Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology
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Comparative Study
Sources of cortical responses to painful CO(2) laser skin stimulation of the hand and foot in the human brain.
To investigate whether the same dipolar model could explain the scalp CO(2) laser evoked potential (LEP) distribution after either hand or foot skin stimulation. ⋯ The dipolar model previously proposed for the hand stimulation LEPs can also satisfactorily explain the LEP distribution obtained after foot stimulation. The earliest activated Sylvian dipolar sources did not change their location when the upper or lower limb was stimulated, as expected from the close projections of hand and foot in the second somatosensory area. No source in the primary somatosensory area was necessary to model the scalp topography of LEPs to hand and foot stimulation.
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Comparative Study
Comparison of visual and auditory evoked cortical potentials in migraine patients between attacks.
As both habituation of pattern reversal visual evoked potentials (PR-VEP) (Schoenen J, Wang W, Albert A, Delwaide PJ. Potentiation instead of habituation characterizes visual evoked potentials in migraine patients between attacks. Eur J Neurol 1995;2:115-122) and intensity dependence of auditory evoked cortical potentials (IDAP) (Wang W, Timsit-Berthier M, Schoenen J. Intensity dependence of auditory evoked potentials in migraine: an indication of cortical potentiation and low serotonergic neurotransmission? Neurology 1996;46:1404-1409) were found abnormal in migraine between attacks, we have searched for intraindividual correlations between both tests in 59 migraine patients (22 with aura [MA], 37 without aura [MO]) and in 23 healthy volunteers (HV). ⋯ The strong negative correlation between the initial amplitude of evoked potentials and their amplitude increase during subsequent averaging confirms that the response potentiation in migraine is likely to be due to a reduced preactivation level of sensory cortices.
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In this study we investigated whether cortical activity related to Parkinsonian resting tremor can be detected by electroencephalography (EEG). ⋯ The results show for the first time that tremor-correlated cortical activity can be detected by electroencephalography. The findings underline that motor areas of the cerebral cortex are involved in the neuronal network generating resting tremor in Parkinson's disease.
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To evaluate possible functional asymmetries of the motor cortex on the hand-dominant versus the non-dominant hemisphere. ⋯ In the right-handers, paired TMS studies showed a functional asymmetry of the motor cortex between the dominant and the non-dominant hand. The left-handers did not show this lateralization. Under TMS investigation their motor cortex function appeared different from that of right-handers.
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Case Reports Clinical Trial Controlled Clinical Trial
Clinical evaluation criteria for the assessment of impaired pain sensitivity by thulium-laser evoked potentials.
Cortical potentials evoked by carbon dioxide laser pulses have been applied in clinical practice to study nociceptive pathways for several years. In this study, we evaluate the properties of an infrared laser (thulium-YAG) with a penetration depth in the skin that matches the intracutaneous depth of nociceptors. ⋯ The thulium-YAG laser is a useful tool for assessment of impaired pain sensitivity. Representative case reports illustrate that unlike for early SEP components, the most frequent LEP abnormalities were amplitude differences.