Equipo , Femenino , Humanos , Imagen por Resonancia Magnética , Mamografía , Curva ROC , Dispersión de Radiación , Estadísticas no Paramétricas , Ultrasonografía Mamaria
12.
J Craniofac Surg ; 30(7): e658-e661, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31261346

RESUMEN

INTRODUCTION: Odontogenic cysts are defined as those cysts that arise from odontogenic epithelium and occur in the tooth-bearing regions of the jaws. Cystectomy, marsupialization, or decompression of odontogenic cyst are the most common treatments proposed for this pathology. The aim of this study is to retrospectively evaluate the result of decompression based on the volumetric reduction of the cystic cavity and new bone formation by cone beam computerized tomography (CBCT). METHODS: The 16 patients affected by a large odontogenic mandibular cyst were enrolled in the study. All the patients underwent a surgical decompression of the cyst followed by the enucleation after a follow-up ranging from 6 to 9 months according to the volume's reduction and new bone formation. All the patients were evaluated with a CBCT before and after the surgical decompression to measure and analyze the percentage of reduction of the cystic volume before proceeding with the enucleation. RESULTS: The decompression of the cyst showed a reduction of the cystic volume ranging from 38.2% to 54.4% proportionally to the treatment duration. The highest percentage of volume reduction observed was 54.4% in 1 patient followed-up for 9 months, before the surgical enucleation. CONCLUSION: In our experience, the decompression seems to be the most suitable technique for the primary treatment of large odontogenic cyst of the jaws followed by the enucleation after 6 to 9 months. The CBCT is an objective method to evaluate the cystic volume reduction after the decompression and helps the surgeon with the surgical planning.


Asunto(s)
Mandíbula/cirugía , Quistes Odontogénicos/cirugía , Cigoma/cirugía , Adolescente , Adulto , Anciano , Tomografía Computarizada de Haz Cónico , Descompresión Quirúrgica/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos , Procedimientos de Cirugía Plástica , Estudios Retrospectivos , Adulto Joven
13.
Neuropsychologia ; 68: 59-70, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25575449

RESUMEN

Although vision offers distinctive information to space representation, individuals who lack vision since birth often show perceptual and representational skills comparable to those found in sighted individuals. However, congenitally blind individuals may result in impaired spatial analysis, when engaging in 'visual' spatial features (e.g., perspective or angle representation) or complex spatial mental abilities. In the present study, we measured behavioral and brain responses using functional magnetic resonance imaging in sighted and congenitally blind individuals during spatial imagery based on a modified version of the mental clock task (e.g., angle discrimination) and a simple recognition control condition, as conveyed across distinct sensory modalities: visual (sighted individuals only), tactile and auditory. Blind individuals were significantly less accurate during the auditory task, but comparable-to-sighted during the tactile task. As expected, both groups showed common neural activations in intraparietal and superior parietal regions across visual and non-visual spatial perception and imagery conditions, indicating the more abstract, sensory independent functional organization of these cortical areas, a property that we named supramodality. At the same time, however, comparisons in brain responses and functional connectivity patterns across experimental conditions demonstrated also a functional lateralization, in a way that correlated with the distinct behavioral performance in blind and sighted individuals. Specifically, blind individuals relied more on right parietal regions, mainly in the tactile and less in the auditory spatial processing. In sighted, spatial representation across modalities relied more on left parietal regions. In conclusions, intraparietal and superior parietal regions subserve supramodal spatial representations in sighted and congenitally blind individuals. Differences in their recruitment across non-visual spatial processing in sighted and blind individuals may be related to distinctive behavioral performance and/or mental strategies adopted when they deal with the same spatial representation as conveyed through different sensory modalities.


Asunto(s)
Percepción Auditiva/fisiología , Ceguera/fisiopatología , Lateralidad Funcional/fisiología , Lóbulo Parietal/fisiología , Percepción Espacial/fisiología , Percepción del Tacto/fisiología , Adulto , Discriminación en Psicología/fisiología , Femenino , Humanos , Imaginación/fisiología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad
14.
Front Hum Neurosci ; 8: 888, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25426045

RESUMEN

Driving is a complex behavior that requires the integration of multiple cognitive functions. While many studies have investigated brain activity related to driving simulation under distinct conditions, little is known about the brain morphological and functional architecture in professional competitive driving, which requires exceptional motor and navigational skills. Here, 11 professional racing-car drivers and 11 "naïve" volunteers underwent both structural and functional brain magnetic resonance imaging (MRI) scans. Subjects were presented with short movies depicting a Formula One car racing in four different official circuits. Brain activity was assessed in terms of regional response, using an Inter-Subject Correlation (ISC) approach, and regional interactions by mean of functional connectivity. In addition, voxel-based morphometry (VBM) was used to identify specific structural differences between the two groups and potential interactions with functional differences detected by the ISC analysis. Relative to non-experienced drivers, professional drivers showed a more consistent recruitment of motor control and spatial navigation devoted areas, including premotor/motor cortex, striatum, anterior, and posterior cingulate cortex and retrosplenial cortex, precuneus, middle temporal cortex, and parahippocampus. Moreover, some of these brain regions, including the retrosplenial cortex, also had an increased gray matter density in professional car drivers. Furthermore, the retrosplenial cortex, which has been previously associated with the storage of observer-independent spatial maps, revealed a specific correlation with the individual driver's success in official competitions. These findings indicate that the brain functional and structural organization in highly trained racing-car drivers differs from that of subjects with an ordinary driving experience, suggesting that specific anatomo-functional changes may subtend the attainment of exceptional driving performance.

