42 ACUTE POLIOMYELITIS
in the neck, back and extremities. Occasionally the pain has been observed to show itself only in the extremity which later becomes paralyzed. The pain is often excessive, and generally diffuse and continuous. Older patients sometimes describe it as radiating. Such pain usually persists only for a short time and disappears with the subsidence of the acute symptoms. It may, however, last for weeks and arouse a suspicion of neuritis.
Many cases on examination show an actual hyperesthesia of the skin, but others do not. This hyperesthesia, which, in my experience, is most marked over the spinal column, has its origin in the tenderness elicited by the movement. Again, in other cases, sensitiveness to pressure over the muscles and nerve trunks may be present and may persist, even as the spontaneous pain. Foerster, Spieler, and others have reported numerous cases of spontaneous pain in the limbs and pain on pressure over the muscles and nerve trunks. Byrom Bramwell demonstrated in several instances that the sporadic do not differ from the epidemic cases with regard to the occurrence of pain; and he pointed out that such pain is often mistakenly attributed to rheumatism.
I shall later consider objective disturbances of sensibility.
The explanation of the sensory irritability is somewhat uncertain. I, myself, am inclined to refer it to implication of the pia. But most observers tend to regard it more as a neuritic process. The possibility of such a process cannot be denied, but, at present, pathological evidence of its existence is lacking. I shall later return to this question; but the signs of irritation could undoubtedly be due to the meningitis, which is invariably demonstrable. To the changes in the pia a series of symptoms, usually ascribed to meningitis, are referable. In the mildest cases, only pain in the neck develops. Frequently, however, rigidity of the neck, demonstrable only on bending the head forward, is also present. Sometimes a distinct contraction may be observed; the head then is retracted. Head retraction may, however, be present without marked contraction of the muscles. Not seldom these symptoms are associated with pain and stiffness in the back; occasionally with orthotonus; more rarely with opisthotonus. In some cases, increased sensitivity of the spinous processes is present. Occasionally Kernig's sign has been noted (New York epidemic, Foerster, Ed. Müller); and occasionally the sciatic phenomenon (Wickman, Lindner and Mally).
