1 Department of Neurology, Division of Pediatric Neurology, College of Physicians & Surgeons of Columbia University, 630 West 168th Street, New York, New York 10032
I certainly concur with the corrections noted by Drs. Soyka, Curless, and Walson. The original letter unfortunately gave the levels with percent signs, i.e., µg/ml%, and this was subsequently published as micrograms per 100 ml. Unfortunately, this error was not corrected prior to publication.
As correctly stated by Drs. Soyka, Curless, and Walson, the level should be micrograms per milliliter or milligrams per liter.
I must compliment those who picked up this error so rapidly; I have also received numerous personal communications regarding the problem.