Quotation from: Manual of Surgery

Written by: Alexander Miles and Alexis Thomson

There is excessive tenderness at the points of emergence of the
different branches on the face, and pressure over one or other of these
points may excite a paroxysm. In typical cases the patient is unable to
take any active part in life. The attempt to eat is attended with such
severe pain that he avoids taking food. In some cases the suffering is
so great that the patient only obtains sleep by the use of hypnotics,
and he is often on the verge of suicide.