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1.
Support Care Cancer ; 27(2): 505-512, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29980908

RESUMO

PURPOSE: Purpose of this study was to retrospectively review our experience of multidisciplinary clinic providing a joint approach by radiation oncologist and anesthetist for patients with cancer pain to evaluate the adequacy and the IMprovement in MAnagement (IM-MA study) of this symptom. METHODS: A Team for Pain Management (TPM) represented by radiation oncologist and anesthetist weekly provided consultations to patient presenting cancer pain. TPM prospectively reported epidemiologic, symptomatic, and pharmacological data. TPM modified pain therapy and indicated antalgic radiotherapy. Patients were evaluated at baseline and after 4 weeks after intervention. RESULTS: From November 2015 to April 2016, 65 patients were evaluated by TPM. At the baseline, 18 patients (27.7%) were undertreated (i.e., receiving inadequate pain management); furthermore, 27 patients (41.5%) despite receiving strong opioids had uncontrolled pain. After 4 weeks from intervention, undertreated patients were reduced to 1.53%. For those patients undergone to radiotherapy, response at 34 weeks was scored as follows: complete response 28.8%, partial response 46.7%, pain progression 0.95%, indeterminate response 23.8%. CONCLUSIONS: A multidisciplinary Team for Pain Management improved the clinical management, optimizing pain control and increasing adequacy of pharmacological management. The TPM intervention seems particularly worth for patients presenting specific features including BTcP, neuropathic pain, severe pain due to bone metastases, and any potential candidate to radiotherapy. Larger series and QoL questionnaires are required to confirm these results.


Assuntos
Anestesistas/tendências , Dor do Câncer/tratamento farmacológico , Manejo da Dor/métodos , Cuidados Paliativos/métodos , Radioterapia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Inquéritos e Questionários
2.
Neurol Sci ; 39(5): 975, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29687311

RESUMO

In the original article, Gina Ferrazzano was affiliated to Department of Neurology and Psychiatry, Neuromed Institute IRCCS, Sapienza University of Rome, Pozzilli, Italy.The corrected affiliation should be: Neuromed Institute IRCCS, Pozzilli, IS, Italy.

3.
Neurol Sci ; 38(5): 819-825, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28215037

RESUMO

The Italian Dystonia Registry is a multicenter data collection system that will prospectively assess the phenomenology and natural history of adult-onset dystonia and will serve as a basis for future etiological, pathophysiological and therapeutic studies. In the first 6 months of activity, 20 movement disorders Italian centres have adhered to the registry and 664 patients have been recruited. Baseline historical information from this cohort provides the first general overview of adult-onset dystonia in Italy. The cohort was characterized by a lower education level than the Italian population, and most patients were employed as artisans, builders, farmers, or unskilled workers. The clinical features of our sample confirmed the peculiar characteristics of adult-onset dystonia, i.e. gender preference, peak age at onset in the sixth decade, predominance of cervical dystonia and blepharospasm over the other focal dystonias, and a tendency to spread to adjacent body parts, The sample also confirmed the association between eye symptoms and blepharospasm, whereas no clear association emerged between extracranial injury and dystonia in a body site. Adult-onset dystonia patients and the Italian population shared similar burden of arterial hypertension, type 2 diabetes, coronary heart disease, dyslipidemia, and hypothyroidism, while hyperthyroidism was more frequent in the dystonia population. Geographic stratification of the study population yielded no major difference in the most clinical and phenomenological features of dystonia. Analysis of baseline information from recruited patients indicates that the Italian Dystonia Registry may be a useful tool to capture the real world clinical practice of physicians that visit dystonia patients.


