Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology
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Randomized Controlled Trial Clinical Trial
Involuntary orientation of attention to unattended deviant nociceptive stimuli is modulated by concomitant visual task difficulty. Evidence from laser evoked potentials.
Recent laser evoked potential (LEP) studies showed that unattended rare intensity-deviant nociceptive stimuli enhance the LEP vertex positivity P2 ('P400 effect'). It was hypothesized to reflect an involuntary switch of attention to nociceptive events. If true the P400 effect (1) should be produced when attention is focused on a task in another sensory modality (primary task), and (2) should be modulated by the primary task difficulty. ⋯ The study provides electrophysiological evidences for an intrusive capacity of pain to attract attention and to decrease behavioural performance in concurrent processes. In turn, such an attentional shift is tampered if attention is very engaged in a concomitant task.
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The aim of this study was to analyse the regularity of the EEG background activity of Alzheimer's disease (AD) patients to test the hypothesis that the irregularity of the AD patients' EEG is lower than that of age-matched controls. ⋯ This article represents a first step in demonstrating the feasibility of ApEn for recognition of EEG changes in AD.
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To study the modulation of jaw-stretch and blink reflexes by experimental posterior temporalis muscle pain. ⋯ Present study suggested that these reflexes are suitable models for probing pontine and medullary pain processing.
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To evaluate clinically and electrophysiologically the effects of selective anesthetic blocks of motor nerve branches to the triceps surae muscle on lower limb stretch reflex in patients with spastic equinus foot. ⋯ Selective anesthetic blocks of nerve branches to the triceps surae muscle are useful in the assessment of lower limb spasticity and can benefit from H reflex investigation. H reflex recordings showed a preferential susceptibility of muscle spindle afferents to local anesthetics and supported the hypothesis of a prominent role of the soleus muscle in spastic ankle. The clinical and electrophysiological effects induced by anesthetic blocks may help to guide therapeutic interventions, such as neurotomy, neurolysis or botulinum toxin injection.