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1.
Arch Orthop Trauma Surg ; 143(11): 6965-6972, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37578657

RESUMO

OBJECTIVE: The purpose of this agreement was to establish consensus statements on the use of low-intensity pulsed ultrasound (LIPUS) in hand surgery. METHODS: Based on Delphi consensus methodology, a preliminary list of questions on the use of LIPUS in hand surgery was developed by an interdisciplinary team of hand and plastic surgeons as well as psychologists and experts from communications science. Based on these, questionnaires were invented and a total of three Delphi rounds have been conducted. Delphi panelists consisted of 11 German hand surgeons with a mean experience in hand surgery of 15 years (7-23 years). Questions and statements were revised during this process, resulting in a consensus at the end of round three. RESULTS: After three Delphi rounds, the following recommendations could be derived. LIPUS can be applied for impaired fracture healing of the digits, metacarpals, carpal bones as well as a prophylactic procedure in order to avoid further revision surgery. LIPUS therapy can be useful in addition to revision surgery for delayed union and non-unions. In the case of certain risk factors (replantation, revascularization, osteoporosis, smoking), it can be applied directly postoperatively in order to prevent impaired fracture healing. It should be applied for 90-120 days. CONCLUSION: There is a consensus among German hand surgeons, when and how LIPUS can be applied for improving fracture healing of the hand. Randomized controlled trials with direct comparison of fracture treatment with and without LIPUS are needed to support these statements with objective data.


Assuntos
Fraturas Ósseas , Terapia por Ultrassom , Humanos , Fraturas Ósseas/terapia , Mãos/cirurgia , Terapia por Ultrassom/métodos , Consolidação da Fratura , Ondas Ultrassônicas
2.
J Clin Med ; 12(15)2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37568459

RESUMO

Burn injuries are a major healthcare challenge worldwide, with up to 50% of all minor burns located on the head and neck. With this study, we sought to describe the effect of facial burns (FB) on health-related quality of life through a prospective and matched cohort study design. Patients completed the 36 Item Short Form (SF-36) and the Hospital Anxiety and Depression Scale (HADS). Results were analyzed based on the distribution of datasets. In total, 55 patients with FB and 55 age-and sex-matched candidates were recruited. The most common mechanism of thermal injury was burns from flames. The FB group scored lower in physical and psychological dimensions than the control group, both acutely and one year after injury. An analysis of each domain showed that subjects in the FB group trended toward improvements in their score after one-year post-burn in physical functioning (acute: 71.0 ± 29.2; one-year: 83.7 ± 23.9; p = 0.02) and bodily pain (acute: 58.5 ± 30.3; one-year: 77.9 ± 30.5; p = 0.01) domains. Additionally, the FB group had significanlyt higher scores for anxiety (FB: 4.8 ± 3.2; control: 2.5 ± 2.8; p = <0.002) and depression (FB: 3.9 ± 3.5; control: 2.1 ± 2.7; p = 0.01) compared to the control. In conclusion, facial burns are associated with physical and psychosocial deficits, as well as elevated levels of psychological distress.

