Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Clin Neurophysiol ; 123(5): 902-9, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21996001

RESUMO

OBJECTIVE: To investigate changes in cortical excitability and short-term synaptic plasticity we delivered 5 Hz repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex in 11 patients with mild-to-moderate Alzheimer's disease (AD) before and after chronic therapy with rivastigmine. METHODS: Resting motor threshold (RMT), motor evoked potential (MEP), cortical silent period (CSP) after single stimulus and MEP facilitation during rTMS trains were tested three times during treatment. All patients underwent neuropsychological tests before and after receiving rivastigmine. rTMS data in patients were compared with those from age-matched healthy controls. RESULTS: At baseline, RMT was significantly lower in patients than in controls whereas CSP duration and single MEP amplitude were similar in both groups. In patients, rTMS failed to induce the normal MEP facilitation during the trains. Chronic rivastigmine intake significantly increased MEP amplitude after a single stimulus, whereas it left the other neurophysiological variables studied unchanged. No significant correlation was found between patients' neuropsychological test scores and TMS measures. CONCLUSIONS: Chronic treatment with rivastigmine has no influence on altered cortical excitability and short-term synaptic plasticity as tested by 5 Hz-rTMS. SIGNIFICANCE: The limited clinical benefits related to cholinesterase inhibitor therapy in patients with AD depend on factors other than improved plasticity within the cortical glutamatergic circuits.


Assuntos
Doença de Alzheimer , Potencial Evocado Motor/efeitos dos fármacos , Córtex Motor/efeitos dos fármacos , Fenilcarbamatos/farmacologia , Fenilcarbamatos/uso terapêutico , Estimulação Magnética Transcraniana , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Análise de Variância , Estudos de Casos e Controles , Eletromiografia , Feminino , Lateralidade Funcional/efeitos dos fármacos , Humanos , Estudos Longitudinais , Masculino , Entrevista Psiquiátrica Padronizada , Músculo Esquelético/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Tempo de Reação , Rivastigmina
2.
G Chir ; 30(4): 153-5, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19419616

RESUMO

Paget breast disease is a kind of intraductal carcinoma that through an intracanalicular diffusion invades the basal epidermal layer, reaching the areola and nipple, producing a typical erythematous desquamative eczematous-like lesion. This neoplasia can remain undetected for a long time and inadequately treated as a dermatological affection. Synchronous or metachronous lesions are very uncommon. Surgical choice is conditioned by the presence of a tumor below the epidermal lesion, by its dimensions, and by the possible lymph node involvement. Surgical therapy can be radical or conservative. From our experience we think that lesion biopsy is always necessary to formulate a correct diagnosis and to schedule an appropriate therapeutic approach. In our case, a biopsy was performed first, then on the basis of the frozen section analysis a radical mastectomy with axillary third level lymph nodes dissection, because of the large dimensions of the lesion and the previous history of a methachronous lesion.


Assuntos
Neoplasias da Mama , Carcinoma Ductal de Mama , Segunda Neoplasia Primária , Doença de Paget Mamária , Idoso , Biópsia , Mama/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Neoplasias da Mama/cirurgia , Carcinoma Ductal de Mama/patologia , Feminino , Humanos , Excisão de Linfonodo , Mamografia , Mastectomia Radical , Estadiamento de Neoplasias , Segunda Neoplasia Primária/patologia , Segunda Neoplasia Primária/cirurgia , Doença de Paget Mamária/diagnóstico por imagem , Doença de Paget Mamária/patologia , Doença de Paget Mamária/cirurgia , Tomografia Computadorizada por Raios X
3.
J Neurol ; 256(6): 933-8, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19252788

RESUMO

We designed this study to investigate possible correlations between variables measuring primary motor cortex excitability detected by single and paired-pulse transcranial magnetic stimulation (TMS) and the severity of clinical manifestations in patients with multiple sclerosis (MS). Thirty patients with MS in remission, 16 with relapsing-remitting (RR), 14 with secondary progressive disease (SP) and 17 healthy subjects participated in the study. In each subject, the central motor conduction time (CMCT) was calculated, and single-pulse and paired-pulse TMS at 3 and 10 ms interstimulus intervals was delivered over the primary motor cortex of the dominant hemisphere to measure the amplitude of motor-evoked potentials (MEPs), motor threshold (MTh), intracortical inhibition (ICI) and facilitation (ICF). Correlations were determined between the patients' TMS findings and magnetic resonance imaging (MRI) (lesion load) and clinical features (expanded disability status scale, EDSS score). EDSS scores were significantly higher in SPMS than in RRMS patients. The MTh was significantly higher, and the MEP was significantly smaller in SPMS patients than in RRMS patients and control subjects. All patients had longer CMCTs than healthy subjects. In all patients, paired-pulse TMS elicited an inhibited test MEP at the 3-ms ISI and a facilitated test MEP at the 10 ms ISI. Post hoc analysis showed that ICI was significantly lower in SPMS patients than in those with RRMS and healthy subjects. EDSS scores correlated significantly with TMS measures (MEP, ICI, CMCT and MTh), but not with MRI lesion load. It was found that intracortical excitability as measured with TMS differs according to the clinical course of MS; it remains normal in patients with low EDSS scores and is altered in patients with high EDSS scores.


