Somatosensory temporal discrimination is prolonged during migraine attacks

Background and objective: Symptoms and signs of sensorial disturbances are characteristic features of a migraine headache. Somatosensory temporal discrimination measures the temporal threshold to perceive two separate somaesthetic stimuli as clearly distinct. This study aimed to evaluate somaesthetic perception in migraine patients by measuring the somatosensory temporal discrimination thresholds.

Methods: The study included 12 migraine patients without aura and 12 volunteers without headache. Somatosensory temporal discrimination threshold (STDT) values were measured in the face (V3) and hands (C7) during a lateralized headache attack and the headache-free interictal period. The disease duration, pain intensity, phonophobia, photophobia, nausea, vomiting, and brush allodynia were also recorded during the migraine attack.

Results: STDT values were within normal limits and not different between the control group and the interictal period in migraine patients. Compared to the headache-free period, STDT values during the attack were significantly prolonged in the contralateral hand (C7) (155.7 ± 84.2 vs 40.6 ± 16.1 ms [P < .001]), ipsilateral hand (C7) (88.6 ± 51.3 vs 31.4 ± 14.2 ms [P < 0.001]), contralateral face (V3) (65.5 ± 35.4 vs 37.6 ± 22.2 ms [P = .006]) and ipsilateral face (V3) (104.1 ± 44.5 vs 37.5 ± 21.4 ms [P < 0.001]) according to the lateralization of the headache. Ictal STDT values of the contralateral hand and ipsilateral face were significantly increased compared to that of the ipsilateral hand and contralateral face (155.7 ± 84.2 ms vs 88.6 ± 5.1.3 ms [P = .001], 104.1 ± 44.5 ms vs 65.5 ± 35.4 ms [P = 0.001]). No allodynia was detected in the areas that were tested for somatosensory temporal discrimination. The visual analog scale scores were correlated with the somatosensory temporal discrimination thresholds of the contralateral hand (r = 0.602, P = .038), whereas no correlation was detected between the somatosensory temporal discrimination thresholds and disease duration, brush allodynia in the forehead, phonophobia, photophobia, nausea and vomiting.

Conclusion: The study demonstrates for the first time that somatosensory temporal discrimination thresholds are elevated during migraine attacks. A transient disruption of the central processing of somaesthetic stimuli during the lateralized migraine attack may provide additional information to understand the mechanisms of the cognitive and sensory perception impairment associated with migraine headache and may have diagnostic value.