Electroencephalography and clinical neurophysiology
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Electroencephalogr Clin Neurophysiol · Sep 1998
Randomized Controlled Trial Clinical TrialRelation of olfactory event-related potentials to changes in stimulus concentration.
The aim of this study was to investigate the influence of odorant concentration on the olfactory event-related potential (OERP). ⋯ The results indicated that both OERP amplitudes and latencies are related to the concentration of olfactory stimuli. They also suggested that latencies exhibit a stronger relation to changes in stimulus intensity compared to OERP amplitudes.
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Electroencephalogr Clin Neurophysiol · Sep 1998
Exteroceptive suppression of temporalis muscle activity in patients with fibromyalgia, tension-type headache, and normal controls.
Changes of the second suppressive period (ES2) of the exteroceptive suppression of the temporalis muscle activity are found in patients with chronic tension-type headache (TTH) and are suggested to reflect an abnormal endogenous pain control system. We investigated whether similar changes are found in patients with the fibromyalgia syndrome (FMS) that is also believed to result from disturbed central pain processing. ⋯ The duration of ES2 (+/-SD) in FMS patients was 30.6+/-7.5 ms and was not significantly different from the control group (33.1+/-7.8 ms), whereas it was significantly shortened in TTH patients (22.9+/-11.5 ms). Our results indicate that, despite similar concepts on the pathophysiology of the two chronic pain disorders, there are no comparable changes of this brain stem reflex activity in FMS.