The proximity of the last migraine attack during both the pre-ictal and interictal periods may alter the neural responses to loss anticipation and reward or loss based consumption, according to a study published in Scientific Reports. The researchers also found that secondary reward processing is sensitive to the different characteristics of migraine state both ictally and interictally.
Researchers recruited patients with episodic migraine (n=29) and headache-free controls (n=41) to investigate the neural responses during different stages of reward processing, based on a hypothesis that there are differences in patients with migraine during reward or loss anticipation and consumption. Researchers also aimed to investigate the possibility that these stimuli influence the duration of migraine history, attack frequency, and time of the last migraine attack before scan session on neural activations.
Participants with migraine kept a headache diary to document the time, duration, and intensity of the attacks, as well as any accompanying symptoms. The study investigators used a monetary incentive delay task to model reward and punishment anticipation. Participants were told they could gain money or avoid financial loss if they responded to a target on a computer screen fast enough. All participants were given a functional magnetic resonance imaging (MRI) scan with a 3T MRI scanner to measure neural responses during anticipation, measured by win-neutral outcome, loss-neutral outcome, success-neutral outcome, and failure-neutral outcome activations.
In patients with episodic migraine, there was decreased activation in 1 cluster covering the right inferior frontal gyrus pars opercularis during reward/no loss consumption, when compared with the controls. There was a significant negative correlation between the time of the last migraine attack before the scan, and activation of the parahippocampal gyrus and the right hippocampus yielded to loss anticipation.
This study is limited by the investigators’ inability to properly measure the impact of high-frequency attacks on reward processing.
To the best of the investigators’ knowledge, this is the first study examining monetary reward and loss processing in patients with episodic migraine. These findings illuminate the potential association between anticipation processes toward aversive events and migraine attacks. More research is needed to determine whether there is a causal relation between them. It remains unclear whether interictal functional brain alterations interact with different pain-related processes.
Kocsel N, Galambos A, Szabó E, et al. Altered neural activity to monetary reward/loss processing in episodic migraine. Sci Rep. 2019;9(1):5420.