Assuntos
Córtex Motor/fisiopatologia , Esclerose Múltipla Crônica Progressiva/fisiopatologia , Esclerose Múltipla Recidivante-Remitente/fisiopatologia , Adulto , Análise de Variância , Eletromiografia , Potencial Evocado Motor , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Motor/patologia , Esclerose Múltipla Crônica Progressiva/patologia , Esclerose Múltipla Recidivante-Remitente/patologia , Condução Nervosa , Inibição Neural/fisiologia , Índice de Gravidade de Doença , Fatores de Tempo , Estimulação Magnética Transcraniana/métodos
4.
G Chir ; 30(1-2): 46-50, 2009.
Artigo em Italiano | MEDLINE | ID: mdl-19272233

RESUMO

The authors, on the basis of a long clinical experience with human fibrin glue in general surgery, compared two different extracellular matrix (collagen), Surgisis and TissueDura, with human fibrin glue, applied during the operation, and sometimes in postoperative, to obtain the healing of perianal fistulas. The collagenic extracellular matrix provides, according to the rationale suggested, an optimal three-dimensional structure for the fibroblastic implant and neoangiogenesis, hence for the fistula "fibrotizzation" and closure. The encouraging results for transphincteric fistulas and a simple and easy technique push to researchers on samples statistically significant.


Assuntos
Implantes Absorvíveis , Colágeno/uso terapêutico , Matriz Extracelular , Adesivo Tecidual de Fibrina/uso terapêutico , Fístula Retal/terapia , Adesivos Teciduais/uso terapêutico , Idoso , Animais , Colágeno/administração & dosagem , Feminino , Cavalos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Suínos
5.
J Neurophysiol ; 99(2): 564-70, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18057113

RESUMO

Short trains of suprathreshold 5-Hz repetitive transcranial magnetic stimulation (rTMS) over primary motor cortex (M1) evoke motor potentials (MEPs) in hand muscles that progressively increase in amplitude via a mechanism that is thought to be similar to short-term potentiation described in animal preparations. Long trains of subthreshold rTMS over dorsal premotor cortex (PMd) are known to affect the amplitude of single-pulse MEPs evoked from M1. We tested whether PMd-rTMS affects short-term facilitation in M1. We also explored the effect of PMd-rTMS on M1 responses evoked by single-pulse TMS of different polarities. We tested in 15 healthy subjects short-term facilitation in left M1 (10 suprathreshold TMS pulses at 5 Hz) after applying rTMS to left PMd (1,500 subthreshold pulses at 1 and 5 Hz). In a sample of subjects we delivered single-pulse TMS with different polarities and paired-pulse TMS at short intervals (SICI) after PMd-rTMS. Short-term facilitation in M1 was reduced after applying 1 Hz to PMd, but was unaffected after 5-Hz PMd-rTMS. PMd-rTMS with 1 Hz reduced the amplitude of MEPs evoked by monophasic posteroanterior (PA) or biphasic anteroposterior (AP)-PA but had little effect on MEPs by monophasic AP or biphasic PA-AP single-pulse TMS. PMd-rTMS left SICI unchanged. PMd-rTMS (1 Hz) reduces short-term facilitation in M1 induced by short 5-Hz trains. This effect is likely to be caused by reduced facilitation of I-wave inputs to corticospinal neurons.


Assuntos
Condicionamento Psicológico , Estimulação Elétrica/métodos , Potencial Evocado Motor/efeitos da radiação , Córtex Motor/fisiologia , Estimulação Magnética Transcraniana , Adulto , Análise de Variância , Relação Dose-Resposta à Radiação , Eletromiografia/métodos , Potencial Evocado Motor/fisiologia , Feminino , Humanos , Masculino , Músculo Esquelético/fisiologia , Músculo Esquelético/efeitos da radiação , Tempo de Reação/fisiologia , Tempo de Reação/efeitos da radiação , Fatores de Tempo
6.
Clin Neurophysiol ; 119(3): 667-674, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18083628

