De rol van de hersenen bij netelroos

Background of the study:

Chronic urticaria, which is appearing in different forms, is a common disease. In this research urticaria factitia (UF), which is precipitated by stroking or scratching, will be examined. In all forms of urticaria the etiology is still unknown. In chronic urticaria, as in other skin diseases, psychological stress is an important contributing factor. Besides, recent research has been done in the relationship between brain activity and skin disease, where by means of functional MRI (fMRI) was demonstrated that some brain regions are more or less activated in atopic dermatitis patients compared to healthy controls. With this knowledge a role for the brain in urticaria is hypothesized. Understanding the origin of
urticaria factitia with the use of MEG (magnetoencephalography, a recording of magnetic fields related to brain activity) and modern network theory can help to unravel the etiology of urticaria factitia

Objective of the study:

The aim of this study is to investigate alterations in brain activity in UF patients by detecting and characterizing MEG changes, using network theory.

Study design:

This investigation is a hypothesis inducing study on which the 'proof of concept' approach is applicable since there is no previous study on this topic. MEG and modern network theory is used to study functional network alterations in UF patients compared to healthy controls.

Study population:

A total of 30 participants will be included: 15 UF patients and 15 healthy controls.

Primary study parameters/outcome of the study:

- Difference in local and global connectivity between UF patients and healthy controls during the baseline measurement

- Difference in local and global connectivity between UF patients and healthy controls after a histamine prick test

- Difference in local and global connectivity between UF patients and healthy controls after dermography

Secundary study parameters/outcome of the study (if applicable):

- Differences in the itch score (VAS) before and after a histamine prick test and dermography, DASS and serum levels of CRH, ACTH, prolactine, cortisol, NGF, BDNF, SP between UF patients and the control group.

- Correlation between ‘global connectivity’ after a histamine prick test and the itch score (VAS), area of a histamine prick test wheal and flare, UCT, CU-Q2oL, DASS and serum levels of CRH, ACTH, prolactine, cortisol, NGF, BDNF, SP.

- Correlation between ‘global connectivity’ after dermography and the itch score (VAS), width of the dermography wheal, UCT, CU-Q2oL, DASS and serum levels of CRH, ACTH, prolactine, cortisol, NGF, BDNF, SP

In case of detectable regional differences in connectivity measures after a histamine prick test or dermography between UF patients and the control group:

- Correlation between ‘local connectivity’ after a histamine prick test and the itch score (VAS), area of a histamine prick test wheal and flare, UCT, CU-Q2oL, DASS and serum levels of CRH, ACTH, prolactine, cortisol, NGF, BDNF, SP.

- Correlation between ‘local connectivity’ after dermography and the itch score (VAS), width of the dermography wheal, UCT, CU-Q2oL, DASS and serum levels of CRH, ACTH, prolactine, cortisol, NGF, BDNF, SP.

Nature and extent of the burden and risks associated with participation, benefit and group relatedness (if applicable):

MEG measurements are non-invasive, taking approximately 1,5 hours, including preperation and testing between the measures. The procedure is not painful in any way, is not considered to be difficult or stressful, and has negligible risks. The same holds true for histamine prick testing and dermography. The participants are asked to visit VU Medical Centre for the investigations. There is no individual benefit from the MEG. The MEG recordings have a higher spatial resolution compared to the conventional electroencephalography (EEG). Since MEG measures brain activity directly,
MEG is favoured compared to fMRI. Total visit time: 2,5 hours.

We hypothesize alterations in brain activity in UF patients before and/or after stimulation by histamine prick test and/or dermography by means of global connectivity and topology measures

MEG resting state measures take around 5 minutes and there will be 3 measures in total. The first measure will be the baseline measure. After this first measure the histamine prick test will take place. After 10 minutes the width of the wheal will be measured in mm. And then the second MEG-measure will be started. After this measure there will be waited for 15 minutes so we are sure the histamine reaction is disappeared, then the dermography test will take place. After 10 minutes the width of the dermography wheal will be measured in mm. And then the last MEG-measure will take place. In total this MEG-procedure including preparation outside the scanner will last around 1,5 hours.

- histamine prick test

- dermography test



15 UF patients are compared with 15 healthy controls regarding MEG changes using network theory measures. These measures will be compared between the two groups in 3 different conditions. All participants will undergo a MEG scan in which all conditions will be measured. The 3 conditions that will be measured are: baseline situation, situation after a histamine prick test and situation after a dermography test.