Electroencephalography in retrolental fibroplasia.

Some children with severe retrolental fibroplasia have mental retardation. It is difficult to determine whether this retarda­ tion is based only on the loss of vision or whether it is related to cerebral damage. With the hope that electroencephalography would give some evidence that would help to separate these factors, a series of children with severe retrolental fibroplasia in cicatricial stages C, D, and E were investigated. Electroencephalography has a limit in the evaluation in the cerebral disturbances in the adult. In the young child the interpretation of cerebral electropotentials is, of course, more difficult because it has not been widely explored and correlated. In children with retrolental fibroplasia the kind of cerebral damage, if any, is unknown. Any measurable evidence that can be obtained by electro­ encephalography should be valuable in the determination of the neurologic status of the child. Electroencephalography is well estab­ lished as a diagnostic aid in neurology. The electroencephalogram has three charac­ teristic components: frequency, usually 1/10 of a second or 10 per second, voltage, usually measured in microvolts, and form of record­ ing, usually sinusoidal but may be sharp and spiky or even flat waves. There are several types of waves and patterns: Alpha waves are usually eight to 13 per second in frequency, five to 100 microvolts in voltage, and sinusoidal in form. Beta waves are generally 15 to 30 per second with voltage of five to 30 microvolts. Delta waves are less than six per second with voltage at least 20 microvolts.