Assuntos
Distonia/diagnóstico , Distonia/epidemiologia , Sistema de Registros , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Progressão da Doença , Distonia/fisiopatologia , Distonia/psicologia , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Adulto Jovem
4.
Eur Rev Med Pharmacol Sci ; 17(4): 507-12, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23467950

RESUMO

BACKGROUND: Atherosclerotic ischemic renal disease is a frequent cause of end-stage renal failure. Correction of renal artery stenosis (RAS) may fail to stabilize or improve renal function. AIMS OF THE STUDY: Carotid and aortic Intima media thickness (IMT), resistance renal resistance index (RI), arterial blood pressure (BP), serum creatinine (SCr), creatinine clearance (CrCl), proteinuria and uricemia were considered as possible predictive factors and measured before renal-artery stenosis correction and during 12 months follow-up. MATERIALS AND METHODS: we performed an observational study on a total of 55 patients to find predictive factors of the outcome of renal function after renal percutaneous transluminal angioplasty and stenting (RPTAs). RESULTS: We found that uricemia, proteinuria and IR were higher at baseline in patients who worsened renal function after revascularization. CONCLUSIONS: The identification of predictive factors (uricemia; proteinuria and RI) of chronic kidney disease (CKD) progression in patients with RAS undergone revascularization could be useful to predict renal long term outcome and to select patients that really could benefit of this.


Assuntos
Hiperuricemia/sangue , Proteinúria/urina , Obstrução da Artéria Renal/diagnóstico , Idoso , Angioplastia com Balão , Aorta Abdominal/diagnóstico por imagem , Artéria Carótida Primitiva/diagnóstico por imagem , Interpretação Estatística de Dados , Feminino , Humanos , Rim/irrigação sanguínea , Rim/diagnóstico por imagem , Rim/patologia , Testes de Função Renal , Masculino , Valor Preditivo dos Testes , Obstrução da Artéria Renal/sangue , Obstrução da Artéria Renal/cirurgia , Obstrução da Artéria Renal/urina , Stents , Túnica Íntima/diagnóstico por imagem , Ultrassonografia Doppler em Cores , Resistência Vascular/fisiologia
5.
Minerva Anestesiol ; 79(1): 7-14, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23090102

RESUMO

BACKGROUND: Neurohumoral, immunologic and metabolic alteration characterize surgical procedures in relation with the intensity of injury, the total operating time and the anesthetic technique. We, therefore, compared the effects of desflurane versus sevoflurane anesthesia on intra and postoperative release of the stress hormones and inflammatory cytokines. METHODS: Fifty Caucasian women undergoing laparoscopic surgery for benign ovarian cysts were randomized to receive inhaled anesthesia with desflurane (DES group; N.=25) or sevoflurane (SEVO group; N.=25), with fentanyl bolus and remifentanil infusion. Plasma levels of noradrenaline, adrenaline, ACTH and cortisol were measured preoperatively (T1), 30 minutes after the beginning of surgery (T2), and 30 minutes, 2 and 4 hours after the end of surgery (T3, T4, T5 respectively). Interleukin 6 (IL-6), glucose and C-reactive protein (CRP) were measured at T1, T2,T3, T4, T5 and 12 hours after the end of surgery (T6). RESULTS: An increase of catecholamines during (T2) and immediately after surgery (T3) was observed in both groups. However, adrenaline and noradrenaline levels were significantly higher in the DES group compared to the SEVO group. Despite a drop of cortisol concentration was observed in both groups, only in the DES group there was a significant difference intraoperatively as compared to the baseline levels and to the SEVO group. While, the consequent increase of ACTH was significantly higher in the SEVO group at T2-T4. The preoperatory levels were restored at T5. Glucose, IL-6, CRP levels and postoperative pain did not show significant differences in timing within the same group and comparing DES vs SEVO group. CONCLUSION: In the present study we demonstrated that desflurane and sevoflurane produced a different stress response in the setting of laparoscopic surgery. The greater release of catecholamines during desflurane anesthesia could have adverse effects in patients with pre-existing cardiovascular disease. In low stress surgery desflurane, as compared to sevoflurane, was associated with a better control of intraoperative cortisol and ACTH response (T2). Moreover, the ACTH secretion resulted attenuated also postoperatively (T3-T4). Both gases did not influence the plasmatic levels of Il-6, CRP and glucose.


