STUDIES ON INTRACRANIAL PRESSURE

Area of Science:

• Physiology
• Neuroscience
• Vascular Biology

Background:

• Cushing's earlier work established a link between intracranial pressure and blood pressure.
• Understanding the cerebral circulation and its response to pressure changes is crucial for neurological research.

Purpose of the Study:

• To confirm and expand upon Cushing's findings regarding intracranial pressure and blood pressure.
• To investigate the mechanisms behind blood pressure changes in response to elevated intracranial pressure.
• To evaluate the efficacy of artificial brain perfusion techniques in canine models.

Main Methods:

• Experimental manipulation of intracranial pressure in dogs.
• Observation of blood pressure responses and vascular changes in various organs.
• Anatomical investigation of cerebral arterial connections, including the internal carotid and internal maxillary arteries.
• Assessment of artificial perfusion methods for canine brains.

Main Results:

• Elevated intracranial pressure above blood pressure induces intestinal, renal, and limb vasoconstriction, preceded by vasodilation.
• The internal maxillary artery in dogs is identified as a significant cerebral artery, with a major anastomotic connection to the internal carotid.
• Artificial brain perfusion in dogs is deemed unreliable due to alternative vascular pathways.
• Intracranial pressure exceeding blood pressure causes complete cerebral anemia, while moderate increases affect the Circle of Willis and basal arteries.

Conclusions:

• The study validates Cushing's findings on intracranial pressure effects.
• Specific vascular responses, including cerebral anemia, are detailed under varying intracranial pressures.
• The anatomical significance of the internal maxillary artery and limitations of artificial perfusion are established.