3.
Eur J Med Res ; 28(1): 116, 2023 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-36907874

RESUMO

BACKGROUND: Peripheral nerve injuries are severe conditions with potential lifelong impairment, which is especially meaningful for the pediatric population. Knowledge on prevalence, injury mechanisms and concomitant injuries is, therefore, of utmost importance to increase clinician awareness and enable early diagnosis and treatment. As current literature on pediatric nerve lesions and concomitant injuries is scarce, we aimed to analyze all details of our patient population. METHODS: A total of 110 667 patients treated at our level 1 trauma center from 2012 to 2021 were evaluated for pediatric peripheral nerve injuries, causes, concomitant injuries and assessed for lesion classification (in continuity, partial lesion, dissection) and further relevant intraoperative findings. RESULTS: We found 5026 patients of all ages with peripheral nerve lesions, whereof 288 were pediatric, resulting in a prevalence of 5.7% of pediatric patients with nerve injuries. Mean age was 12.4 ± 4.6 years. Most common lesions were digital nerves (48.2%), followed by median (14.9%), ulnar (14.6%), radial (8.8%), peroneal nerve (5.2%) and brachial plexus injuries (2.1%). Of all pediatric nerve injuries, 3.8% were iatrogenic, only 30.2% had preserved continuity and 47.3% a concomitant vessel injury. Fractures were accompanied in 22.6%. DISCUSSION: We observed that a large proportion of injures had complete transections, often accompanied by concomitant vessel injuries especially in distally located injuries, highlighting the importance of early surgical exploration. Radial, ulnar and lower extremity nerve injuries were often associated with fractures. Early surgical nerve repair is key to improve motor and sensory outcomes. Knowledge on mechanisms and concomitant injuries facilitates timely diagnosis and treatment, thereby potentially preventing lifelong impairment.


Assuntos
Fraturas Ósseas , Traumatismos dos Nervos Periféricos , Humanos , Criança , Adolescente , Traumatismos dos Nervos Periféricos/cirurgia , Prevalência , Centros de Traumatologia , Extremidades , Estudos Retrospectivos
4.
J Pers Med ; 13(2)2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36836582

RESUMO

BACKGROUND: Nerve entrapment has been hypothesized to contribute to the multicausal etiology of axonopathy in sensorimotor diabetic neuropathy. Targeted surgical decompression reduces external strain on the affected nerve and, therefore, may alleviate symptoms, including pain and sensory dysfunction. However, its therapeutic value in this cohort remains unclear. AIM: Quantifying the treatment effect of targeted lower extremity nerve decompression in patients with preexisting painful sensorimotor diabetic neuropathy and nerve entrapment on pain intensity, sensory function, motor function, and neural signal conduction. STUDY DESIGN: This prospective, controlled trial studies 40 patients suffering from bilateral therapy-refractory, painful (n = 20, visual analogue scale, VAS ≥ 5) or painless (n = 20, VAS = 0) sensorimotor diabetic neuropathy with clinical and/or radiologic signs of focal lower extremity nerve compression who underwent unilateral surgical nerve decompression of the common peroneal and the tibial nerve. Tissue biopsies will be analyzed to explore perineural tissue remodeling in correlation with intraoperatively measured nerve compression pressure. Effect size on symptoms including pain intensity, light touch threshold, static and moving two-point discrimination, target muscle force, and nerve conduction velocity will be quantified 3, 6, and 12 months postoperatively, and compared (1) to the preoperative values and (2) to the contralateral lower extremity that continues non-operative management. CLINICAL SIGNIFICANCE: Targeted surgical release may alleviate mechanical strain on entrapped lower extremity nerves and thereby potentially improve pain and sensory dysfunction in a subset of patients suffering from diabetic neuropathy. This trial aims to shed light on these patients that potentially benefit from screening for lower extremity nerve entrapment, as typical symptoms of entrapment might be erroneously attributed to neuropathy only, thereby preventing adequate treatment.

5.
J Burn Care Res ; 44(1): 95-105, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36300728

RESUMO

An objective burn scar assessment is essential to informed therapeutic decision-making and to monitor scar development over time. However, widely employed scar rating scales show poor inter-rater reliability. For this study we developed a standardized measurement protocol for the Cutometer© applicable for objective burn scar assessment in everyday clinical practice. We developed a measurement protocol for the Cutometer© MPA 580 including a scar site relocation technique based on anatomical landmarks. The protocol emerged through several steps: Identifying key factors for valid and reliable measurements, preliminary testing, specification of technical details, refining the protocol and final testing. Consecutively, the protocol was validated for inter-rater reliability by assessing 34 burn scars in 17 patients by four clinicians and computing an Intra-class Correlation Coefficient (ICC). Parameter R0, representing scar pliability, was identified as the best suited output parameter yielding excellent inter-rater reliability for average measures (ICC 0.92 [95% CI 0.86; 0.96]) and acceptable reliability for single measures (ICC: 0.74 [0.61; 0.84]). The pressure applied on the measuring probe was identified as an influential confounding factor for reliable measurements. Rater gender did not influence reliability of measurements. The introduced standardized measurement protocol for the Cutometer© MPA 580 enables an objective and reliable burn scar assessment for clinical as well as research purposes.