RESUMO

OBJECTIVE: We designed this study to find out whether 5Hz repetitive transcranial magnetic stimulation (rTMS) would disclose changes in cortical plasticity after acute intake of ethanol and in patients with chronic alcohol consumption. METHODS: Ten stimuli-5Hz-rTMS trains were applied over the primary motor cortex in 10 healthy subjects before and after acute ethanol intake and in 13 patients with chronic ethanol abuse, but negative blood ethanol levels when studied. The motor evoked potential (MEP) amplitude and the cortical silent period (CSP) duration during the course of rTMS trains were measured. Short-interval intracortical inhibition (3ms) and intracortical facilitation (10ms) were studied by paired-pulse TMS in 4 healthy subjects and 4 patients. RESULTS: In healthy subjects before and after acute ethanol intake, 5Hz-rTMS produced a significant increase in the MEP size and CSP duration during rTMS. The first CSP in the train was significantly longer after than before ethanol intake. In patients 5Hz-rTMS failed to produce the normal MEP facilitation but left the CSP increase unchanged. CONCLUSIONS: Acute and chronic ethanol intake alters cortical excitability and short-term plasticity of the primary motor cortex as tested by the MEP size facilitation and CSP lengthening after 5Hz-rTMS. SIGNIFICANCE: This finding suggests that rTMS is a valid tool for investigating the effects of ethanol on cortical plasticity in humans.


Assuntos
Alcoolismo/fisiopatologia , Depressores do Sistema Nervoso Central/administração & dosagem , Etanol/administração & dosagem , Potencial Evocado Motor/efeitos dos fármacos , Córtex Motor/efeitos dos fármacos , Estimulação Magnética Transcraniana , Adulto , Análise de Variância , Depressão Alastrante da Atividade Elétrica Cortical/efeitos dos fármacos , Limiar Diferencial/efeitos dos fármacos , Estimulação Elétrica/métodos , Eletromiografia/métodos , Etanol/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Córtex Motor/fisiopatologia
7.
Exp Brain Res ; 180(1): 105-11, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17265042

RESUMO

We evaluated the effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) on motor performance and motor learning of a rapid index finger movement. Two groups of healthy right-handed subjects underwent either "real" rTMS (1800 stimuli over the first dorsal interosseous (FDI) muscle hot spot given at 5 Hz and intensity of 90% of resting motor threshold-RMT) or "sham" stimulation. Both groups performed 60 rapid abductions of the right index finger before and after rTMS. The kinematic variables measured were amplitude, duration, peak velocity and peak acceleration. We also evaluated RMT and motor-evoked potential (MEP) amplitude before, 5 and 30 min after rTMS. In both groups practice significantly increased peak velocity, peak acceleration and amplitude and decreased movement duration independently from the type of intervention ("real" and "sham"). "Real" rTMS significantly increased cortical excitability as measured by MEP amplitude whereas "sham" rTMS did not. In our study, 5 Hz rTMS failed to improve either the motor performance or the motor learning of a rapid index-finger abduction despite the increase in cortical excitability of the primary motor cortex. Since motor behaviour engages a distributed cortical and subcortical neuronal network, excitatory conditioning of the primary motor cortex is probably not sufficient to influence the behavioural output.


Assuntos
Potencial Evocado Motor/fisiologia , Dedos/inervação , Córtex Motor/fisiologia , Movimento/fisiologia , Estimulação Magnética Transcraniana , Adulto , Análise de Variância , Limiar Diferencial , Estimulação Elétrica , Eletromiografia , Potencial Evocado Motor/efeitos da radiação , Feminino , Dedos/fisiologia , Humanos , Masculino
8.
Neurol Sci ; 28(6): 331-5, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18175081

RESUMO

Allgrove syndrome is a rare autosomal recessive disorder characterised by childhood onset, alacrima, oesophageal achalasia, adrenocortical insufficiency, neurological and occasionally autonomic involvement. Although the disease has been associated with mutations in the ALADIN gene on chromosome 12q13, it is genetically heterogeneous. The case we report is interesting because of its onset in adulthood, long duration of disease and prominent neurological dysfunctions. After the onset of neurological abnormalities the diagnosis went unrecognised for years until the patient presented for evaluation of dysphagia. The presence of achalasia with dysphagia, adrenal insufficiency, reduced tear production, optic atrophy and peripheral motor-sensory neuropathy with axonal loss led us to clinically diagnose Allgrove syndrome even though a genetic study showed no mutations in the ALADIN gene exons. The case we report shares many clinical features with Allgrove syndrome and, even with the limitations of a single case, underlines the variability in this syndrome and the need for appropriate investigations along with a multidisciplinary approach.


