How to Distinguish between Venous and Arterial Strokes and Why?

Abstract

Cerebral venous infarct is considered to be rare (0-5% of all strokes). In some cases venous infarcts with no specific signs on conventional CT or MR study are not diagnosed due to incomplete examination. A venous infarct more often (63%) than an arterial (15%) infarct is accompanied by hemorrhage (primary or secondary in the early period) and a high risk of hemorrhage should be a contraindication to intravenous thrombolysis. Consequently, the definition of the kind of a stroke should lead to different therapeutic tactics. Using MR and CT angiographic and perfusion techniques in the urgent examination of patients with an infarct, considering time necessary for the "time window", can lead to exact diagnosis and fewer complications.

MRI ischemic and hemorrhagic lesions in arterial and venous territories characterize central nervous system intravascular lymphoma in dogs

“…22 Guidelines in human medicine for diagnosing venous infarction include: infarction not conforming to a major arterial vascular territory, crossing the typical arterial boundaries, or extending over more than one arterial distribution; presence of multiple isolated lesions; involvement of subcortical regions with sparing of the cortex, or cortical-subcortical topography; often hemorrhagic component; proximity to a venous sinus. [24][25][26][27][28] The retrograde venous pressure caused by thrombosis severely reduces the cerebral blood flow through a vicious cycle of increased intracranial pressure, blood-brain barrier disruption with edema and hemorrhage, and reduced CSF drainage, leading to neuroparenchymal ischemia and necrosis. 23,26,29,30 The restricted diffusion in acute venous thrombosis suggests that cytotoxic edema is mainly responsible for the MRI changes, and that vasogenic edema follows but is not the primary pathological event.…”

“…33,34 Venous infarction is more frequently accompanied by hemorrhage because of venous stasis and rupture of the blood-brain barrier. 27,30,32 In such cases, blood is intermixed with edematous brain tissue. Intraparenchymal hemorrhage may also occur following vessel disruption, leading to a primary hematoma without an ischemic component.…”

“…The unpaired anatomy of the dorsal sagittal sinus implies symmetry of the lesions, however asymmetric lesions topographically distant from the occlusion site are also reported in humans, reflecting variable collateral venous circulation 25,26,32 . Human venous infarcts are typically localized in the parietal‐occipital region and corpus callosum, areas rarely affected in arterial infarcts 27 . Areas of overlapping venous and arterial territories can be found in the thalamus and basal nuclei.…”

Acute cerebral microbleeds at the edge of lacunar strokes: cause or result

“…The CMBs and the lacunar infarctions may be unrelated events on juxtapositioned vessels, or the CMB may be haemorrhagic conversion of the arterial or venous infarction. 8 On the other hand, the locations of the CMBs relative to the infarction areas may suggest a causal relationship to the lacunar infarcts, that is, occlusion of the lenticulostriatal branches leading to infarction of their supplying territories. CMBs are considered to arise as small perivascular bleedings in the acute phase, and to change to focal accumulation of hemosiderin-containing macrophages at least several days after the bleeding.…”

Clinical and instrumental indicators of intracranial venous stasis and secondary ischemia in cerebral sinus thrombosis. A review

“…The widespread use of diffusion and perfusion protocols that allow detecting edema and perfusion disorders already in the first hours of the disease has led to the loss of relevance of the classification of venous ischemia based on the abnormality of the T2WI signal on MRI [66]. Lesion localization close to a thrombosed sinus or vein is not typical for the arterial stroke [75]. MR images contrast enhancement allows one to see a symptom similar to empty delta sign symptom on CT in thrombotic sinus occlusion [76] when on T1WIagainst the background of contrast-enhanced sinus walls as a thrombus in the sinus lumen -looks much less intense.…”