ELECTROMYOGRAPHY AND BIOPSY CORRELATION WITH SUGGESTED PROTOCOL FOR EVALUATION OF THE FLOPPY INFANT

Eighty infants with nonarthrogrypotic floppy infant syndrome (FIS) wer e evaluated between 1979 and 1990. Electromyographic data were correla ted with results of muscle and nerve biopsies in 41 of 80 who had conc omitant biopsies (38) or other diagnostic analyses (3). A diagnosis wa s made of Werdnig-Hoffmann disease (WHD) in 15, a congenital infantile polyneuropathy (IPN) in 3, neuromuscular transmission defect (NMTD) i n 2, myopathy in 12, and presumed ''central'' hypotonia in 9. A very p ositive correlation rate between nerve conduction studies with electro myography and biopsy results was found in 93% (14 of 15) with WHD and 100% in IPN (3 of 3). However, only 4 of 10 infants (40%) with biopsy- proven myopathy had an abnormal EMG. Only once did the results of elec tromyography and biopsy conflict. (C) 1994 John Wiley and Sons, Inc.