History of occlusive cerebrovascular disease. II. After Moniz, with special reference to surgical treatment.

Angiography and related procedures are discussed. Ophthalmodynamometry, recording of bruits and temporal pulse, and thermography have been mentioned. Transient ischemic attacks (TIAs) and some causes are described: embolic obstruction, followed by absorption of the clot or its removal in the blood, with symtomatic recovery; hemodynamic crisis resulting from lowering of systemic blood pressure by hemorrhage due to trauma, gastrointestinal bleeding, and other causes with recovery following blood replacement.

History of occlusive cerebrovascular disease I. from Wepfer to Moniz.

Occlusive cerebrovascular disease of carotid and vertebral arteries was described by Wepfer in 1658 and by Willis in 1665. Wepfer thought apoplexy resulted from occlusive disease of the vessels. Willis described collateral channels between these vessels, which prevented the development of stroke.

Cerebral contusions: re-evaluation of the mechanism of their development.

At the present writing, the biomechanics of "coup-contrecoup" contusions may be summarized as follows: 1) "Coup" contusions are caused by the slapping effect of discrete areas of inbeding bone during impact. "Contrecoup" contusions are caused by the movements of the brain against irregular and rough bony enviornment. 2) When the head is relatively fixed, a blunt discrete impact causes a "coup" lesion with no "contrecoup" effect.

Re-evaluation of the biomechanics of blunt impact injury of the head.

With blunt impacts, there may be bruising or tearing of scalp, elastic deformation of the skull with or without linear fracture, mass motions or relative movements of the brain mass--inertial stress propagation--as well as pressure gradients. Mass motions of the brain may cause concussion, vascular tears with extravasation and contusions of the cerebral surface as well as lesions in the deeper portions of the cerebral mass. Coup contusion is caused by the inbending bone at the impact site striking the immobile head.