Common hippocampal structural and functional changes in migraine.
The hippocampus is classically involved in memory consolidation, spatial navigation and is involved in the stress response. Migraine is an episodic disorder characterized by intermittent attacks with a number of physiological and emotional stressors associated with or provoking each attack. Given that migraine attacks can be viewed as repeated stressors, alterations in hippocampal function and structure may play an important role in migraine pathophysiology. Using high-resolution magnetic resonance imaging, hippocampal morphometric and functional differences (in response to noxious heat stimulation) were compared in age and gender-matched acute episodic migraineurs with high (HF) versus low (LF) frequency of migraine attacks. Morphometric results were compared with age and gender-matched healthy control (HC) cohort. Significant larger bilateral hippocampal volume was found in LF group relative to the HF and HC groups suggestive of an initial adaptive plasticity that may then become dysfunctional with increased frequency. Functional correlates of greater deactivation (LF > HF) in the same hippocampal regions in response to noxious stimulation was also accompanied by overall reduction in functional connectivity of the hippocampus with other brain regions involved in pain processing in the HF group.
The results implicate involvement of hippocampus in the pathophysiology of the migraine
Mol Pain. 2011 Sep 21;7:71.
Migraine attacks the Basal Ganglia.
Maleki N, Becerra L, Nutile L, Pendse G, Brawn J, Bigal M, Burstein R, Borsook D.
Department of Radiology, Children’s Hospital Boston, Harvard Medical School, Boston, MA 02115, USA.
With time, episodes of migraine headache afflict patients with increased frequency, longer duration and more intense pain. While episodic migraine may be defined as 1-14 attacks per month, there are no clear-cut phases defined, and those patients with low frequency may progress to high frequency episodic migraine and the latter may progress into chronic daily headache (> 15 attacks per month). The pathophysiology of this progression is completely unknown. Attempting to unravel this phenomenon, we used high field (human) brain imaging to compare functional responses, functional connectivity and brain morphology in patients whose migraine episodes did not progress (LF) to a matched (gender, age, age of onset and type of medication) group of patients whose migraine episodes progressed (HF).
In comparison to LF patients, responses to pain in HF patients were significantly lower in the caudate, putamen and pallidum. Paradoxically, associated with these lower responses in HF patients, gray matter volume of the right and left caudate nuclei were significantly larger than in the LF patients. Functional connectivity analysis revealed additional differences between the two groups in regard to response to pain.
Supported by current understanding of basal ganglia role in pain processing, the findings suggest a significant role of the basal ganglia in the pathophysiology of the episodic migraine
Curr Opin Neurol. 2012 Jun;25(3):252-62.
Migraine changes the brain: neuroimaging makes its mark.
Sprenger T, Borsook D.
Department of Neurology, University Hospital Basel, Basel, Switzerland.
PURPOSE OF REVIEW:
This review summarizes key findings of the current literature on functional neuroimaging in migraine and describes how these studies have changed our view of the disorder.
Recent studies have started not only to investigate the global cerebral activation pattern during migraine attacks, but to address specific aspects of migraine attacks such as photophobia, osmophobia as well as pain perception with the aim of disentangling the underlying mechanisms. There is also more and more evidence that the migraine brain is abnormal even outside of attacks and that repeated attacks are leading to functional and structural alterations in the brain, which may in turn drive the transformation of migraine to its chronic form. Some new results are pinpointing toward a potential role of interesting new brain areas in migraine pathophysiology such as the temporal cortex or the basal ganglia.
Neuroimaging studies are beginning to shed light on the mechanisms underlying the development and evolution of migraine and its specific symptoms. Future studies have the potential to also improve our understanding of established and upcoming treatment approaches and to monitor treatment effects in an objective and noninvasive way.
Neurol Sci. 2012 May;33 Suppl 1:95-7.
From neuroimaging to clinical setting: what have we learned from migraine pain?
Colombo B, Dalla Costa G, Dalla Libera D, Comi G.
Department of Neurology, Headache Center, IRCCS San Raffaele Hospital, Vita-Salute University, Via Olgettina 48, 20100, Milan, Italy, email@example.com.
In the last 15 years, the neuroimaging of patients suffering from migraine with or without aura has improved our understanding of the mechanisms underlying the pathophysiology of the disease. A great number of studies based on modern imaging techniques, such as structural imaging and functional imaging emphasize that in migraine patients suffering from repetitive pain attacks, both significant abnormalities of function and diffuse structural changes of brain white and gray matter become striking features of the disease. The hypothesis that migraine pain is due to a global brain disorder with substantial brainstem involvement leading to secondary blood flow changes in the posterior circulation is reinforced by several elegant studies. Clinical application of functional imaging findings in migraine is yet to be considered, since the specificity of some results has to be determined. Nevertheless, functional MRI techniques have a vast potential for exploring the pathophysiology of pain in migraine patients.