Gerwig M, Niehaus L, Kastrup O, Stude P, Diener HC. Visual cortex excitability in migraine evaluated by single and paired magnetic stimuli.
Headache 2006;
45:1394-9. [PMID:
16324172 DOI:
10.1111/j.1526-4610.2005.00272.x]
[Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE
To determine the excitability of the visual cortex by phosphene thresholds (PT) in patients with migraine using transcranial magnetic stimulation (TMS) with single- and paired-pulses.
METHODS
Nineteen patients with migraine with aura (MWA), 19 patients with migraine without aura (MWoA), and 22 control subjects were included. Patients were free from preventive anti-migraine treatment and were investigated within 3 days before or after an acute migraine attack. In each subject, PT were assessed by single-pulse and paired-pulse TMS with an interstimulus interval of 50 ms.
RESULTS
The main effect of diagnosis indicated that mean PT were significantly lower in migraine patients than in control subjects (P = .001). Using single-pulse TMS, mean PT tended to be lower in MWoA-patients (57.7 +/- 11.8%) compared with control subjects (64.4 +/- 10.5%) (P = .064). In MWA-patients, mean PT (53.1 +/- 5.7%) were significantly lower compared with controls (P < .001). Using TMS with paired pulses, mean PT were significantly reduced in MWoA-patients (40.3 +/- 4.9%, P = .017) as well as in MWA-patients (39.6 +/- 4.2%, P = .005) compared with controls (44.6 +/- 6.0%). The main effect of stimulation type indicated that mean PT were lower determined with paired-pulse stimulation than with single pulses (P < .001).
CONCLUSIONS
PT are reduced in patients with migraine in the interictal state suggesting an increased excitability of visual cortical areas. Compared with single-pulse TMS, paired-pulse magnetic stimulation is more efficient to elicit phosphenes. This technique provides the opportunity to evaluate visual cortex excitability with lower stimulus intensities and less discomfort.
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