Assuntos
Anestésicos Inalatórios/efeitos adversos , Isoflurano/análogos & derivados , Éteres Metílicos/efeitos adversos , Estresse Fisiológico/efeitos dos fármacos , Adulto , Anestesia por Inalação , Catecolaminas/sangue , Citocinas/sangue , Desflurano , Feminino , Procedimentos Cirúrgicos em Ginecologia , Proteínas de Choque Térmico/metabolismo , Hemodinâmica/efeitos dos fármacos , Humanos , Isoflurano/efeitos adversos , Laparoscopia , Cistos Ovarianos/cirurgia , Dor Pós-Operatória/epidemiologia , Sevoflurano
6.
Eur Rev Med Pharmacol Sci ; 16(11): 1570-5, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23111973

RESUMO

BACKGROUND: We recently demonstrated that pneumoperitoneum affects diastolic echocardiographic findings in healthy women scheduled for gynaecologic laparoscopy. No reports have been conducted in order to assess the echocardiographic consequences in hypertensive subjects during laparoscopic procedures. AIM: The aim of this study was to evaluate Left Ventricular filling pressures in hypertensive women with and without diastolic dysfunction, combining the tissue Doppler imaging technique and the plasmatic levels of amino terminal proBNP. MATERIALS AND METHODS: Doppler recordings of mitral inflow, tissue Doppler imaging of mitral annulus and N-terminal-proBNP plasmatic levels were obtained in 40 hypertensive women with or without diastolic dysfunction. Measurements were executed in awake patients (T0), after the induction of anesthesia (T1), 10 and 20 minutes after the creation of the pneumoperitoneum (T2 and T3, respectively) and at the end of the surgery (T4). Furthermore, we collected the last blood sample after 12 hours (T5). RESULTS: The E/Ea ratio for the evaluation of left ventricular filling pressures were higher in the diastolic dysfunction group than in the non diastolic dysfunction and significantly increased after pneumoperitoneum. Pneumoperitoneum increased the plasmatic levels of natriuretic peptide in both groups. At the end of the procedure we did not observe any further significant alteration. CONCLUSIONS: Pneumoperitoneum produces a consistent increase of ventricular filling pressures in a population of hypertensive patients with and without diastolic dysfunction. Moreover, there is a significant but transient rise in NT-proBNP after gas insufflation in both groups, most accentuated in the diastolic dysfunction group.


Assuntos
Hipertensão/fisiopatologia , Peptídeo Natriurético Encefálico/sangue , Fragmentos de Peptídeos/sangue , Pneumoperitônio Artificial/efeitos adversos , Disfunção Ventricular Esquerda/fisiopatologia , Adulto , Ecocardiografia Doppler , Feminino , Humanos , Hipertensão/sangue , Hipertensão/diagnóstico por imagem , Pessoa de Meia-Idade , Disfunção Ventricular Esquerda/sangue , Disfunção Ventricular Esquerda/diagnóstico por imagem
7.
Artigo em Inglês | MEDLINE | ID: mdl-23367404

RESUMO

Driving tasks are vulnerable to the effects of sleep deprivation and mental fatigue, diminishing driver's ability to respond effectively to unusual or emergent situations. Physiological and brain activity analysis could help to understand how to provide useful feedback and alert signals to the drivers for avoiding car accidents. In this study we analyze the insurgence of mental fatigue or drowsiness during car driving in a simulated environment by using high resolution EEG techniques as well as neurophysiologic variables such as heart rate (HR) and eye blinks rate (EBR). Results suggest that it is possible to introduce a EEG-based cerebral workload index that it is sensitive to the mental efforts of the driver during drive tasks of different levels of difficulty. Workload index was based on the estimation of increase of EEG power spectra in the theta band over prefrontal areas and the simultaneous decrease of EEG power spectra over parietal areas in alpha band during difficult drive conditions. Such index could be used in a future to assess on-line the mental state of the driver during the drive task.


