Change in brain network connectivity during PACAP38-induced migraine attacks: A resting-state functional MRI study

What Was Tested

This randomized controlled trial paper looks at PACAP in the context of migraine.

To investigate resting-state functional connectivity in the salience network (SN), the sensorimotor network (SMN), and the default mode network (DMN) during migraine attacks induced by pituitary adenylate cyclase-activating polypeptide-38 (PACAP38).

Who Took Part

According to the abstract, 24 patients were involved.

PubMed indexes the participants as young adults and adults, women only.

In a double-blind, randomized study, 24 female migraine patients without aura received IV PACAP38 or vasoactive intestinal polypeptide (VIP) over 20 minutes.

How the Study Was Run

The researchers set it up as a randomized, double-blind and placebo-controlled study.

Random assignment meant chance, not the researchers, decided who got PACAP and who got the comparison, which limits bias.

Neither the patients nor the staff measuring them knew who was on PACAP, so expectations could not easily colour the readings.

A placebo (an inactive look-alike) gave the PACAP group a baseline to be compared against.

Both peptides are closely related and cause vasodilation, but only PACAP38 induces migraine attacks.

VIP was therefore used as active placebo.

Resting-state functional MRI was recorded before and during PACAP38-induced migraine attacks and before and after VIP infusion.

The researchers analyzed data by Statistical Parametric Mapping 8 and the Resting-State fMRI Data Analysis Toolkit for Matlab in a seed-based fashion.

What Was Measured

Topics PubMed links to this paper include Brain, Brain Mapping, Magnetic Resonance Imaging, Migraine Disorders, Nerve Net, Neurotransmitter Agents and Pituitary Adenylate Cyclase-Activating Polypeptide.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of PACAP in 24 patients in people with migraine.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

Its findings take up roughly 5 sentences of the abstract and are left out here on purpose; the source paper is the place to read them.

The publication is from 2016 (Neurology), a journal based in United States.

More context: the PACAP compound page, Migraine research.