Arterial dissection refers to the abnormal, and usually abrupt, formation of a tear along the inside wall of an artery. As the tear becomes larger, it forms a small pouch which is called a “false lumen.” The blood that accumulates inside this false lumen can generate blood clots or otherwise block blood flow, leading to a stroke. The carotid and vertebral arteries can be damaged by neck injuries or even forceful neck movements.
Symptoms
Arterial dissection can cause a droopy eye lid with a small pupil on the same side, headache, neck pain, or stroke symptoms.
Diagnosis
Typically, a magnetic resonance imaging (MRI) and MR Angiogram are done to look at the brain and the blood vessels of the head and neck and visualize a tear within the wall of an artery. Sometimes a catheter cerebral angiogram (also called arteriogram), which is a special test in which a neuroradiologist injects dye into the blood vessels in the brain and obtains images of the blood vessels, or computed tomography (CT) angiogram may be performed.
Treatment
Treatment is usually with blood thinners such as warfarin or low molecular weight heparin for 3 to 6 months followed by aspirin therapy.

The Johns Hopkins Bayview Medical Center and The Johns Hopkins Hospital have earned the Gold Seal of Approval for stroke care from the Joint Commission on Accreditation of Healthcare Organizations (JCAHO). Hopkins Bayview achieved its designation in January, 2005 and JHH did so in May, 2005. Both are amongst the first hospitals in Maryland to be awarded the distinct Primary Stroke Center Certification. 