Assuntos
Condução de Veículo , Eletroencefalografia/métodos , Fadiga Mental , Piscadela , Frequência Cardíaca , Humanos
8.
Eur Rev Med Pharmacol Sci ; 13(4): 317-9, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19694348

RESUMO

Fibromuscular dysplasia (FMD) is a non-inflammatory, non-atherosclerotic vascular disease that has been reported in renal and internal carotid arteries and in almost every arterial bed, primarily affecting young to middle-aged people, mainly female individuals. These patients may be asymptomatic or may present with hypertension. A 29 year-old hypertensive woman was referred for a renal color Doppler ultrasound (CDU) scan because of a suspicion of renovascular hypertension and we revealed the presence of three separate stenosis on the right renal artery. Digital selective angiography (DSA) and percutaneous transluminal angioplasty (PTA) were performed but an incomplete dilation of the vessel was obtained. Because of the suboptimal result, it was decided to stent the lesions during two different procedures. Percutaneous transluminal renal angioplasty is the primary treatment of renal FMD, but should not be excluded primary stent implantation as an alternative technique to surgical revascularization.


Assuntos
Displasia Fibromuscular/cirurgia , Obstrução da Artéria Renal/cirurgia , Stents , Adulto , Angiografia Digital/métodos , Angioplastia com Balão/métodos , Feminino , Displasia Fibromuscular/diagnóstico por imagem , Humanos , Obstrução da Artéria Renal/diagnóstico por imagem , Ultrassonografia Doppler em Cores/métodos
9.
Cells Tissues Organs ; 178(3): 129-38, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15655330

RESUMO

Sphingosine-1-phosphate (S1P) is a lipid mediator, which affects many essential processes such as cell proliferation, differentiation and contraction in many cell types. We have previously demonstrated that the lipid mediator elicits Ca(2+) transients in a myoblastic cell line (C2C12) by interacting with its specific receptors (S1PR(s)). In the present study, we wanted to correlate the Ca(2+) response with activation of myoblastic cell contractility. C2C12 cells were first investigated for the expression and cellular organization of cytoskeletal proteins by immunoconfocal microscopy. We found that myoblasts exhibited a quite immature cytoskeleton, with filamentous actin dispersed as a web-like structure within the cytoplasm. To evaluate intracellular Ca(2+) mobilization, the cells were loaded with a fluorescent Ca(2+) indicator (Fluo-3), stimulated with S1P and simultaneously observed with differential interference contrast and fluorescence optics. Exogenous S1P-induced myoblastic cell contraction was temporally unrelated to S1P-induced intracellular Ca(2+) increase; cell contraction occurred within 5-8 s from stimulation, whereas intracellular Ca(2+) increase was evident only after 15-25 s. To support the Ca(2+) independence of myoblastic cell contraction, the cells were pretreated with a Ca(2+) chelator, BAPTA/AM, prior to stimulation with S1P. In these experimental conditions, the myoblasts were still able to contract, whereas the S1P-induced Ca(2+) transients were completely abolished. On the contrary, when C2C12 cells were induced to differentiate into skeletal myotubes, they responded to S1P with a rapid cell contraction concurrent with an increase in the intracellular Ca(2+). These data suggest that Ca(2+)-independent mechanism of cell contraction may be replaced by Ca(2+)-dependent ones during skeletal muscle differentiation.


Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Cálcio/metabolismo , Ácido Egtázico/análogos & derivados , Lisofosfolipídeos/farmacologia , Contração Muscular/efeitos dos fármacos , Esfingosina/análogos & derivados , Esfingosina/farmacologia , Actinas/efeitos dos fármacos , Animais , Linhagem Celular , Tamanho Celular/efeitos dos fármacos , Quelantes/farmacologia , Citoesqueleto/efeitos dos fármacos , Ácido Egtázico/farmacologia , Técnica Indireta de Fluorescência para Anticorpo , Corantes Fluorescentes , Processamento de Imagem Assistida por Computador , Cinética , Camundongos , Microscopia Confocal , Mioblastos
10.
Minerva Anestesiol ; 69(5): 338-41, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12768163

RESUMO

The authors briefly review the main risk factors for fatal asthma, near-fatal asthma, rapid onset asthma and slow onset asthma. The most recent data in the international literature are also shortly reviewed and discussed.


