N LINES IN A MYOPATHY WITH MYOSIN LOSS

N lines can be seen by electron microscopy within the I band of skelet al muscle, but are poorly visualized in conventional preparations. We present a case of acute quadriplegic myopathy with myosin loss and pro minent N lines. The only other reported cases of N lines were also see n in patients with myosin loss from diverse etiologies. Myosin loss an d the subsequent detachment of titin from myosin may result in the for mation of prominent N lines. (C) 1998 John Wiley & Sons, Inc.