Peripheral levels of BDNF and NGF in primary headaches

Neurotrophins, such as brain-derived neurotrophic factor (BDNF) and nerve
growth factor (NGF), have been implicated in the generation and modulation of
pain. To investigate whether alterations in neurotrophin levels can be detected in
subjects suffering from nociceptive disorders, such as primary headaches, we
determined the peripheral (platelet and plasma) levels of BDNF and NGF in
patients suffering from migraine, with or without aura, or cluster headache (CH),
in the interictal phase, and in healthy volunteers. All primary headaches patients
studied showed significantly decreased platelet levels of BDNF (migraine vs.
controls P < 0.001; CH vs. controls P < 0.01), while a selective reduction of platelet
NGF was observed in migraine sufferers and not in CH patients compared with
control subjects (migraine vs. controls P < 0.001). These changes were not accompanied
by significant modifications of neurotrophin plasma levels. Our findings
show for the first time that changes in peripheral levels of neurotrophines (BDNF
and NGF) occur in patients suffering from different types of primary headaches,
suggesting a potential involvement of BDNF and NGF in the pathophysiology of
these disorders, and raising the possibility that differences in peripheral neurotrophins
may help to distinguish migraine biologically from CH