Brainstem activation in cluster headache: an adaptive behavioural response?
BACKGROUND
The functional neuroimaging of headache patients has revolutionized our understanding of the pathophysiology of primary headaches, providing unique insights into these syndromes. Indeed, functional neuroimaging studies have shown the activation of specific brain structures, the brainstem in migraine and posterior hypothalamus in cluster headache (CH), as well as in other trigeminal autonomic cephalalgias. We describe the functional neuroimaging findings in a patient suffering from CH headache, investigated with functional magnetic resonance imaging (fMRI) during typical pain attacks.


METHODS
Two typical, consecutive CH attacks were investigated by two fMRI imaging sessions on the same day. Both fMRI scans were performed at rest, during the CH attacks and the pain-free state induced by subcutaneous administration of sumatriptan.


RESULTS
Significant activation of the bilateral red nucleus, ventral pons and trigeminal root entry zone ipsilaterally to the pain side was detected during the pain state, in addition to the hypothalamic region ipsilaterally to the pain side.


CONCLUSIONS
Being that such structures are mainly involved in motor function and reactive behaviour, their activation, in our hypothesis, may be linked to pain avoidance and may well represent a defence reaction in cluster headache, which is characterised by a "fight-or-flight" type behavioural pattern during pain attacks.
Neurology Unit, Guglielmo da Saliceto Hospital, Piacenza, Italy. n.morelli@inwind.it
Nicola
N
Morelli
Eugenia
E
Rota
Sara
S
Gori
Donata
D
Guidetti
Emanuele
E
Michieletti
Roberto
R
De Simone
Francesco
F
Di Salle
D000328:Adult; D001933:Brain Stem / Q000503:physiopathology*; D003027:Cluster Headache / Q000503:physiopathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male