Assuntos
Insuficiência Adrenal/genética , Transtornos Cromossômicos/genética , Cromossomos Humanos Par 12 , Acalasia Esofágica/genética , Proteínas do Tecido Nervoso/genética , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Insuficiência Adrenal/complicações , Adulto , Transtornos Cromossômicos/complicações , Síndromes do Olho Seco/etiologia , Acalasia Esofágica/complicações , Genes Recessivos , Humanos , Masculino , Mutação
9.
Exp Brain Res ; 176(4): 588-93, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16900360

RESUMO

We investigated the post-train effects of repetitive transcranial magnetic stimulation (rTMS) on motor evoked potential (MEP) size and cortical silent period (SP) duration. rTMS was delivered over the primary motor cortex in trains of 5, 10, 20, 40 and 60 stimuli in normal subjects at rest and in trains of 5, 10 and 20 stimuli during voluntary muscle contraction. The intensity of stimulation was 120% of resting motor threshold. Test MEPs were delivered at different interstimulus intervals after rTMS ended. At rest, 5 Hz trains produced an increase in the MEP size that persisted after the end of the trains. Trains of 5 stimuli produced after-effects that persisted for 0.5 s, whereas trains of 40 and 60 stimuli produced a facilitation that lasted for several seconds. 5 Hz-rTMS delivered during muscle contraction increased the SP duration during stimulation but the increase persisted for only 1 s after the train ended. The present experiments show that the after-effects of rTMS on MEP amplitude and SP duration have different time-courses. rTMS probably elicits its after-effects on excitatory and inhibitory cortical elements through different physiological mechanisms.


Assuntos
Potencial Evocado Motor/fisiologia , Córtex Motor/fisiologia , Movimento/fisiologia , Inibição Neural/fisiologia , Plasticidade Neuronal/fisiologia , Adulto , Eletromiografia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular/fisiologia , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Tempo de Reação/fisiologia , Valores de Referência , Transmissão Sináptica/fisiologia , Fatores de Tempo , Estimulação Magnética Transcraniana
10.
Exp Brain Res ; 174(4): 667-72, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16896986

RESUMO

Repetitive transcranial magnetic stimulation (rTMS) delivered at 5 Hz frequency and suprathreshold intensity progressively increases the size of muscle evoked potentials (MEPs) and the duration of the cortical silent period (CSP) in normal subjects. The aim of this study was to evaluate the effects of topiramate (TPM) at different doses on cortical excitability variables tested with rTMS. We tested the facilitation of the MEP size and CSP duration evoked by focal rTMS in eight patients before and after treatment with TPM at different doses for chronic neuropathic pain. In each patient, rTMS (5 Hz frequency-120% resting motor threshold) was applied at baseline and during the TPM induction phase (drug intake schedule: week I 25 mg/day, week II 50 mg/day, week III 75 mg/day, week IV 100 mg/day) and total TPM plasma concentrations were measured. The effects on the MEP size of 5 Hz-rTMS delivered over repeated sessions were tested in eight control subjects. TPM had no effect on the resting motor threshold. Antiepileptic treatment at increasing doses abolished the normal rTMS-induced MEP facilitation. ANOVA showed that this was a dose-related effect. Accordingly, in patients receiving TPM at higher doses (75 and 100 mg) rTMS failed to elicit the MEP facilitation. TPM left the progressive lengthening of the CSP during the rTMS train unchanged. In control subjects, rTMS applied over repeated sessions elicited a constant increase in MEP size. Our results suggest that TPM modulates the excitatory intracortical interneurons probably by altering rTMS-induced synaptic potentiation. These drug-induced effects are related to TPM doses and plasma concentrations. In conclusion, rTMS may be useful for quantifying the effectiveness of antiepileptic drugs and for assessing individual responses to different drugs but acting through similar mechanisms, thus combining functional neurophysiological information and laboratory data.


Assuntos
Potencial Evocado Motor/efeitos dos fármacos , Frutose/análogos & derivados , Córtex Motor , Fármacos Neuroprotetores/uso terapêutico , Estimulação Magnética Transcraniana , Adulto , Análise de Variância , Doença Crônica , Limiar Diferencial/efeitos dos fármacos , Limiar Diferencial/efeitos da radiação , Relação Dose-Resposta a Droga , Estimulação Elétrica , Eletromiografia , Potencial Evocado Motor/efeitos da radiação , Frutose/farmacologia , Frutose/uso terapêutico , Humanos , Pessoa de Meia-Idade , Córtex Motor/efeitos dos fármacos , Córtex Motor/fisiopatologia , Córtex Motor/efeitos da radiação , Neuralgia/tratamento farmacológico , Neuralgia/fisiopatologia , Fármacos Neuroprotetores/farmacologia , Topiramato
11.
Clin Neurophysiol ; 117(8): 1677-81, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16793338

