Emissary veins passing through the foramen ovale, jugular foramen, foramen lacerum, and hypoglossal canal. Because the emissary veins are valveless, they are an important part in selective brain cooling through bidirectional flow of cooler blood from the evaporating surface of the head. In general, blood flow is from external to internal but the flow can be altered by increased intracranial pressure. A type of emissary vein goes through the sphenoidal emissary foramen inferior to the zygomatic arch with the cavernous sinus on the inside of the skull. This is an important route for spread of infection because cranial nerve VI and the
Drug delivery to the brain area. There are several important factors in making this a viable solution for drug delivery. The first is that the loaded microbubble must not be substantially greater than the unloaded bubble. This ensures that the diffusion will be similar and the ultrasound disruption will be enough to induce diffusion. A second factor that must be determined is the stability of the loaded micro-bubble. This means is the drug fully retained in the bubble or is there leakage. Lastly, it must be determined how the drug is to be released from the microbubble once it passes through the blood–brain barrier. Studies