Low-frequency oscillations in human tibial somatosensory evoked potentials.
نویسندگان
چکیده
Oscillatory cerebral electric activity has been related to sensorial and perceptual-cognitive functions. The aim of this work is to investigate low frequency oscillations (<300 Hz), particularly within the gamma band (30-110 Hz), during tibial stimulation. Twenty-one volunteers were subjected to 5 Hz stimulation by current pulses of 0.2 ms duration and the minimum intensity to provoke involuntary twitch. EEG signals without (spontaneously) and during stimulation were recorded at primary somatosensory area. A time-frequency analysis indicated the effect of the stimulus artifact in the somatosensory evoked potential (SEP) frequencies up to 5 ms after the stimulus. The oscillations up to 100 Hz presented the highest relative power contribution (approximately 99%) for the SEP and showed difference (p<0.01) from the frequencies of the spontaneously EEG average. Moreover, the range 30-58 Hz was identified as the band with the highest contribution for the tibial SEP morphology (p<0.0001).
منابع مشابه
High-frequency somatosensory thalamocortical oscillations and psychopathology in schizophrenia.
Human cortical somatosensory evoked potentials (SEPs), which are presumably generated in afferent thalamocortical and early cortical fibers, reveal a burst of superimposed early (N20) high-frequency oscillations (HFOs), around 600 Hz. There is increasing evidence of an imbalance of thalamocortical systems in schizophrenic patients. In order to assess correlations between somatosensory evoked os...
متن کاملCharacteristics of very high frequency oscillations of somatosensory evoked potentials in humans with epilepsy
We previously firstly reported very high frequency oscillations (VHFOs, over 1,000 Hz) in somatosensory evoked potentials (SEP) recorded by subdural electrodes following median nerve stimulation on 6 patients. In this study, we fatherly studied the characteristics and the clinical significance of VHFOs) in SEP elicited by stimulating not only the median, but also the ulnar nerves. Conventional ...
متن کاملHuman proprioceptive adaptations during states of height-induced fear and anxiety.
Clinical and experimental research has demonstrated that the emotional experience of fear and anxiety impairs postural stability in humans. The current study investigated whether changes in fear and anxiety can also modulate spinal stretch reflexes and the gain of afferent inputs to the primary somatosensory cortex. To do so, two separate experiments were performed on two separate groups of par...
متن کاملSomatosensory evoked potentials following stimulation of the lower limb in cortical reflex myoclonus.
Generating mechanisms of giant somatosensory evoked potentials (SEPs) following stimulation of the posterior tibial nerve as well as the big toe were investigated in three patients with cortical reflex myoclonus. Scalp distributions of recognisable components were very similar to those in normal subjects, except that their amplitude was much larger. The tibial nerve SEPs were remarkably attenua...
متن کاملSomatosensory evoked potentials of the dog: recording techniques and normal values.
Median and tibial nerve somatosensory evoked potentials (SSEPs) of 5 sedated dogs were studied to determine their normal features and optimal stimulation and recording techniques. Cortical potentials were mapped from an extensive array of skull electrodes as each limb was independently stimulated with subdermal needles. The effects of bandpass and stimulus intensity and rate were also assessed....
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Arquivos de neuro-psiquiatria
دوره 64 2B شماره
صفحات -
تاریخ انتشار 2006