RESUMO

OBJECTIVE: TMS techniques have provided controversial information on motor cortical function in Huntington's disease (HD). We investigated the excitability of motor cortex in patients with HD using repetitive transcranial magnetic stimulation (rTMS). METHODS: Eleven patients with HD, and 11 age-matched healthy subjects participated in the study. The clinical features of patients with HD were evaluated with the United Huntington's Disease Rating Scale (UHDRS). rTMS was delivered with a Magstim Repetitive Magnetic Stimulator through a figure-of-8 coil placed over the motor area of the first dorsal interosseus (FDI) muscle. Trains of 10 stimuli were delivered at 5 Hz frequency and suprathreshold intensity (120% resting motor threshold) with the subjects at rest and during voluntary contraction of the target muscle. RESULTS: In healthy subjects at rest, rTMS produced motor evoked potentials (MEPs) that increased in amplitude over the course of the trains. Conversely in patients, rTMS left the MEP size almost unchanged. In both groups, during voluntary contraction rTMS increased the silent period (SP) duration. CONCLUSIONS: Because rTMS modulates motor cortical excitability by activating cortical excitatory and inhibitory interneurons these findings suggest that in patients with HD the excitability of facilitatory intracortical interneurones is decreased. SIGNIFICANCE: We suggest that depressed excitability of the motor cortex in patients with HD reflects a disease-related weakening of cortical facilitatory mechanisms.


Assuntos
Doença de Huntington/fisiopatologia , Córtex Motor/fisiopatologia , Estimulação Magnética Transcraniana , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
12.
Neurotox Res ; 9(2-3): 141-4, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16785111

RESUMO

Botulinum toxin injected into a muscle may diffuse to nearby muscles thus producing unwanted effects. In patients with hemifacial spasm, we evaluated clinically and neurophysiologically, whether botulinum toxin type A (BoNT-A) diffuses from the injection site (orbicularis oculi) to untreated muscles (orbicularis oris from the affected side and orbicularis oculi and oris from the unaffected side). We studied 38 patients with idiopathic hemifacial spasm. Botulinum toxin was injected into the affected orbicularis oculi muscle alone (at 3 standardized sites) at a clinically effective dose. Patients were studied before (T0) and 3-4 weeks after treatment (T1). We evaluated the clinical effects of botulinum toxin and muscle strength in the affected and unaffected muscles. We also assessed the peak-to-peak amplitude compound muscle action potential (CMAP) recorded from the orbicularis oculi and orbicularis oris muscles on both sides after supramaximal electrical stimulation of the facial nerve at the stylomastoid foramen. In all patients, botulinum toxin treatment reduced muscle spasms in the injected orbicularis oculi muscle and induced no muscle weakness in the other facial muscles. The CMAP amplitude significantly decreased in the injected orbicularis oculi muscle, but remained unchanged in the other facial muscles (orbicularis oris muscle on the affected side and contra-lateral unaffected muscles). In conclusion, in patients with hemifacial spasm, botulinum toxin, at a clinically effective dose, induces no clinical signs of diffusion and does not reduce the CMAP size in the nearby untreated orbicularis oris or contralateral facial muscles.


Assuntos
Toxinas Botulínicas Tipo A/farmacocinética , Espasmo Hemifacial/metabolismo , Músculo Esquelético/metabolismo , Fármacos Neuromusculares/farmacocinética , Potenciais de Ação/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Toxinas Botulínicas Tipo A/uso terapêutico , Difusão , Estimulação Elétrica , Nervo Facial/efeitos dos fármacos , Nervo Facial/fisiologia , Feminino , Espasmo Hemifacial/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Fármacos Neuromusculares/uso terapêutico , Neurofisiologia
13.
Exp Brain Res ; 173(1): 180-4, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16783556

RESUMO

Aim of the present study was to evaluate the acute and long-term effects of low-frequency repetitive transcranial magnetic stimulation (rTMS) on focal epileptiform interictal EEG activity in a patient with fixation-off sensitivity and partial epilepsy. Real and sham rTMS were delivered over the vertex. Two trains of 500 stimuli per day were delivered at 0.33 Hz frequency and threshold intensity for five consecutive days. The number of posterior EEG spikes and spike-and-wave complexes/min before and after the application of rTMS were compared in a blinded manner. In our patient, real-rTMS induced a long-lasting decrease in the number of posterior EEG spikes and spike-and-wave complexes/min. Despite the limitations of a single case report, our study confirms that low-frequency rTMS significantly reduces interictal focal epileptic activity over time.


