WARNING AGAINST INTRATHECAL USE OF METHYLENE BLUE
To the Editor:—
For at least 30 years methylene blue has been used by neurosurgeons as a dye to color the cerebrospinal fluid. In most instances the dye has been injected into hydrocephalic ventricles in the effort to demonstrate the presence or absence of a block somewhere within the ventricular system. Under these circumstances the dye becomes almost immediately very dilute. Emboldened by the use of the dye in this fashion, neurosurgeons have, on...