Migraine worsening after COVID-19 and COVID-19 vaccination: Are we facing a nocebo effect?

In clinical practice patients may report migraine worsening as a consequence of COVID-19 (either infection or vaccines), however, data in this area are lacking. We aimed to investigate the link between COVID-19 and COVID-19 vaccination with migraine worsening and its associated factors.

An online survey was sent to migraine patients followed up in a Spanish Headache Clinic, collecting demographic data, and information regarding SARS-CoV-2 infection and vaccination. We asked patients if they had noticed worsening of their migraine after these events and assessed concerns about infection, vaccination and migraine worsening. We also extracted data from participants' own electronic diaries (e-diaries), including 1-month data before and after their reported infection and/or vaccination. We compared participants who self-reported migraine worsening since infection or vaccination with those who did not.

Of 550 participants, 44.9% (247/550) reported having had COVID-19 at least once and 83.3% (458/550) had been vaccinated. Sixty-one patients reported migraine worsening since COVID-19 and 52 since the vaccination. Among the risk factors for perceived migraine worsening in the two settings (infection and vaccination) was concern about migraine worsening itself (infection: odds ratio [OR] 2.498 [95% CI: 1.02-6.273], p = 0.046; vaccination: OR 17.3 [95% CI: confidence interval 5.3-68], p < 0.001). e-diary information was available for 136 of the 550 patients, 38.2% (52/136) for COVID-19 and 39.7% (54/136) for vaccination. We observed no significant difference in headache frequency 1 month before and after infection or vaccination, even when comparing patients with and without self-reported migraine worsening.

Our preliminary data point to a negligible role of the infection and vaccination on migraine worsening and to the possible presence of a nocebo effect in these settings, as a remarkable proportion of patients had a clear perception of migraine worsening.