Thrombotic (80% of<unk>  CVA)
Atherosclerosis
Vasculitis
Vertebral and carotid artery dissection
Often preceded by yoga, spinal manipulation, coughing, vomiting
Polycythemia
Hypercoagulable state (oral contraceptives, antiphospholipid antibodies, protein S and C deficiencies, sickle cell anemia)
Infection
Toxicologic exposure (cocaine, amphetamines, etc.)
Embolic (20% of<unk>  CVA)
Valvular vegetations
Mural thrombi
Arterial-arterial emboli from proximal source (ex. amaurosis fugax -> emboli from a proximal carotid artery plaque embolizes to the ophthalmic artery, causing transient monocular blindness)
Fat emboli
Septic emboli
Hypoperfusion
Cardiac failure resulting in systemic hypotension
Atherosclerosis
Vasculitis
Vertebral and carotid artery dissection
Often preceded by yoga, spinal manipulation, coughing, vomiting
Polycythemia
Hypercoagulable state (oral contraceptives, antiphospholipid antibodies, protein S and C deficiencies, sickle cell anemia)
Infection
Toxicologic exposure (cocaine, amphetamines, etc.)
Often preceded by yoga, spinal manipulation, coughing, vomiting
Valvular vegetations
Mural thrombi
Arterial-arterial emboli from proximal source (ex. amaurosis fugax -> emboli from a proximal carotid artery plaque embolizes to the ophthalmic artery, causing transient monocular blindness)
Fat emboli
Septic emboli
Cardiac failure resulting in systemic hypotension
Ischemic stroke
Stroke
Hemorrhagic stroke
Seizures/postictal paralysis 
Subarachnoid hemorrhage
Syncope
Vertebral and carotid artery dissection
Subdural hemorrhage