Assuntos
Queimaduras , Cicatriz , Humanos , Cicatriz/diagnóstico , Cicatriz/etiologia , Cicatriz/patologia , Reprodutibilidade dos Testes , Queimaduras/complicações , Queimaduras/cirurgia , Variações Dependentes do Observador , Microcirurgia
6.
J Pers Med ; 12(10)2022 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-36294687

RESUMO

(1) Background: Peripheral nerve injuries are severe injuries with potentially devastating impairment of extremity function. Correct and early diagnosis as well as regular regeneration observation is of utmost importance for individualized reconstruction and the best possible results. Currently, diagnoses and follow-up examinations are based on clinical examinations supported with electroneurography, which often causes delays in treatment and can result in impaired healing. However, there is currently no diagnostic device that can reliably correlate the anatomic-pathological parameters with the functional-pathological changes initially and during therapy. With new technologies such as MR neurography (MRN), precise visualization of potential nerve damage and visualization of the reinnervation processes is assumed to accelerate clinical decision making and accompaniment of individualized treatment. (2) Methods/Design: This prospective clinical study will examine 60 patients after peripheral nerve lesion aged 18-65 years from trauma timepoint onward. Patients should be observed over a period of 18-24 months with regular clinical examinations, electroneurography, and ultrasound to compare the potential of MRN to current gold-standard diagnostic tools. Furthermore, 20 patients with the same inclusion criteria stated above, with an internal fixation and osteosyntheses of humerus fractures, will be examined to determine the visibility of peripheral nerve structures in close proximity to metal. (3) Discussion: Peripheral nerve injuries are often accompanied with severe, expensive, and long-lasting impairment of extremity function. An early and precise diagnosis of the nerve lesion, as well as the healing course, is crucial to indicate the right therapy as soon as possible to save valuable time for nerve regeneration. Here, new technologies such as MRN aim to visualize nerve injuries on fascicular level, providing not only early diagnosis and therapy decisions, but also providing a precise tool for monitoring of reinnervation processes. As severe injuries of a nerve are often accompanied with bone fractures and internal fixation, we also aim to evaluate the visualization feasibility of nerves in close proximity to metal, and ultimately improve the outcome and extremity function of patients after a peripheral nerve injury.

7.
J Pers Med ; 12(10)2022 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-36294812

RESUMO

BACKGROUND: Peripheral nerve lesions are associated with debilitating long-term consequences. Albeit being essential for evidence-based clinical decision making, epidemiological and etiological data are scarce. We therefore aimed to comprehensively analyze epidemiological and etiological factors of peripheral nerve lesions in one of the largest cohorts. METHODS: We screened a total of 110,667 patients treated at our level I trauma center between January 2012 and July 2020 for nerve lesions. Subsequently, demographics, etiologies, concomitant injuries, and lesion characteristics were analyzed. RESULTS: A total of 5026 patients, predominantly young males suffering from non-work-related nerve injuries, were treated. Proximal levels of injury were more likely to be accompanied by fractures, whereas more distal injuries with concomitant vessel or tendon injury. Main causes were 54.6% lacerations. Acute traumatic nerve injury was treated within 24 h in 55.9% of cases. CONCLUSIONS: Given the young age of affected patients, early diagnosis and treatment in specialized centers may facilitate their early return to work and improve long-term functional outcomes. The data show the importance of a special attention on nerve injuries, which may be masked by large accompanying injuries. New findings on lesion characteristics of selected subgroups and accompanying circumstances can support a change in treatment strategies.

