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Visual Cortex Excitability in Migraine Evaluated by Single and Paired Magnetic Stimuli
Author(s) -
Gerwig Marcus,
Niehaus Ludwig,
Kastrup Oliver,
Stude Philipp,
Diener Hans C.
Publication year - 2005
Publication title -
headache: the journal of head and face pain
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.14
H-Index - 119
eISSN - 1526-4610
pISSN - 0017-8748
DOI - 10.1111/j.1526-4610.2005.00272.x
Subject(s) - phosphene , migraine , aura , transcranial magnetic stimulation , migraine with aura , medicine , stimulation , interstimulus interval , pulse (music) , visual cortex , ictal , anesthesia , audiology , psychology , neuroscience , electroencephalography , psychiatry , detector , electrical engineering , engineering
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.