It is obvious that manual therapies such as chiropractic and massage can help with cervicogenic headaches that are caused by referred pain from structures in the neck. How though, is it that both migraines and tension headaches can be helped by treating the joints and muscles of the neck?
A key concept to understand is that of sensory convergence. In addition to sensations from the head, the upper neck also has nerve endings that relay information to the trigeminocervical nucleus (TCN). If there is any sort of mechanical issue in the neck such as postural strain this will feed into the TCN and bring it closer to threshold, which could then act as a further trigger to over-reaction to other environmental triggers.
It is also known that manual therapies have a stimulatory effect on the pain modulation pathways in the brain, which can further dampen brainstem sensitisation in the TCN and move the patient further from threshold point.
Combining manual therapies with a range of other ancillary techniques such as exercise, postural retraining, and breathing/mindfulness techniques have all been shown to be helpful as an overall management strategy.