8.
J Pers Med ; 12(7)2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35887666

RESUMO

Complex regional pain syndrome (CRPS) can result in a devastating condition. For a small number of patients, there is a non-response to any existing multimodal therapies and they ultimately request amputation. Such a drastic and final decision is not easy to take for both the patient and the surgeon and requires careful and interdisciplinary assessments and considerations. Furthermore, new surgical procedures, such as targeted muscle reinnervation (TMR) and hybrid prosthetic fitting, and multidisciplinary board advice should be included when considering amputation. In order to help other therapeutic teams in decision making for such rare but more than demanding cases, we aimed to propose an advanced algorithm for amputation indications in CRPS patients combining all these new factors. This algorithm consists of extensive pre-operative psychiatric assessment, diagnostic hybrid prosthetic fitting including fMRI analyses, multidisciplinary board advice as well as targeted muscle reinnervation and amputation procedures with final prosthetic fitting and rehabilitation. By involving multiple disciplines, this algorithm should provide optimized and individualized patient treatment on the one hand and a reliable base for decision making for therapists on the other.

9.
Handchir Mikrochir Plast Chir ; 52(6): 497-504, 2020 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-32968995

RESUMO

INTRODUCTION: More than half a million patients suffer from minor burns in Germany per year. In 2018, almost 2000 patients needed intensive care for their burn injuries. Despite high standards of burn care, mortality remains high. Burn injuries may lead to long-term sequelae. In order to provide up-to-date burn care, guidelines are available online with public access. METHODS AND RESULTS: This overview presents a summary of the German AWMF guideline for the treatment of thermal injuries in adults (https://www.awmf.org/leitlinien/detail/ll/044-001.html). Experts of eleven different medical organisations and specialties have contributed to this S2k guideline with their expertise. The focus of the article is on acute burn wound assessment, the indication for specialised care in burn centres, the management of the burn wound at the trauma scene and in hospitals as well as scar management and rehabilitation. CONCLUSION: This overview reports on the consensus-based treatment of acute burn wounds in adults in Germany. The article is intended to guide doctors and professional caretakers to perform state-of-the-art burn care. The current guideline aims to improve burn outcome.


Assuntos
Queimaduras , Adulto , Unidades de Queimados , Queimaduras/terapia , Alemanha , Humanos
10.
Trials ; 20(1): 752, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856888

RESUMO

BACKGROUND: Severe burn injuries result in relevant restrictions of physical capacity as well as psychological and social integrity and require a specialized rehabilitation. There is a common agreement, among national as well as international burn associations, that burn rehabilitation is a complex, dynamic process which needs an interdisciplinary and specialized treatment team. There is wide agreement that more research is needed in this field. METHODS/DESIGN: The aim of the study is to examine the effectiveness and efficiency of our new ICF (International Classification of Functioning, Disability and Health)-based rehabilitation for thermal injuries. Because of ethical reasons, we have chosen a prospective non-randomized design, which takes place at two different rehabilitation centers. At center A, a newly developed ICF-based rehabilitation program was established; at rehabilitation center B, a well-established rehabilitation program has existed for 20 years and is used as reference. The primary research question addresses the "Pre-post comparison of the physical and psychological outcome measurements," secondary question I looks at the "Examination of the non-inferiority of the new treatment concept with the established concept," and secondary question II is the "Analysis of the rehabilitation process based on the rehabilitation cycle." Only patients of the two burn rehabilitation centers who are insured by workers' compensation will be asked to participate in this study to avoid outcome bias by insurance status. A physical examination (physical working capacity testing, grip strength, range of motion, and scar evaluation by Cutometer and Vancouver Scar Scale) and a standardized questionnaire battery (Burn Specific Health Scale-Brief , Short Form 36, Impact of Event Scale-Revised, the German version of the Symptom Checklist, the Freiburg Social Support Questionnaire, Patient/Client Satisfaction Questionnaire, Disabilities of the Arm, Shoulder and Hand, and Lower Extremity Functional Scale ) measure physical and psychological conditions. Data will be taken on admission, during stay, and on discharge of the rehabilitation program and at follow-up 3 and 12 months after discharge. A minimum of 162 participants will be enrolled in this clinical longitudinal, prospective, observational study. DISCUSSION: The proof of the effectiveness of the ICF-based rehabilitation program for thermal injuries will give evidence in a comprehensive way for the first time in this field. As result, a standardized rehabilitation concept will be introduced, which can be provided to other rehabilitation institutions treating thermal injuries. TRIAL REGISTRATION: German Clinical Trials Register, DRKS00017702. Registered on 2 September 2019.


