A volumetric magnetic resonance imaging study in migraine

DOI: https://doi.org/10.1186/s41983- 021- 00372- 7

Abstract-Summary The aim of the study is to assess volumetric brain changes in migraineurs compared with controls, and in episodic migraine in comparison to chronic type.

Migraine patients had significant reduction of the volume of total brain, grey matter, brain stem, cerebellum, basal ganglia, thalamus, hippocampus and amyg- dala in comparison to control subjects.

Patients with chronic migraine had significant reduction in volume of total brain, grey matter, cerebellum and frontal lobe thickness in comparison to those with epi- sodic migraine.

Chronic migraineurs showed significant reduction in grey matter, in areas involved in processing of pain, cognition and multisensory integration versus patients with episodic migraine, which adds insight into the pathophysiology of migraine as a progressive disorder that may have long-term impacts on the brain as regards structure and function.

3.4 Neuroimaging

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Background These changes are found to be increasing along with increased number of migraine attacks, which represent a form of the disorder's anatomic progression [421, 422]. Migraine is considered as a continuum of illness which is composed of chronic and episodic forms.

Annually, it is reported 3% of patients who have an episodic migraine progress

into chronic migraine.

Both structural and functional abnormalities in pain processing regions, sensiti- zation of the trigeminal system, cortical hyper-excitability and excessive release of vasoactive peptides have been given as the underlying pathological mechanisms responsible for chronic migraine [423]. This study aims to investigate the total and segmental changes of brain volume in migraine patients in comparison to healthy controls, and in patients with episodic migraine in comparison to chronic type of migraine and correlate the results with headache duration and frequency using auto- mated tissue segmentation technique.

Methods According to the attack rate per month, the patients were divided into two groups: 14 patients who suffered from episodic migraine and 11 patients who suffered from chronic migraine.

Twenty-five healthy persons are randomly selected as a control group who were matched for gender and age; all of them had no history of any systemic, psychiatric or neurological disorders.

A form for assessment of headache has been completed by all patients which include demographic data regarding age, gender, occupation and character of migraine including headache duration and frequency of attacks, character and loca- tion of pain, associated with aura or not.

The score is quantified by the total number of days of activity limitations due to migraine in the past 3 months [424]. The Beck Depression Inventory (BDI) was applied to all participants to assess if anyone has depression and its severity [425] and Brief Cognitive Assessment tool (BACT) were conducted to all persons in con- trol group and patients to assess the cognitive function for everyone.

Results Twenty-five patients with migraine headache (7 men 28% and 18 women 72%) with mean age (31.00 ± 6.93) as patients group and twenty-five subjects (8 men 32.00% and 17 women 68.00%) with no symptoms of migraine as control group, mean age (30.88 ± 6.79) with age and sex-matched between two groups.

The patients group was divided into another two subgroups: 14 patients diag- nosed as episodic migraine (56%) with mean age (28.35 ± 6.87) and 11 patients diagnosed as chronic migraine (44.0%) with mean age (34.36 ± 5.62), with statis- tically significant difference between two subgroups as patients with CM were older.

There was no significant correlation between total brain volumetric parameters

and duration of the disease or frequency of attacks in patients group.

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3 Diagnosis

Discussion The most important finding of this study is that migraine patients had statistically sig- nificant decreased brain volume in comparison to age and sex-matched control sub- jects regarding total brain volume (cortex volume, cerebral white matter volume, and total grey matter volume) and segmental brain volume (the cerebellum, brainstem, thalamus-proper, caudate and putamen volume, hippocampus and amygdala volume). Some studies including our current study showed diminished brain stem grey matter volume in migraine patients [426] and CM patients [427]. However in com- parison to our study, others demonstrated volume increase of brain stem and sub- regions in migraine with aura [428] and in medication-overuse headache [429]. In our study, There was significant reduction in the volume of both amygdala and hippocampus in migraine patients in comparison to controls.

The volume reduction of the prefrontal cortex in patients with chronic migraine may be explained by impairment of function [430] and defective pain inhibition, which could stimulate migraine attacks and help migraine chronicity [431, 432]. In this study, we found negative important association between period of the disease and both left medial orbitofrontal thickness and right caudal middle frontal thickness.

Conclusions Migraineurs showed volumetric brain changes mainly in areas related to central processing of pain and in areas specific for migraine (such as brain stem) when compared to healthy controls.

Chronic migraineurs showed significant reduction in grey matter, in areas involved in processing of pain, cognition and multisensory integration versus patients with episodic migraine, which adds insight into the pathophysiology of migraine as a progressive disorder that may have long-term impacts on the brain as regards structure and function.

Acknowledgement A machine generated summary based on the work of Naguib, Laila Elmously; Abdel Azim, Ghada Saed; Abdellatif, Mohammed Abdelrazek. 2021  in The Egyptian Journal of Neurology, Psychiatry and Neurosurgery.

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