"Infantile paralysis" has been a common disease for years, yet without paralysis no diagnosis has been positive. The early clinical picture is that of infection or meningitis; when properly coordinated it is only suggestive of poliomyelitis, and even with lumbar puncture there is still some degree of doubt. During the recent epidemic in Los Angeles I made a few hundred observations of a symptom in sixteen cases which seemed absolutely characteristic of the preparalytic stage. The symptom has been of great value to me, and inasmuch as it is not mentioned in any text-book or the recent literature I am submitting it to the readers of The Journal for their criticism.
The symptom referred to is a peculiar twitching, tremulous or convulsive movement of certain groups of muscles lasting from a few seconds to less than a minute. The amplitude of vibration is greater than a tremor, not