The difficulties attendant to making a diagnosis of acute infectious polyneuritis during an epidemic of poliomyelitis were emphasized in a recent minor epidemic of poliomyelitis. Acute infectious polyneuritis was first described in 1908 by Laurens.1The original article of Guillain, Barré and Strohl2in 1916 defined the syndrome as one characterized by a slowly ascending paralysis, a normal cell count with increased protein of the cerebrospinal fluid and a favorable prognosis. The condition has most often been called Guillain-Barré's syndrome. Casamajor3emphasized the nominal usage because of the inadequacy of the various descriptive names applied to the condition. Yet, because of our reluctance to use proper names, we shall continue to call it acute infectious polyneuritis. The necessity for differentiating between acute infectious polyneuritis and acute anterior poliomyelitis is more than an academic consideration. The all important question of prognosis is always uppermost in both the physician's