Assuntos
Asma/fisiopatologia , Doença Aguda , Asma/diagnóstico , Hospitalização , Humanos , Fatores de Risco
11.
Histol Histopathol ; 18(2): 359-69, 2003 04.
Artigo em Inglês | MEDLINE | ID: mdl-12647785

RESUMO

Gap-junctions are specialized regions of intercellular contacts allowing electrical impulse propagation among adjacent cardiomyocytes. Connexin43 (Cx43) is the predominant gap-junction protein in the working ventricular myocardium and its reduced expression has been extensively implicated in the genesis of conduction abnormalities and re-entry arrhythmia of chronically hypertrophied hearts. In contrast, data on the role played by this protein during cardiac remodeling and early phases of developing hypertrophy are lacking. Therefore, in the present study, we investigated this issue using an experimental model of pig left ventricle (LV) volume overloading consisting in the creation of an aorto-cava fistula. At scheduled times (6, 24, 48, 96, 168 h, and 2, 3 months after surgery) echocardiographic and haemodynamic measurements were performed and myocardial biopsies were taken for the morphological and biochemical analyses. When faced with the increased load, pig myocardium underwent an initial period (from 6 up to 48 h) of remarkable tissue remodeling consisting in the occurrence of cardiomyocyte damage and apoptosis. After that time, the tissue developed a hypertrophic response that was associated with early dynamic changes (up-regulation) in Cx43 protein expression, as demonstrated by Western blot and confocal immunofluorescence analyses. However, an initial transient increase of this protein was also found after 6 h from surgery. With the progression of LV hypertrophy (from 168 hr up to 3 months), a reduction in the myocardial Cx43 expression was, instead, observed. The increased expression of Cx43 protein during acute hypertrophic response was associated with a corresponding increase in the levels of its specific mRNA, as detected by RT-PCR. We concluded that up-regulation of Cx43 gap-junction protein could represent an immediate compensatory response to support the new working conditions in the early stages of ventricular overloading.


Assuntos
Adaptação Fisiológica/fisiologia , Conexina 43/biossíntese , Coração/fisiologia , Miocárdio/metabolismo , Animais , Apoptose/fisiologia , Western Blotting , Tamanho Celular , Densitometria , Fibrose , Hemodinâmica/fisiologia , Microscopia Confocal , Microscopia Eletrônica , Contração Miocárdica/fisiologia , Miocárdio/ultraestrutura , RNA Mensageiro/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Suínos , Função Ventricular Esquerda/fisiologia
12.
Surg Endosc ; 17(5): 832, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-15765552

RESUMO

Laparoscopy is becoming a current approach for appendectomy. The technique is considered safe with few complications. We observed a young woman affected by meralgia paresthetica that developed after laparoscopic appendectomy. The femorocutaneous lateral nerve probably was damaged by insertion of a trocar in the right abdominal quadrant too close to the nerve course. Although meralgia paresthetica is not considered a frequent complication of laparoscopic appendectomy, it should be taken into account to avoid nerve lesion.


Assuntos
Apendicectomia/efeitos adversos , Neuropatia Femoral/etiologia , Laparoscopia/efeitos adversos , Parestesia/etiologia , Adulto , Feminino , Humanos
13.
Minerva Anestesiol ; 67(4): 223-7, 2001 Apr.
Artigo em Italiano | MEDLINE | ID: mdl-11376514

RESUMO

The authors describe the application of NIV as a useful tool to correct hypercarbia, gas exchanges and to reduce the complications caused by mechanical ventilation with ETT in patients with acute exacerbation of COPD and acute asthma attack.