15.
Front Hum Neurosci ; 7: 839, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24367315

RESUMEN

IN LIFE, EVERYONE GOES THROUGH HURTFUL EVENTS CAUSED BY SIGNIFICANT OTHERS: a deceiving friend, a betraying partner, or an unjustly blaming parent. In response to painful emotions, individuals may react with anger, hostility, and the desire for revenge. As an alternative, they may decide to forgive the wrongdoer and relinquish resentment. In the present study, we examined the brain correlates of forgiveness using functional Magnetic Resonance Imaging (fMRI). Healthy participants were induced to imagine social scenarios that described emotionally hurtful events followed by the indication to either forgive the imagined offenders, or harbor a grudge toward them. Subjects rated their imaginative skills, levels of anger, frustration, and/or relief when imagining negative events as well as following forgiveness. Forgiveness was associated with positive emotional states as compared to unforgiveness. Granting forgiveness was associated with activations in a brain network involved in theory of mind, empathy, and the regulation of affect through cognition, which comprised the precuneus, right inferior parietal regions, and the dorsolateral prefrontal cortex. Our results uncovered the neuronal basis of reappraisal-driven forgiveness, and extend extant data on emotional regulation to the resolution of anger and resentment following negative interpersonal events.

16.
PLoS One ; 8(10): e77764, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24204955

RESUMEN

The present study was designed to investigate the brain functional architecture that subserves visuo-spatial and motor processing in highly skilled individuals. By using functional magnetic resonance imaging (fMRI), we measured brain activity while eleven Formula racing-car drivers and eleven 'naïve' volunteers performed a motor reaction and a visuo-spatial task. Tasks were set at a relatively low level of difficulty such to ensure a similar performance in the two groups and thus avoid any potential confounding effects on brain activity due to discrepancies in task execution. The brain functional organization was analyzed in terms of regional brain response, inter-regional interactions and blood oxygen level dependent (BOLD) signal variability. While performance levels were equal in the two groups, as compared to naïve drivers, professional drivers showed a smaller volume recruitment of task-related regions, stronger connections among task-related areas, and an increased information integration as reflected by a higher signal temporal variability. In conclusion, our results demonstrate that, as compared to naïve subjects, the brain functional architecture sustaining visuo-motor processing in professional racing-car drivers, trained to perform at the highest levels under extremely demanding conditions, undergoes both 'quantitative' and 'qualitative' modifications that are evident even when the brain is engaged in relatively simple, non-demanding tasks. These results provide novel evidence in favor of an increased 'neural efficiency' in the brain of highly skilled individuals.


Asunto(s)
Conducción de Automóvil , Encéfalo/fisiología , Lateralidad Funcional , Imagen por Resonancia Magnética , Desempeño Psicomotor , Percepción Espacial/fisiología , Percepción Visual/fisiología , Adulto , Mapeo Encefálico , Estudios de Casos y Controles , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Adulto Joven
17.
Exp Biol Med (Maywood) ; 236(2): 138-44, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21321310

RESUMEN

The visual motion-responsive middle temporal complex (hMT+) is activated during tactile and aural motion discrimination in both sighted and congenitally blind individuals, suggesting a supramodal organization of this area. Specifically, non-visual motion processing has been found to activate the more anterior portion of the hMT+. In the present study, repetitive transcranial magnetic stimulation (rTMS) was used to determine whether this more anterior portion of hMT+ truly plays a functional role in tactile motion processing. Sixteen blindfolded, young, healthy volunteers were asked to detect changes in the rotation velocity of a random Braille-like dot pattern by using the index or middle finger of their right hand. rTMS was applied for 600 ms (10 Hz, 110% motor threshold), 200 ms after the stimulus onset with a figure-of-eight coil over either the anterior portion of hMT+ or a midline parieto-occipital site (as a control). Accuracy and reaction times were significantly impaired only when TMS was applied on hMT+, but not on the control area. These results indicate that the recruitment of hMT+ is necessary for tactile motion processing, and thus corroborate the hypothesis of a 'supramodal' functional organization for this sensory motion processing area.