Assuntos
Queimaduras/reabilitação , Avaliação da Deficiência , Pessoas com Deficiência/reabilitação , Classificação Internacional de Funcionalidade, Incapacidade e Saúde , Atividades Cotidianas , Adulto , Queimaduras/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Estudos Prospectivos , Resultado do Tratamento
11.
J Burn Care Res ; 39(2): 252-260, 2018 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-28570312

RESUMO

The Burn Specific Health Scale-Brief (BSHS-B) is one of the most commonly used instruments to measure quality of life after burns. Our aim was to establish and to provide a German version of the BSHS-B for all German-speaking burn facilities. Translation and cross-cultural adaptation of the original English version into the German language was conducted. In a pilot study, 20 burn patients qualitatively validated the translated version concerning comprehensibility and content validity. The final version was then quantitatively validated by 364 patients who were treated in our burn center between 2011 and 2015. Internal consistency and test-retest reliability were assessed. Criterion validity was determined by correlating the subscales with relevant instruments (Short-Form Health Survey 36, Hospital Anxiety and Depression Scale, and Disabilities of the Arm, Shoulder and Hand Outcome Measure). The structure of the German version was investigated by principal component analysis. Confirmatory factor analysis was used to compare the structure with the original 9-factor structure and the second-order 3-factor structure. Qualitative testing revealed adequate comprehension and content validity. Cronbach's alphas ranged from α = 0.80 to α = 0.92. The test-retest reliability ranged from r = 0.72 to r = 0.97. The subscales correlated significantly with the measures of criterion validity (r = 0.30 to r = -0.77). The principal component analysis results showed a satisfactory overlap with the original data structure, except for the Affect and Sexuality domains, which were merged into 1 factor. The confirmatory factor analyses revealed the best model fit for the second-order 3-factor structure, excluding the Work domain. The Ludwigshafen German version of the BSHS-B shows good psychometric properties. It is well suited for clinical use, further research, and international comparison.


Assuntos
Queimaduras/complicações , Queimaduras/psicologia , Nível de Saúde , Qualidade de Vida , Inquéritos e Questionários , Adulto , Feminino , Alemanha , Humanos , Idioma , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Análise de Componente Principal , Psicometria , Reprodutibilidade dos Testes , Traduções , Adulto Jovem
12.
Front Psychol ; 1: 206, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21833262

RESUMO

In the past, sensory saltation phenomena (Geldard and Sherrick, 1972) have been used repeatedly to analyze the spatiotemporal integration capacity of somatosensory and other sensory mechanisms by means of their psychophysical characteristic. The core phenomenon consists in a systematic mislocalization of one tactile stimulus (the attractee) toward another successive tactile stimulus (the attractant) presented at another location, increasing with shorter intervals. In a series of four experiments, sensory saltation characteristics were studied at the forearm and the abdomen. Participants reported the perceived positions of attractees, attractants, and reference stimuli by pointing. In general, saltation characteristics compared well to those reported in previous studies, but we were able to gain several new insights regarding this phenomenon: (a) the attractee-attractant interval did not exclusively affect the perceived attractee position, but also the perceived attractant position; (b) saltation characteristics were very similar at different body sites and orientations, but did show differences suggesting anisotropy (direction-dependency) in the underlying integration processes; (c) sensory saltation could be elicited with stimulation patterns crossing the body midline on the abdomen. In addition to the saltation-specific results, our experiments demonstrate that pointing reports of perceived positions on the body surface generally show pronounced systematic biases compared to veridical positions, moderate intraindividual consistency, and a high degree of inter-individual variability. Finally, we address methodological and terminological controversies concerning the sensory saltation paradigm and discuss its possible neurophysiological basis.