Assuntos
Doença Pulmonar Obstrutiva Crônica/terapia , Respiração Artificial/métodos , Estado Asmático/terapia , Doença Aguda , Humanos , Máscaras , Respiração com Pressão Positiva , Insuficiência Respiratória/terapia
14.
Recenti Prog Med ; 91(11): 562-6, 2000 Nov.
Artigo em Italiano | MEDLINE | ID: mdl-11125948

RESUMO

The disfunction of the autonomic system nervous is a frequent finding in diabetes mellitus. Among objective tests proposed for its diagnosis, those assessing cardiovascular reflexes (cardiovascular tests: CVTs) explore the autonomic functionality by means of a group of standardized manoeuvres of relatively easy execution that study the baroreceptorial reflex arc. In our study, CVTs were performed in a population of 207 diabetic patients with no symptoms of autonomic neuropathy. A computerized automatic system (Cardionomic) was utilized. CTVs included: Deep Breathing, Lying to Standing, Valsalva Manoeuvre, Orthostatic Hypotension, Standing to Lying and Cough Test. Diabetic patients were broken down in groups according to: a) age, b) HbA1c levels, c) disease duration. We have then compared the presence of diabetic complications between the group of diabetics positive for cardiovascular disautonomia (CVD+) with another group of diabetics who were negative for cardiovascular disautonomia (DCV-). Our results show a remarkable correlation between autonomic neuropathy and patients age, HbA1c levels and disease duration. Also they show a strong positive correlation between CDV+ and the severity of arteriopathy. We conclude that autonomic neuropathy may play an important role in the pathogenesis of diabetic arteriopathy.


Assuntos
Doenças do Sistema Nervoso Autônomo/diagnóstico , Neuropatias Diabéticas/diagnóstico , Técnicas de Diagnóstico Cardiovascular , Adulto , Arteriosclerose/diagnóstico , Arteriosclerose/etiologia , Doenças do Sistema Nervoso Autônomo/etiologia , Angiopatias Diabéticas/diagnóstico , Angiopatias Diabéticas/etiologia , Neuropatias Diabéticas/etiologia , Diagnóstico por Computador/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sensibilidade e Especificidade
15.
Mov Disord ; 15(5): 938-46, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11009202

RESUMO

In this article we studied spinal and cortical inhibitory mechanisms in patients with Huntington's disease. To evaluate spinal cord inhibitory circuitries, we assessed reciprocal inhibition between antagonist forearm muscles and the recovery cycle of the H reflex in the flexor carpi radialis. Patients showed a significant decrease in the presynaptic phase of reciprocal inhibition reaching a minimum at the conditioning-test interval of 20 msec and an abnormal facilitation of the test H reflex at the conditioning test interval of 40 to 60 msec. Throughout its time course (10-200 msec), the H reflex recovery cycle showed a more prominent facilitation in patients than in control subjects. To assess whether the observed pathophysiological abnormalities might have arisen from an abnormal motor cortical excitability, we examined the recovery cycle of the motor potentials evoked by paired transcranial magnetic stimuli. We found that the inhibitory mechanisms controlling motor cortical excitability were normal. An interpretation of the spinal cord abnormalities is that the intrinsically normal but deafferentated motor cortex in Huntington's disease partly loses its inhibitory control, thus disinhibiting spinal cord circuitry. Our findings from paired transcranial magnetic stimulation suggest that cortical motor areas are not hyperexcitable in Huntington's disease. Hence, the postulated thalamocortical overactivity in experimental models of Huntington's disease needs to be reappraised.


Assuntos
Doença de Huntington/fisiopatologia , Córtex Motor/fisiopatologia , Inibição Neural , Medula Espinal/fisiopatologia , Adulto , Idoso , Estudos de Casos e Controles , Estimulação Elétrica , Eletromiografia , Feminino , Reflexo H , Humanos , Magnetismo , Masculino , Pessoa de Meia-Idade , Modelos Neurológicos , Córtex Motor/patologia , Vias Neurais/fisiopatologia , Terminações Pré-Sinápticas , Medula Espinal/patologia
16.
Electroencephalogr Clin Neurophysiol ; 105(2): 109-15, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9152203

