CONCUSSION OF THE BRAIN (Lat. con cussio, shock. from concutcrc, to shake together, from corn-, together + quaterc, to shake). The name given to a group of symptoms which result from injuries to the head, but are not due to fracture or to perceptible laceration of vessels or brain substance. The condition has been widely discussed and extensively studied by many means of experimentation. but authorities still disagree as to whether it is due to laceration of minute blood-vessels, to altered vibratory changes in the molecules of the brain-cells, or to a change in the disposition of the cerebrospinal fluid. At present, almost all surgeons deny that concussion of itself is fatal, and autopsies show almost in variably some apparent lesion of vessels or brain substance in those fatal cases which have simu lated concussion, but which were really instances of contusion or laceration. The symptoms vary in mild and severe cases. In the former, when the patient is 'stunned' by a fall or a blow on the head, there is dizziness. disturbances of vision and noises in the ears, loss of strength, so that the patient falls, the face is pale and covered with a cold perspiration, the respiration is shal low, the pulse feeble and often slower than normal. In graver cases these symptoms become
intensified. or the most extreme symptoms may develop instantly. There is complete unconscious ness, the body is cold and relaxed. the pupils widely dilated and unresponsive to light, the respiration scarcely distinguishable, the pulse weak, irregular, and slow. Vomiting is also fre quent. This condition may last for several hours or even for a day or more, after which reaction slowly occurs, and recovery is complete. Fre quently the symptoms of contusion or hemorrhage may follow, and the subsequent history becomes that of severe brain injury. Protracted symp toms of concussion are usually regarded as sug gestive of a more serious injury. The treatment is expectant: it consists in the application of warmth to the body, stimulation of respiration and pulse if necessary, and in keeping the pa tient in absolute quiet. A surgical operation is, of course, not indicated in pure concussion, but only in such eases as give symptoms of gross brain lesions. See SHOCK.