What Is Microvascular Cranial Nerve Palsy?

Microvascular Cranial Nerve Palsy (MCNP) is when blood flow to certain nerves in your head (called cranial nerves) is blocked. As a result, you may not be able to move your eye a certain way. Also, you will have double vision. Double vision is when you see two of a single image—either side by side, or one above the other.

Your brain sends signals to your eye muscles through 3 nerves. If blood flow to one of these nerves is reduced, certain muscles cannot move the eye.

Doctors do not know for sure why the tiny blood vessels that go to your cranial nerves get blocked. MCNP is very common in older adults. It is more likely to happen to those who have diabetes and high blood pressure. In fact, it is sometimes called “diabetic palsy.”

MCNP almost always gets better on its own in about 6–12 weeks, and your vision returns to normal.