Head pain occurs in 50–75% of all cases of<unk> . It tends to be located at the back of the head, either on the affected side or in the middle, and develops gradually. It is either dull or pressure-like in character or throbbing. About half of those with<unk>  consider the headache distinct, while the remainder have had a similar headache before. It is suspected that<unk>  with headache as the only symptom is fairly common; 8% of all cases of<unk>  and carotid dissection are diagnosed on the basis of pain alone. Obstruction of blood flow through the affected vessel may lead to dysfunction of part of the brain supplied by the artery. This happens in 77–96% of cases. This may be temporary ("transient ischemic attack") in 10–16% of cases, but many (67–85% of cases) end up with a permanent deficit or a stroke. The<unk>  artery supplies the part of the brain that lies in the posterior fossa of the skull, and this type of stroke is therefore called a posterior circulation infarct. Problems may include difficulty speaking or swallowing (lateral medullary syndrome); this occurs in less than a fifth of cases and occurs due to dysfunction of the brainstem. Others may experience unsteadiness or lack of coordination due to involvement of the cerebellum, and still others may develop visual loss (on one side of the visual field) due to involvement of the visual cortex in the occipital lobe. In the event of involvement of the sympathetic tracts in the brainstem, a partial Horner's syndrome may develop; this is the combination of a drooping eyelid, constricted pupil, and an apparently sunken eye on one side of the face. If the dissection of the artery extends to the part of the artery that lies inside the skull, subarachnoid hemorrhage may occur (1% of cases). This arises due to rupture of the artery and accumulation of blood in the subarachnoid space. It may be characterized by a different, usually severe headache; it may also cause a range of additional neurological symptoms. 13–16% of all people with<unk>  or carotid dissection have dissection in another cervical artery. It is therefore possible for the symptoms to occur on both sides, or for symptoms of carotid artery dissection to occur at the same time as those of<unk> . Some give a figure of multiple vessel dissection as high as 30%.
Vertebral artery dissection
Cervical artery dissection
Carotid artery dissection
Posterior cerebral artery syndrome
Middle cerebral artery syndrome
Anterior cerebral artery syndrome
ROSAH syndrome
Pseudosubarachnoid hemorrhage