Assuntos
Transtornos da Motilidade Ocular/terapia , Estimulação Magnética Transcraniana , Adulto , Análise de Variância , Eletroencefalografia/métodos , Eletromiografia , Epilepsia/complicações , Epilepsia/terapia , Estudos de Avaliação como Assunto , Potencial Evocado Motor/fisiologia , Potencial Evocado Motor/efeitos da radiação , Feminino , Humanos , Tempo de Reação/fisiologia , Tempo de Reação/efeitos da radiação , Fatores de Tempo
14.
Clin Neurophysiol ; 117(1): 103-9, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16364684

RESUMO

OBJECTIVE: In this study, we tested the excitability of cortical motor areas in patients with Alzheimer's disease. Because repetitive transcranial magnetic stimulation (rTMS) modulates cortical excitability, possibly by inducing a short-term increase in synaptic efficacy, we used rTMS to investigate motor cortex excitability in patients with Alzheimer's disease. METHODS: We tested the changes in the size and threshold of motor evoked potential (MEP) and cortical silent period (CSP) duration evoked by focal rTMS delivered in 10 trains of 10 stimuli at 5Hz frequency and 120% rMth intensity in a group of patients with Alzheimer's disease, and age-matched controls. In a further session, rTMS was also delivered at 1Hz frequency (trains of 10 stimuli, 120% rMth). RESULTS: Whereas in control subjects, 5Hz-rTMS elicited normal MEPs that progressively increased in size during the train, in patients, it elicited MEPs that decreased in size. The increase in the duration of the CSP was similar in patients and healthy controls. One hertz rTMS left the MEP amplitude unchanged in patients and healthy controls. CONCLUSIONS: The lack of MEP facilitation reflects an altered response to 5Hz-rTMS in patients with Alzheimer's disease. SIGNIFICANCE: Our rTMS findings strongly suggest an altered cortical plasticity in excitatory circuits within motor cortex in patients with Alzheimer's disease.


Assuntos
Doença de Alzheimer/fisiopatologia , Potencial Evocado Motor/efeitos da radiação , Córtex Motor/efeitos da radiação , Estimulação Magnética Transcraniana , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Estudos de Casos e Controles , Limiar Diferencial/efeitos da radiação , Relação Dose-Resposta à Radiação , Eletromiografia/métodos , Potencial Evocado Motor/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Córtex Motor/fisiopatologia , Periodicidade
15.
Neurology ; 64(11): 1906-12, 2005 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-15955942

RESUMO

OBJECTIVE: To explore the impact of dopaminergic therapy on facilitatory premotor-motor interactions in patients with Parkinson disease (PD). METHODS: Ten patients with PD and 10 age-matched healthy volunteers received repetitive transcranial magnetic stimulation (rTMS) over the left dorsal premotor cortex (5 Hz, 1,500 stimuli, 90% of active motor threshold). Patients were studied while "on" and "off" medication. Motor evoked potentials (MEPs) were recorded from the right first dorsal interosseus muscle before and after rTMS to quantify changes in motor cortical excitability. The after-effects of rTMS on motor function were assessed using the Unified Parkinson's Disease Rating Scale and the kinematics of ballistic wrist flexions. RESULTS: MEPs evoked from the ipsilateral motor cortex were increased after premotor rTMS in relaxed normal subjects, consistent with an increase in motor cortex excitability. In patients with PD, the effect of premotor rTMS was modified by medication. When patients were in a practically defined "off" state, premotor rTMS had no effect on MEPs, whereas when they were in the "on" state, premotor rTMS facilitated MEPs. Premotor rTMS had no effect on clinical parkinsonian symptoms or motor performance of ballistic wrist movements, regardless of whether patients were in the "on" or "off" state. CONCLUSIONS: In Parkinson disease, the ability of premotor-motor connections to increase motor cortical excitability is defective but restored to normal by dopaminergic medication. Dopamine deficiency in the basal ganglia may affect the way that frontal motor areas interact with each other.


Assuntos
Dopaminérgicos/farmacologia , Vias Eferentes/efeitos dos fármacos , Córtex Motor/efeitos dos fármacos , Doença de Parkinson/tratamento farmacológico , Recuperação de Função Fisiológica/efeitos dos fármacos , Adulto , Idoso , Dopaminérgicos/uso terapêutico , Vias Eferentes/fisiologia , Vias Eferentes/fisiopatologia , Eletromiografia , Potencial Evocado Motor/efeitos dos fármacos , Potencial Evocado Motor/fisiologia , Feminino , Mãos/inervação , Mãos/fisiologia , Mãos/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Córtex Motor/fisiologia , Córtex Motor/fisiopatologia , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Músculo Esquelético/fisiopatologia , Doença de Parkinson/fisiopatologia , Recuperação de Função Fisiológica/fisiologia , Estimulação Magnética Transcraniana , Resultado do Tratamento
16.
Exp Brain Res ; 163(1): 114-7, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15940502

