<unk>  is defined as an episode of neurological dysfunction caused by focal cerebral, spinal, or retinal infarction.  Infarction of the central nervous system serves as the main pathogenetic mechanism implicated in the etiology of<unk> .  CNS Infarction refers to brain, spinal cord, or retinal cell death attributable to<unk> , based on:
1. Pathological, imaging, or other objective evidence of cerebral, spinal cord, or retinal focal<unk>  injury in a defined vascular distribution; or
2. Clinical evidence of cerebral, spinal cord, or retinal focal<unk>  injury based on symptoms persisting ≥24 hours or until death, and other etiologies excluded.
CNS infarction also include:
Hemorrhagic infarction ("hemorrhagic transformation of infarction", "hemorrhagic conversion of infarction") - This may occur spontaneously or due to antithrombotic or thrombolytic treatment.  They generally lack a mass effect, and are managed according to<unk>  recommendations.  There are two types:
Time of onset is defined as when the patient was last awake and symptom-free or known to be “normal".
Ischemic stroke
Hemorrhagic stroke
Subarachnoid hemorrhage
Watershed stroke
Carotid artery dissection
Migraine
Stroke
Vertebral artery dissection