Background: It has been suggested that patients with migraine are at a higher risk of developing essential tremor (ET). In addition, it was shown that patients with migraine are at higher risk of subclinical vascular infarcts in the cerebellum, a structure believed to be implicated in ET.
Objective: Determine whether patients with migraine who do not show clinically detectable ET have subtle alteration in their physiological tremor characteristics that may serve as a predictor for the eventual appearance of ET.
Methods: The physiological tremor of 30 patients with migraine (25 women, mean age: 41 +/- 8 years) was examined using a laser displacement sensor. Tremor was recorded in 5 conditions: hand-rest, hand-postural, finger-rest, finger-postural, and finger-loading (70 g). We also recorded tremor in healthy controls who never experienced migraine. Amplitude, median power frequency, power dispersion (width of a frequency band containing 68% of the power), and power distribution within 3 predetermined frequency bands of interest (3.5 to 7.5, 7.5 to 12.5, and 16 to 30 Hz) were assessed in each condition.
Results: All tremor characteristics described above were very similar between the migraine group and controls. These results were supported by the lack of correlation between tremor characteristics and the number of years of experiencing migraine (ranging from 3 to 41 years; mean: 20 +/- 10). Patients with aura (N = 21) had tremor characteristics similar to that of patients without aura (N = 9) and controls.
Conclusion: These results suggest that, if a link exists between migraine and ET, the latter might be the result of an "acute event" (eg, stroke) rather than a progressive alteration of tremorogenic mechanisms.