Ivan Milanov | Search PubMed

PubMed2002

Electrophysiological evidence for trigeminal neuron sensitization in patients with migraine.

The electrically elicited corneal reflex is a useful tool for exploring the trigeminal system in humans and it may provide additional evidence pointing to a dysfunction of this system in migrainous patients. Tactile perception, corneal reflex and pain thresholds were studied in 48 migraine without aura patients during pain-free periods and compared with those observed in 24 controls. Twenty-eight of the patients had strictly unilateral headache, while the other 20 had bilateral or side-shifting pain during attacks. Both migraine subgroups (bilateral and unilateral) showed significantly lower thresholds compared with controls. The lowest values were observed on the symptomatic side of unilateral migraine patients. These findings suggest that sensorimotor mechanisms and/or pain control systems at the trigeminal level are impaired in migraine. The bilateral location of these abnormalities seems to point to a centrally located dysfunction.

Adult↗

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Correlation between tremor parameters.

The relationship between clinically scored tremor and electromyographic measurements of tremor amplitude is not clear and few reports have examined correlations between different tremor parameters. The aim of this study was to evaluate the correlations between different tremor parameters, clinical tremor scoring, age and disease duration. A total of 525 patients with different types of tremor were included in this study. Tremor in various limb positions was graded according to the Webster Tremor Scale. Surface electromyographic recordings of the limb found, in each position, to be most involved were performed in all the patients. The Spearman rank correlation coefficient was used to analyse the relationship between clinical and electromyographic parameters, while the Pearson correlation coefficient was used to analyse the relationship between the electromyographic parameters. Our results revealed moderate correlation between tremor amplitude as measured by electromyography and Webster tremor scores. The correlation between different tremor parameters revealed that low frequency tremors have higher amplitude, and longer burst duration, interval between bursts and missing interval. As the disease progresses, the tremor amplitude increases, while the frequency decreases. A strong positive correlation emerged between corresponding tremor parameters in different limb positions. This suggests that the tremor in all limb positions is generated by the same oscillator. In conclusion, a good correlation was found between clinically scored tremor and EMG measurements of tremor amplitude. The electromyographic examination is a useful tool for researching tremor mechanisms.

Age of Onset↗