RESUMO

We studied the effect of electrical stimulation of the C5-C8 dermatomes on voluntary electromyographic activity (EMG) recorded from the ipsilateral first dorsal interosseus (FDI), abductor digiti minimi, flexor and extensor carpi, triceps brachii, biceps brachii, and orbicularis oculi muscles of healthy humans. Finger stimulation (C6-C8) produced an EMG inhibition (silent period, SP), which progressively decreased in duration from distal to proximal muscles; in the biceps it induced a slight facilitation and in the orbicularis oculi muscle, it had no effect. Stimulation of the C5 dermatome induced no response in either distal or proximal muscles. Only high-intensity stimuli evoked clear silent periods. The threshold for evoking an SP was almost double that required for sensory action potentials, 3.25 times the sensory threshold, and decidedly above the pain threshold. An indirect estimation of the conduction velocity of SP afferent fibres placed them in the A-delta group of myelinated fibres. In double-shock experiments, used to study the recovery cycle of the SP in the FDI muscle after finger stimulation, neither low- nor high-intensity conditioning stimuli delivered 100-500 ms before the test stimulus changed test SPs. Experiments designed to evaluate motoneuronal excitability showed that in relaxed FDI muscle, finger stimulation markedly reduced the F wave at the 50 ms time interval, the time when the SP normally occurs. Our findings demonstrate that the activation of A-delta afferents from the fingers inhibits the C7-T1 motoneurons postsynaptically, through an oligosynaptic spinal circuit. We propose that the strong inhibitory effect exerted by noxious cutaneous stimuli on all distal muscles may contribute to a defence action which is specific for the human upper limb.


Assuntos
Braço , Músculo Esquelético/inervação , Fenômenos Fisiológicos da Pele , Potenciais de Ação , Adulto , Condicionamento Psicológico , Estimulação Elétrica/métodos , Eletromiografia , Mãos , Humanos , Músculos/inervação , Fenômenos Fisiológicos do Sistema Nervoso , Condução Nervosa , Neurônios Aferentes/fisiologia , Nociceptores/fisiologia , Dor , Tempo de Reação , Sensação/fisiologia , Limiar Sensorial , Pele/inervação
17.
Mov Disord ; 9(2): 178-82, 1994 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8196679

RESUMO

The silent period evoked by transcranial (TCS) and nerve stimulation was studied in the hand muscles in 13 patients with Huntington's disease and in 11 normal subjects. The duration of the silent period after TCS was longer in patients and correlated significantly with the severity of chorea; in contrast, the duration of the silent period after nerve stimulation was similar in patients and controls. The prolongation of the cortical silent period suggests that the duration of the silent period is a functional correlate reflecting basal ganglia influence over the motor cortex.


Assuntos
Terapia por Estimulação Elétrica , Eletromiografia , Doença de Huntington/fisiopatologia , Músculos/inervação , Inibição Neural/fisiologia , Adulto , Idoso , Gânglios da Base/fisiopatologia , Potenciais Evocados/fisiologia , Feminino , Humanos , Doença de Huntington/terapia , Masculino , Pessoa de Meia-Idade , Córtex Motor/fisiopatologia , Contração Muscular/fisiologia , Vias Neurais/fisiopatologia
18.
Exp Brain Res ; 98(3): 501-6, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8056070

RESUMO

We studied in humans the effects of transcranial stimulation of cortical motor areas on the execution of single and sequential rapid arm movements. In a reaction time paradigm with an auditory "go" signal, stimulation given after an auditory tone and before the start of movements delayed the onset but did not affect the subsequent performance of single or sequential movements; high intensities of cortical stimulation determined a long-lasting inhibition of movements. Cortical stimulation given during the execution of a sequential movement temporarily interrupted the movements. Reaction time was not prolonged and movements were not inhibited when cortical stimulation was delivered before the auditory tone and the start of movement. Neither electrical stimulation of the corticospinal tracts at the cervico medullary junction nor magnetic stimulation of the cervical roots delayed the onset or interrupted the execution of movements. Transcranial stimulation affects the performance of both single and sequential movements, through cortical mechanisms that interfere with the transfer of the motor program from other cortical structures to the motor cortex.


Assuntos
Braço/fisiologia , Córtex Motor/fisiologia , Movimento/fisiologia , Adulto , Estimulação Elétrica , Humanos , Bulbo/fisiologia , Pescoço , Medula Espinal/fisiologia , Estimulação Magnética Transcraniana
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