RESUMO

Repetitive transcranial magnetic stimulation (rTMS) delivered at various intensities and frequencies excites cortical motor areas. Trains of stimuli (at 5-Hz frequency, and suprathreshold intensity) progressively increase the size of motor evoked potentials (MEPs) and the duration of the cortical silent period (CSP) in normal subjects. Because antiepileptic drugs, acting mainly on sodium channels, depress MEP facilitation during rTMS, we suggested that rTMS trains facilitate the MEP size by inducing synaptic potentiation primarily involving voltage-gated sodium channels. The aim of this study was to evaluate the effect of lidocaine-a drug that acts selectively on sodium channels-on the rTMS-induced changes in cortical excitability. We tested the changes in motor threshold, MEP size, CSP duration evoked by focal rTMS and the M-wave amplitude in healthy subjects before and after lidocaine infusion. Lidocaine abolished the normal rTMS-induced facilitation of MEPs but left the other rTMS variables and the M-wave unchanged. Our results suggest that the MEP facilitation related to rTMS-induced synaptic potentiation results from an increase in cortical excitatory interneuron excitability that involves voltage-gated sodium channels.


Assuntos
Anestésicos Locais/farmacologia , Estimulação Elétrica , Potencial Evocado Motor/efeitos dos fármacos , Lidocaína/administração & dosagem , Magnetismo , Eletromiografia , Potencial Evocado Motor/fisiologia , Humanos , Injeções Intravenosas , Canais de Sódio/fisiologia , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia
17.
Exp Brain Res ; 160(3): 368-74, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15480605

RESUMO

Despite indisputable evidence that repetitive transcranial magnetic stimulation (rTMS) modulates motor cortical excitability, the effects of subthreshold low-frequency rTMS on intracortical inhibition (ICI) are controversial. In this paper we investigated whether increasing the level of baseline ICI increases the sensitivity of ICI for disclosing the after-effects of rTMS on cortical excitability. In experiment 1, we studied changes in ICI, tested at two different baseline levels, after a train of 900 subthreshold rTMS pulses delivered at 1 Hz. In experiment 2, we studied whether the same conditioning rTMS train changed the ICI threshold, and in experiment 3 whether it changed the facilitatory I-wave interaction. Conditioning rTMS reduced ICI tested at a baseline level of 75% but left ICI tested at a baseline level of 50% unchanged. It also increased the ICI threshold but left the facilitatory I-wave interaction unchanged. These findings suggest that conditioning rTMS selectively reduced ICI tested at a baseline level of 75% by increasing the threshold for evoking inhibition in the motor cortex. The inhibitory system mediating ICI may therefore be more efficient than other motor cortical systems in reducing high cortical excitability after external intervention. Hence studies investigating the after-effects of rTMS should standardize ICI levels at baseline.


Assuntos
Campos Eletromagnéticos , Potencial Evocado Motor/fisiologia , Córtex Motor/fisiologia , Inibição Neural/fisiologia , Limiar Sensorial/fisiologia , Adulto , Análise de Variância , Feminino , Humanos , Masculino
18.
Exp Brain Res ; 154(4): 488-93, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14579005

RESUMO

Repetitive transcranial magnetic stimulation (rTMS) delivered at various intensities and frequencies excites cortical motor areas. Trains of stimuli (at 5 Hz frequency, and suprathreshold intensity) progressively increase the size of muscle evoked potentials (MEPs) and the duration of the cortical silent period (CSP) in normal subjects. The aim of this study was to evaluate the effect of the antiepileptic drugs carbamazepine, gabapentin, and topiramate on cortical excitability variables tested with rTMS. We tested the changes in motor threshold, MEP size and CSP duration evoked by focal rTMS in 23 patients with neuropathic pain before and after a 1-week course of treatment with carbamazepine, gabapentin, topiramate and placebo. None of the three antiepileptic drugs changed the resting or active magnetic and electrical motor threshold. Antiepileptic treatment, but not placebo, abolished the normal rTMS-induced facilitation of MEPs, but left the progressive lengthening of the CSP during the rTMS train unchanged. Our results suggest that carbamazepine, gabapentin and topiramate modulate intracortical excitability by acting selectively on excitatory interneurons.


Assuntos
Anticonvulsivantes/farmacologia , Campos Eletromagnéticos , Potencial Evocado Motor/efeitos dos fármacos , Córtex Motor/efeitos dos fármacos , Análise de Variância , Potencial Evocado Motor/fisiologia , Humanos , Pessoa de Meia-Idade , Córtex Motor/fisiologia , Método Simples-Cego
19.
Tumori ; 89(4 Suppl): 215-9, 2003.
Artigo em Italiano | MEDLINE | ID: mdl-12903598

