The scalp has nerves which are mapped by the brain as coming from the
scalp but there are almost no muscles of significance in the scalp.
The normal pain of a headache or pain in the scalp region is usually
due to irritation of those nerves in that area being irritated along
their path prior to entering the spine.
The phantom limb phenomenon is a person's ability to feel their limb
(i.e. foot) even though the limb (leg) has been amputated. This is due
to the nature of nerves to run the full length from their starting point
to their next junction at the spine. Any place along that path that
the nerve is stimulated (irritated) the full nerve signal is initiated
and sent to the brain. The brain maps that nerve as having started at
a certain point even though the actual starting point is no longer there.
Therefore the pain is "felt" as coming from the non-existant
This same principle is why pain is felt in the scalp, temples, forehead
when the nerves that start there actually are being irritated as they
pass through the muscles at the back of the neck before they enter the
spine. To deal with this pain the proper treatment is NOT at the point
of pain in the scalp but at the point of irritation in the neck muscles.