As new and elaborate tools for medical diagnosis are developed, time-honored and simpler methods are often neglected. This we believe to be true of the technique of transillumination, as applied to the diagnosis of intracranial pathology.
Illumination of the cranial cavity by sunlight and candle was described as early as 1831 by Richard Bright1 (Fig. 1). In 1910, Strasburger2 commented on its use in evaluation of the hydrocephalic child, and during the early part of this century von Bokay3 developed the technique of transillumination to a remarkable degree. More recently, there has been renewed interest in this technique, but the majority of physicians still employ it only rarely and are unaware of its considerable value in neurologic diagnosis.
During the past few years, the routine use of transillumination in the examination of infants and children with neurologic disease on the wards of the Children's Service of the