13.
Somatosens Mot Res ; 26(1): 11-7, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19283552

RESUMO

Distortions of the body image have been repeatedly reported for various clinical conditions, but direct experimental analyses of the perceptual changes involved are still scarce. In addition, most experimental studies rely on cerebral activation patterns to assess neuroplastic changes in central representation, although the relationship between cerebral topography and the topology of the perceptual space is not clear. This study examines whether the direct psychophysical mapping approach we introduced recently (Trojan et al., Brain Res 2006;1120:106-113) is capable of tracking perceptual distortions in the somatotopic representation of heat-pain stimuli. Eleven healthy participants indicated the perceived positions of CO(2) laser stimuli, repetitively presented to the dorsal forearm, with a 3D tracking system in two consecutive sessions, separated by the topical application of capsaicin cream. In line with earlier reports, we expected that the resulting individual perceptual maps (i.e., one-dimensional projections of the perceived positions onto the forearm surface) would be subject to modulation through the altered sensory input, to be measured in terms of altered topological parameters. We found that the topology and metrics of the somatotopic representation were well preserved in the second session, but that the perceptual map was compressed to a smaller range in 9 out of 11 participants. By providing dimensional measures of perceptual representations, perceptual maps constitute an independent, genuinely psychological complement to the topography of cortical activations measured with neuroimaging methods. In addition, we expect them to be useful in diagnosing pathological changes in body perception accompanying chronic pain and other disorders.


Assuntos
Mapeamento Encefálico/métodos , Hiperalgesia/fisiopatologia , Nociceptores/fisiologia , Dor/fisiopatologia , Psicofísica/métodos , Córtex Somatossensorial/fisiologia , Adulto , Capsaicina , Feminino , Temperatura Alta/efeitos adversos , Humanos , Processamento de Imagem Assistida por Computador , Lasers , Masculino , Testes Neuropsicológicos , Percepção/fisiologia , Estimulação Física , Fármacos do Sistema Sensorial , Córtex Somatossensorial/anatomia & histologia , Adulto Jovem
14.
J Clin Neurophysiol ; 24(1): 76-83, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17277582

RESUMO

The presence of perceptual sensitization and related brain responses was examined in 14 chronic low back pain (CLBP) patients and 13 healthy controls comparable in age and sex. Multichannel EEG recordings and pain ratings were obtained during the presentation of 800 painful electrical intramuscular and intracutaneous stimuli each to the left m. erector spinae and the left m. extensor digitorum. Perception and pain thresholds were not significantly different between the two groups, though patients showed significantly more perceptual sensitization. Across all stimulation conditions, a larger EEG component 80 milliseconds after stimulation was observed in the CLBP group. No significant group differences were found for the N150. The component 260 milliseconds after stimulus onset was significantly smaller in the CLBP group. N80, N150, and perceptual sensitization were significantly positively correlated. These results indicate enhanced perceptual sensitization and enhanced processing of the sensory-discriminative aspect of pain, as expressed in the N80 component, in CLBP patients. This may be one neurophysiologic basis of sensitization and the chronicity process. The lower P260 component in the patients may be explained in terms of tonic pain inhibiting phasic pain or may be related to the affective distress observed in this patient group.


