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1.
Reprod Domest Anim ; 59(6): e14627, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38837827

RESUMO

The efficiency of bovine in vitro embryo production can be significantly improved by splitting embryos at different stages. However, the blastocyst quality of in vitro-produced demi-embryos remains unexplored. The objective of this research was to compare embryo developmental rates and quality of bovine demi-embryos produced by two different strategies: (a) embryo bisection (BSEC) and (b) 2-cell blastomere separation (BSEP). To determine demi-embryos quality, we evaluated total blastocyst cell number and proportion of SOX2+ cells. Additionally, the expression of SOX2, NANOG, OCT4, CDX2, IFNT, BAX and BCL genes and let-7a and miRNA-30c Micro RNAs was analysed. BSEP resulted in improved blastocyst development, higher ICM cells and a significantly higher expression of IFNΤ than demi-embryos produced by BSEC. Let-7a, which is associated with low pregnancy establishment was detected in BSEC, while miRNA-30c expression was observed in all treatments. In conclusion, BSEP of 2-cell embryos is more efficient to improve in vitro bovine embryo development and to produce good quality demi-embryos based on ICM cell number and the expression pattern of the genes explored compared to BSEC.


Assuntos
Blastocisto , Blastômeros , Técnicas de Cultura Embrionária , Desenvolvimento Embrionário , Animais , Bovinos/embriologia , Feminino , Técnicas de Cultura Embrionária/veterinária , Blastômeros/citologia , Fertilização in vitro/veterinária , MicroRNAs/genética , MicroRNAs/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Gravidez
2.
J Prev Med Hyg ; 60(1): E12-E17, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31041405

RESUMO

INTRODUCTION: In recent years, a phenomenon known as "vaccine hesitancy" has spread throughout the world, even among health workers, determining a reduction in vaccination coverage (VC).A study aimed at evaluating VC among healthcare workers (HCWs) in 10 Italian cities (L'Aquila, Genoa, Milan, Palermo, Sassari, Catanzaro, Ferrara, Catania, Naples, Messina) was performed. MATERIALS AND METHODS: Annex 3 of the Presidential Decree n. 445 of 28 December 2000 was used to collect information on the vaccination status of HCWs. The mean and standard deviation (SD) were calculated with regard to the quantitative variable (age), while absolute and relative frequencies were obtained for categorical data (sex, professional profile, working sector, vaccination status). The connection between VC and the categorical variables was evaluated by chi-square method (statistical significance at p < 0.05). The statistical analyses were performed by SPSS and Stata software. RESULTS: A total of 3,454 HCWs participated in the project: 1,236 males and 2,218 females.The sample comprised: physicians (26.9%), trainee physicians (16.1%), nurses (17.2%) and other professional categories (9.8%). Low VC was generally recorded. Higher VC was found with regard to polio, hepatitis B, tetanus and diphtheria, while coverage was very low for measles, mumps, rubella, pertussis, chickenpox and influenza (20-30%). CONCLUSIONS: This study revealed low VC rates among HCWs for all the vaccinations. Measures to increase VC are therefore necessary in order to prevent HCWs from becoming a source of transmission of infections with high morbidity and/or mortality both within hospitals and outside.


Assuntos
Enfermeiras e Enfermeiros/estatística & dados numéricos , Médicos/estatística & dados numéricos , Cobertura Vacinal/estatística & dados numéricos , Adulto , Estudos Transversais , Feminino , Pessoal de Saúde/estatística & dados numéricos , Humanos , Transmissão de Doença Infecciosa do Profissional para o Paciente , Itália , Masculino , Pessoa de Meia-Idade
3.
Funct Neurol ; 22(4): 173-193, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29306355