RESUMO

INTRODUCTION: The aim to individuate the eventual correlation between the two pathologies has justified deeper studies to achieve new prospective approaches for both disease. BACKGROUND: We have selected 4 groups of patients who presented an association between the two pathologies: a) malignant breast pathology associated to a malignant thyroid pathology, b) patients with breast carcinoma who presented association with some thyroid alterations, c) patients with thyroid carcinoma who presented association with some breast alterations, d) patients who presented some associations between benign breast pathology and benign thyroid pathology. MATERIALS AND METHODS: We have excluded all patients with a clear physiological or surgical menopausal status, and we've so considered only patients with a regular menstrual cycle. We've so selected a group of 120 patients and we've performed in all these patients during the early follicular phase the following exams: breast echographic evaluation and thyroid echographic-structure and volume determination and finally hormonal determinations we have so obtained two breast subgroups: 32 patients with hyperestrogenic integrative hormonal characteristics, 28 patients subjected to adjuvant hormonal therapy with hypoestregenic hormonal status and finally two thyroid subgroups, 22 patients showing clinical or subclinical hypothyroidism, 38 patients showing clinical or subclinical hyperthyroidism. We've compared these data to a random age-matched health control women group of 25 patients. RESULTS: The first group of patient showed a thyroid hormonal pattern of subclinical hypothyroidism or at least free T3 and free T4 mean value currently under and TSH and TPO Ab levels curve currently over the mean values of the control group. The second group showed the TSH suppressed with free T3 and free T4 curves currently over the mean value of the control group. The third group showed slight elevations in serum PRL levels curve. The fourth group showed increased estrogen levels-curve, often over the mean value of the control group. CONCLUSION: How much is it allowed to perform an hormonal therapy, specially for a benign pathology if we're not yet able to understand the deep and unknown interaction between breast and thyroid?


Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Estrogênios/fisiologia , Neoplasias da Glândula Tireoide/tratamento farmacológico , Adulto , Autoanticorpos/sangue , Doenças Mamárias/epidemiologia , Doenças Mamárias/fisiopatologia , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/fisiopatologia , Quimioterapia Adjuvante , Comorbidade , Moduladores de Receptor Estrogênico/uso terapêutico , Estrogênios/sangue , Feminino , Humanos , Iodeto Peroxidase/imunologia , Ciclo Menstrual , Pessoa de Meia-Idade , Modelos Biológicos , Neoplasias Primárias Múltiplas/epidemiologia , Neoplasias Primárias Múltiplas/fisiopatologia , Tamanho do Órgão , Prolactina/sangue , História Reprodutiva , Doenças da Glândula Tireoide/epidemiologia , Doenças da Glândula Tireoide/fisiopatologia , Glândula Tireoide/diagnóstico por imagem , Hormônios Tireóideos/sangue , Neoplasias da Glândula Tireoide/epidemiologia , Neoplasias da Glândula Tireoide/fisiopatologia , Tireotropina/sangue , Ultrassonografia Mamária
20.
Brain ; 126(Pt 8): 1745-54, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12821524

RESUMO

In patients with dystonia, abnormal movements are commonly triggered or made worse by voluntary action. By means of transcranial magnetic stimulation (TMS), we investigated changes in motor cortex excitability before the execution of wrist voluntary movements in patients with upper limb dystonia and normal control subjects. Magnetic stimulation was delivered by two Magstim 200 stimulators connected through a Bistim module to a figure-of-eight coil placed over the motor area of the forearm extensor muscles. A subthreshold (80% of the rest motor threshold) conditioning stimulus was delivered 3 ms before the suprathreshold (120% of the rest motor threshold) test stimulus and the degree of inhibition of the conditioned motor evoked potentials (MEPs) was taken as an indicator of intracortical inhibition. MEPs were recorded over the forearm extensor muscles of the right arm. To study MEP amplitudes and intracortical inhibition before the onset of wrist extension in the pre-movement condition, TMS pulses were delivered from 0 ms to 100 ms after the go-signal. Besides the pre-movement condition, intracortical inhibition and the unconditioned MEP size were also investigated at rest and during tonic wrist extension. In healthy subjects studied before the wrist movement, the unconditioned MEP amplitude increased progressively and intracortical inhibition decreased significantly. Before movement in dystonic patients, the unconditioned MEP amplitude remained significantly unchanged from resting values and intracortical inhibition decreased less than it did in healthy subjects. In both groups studied during contraction, the unconditioned MEP amplitude increased and intracortical inhibition decreased from values at rest. In conclusion, these findings from reaction time tasks in patients with primary dystonia provide evidence of abnormal pre-movement motor cortex excitability. This abnormality is due to an altered release or running of motor programmes.


Assuntos
Distonia/fisiopatologia , Córtex Motor/fisiopatologia , Movimento , Adulto , Eletromiografia , Potencial Evocado Motor , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular , Inibição Neural , Tempo de Reação , Recrutamento Neurofisiológico , Punho/fisiopatologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...