They present muscles which are tender, and indurated. Biopsies reveal a pathognomonic inflammatory response. This is a rare, A.D. disorder in which, for reasons not known, the body's immune system attacks and gradually destroys the receptors in muscles that are responsible for picking up nerve impulses. The muscles, consequently become weak and fine easily. The eyes, face, throat and limb muscles are most commonly affected.
Sufferers usually exhibit drooping eyelids, a blank facial expression plus weak, hesitant speech.
It affects more women than men. There are two specific forms. A viral infection which, at its worst destroys the anterior hom cells in the spinal cord and brain stem motor nuclei, causing paralysis. The disease can be mild, severely disabling, or fatal. It has almost completely disappeared from the developed countries since vaccination began in the 1950's.