Assuntos
Mapeamento Encefálico , Encéfalo/fisiopatologia , Eletroencefalografia , Dor Lombar/fisiopatologia , Síndromes da Dor Miofascial/fisiopatologia , Limiar da Dor , Doença Aguda , Adulto , Idoso , Doença Crônica , Potenciais Somatossensoriais Evocados , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
15.
Brain Res ; 1120(1): 106-13, 2006 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-16982038

RESUMO

Brain activation patterns derived from neurofunctional methods are often implicitly regarded as being directly related to subjective perceptual experience in an iso- or at least homomorph manner, neglecting the operational differences between these two dimensions. This paper (a) introduces a method for assessing 'perceptual maps' of stimulation patterns presented to the body surface, providing a means to parametrically relate neural representation and subjective percept, and (b) applies this method to demonstrate the existence of 'somatotopic maps' of hot and painful stimulus patterns independent from mechanoceptive co-activation. Brief (90 ms) CO2 laser pulses were presented in an array of multiple stimulation sites on the dorsal forearms (N. radialis area, C7 dermatome) of healthy subjects. Perceived locations were indicated with a 3D tracker without touching the skin, and (mis-)localizations in distal-proximal direction were analyzed. Stimuli were localized with overall mean errors of 22 mm (SD: 16 mm) toward the wrist and 24 mm (SD: 18 mm) toward the elbow. Somatotopic representation of thermal-nociceptive stimuli could be demonstrated in all subjects, independent from mechanoceptive co-activation. The perceptual maps revealed striking individual (mis-)localization patterns, many subjects exhibiting 'stretched', some 'condensed' somatotopic representations. In estimating the mapping parameters from physical to perceptual space linear regressions generally provided a good fit (adj. R2>0.80 in 10 out of 12 subjects). Nonlinear models were advantageous in some subjects only. Our method can be useful in assessing inter-individual differences or experimentally induced shifts in somatotopic processing.


Assuntos
Temperatura Alta , Limiar da Dor/fisiologia , Dor , Percepção/fisiologia , Sensação/fisiologia , Pele/inervação , Adulto , Feminino , Humanos , Lasers , Masculino , Psicofísica/métodos , Análise de Regressão
16.
Exp Brain Res ; 170(1): 88-96, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16328290

RESUMO

In sensory saltation, first reported by Geldard and Sherrick (Science 178:178-179, 1972), a stimulus is displaced towards a second one following closely in time and space as a function of the delay between the stimuli. The distance between stimulus locations is restricted by the extension of sensory fields in the primary somatosensory cortex. Saltation is assumed to reflect dynamic changes in these cortical representations. The present study demonstrates for the first time saltation in thermoceptive and nociceptive pathways with CO(2) laser stimulation. Stimuli were presented to the dorsal forearms of 18 healthy subjects at two intensities. Saltation patterns consisted of a reference stimulus S0 near the wrist, the first test stimulus S1 at the reference location after a fixed onset delay of 1,000 ms, and a second test stimulus S2 at a location 105 mm distant from reference after a variable onset delay of 60-516 ms. Perceived positions were indicated by the subjects without skin contact with a 3D tracker. As expected, subjects mislocalized S1 towards S2. Mean S1 displacement was 51+/-36 mm. Decreasing delays between S1 and S2 resulted in increasing displacements, independent of intensity. However, since no clear-cut discrimination of thermal versus nociceptive activation could be achieved definite conclusions about differences between the two modalities cannot be drawn. In addition, effects of body site on the saltation characteristics were observed. The saltation paradigm constitutes a promising approach to the functional analysis of spatiotemporal dynamics in thermoceptive and nociceptive networks to supplement brain-mapping approaches to cortical sensory fields.


Assuntos
Ilusões/fisiologia , Rede Nervosa/fisiologia , Nociceptores/fisiologia , Percepção Espacial/fisiologia , Termorreceptores/fisiologia , Percepção do Tempo/fisiologia , Adulto , Braço/fisiologia , Córtex Cerebral/fisiologia , Feminino , Temperatura Alta , Humanos , Lasers , Masculino , Fibras Nervosas Mielinizadas/fisiologia , Fibras Nervosas Amielínicas/fisiologia , Estimulação Física , Temperatura
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