Dear Jussi:
It sounds (it is very difficult to give you an exact diagnosis without being able to examine you or see the lab work) like you might have a benign disorder. But, usually when we are in doubt we like to perform tests to prove that we are not missing a diagnosis of a worrisome disease. If I were you, I would see a neurologist, get a good neurological exam and confirm that you are not experiencing a bad disease.
Sincerely,
CCF Neuro MD
Dear Jussi:
Have you ever had such a headache in the past? New onset headache can be due to many things, stress or tension type headache, medication, to vascular malformations or even masses. What you need is a good neurological exam to see if there are associated focal neurological deficits. If there are no deficits then that would suggest that the headache and minor muscle twitching are not due to something neurological worrisome. This does not mean that what you are experiencing is trival, just that it isn't a tumor or mass lesion or vascular ischemia. There are a vast array of etiologies to what symptoms you describe. So, as recommended I would seek a neurologist who can take a good history, personally examine you and then decide on the best course of action to pursue a diagnosis.
Sincerely,
CCF Neuro MD