The use of the laser in neurological surgery.

Lasers generate unidirectional beams of monochromatic, and temporally and spatially coherent electromagnetic radiation that are capable of vaporizing and coagulating biological tissue. Specific physical characteristics of laser energies of different wavelengths impart to each form of surgical laser specific potentials for clinical use in neurological surgery. The major advantages of surgical lasers appear to be improved precision, reduction of surgically related mechanical trauma, reduction of blood loss, and decreased operative time. Improvement of operative mortality and morbidity and increased longevity that might result from its use would make the laser cost effective.

Phencyclidine abuse mimicking head injury.

Phencyclidine hydrochloride (PCP) is a psychoactive drug that in small doses produces agitation, excitement, and disorientation, but in larger doses results in stupor, convulsions, coma, and death. Two accident victims under the effects of phencyclidine were in coma. A history of phencyclidine abuse was not initially available in either instance. Head injury was suspected in both patients, although their neurological symptoms suggested a state of sensory blockade. Phencyclidine abuse should be considered in all patients with atypical coma despite a clear history of trauma.