RESUMO
BACKGROUND: Transcranial static magnetic field stimulation (tSMS) in humans reduces cortical excitability. OBJECTIVE: The objective of this study was to determine if prolonged tSMS (2 h) could be delivered safely in humans. Safety limits for this technique have not been described. METHODS: tSMS was applied for 2 h with a cylindric magnet on the occiput of 17 healthy subjects. We assessed tSMS-related safety aspects at tissue level by measuring levels of neuron-specific enolase (NSE, a marker of neuronal damage) and S100 (a marker of glial reactivity and damage). We also included an evaluation of cognitive side effects by using a battery of visuomotor and cognitive tests. RESULTS: tSMS did not induce any significant increase in NSE or S100. No cognitive alteration was detected. CONCLUSIONS: Our data indicate that the application of tSMS is safe in healthy human subjects, at least within these parameters.
Assuntos
Córtex Cerebral/fisiologia , Estimulação Magnética Transcraniana/efeitos adversos , Adulto , Atenção/fisiologia , Cognição/fisiologia , Feminino , Humanos , Magnetismo , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Fosfopiruvato Hidratase/metabolismo , Desempenho Psicomotor/fisiologia , Proteínas S100/metabolismo , Segurança , Comportamento Verbal/fisiologia , Adulto JovemRESUMO
Plasticity of sensory function has become an object of study because of its proposed role in the recovery of function after central nervous system damage. Normal pregnancy may provide a useful in vivo model to study the effects of progressive reduction in the abdominal skin receptor density. As such changes are confined to abdominal skin, other parts of the body are only moderately affected by pregnancy and therefore can provide a control for other changes during pregnancy. The two-point discrimination test (TPDT) of the skin is a simple test of the sensory function. We conducted the TPDT in a pregnant population longitudinally studied at different pregnancy stages and in different skin regions. In this pregnant population, we found a reduction in sensory sensibility that was not skin region specific. In particular, the increase in abdominal circumference did not produce different effects of TPDT on the belly compared to the dorsum or the hand. This suggests that the sensory system is able to compensate for the reduction in peripheral information flow through central nervous system plasticity.