RESUMO

Neurophysiological testing of the pelvic floor is recognized as an essential tool to identify pathophysiological mechanisms of pelvic floor disorders, support clinical diagnosis, and aid in therapeutic decisions. Nevertheless, the diagnostic value of these tests in specific neurological diseases of the pelvic floor is not completely clarified. Seeking to fill this gap, the members of the Neurophysiology of the Pelvic Floor Study Group of the Italian Clinical Neurophysiology Society performed a systematic review of the literature to gather available evidence for and against the utility of neurophysiological tests. Our findings confirm the utility of some tests in specific clinical conditions [e.g. concentric needle electromyography, evaluation of sacral reflexes and of pudendal somatosensory evoked potentials (pSEPs) in cauda equina and conus medullaris lesions, and evaluation of pSEPs and perineal sympathetic skin response in spinal cord lesions], and support their use in clinical practice. Other tests, particularly those not currently supported by high-level evidence, when employed in individual patients, should be evaluated in the overall clinical context, or otherwise used for research purposes.


Assuntos
Eletromiografia , Potenciais Somatossensoriais Evocados/fisiologia , Doenças Musculares/patologia , Diafragma da Pelve/fisiopatologia , Feminino , Humanos , Itália , Masculino , Doenças da Medula Espinal/fisiopatologia
4.
Mult Scler ; 21(5): 622-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25257616

RESUMO

BACKGROUND: Radial shock wave therapy (RSWT) has been extensively used in rehabilitative medicine to treat pain, and more recently muscle hypertonia, in patients with cerebral palsy and stroke. OBJECTIVES: To assess the long-term effects of RSWT in a cohort of subjects affected by multiple sclerosis (MS) who were suffering from painful hypertonia of ankle extensor muscles. METHODS: In this randomised, double blind, placebo-controlled study, we treated 34 patients with four sessions of RSWT (once weekly) and treated 34 patients with placebo. Participants were assessed at baseline, 1 week after the first session, and 1 week and 4 weeks after the last session. We measured pain using the visual analogue scale for pain, while we assessed muscle tone using the modified Ashworth scale and evaluated spinal excitability using the H-reflex. RESULTS: After RSWT, muscle tone decreased 1 week after the last session and pain decreased at all the follow-up evaluations, while spinal excitability was unaffected. No significant changes were found after the placebo treatment. CONCLUSIONS: RSWT can reduce pain and muscle tone in MS patients without adverse effects. The lack of RSWT effects on spinal excitability supports the idea that RSWT is likely to act on non-reflex hypertonia, for example reducing muscle fibrosis.


Assuntos
Eletrochoque , Esclerose Múltipla/terapia , Hipertonia Muscular/terapia , Manejo da Dor/métodos , Adulto , Idoso , Tornozelo , Estudos de Coortes , Método Duplo-Cego , Eletromiografia , Feminino , Reflexo H , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/complicações , Hipertonia Muscular/etiologia , Dor/etiologia , Resultado do Tratamento
7.
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
8.
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
9.
Clin Neurophysiol ; 115(5): 1063-8, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15066531

RESUMO

OBJECTIVE: Ovarian steroids influence neural excitability. Using repetitive transcranial magnetic stimulation (rTMS) we investigated changes in cortical excitability during the menstrual cycle. METHODS: Eight women underwent rTMS on Days 1 and 14 of the menstrual cycle. As a control group, 8 age-matched men were also tested twice, with a 14-day interval between the two experimental sessions. Repetitive magnetic pulses were delivered in trains of 10 stimuli (5 Hz frequency and 120% of the motor threshold calculated at rest) to the left motor area of the first dorsal interosseous muscle. RESULTS: In women, the motor evoked potential (MEP) size did not increase on Day 1, but it increased progressively during the train on Day 14. The duration of the silent period progressively lengthened during the train on both days. In men the MEP increased in size, and the silent period lengthened to a similar extent on both days. CONCLUSIONS: In women, hormone changes related to the menstrual cycle alter cortical excitability. SIGNIFICANCE: Low estrogen levels probably reduce cortical excitability because their diminished action on sodium channels reduces recruitment of excitatory interneurons during rTMS thus abolishing the MEP facilitation.


Assuntos
Córtex Cerebral/fisiologia , Hormônios/fisiologia , Ciclo Menstrual/metabolismo , Ovário/metabolismo , Adulto , Análise de Variância , Estimulação Elétrica/métodos , Potencial Evocado Motor , Feminino , Humanos , Magnetismo , Masculino
10.
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
12.
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
13.
Neurology ; 60(6): 1012-5, 2003 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-12654970

RESUMO

OBJECTIVE: To study the distribution of prior scoliosis among patients with primary adult-onset cervical dystonia (CD) and matched control subjects. METHODS: Case and control subjects were selected among consecutive outpatients attending four Italian centers. Control outpatients were matched for age (+/-5 years), sex, and referral center. Information on prior scoliosis, other spine diseases, and family history of dystonia was obtained by a standardized questionnaire and supported by medical records. Conditional logistic regression models were used to adjust simultaneously for age, disease duration, and education level and to determine the independent association of exposure variables with the outcome. RESULTS: Prior scoliosis developing in middle or late childhood or at around the puberty occurred more frequently among 72 case patients than among 144 neurologic control subjects. No subject reported conditions considered to be responsible for secondary scoliosis. The association of scoliosis and CD was not confounded by age, duration of disease, education level, other spine diseases, or family history of dystonia (adjusted odds ratio [OR] 6.8; 95% CI 1.5 to 29.5; p = 0.011). The OR of family history of dystonia (18.7; 95% CI 2.4 to 147.5; p = 0.005) fell to 11.7 (95% CI 1.3 to 103; p = 0.03) after controlling for scoliosis. CONCLUSIONS: Prior scoliosis may increase the risk of developing CD. The observed decrease in the magnitude of the association between family history of dystonia and CD after controlling for scoliosis suggests a link between the two conditions.


Assuntos
Escoliose/epidemiologia , Torcicolo/epidemiologia , Adolescente , Adulto , Idade de Início , Idoso , Estudos de Casos e Controles , Criança , Comorbidade , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Razão de Chances
14.
J Neurol Neurosurg Psychiatry ; 74(2): 265-7, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12531967

RESUMO

The relation between age at dystonia onset and sex was investigated in 264 patients with cranial-cervical dystonia and 56 patients with upper limb dystonia. In cranial-cervical dystonia, women had a significantly greater age at the onset of dystonia than men. The association was independent of duration of disease and distance of referral, but it was no longer detectable after adjustment for educational level. In upper limb dystonia, men and women did not differ for age at dystonia onset, duration of disease, education level, or distance of referral. A significant inverse association between age at the onset of dystonia and education was observed in both cranial-cervical dystonia and upper limb dystonia series.


Assuntos
Distúrbios Distônicos/diagnóstico , Adulto , Fatores Etários , Idoso , Braço/inervação , Viés , Distúrbios Distônicos/epidemiologia , Feminino , Inquéritos Epidemiológicos , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Fatores Sexuais
15.
Neurology ; 59(12): 1851-9, 2002 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-12503582

RESUMO

Transcranial magnetic stimulation (TMS) is a technique that can activate cortical motor areas and the corticospinal tract without causing the subject discomfort. Since TMS was introduced, numerous applications of the technique have been developed for the evaluation of neurologic diseases. Standard TMS applications (central motor conduction time, threshold and amplitude of motor evoked potentials) allow the evaluation of motor conduction in the CNS. Conduction studies provide specific information in neurologic conditions characterized by clinical and subclinical upper motor neuron involvement. In addition, they have proved useful in monitoring motor abnormalities and the recovery of motor function. TMS also gives information on the pathophysiology of the processes underlying the various clinical conditions. More complex TMS applications (paired-pulse stimulation, silent period, ipsilateral silent period, input-output curve, and evaluation of central fatigue) allow investigation into the mechanisms of diseases causing changes in the excitability of cortical motor areas. These techniques are also useful in monitoring the effects of neurotrophic drugs on cortical activity. TMS applications have an important place among the investigative tools to study patients with motor disorders.


Assuntos
Encéfalo/efeitos da radiação , Campos Eletromagnéticos , Encéfalo/fisiologia , Campos Eletromagnéticos/efeitos adversos , Epilepsia/terapia , Potencial Evocado Motor/efeitos da radiação , Fadiga/etiologia , Lateralidade Funcional/fisiologia , Humanos , Córtex Motor/fisiologia , Córtex Motor/efeitos da radiação , Doença dos Neurônios Motores/terapia , Transtornos dos Movimentos/terapia , Osteofitose Vertebral/terapia , Acidente Vascular Cerebral/terapia
16.
Mov Disord ; 17(3): 467-73, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12112192

RESUMO

We investigated the neurophysiological and clinical effects of repetitive magnetic stimulation (rTMS) delivered to the cortical motor areas in healthy subjects and patients with Parkinson's disease. rTMS was delivered with a high speed magnetic stimulator (Cadwell, Kennewick, WA) through a figure-eight coil centred on the primary motor area at a stimulus intensity of 120% motor threshold. Trains of 10 stimuli were delivered at frequencies of 5 Hz while subjects were at rest and during a voluntary contraction of the contralateral first dorsal interosseous muscle. In normal subjects at rest, the muscle evoked responses (MEPs) to each stimulus in a train of magnetic stimuli progressively increased in size during the train. rTMS left the MEPs unchanged in patients off therapy and had a small facilitatory effect in those on therapy. In normal subjects and patients, 5-Hz rTMS trains delivered during a voluntary contraction of the target muscle left the MEP unchanged in size. MEPs were followed by a silent period that increased in duration during the course of the train. The silent period duration increased to a similar extent in patients and controls. The reduced rTMS-induced facilitation of MEPs in patients with Parkinson's disease reflects a decreased facilitation of the excitatory cells in the cortical motor areas.


Assuntos
Córtex Motor/fisiopatologia , Doença de Parkinson/fisiopatologia , Idoso , Estimulação Elétrica , Eletromiografia , Potencial Evocado Motor , Antebraço/inervação , Humanos , Magnetismo , Pessoa de Meia-Idade , Neurônios Motores , Inibição Neural
17.
Clin Neurophysiol ; 112(8): 1470-4, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11459687

RESUMO

OBJECTIVES: In a group of patients with Huntington's disease and age-matched controls, we studied the cortical silent period (SP) elicited by single transcranial magnetic stimulation (TMS) pulses. METHODS: We measured the area of the pre-stimulus electromyographic (EMG) activity, the area of the motor evoked potentials (MEPs) and the duration of the SP induced by stimuli delivered at an intensity of 150% of motor threshold with a round coil placed over the vertex. We determined the cortical SP by sampling only the 5 traces containing the shortest SPs and by collecting 10 consecutive unselected traces without selecting trials. RESULTS: Patients and controls had normal EMG background areas, and MEP latencies and areas. Whereas data measured from selected trials gave a normal duration of the SP (patients, 154+/-58 ms; controls, 166+/-22 ms), data from unselected trials yielded a significantly longer SP duration in patients than in controls (356+/-251 vs. 159+/-44 ms) and also a larger variance and range. CONCLUSIONS: We conclude that in Huntington's disease, an abnormal cortical SP is best sought by collecting unselected consecutive traces. We suggest that the prolonged SP in HD originates from a dysfunction of the mechanisms controlling the restart of voluntary movement after TMS.


Assuntos
Potenciais Somatossensoriais Evocados/fisiologia , Doença de Huntington/fisiopatologia , Neurônios Motores/fisiologia , Adulto , Idoso , Estimulação Elétrica , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora
18.
Neurology ; 56(1): 123-6, 2001 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-11148252

RESUMO

In a series of 24-hour ambulatory EEG recordings from 1,000 consecutive adult outpatients (44.5% with generalized and 55.5% with partial epilepsy, one recording per patient), the authors found only 46 (4.6%) activations of epileptiform discharges on awakening. All recordings came from patients with idiopathic generalized epilepsy, predominantly with juvenile myoclonic epilepsy and generalized tonic-clonic seizures on awakening. Multiple spike discharges that develop with an unusually delayed onset after arousal (more than 10 minutes) might help to discriminate juvenile myoclonic epilepsy.


Assuntos
Eletroencefalografia , Epilepsia Generalizada/diagnóstico , Adulto , Idoso , Nível de Alerta , Epilepsia Tônico-Clônica/diagnóstico , Humanos , Pessoa de Meia-Idade , Epilepsia Mioclônica Juvenil/diagnóstico , Estudos Retrospectivos
19.
Ann Neurol ; 48(1): 20-6, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10894212

RESUMO

To find out whether botulinum toxin alters the excitability of cortical motor areas, we studied intracortical inhibition with transcranial magnetic stimulation in patients with upper limb dystonia before, 1 month after, and 3 months after the injection of botulinum toxin type A in the affected muscles. Eleven normal subjects and 12 patients with dystonia involving the upper limbs (7 with generalized dystonia, 2 with segmental dystonia, and 3 with focal dystonia) were studied. Patients were assessed clinically with the Dystonia Movement Scale. Paired magnetic stimuli were delivered by two Magstim 200 magnetic stimulators connected through a Bistim module to a figure-of-eight coil placed over the motor area of the forearm muscles. Paired stimulation was given at rest. A subthreshold (80% of motor threshold) conditioning stimulus was delivered 3 and 5 msec before the suprathreshold (120% of motor threshold) test stimulus. Electromyographic signals were recorded over the flexor or extensor muscles of the forearm on the affected side. We measured the amplitude of the test motor evoked potential (expressed as a percentage of the unconditioned motor evoked potential). All results were compared using ANOVA. In all patients, a botulinum toxin type A injection (50-100 mouse units) reduced dystonic movements in the arm. In normal subjects, electromyographic recordings showed significant inhibition of the test response. Before botulinum toxin injection, patients had less test response inhibition than normal subjects. One month after injection, patients had test response inhibition similar to that of normal subjects. At 3 months after injection, they again had less inhibition than normal subjects or patients at 1 month after injection. In conclusion, our data suggest that botulinum toxin can transiently alter the excitability of the cortical motor areas by reorganizing the inhibitory and excitatory intracortical circuits. The cortical changes probably originate through peripheral mechanisms.


Assuntos
Toxinas Botulínicas Tipo A/administração & dosagem , Distonia/tratamento farmacológico , Distonia/fisiopatologia , Córtex Motor/efeitos dos fármacos , Inibição Neural/efeitos dos fármacos , Fármacos Neuromusculares/administração & dosagem , Adulto , Mapeamento Encefálico , Eletromiografia , Potencial Evocado Motor/efeitos dos fármacos , Potencial Evocado Motor/fisiologia , Feminino , Humanos , Magnetismo , Masculino , Pessoa de Meia-Idade , Córtex Motor/fisiopatologia , Inibição Neural/fisiologia
20.
Clin Neurophysiol ; 111(7): 1184-90, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10880791

RESUMO

OBJECTIVES: We investigated whether the type of sub-movement cueing during the execution of motor sequences influences the movement time in patients with Huntington's disease. METHODS: The kinematic variables of rapid sequential free arm movements executed with different types of sub-movement cueing - externally-triggered (ET) and self-initiated (SI) tasks - were analyzed in 7 patients and 7 healthy controls. The ET task required subjects to initiate movements in response to consecutive visual go signals; the SI task allowed them to start at will. RESULTS: HD patients performed ET and SI tasks slower than normal subjects. Both groups executed ET sequences slower than SI, but movement times for the two tasks differed less in patients than in controls. Patients paused normally between sub-movements during the SI task, but they had slower reaction times for all the sub-movements of the ET task. CONCLUSIONS: Slower execution of both motor tasks indicates that HD patients are bradykinetic in performing sequential free arm movements. Our finding that total movement times for SI and ET tasks differ less in patients than in controls suggests that HD impairs internal more than external cueing mechanisms.


Assuntos
Sinais (Psicologia) , Doença de Huntington/fisiopatologia , Atividade Motora , Tempo de Reação , Adulto , Idoso , Análise de Variância , Braço , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Movimento , Testes Neuropsicológicos
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