Asunto(s)
Percepción de Movimiento/efectos de la radiación , Lóbulo Temporal/fisiología , Lóbulo Temporal/efectos de la radiación , Percepción del Tacto/efectos de la radiación , Estimulación Magnética Transcraneal , Humanos
18.
Front Syst Neurosci ; 4: 159, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21191477

RESUMEN

Human middle temporal complex (hMT+) responds also to the perception of non-visual motion in both sighted and early blind individuals, indicating a supramodal organization. Visual experience, however, leads to a segregation of hMT+ into a more anterior subregion, involved in the supramodal representation of motion, and a posterior subregion that processes visual motion only. In contrast, in congenitally blind subjects tactile motion activates the full extent of hMT+. Here, we used fMRI to investigate brain areas functionally connected with the two hMT+ subregions (seeds) during visual and tactile motion in sighted and blind individuals. A common functional connectivity network for motion processing, including bilateral ventral and dorsal extrastriate, inferior frontal, middle and inferior temporal areas, correlated with the two hMT+ seeds both in sighted and blind individuals during either visual or tactile motion, independently from the sensory modality through which the information was acquired. Moreover, ventral premotor, somatosensory, and posterior parietal areas correlated only with the anterior but not with the posterior portion of hMT+ in sighted subjects, and with both hMT+ seeds in blind subjects. Furthermore, a correlation between middle temporal and occipital areas with primary somatosensory seeds was demonstrated across conditions in both sighted and blind individuals, suggesting a cortico-cortical pathway that conveys non-visual information from somatosensory cortex, through posterior parietal regions, to ventral extrastriate cortex. These findings expand our knowledge about the development of the functional organization within hMT+ by showing that distinct patterns of brain functional correlations originate from the anterior and posterior hMT+ subregions as a result of visual experience.

19.
J Neurosci ; 29(31): 9719-24, 2009 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-19657025

RESUMEN

Observing and learning actions and behaviors from others, a mechanism crucial for survival and social interaction, engages the mirror neuron system. To determine whether vision is a necessary prerequisite for the human mirror system to develop and function, we used functional magnetic resonance imaging to compare brain activity in congenitally blind individuals during the auditory presentation of hand-executed actions or environmental sounds, and the motor pantomime of manipulation tasks, with that in sighted volunteers, who additionally performed a visual action recognition task. Congenitally blind individuals activated a premotor-temporoparietal cortical network in response to aurally presented actions that overlapped both with mirror system areas found in sighted subjects in response to visually and aurally presented stimuli, and with the brain response elicited by motor pantomime of the same actions. Furthermore, the mirror system cortex showed a significantly greater response to motor familiar than to unfamiliar action sounds in both sighted and blind individuals. Thus, the mirror system in humans can develop in the absence of sight. The results in blind individuals demonstrate that the sound of an action engages the mirror system for action schemas that have not been learned through the visual modality and that this activity is not mediated by visual imagery. These findings indicate that the mirror system is based on supramodal sensory representations of actions and, furthermore, that these abstract representations allow individuals with no visual experience to interact effectively with others.


Asunto(s)
Ceguera/fisiopatología , Encéfalo/fisiopatología , Desempeño Psicomotor/fisiología , Estimulación Acústica , Adulto , Percepción Auditiva/fisiología , Mapeo Encefálico , Femenino , Mano , Humanos , Imagen por Resonancia Magnética , Masculino , Reconocimiento en Psicología/fisiología , Percepción Visual/fisiología
20.
Cereb Cortex ; 17(12): 2933-9, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17372275

RESUMEN

We investigated whether the visual hMT+ cortex plays a role in supramodal representation of sensory flow, not mediated by visual mental imagery. We used functional magnetic resonance imaging to measure neural activity in sighted and congenitally blind individuals during passive perception of optic and tactile flows. Visual motion-responsive cortex, including hMT+, was identified in the lateral occipital and inferior temporal cortices of the sighted subjects by response to optic flow. Tactile flow perception in sighted subjects activated the more anterior part of these cortical regions but deactivated the more posterior part. By contrast, perception of tactile flow in blind subjects activated the full extent, including the more posterior part. These results demonstrate that activation of hMT+ and surrounding cortex by tactile flow is not mediated by visual mental imagery and that the functional organization of hMT+ can develop to subserve tactile flow perception in the absence of any visual experience. Moreover, visual experience leads to a segregation of the motion-responsive occipitotemporal cortex into an anterior subregion involved in the representation of both optic and tactile flows and a posterior subregion that processes optic flow only.


Asunto(s)
Ceguera/fisiopatología , Percepción de Movimiento , Red Nerviosa/fisiopatología , Estimulación Luminosa/métodos , Estimulación Física/métodos , Lóbulo Temporal/fisiopatología , Tacto , Adaptación Fisiológica , Adulto , Mapeo Encefálico , Humanos , Imagen por Resonancia Magnética , Masculino , Plasticidad Neuronal
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA