34 yo male SLE w/ renal failure, presenting with expressive aphasia.
 

Noncontrast CT Head; MRA of the neck; MRA of the head; T1-w MR pre and post contrast; MR diffusion; MR T2-w and MR flair

Noncontrast CT Head
1. Hyperacute cytogenic edema in the retrosylvian area on the left. No hyperacute arterial or venous intraluminal thrombus is evident.
2. No hemorrhagic conversion is evident.
3. Chronic right maxillary sinusitis with chronic bone reaction but no bone dehiscence to suggest aggressive disease.

MRA of the Neck
1. Negative MRA of the neck with no evidence of arterial size asymmetry nor atherosclerotic nor arteriopathy (FMD or dissection) changes.

MRA of the Head
1. Patient has known autoimmune disorder (SLE). There are subtle arterial luminal arterial size changes, which could be vasospastic, but are more likely (in the absence of thunderclap headache symptoms), is more likely related to a secondary inflammatory angiitis rather than RCVS.

T1-w pre and post contrast
1. Hyperacute ischemic event in the left retrosylvian region. There is no proximal arterial nor venous cause. There is distal arterial angiitis evident on the head MRA. There is also evidence of multicentric sites of subacute laminar necrosis in other area of the cerebrum. This combination of imaging observations combined with a clinical history of SLE makes this most likely a transcapillary form of stroke in all locations. The basis is secondary angiitis associated in the SLE. These patients often have clotting abnormalities as well. Therefore, screen for APLA (immunebased antiphospholipid antibody syndrome).

MR diffusion sequence
1. MR diffusion is positve (i.e. hyperacute stroke) in the left retrosylvian area. The diffusion intensity favors the cortex, plus there are multiple other sites of cortical laminar necrosis. This implies the cortex in the left retrosylvian will evolve in the same way. Laminar necrosis indicates an absence of collateral reflow and is therefore consistent with a transcapillary type of ischemic event. 

MR T2-w and MR flair sequences
1.Hyperacute stroke with the post ischemic edema predominantly in the cortex consistent with a transcortical stroke associated with secondary, SLE-related, small vessel CNS angiitis.
2. The more chronic ischemic white matter demyelination in the bilateral centrum semiovale white matter follows the Virchow-Robin spaces, which, along with the multicentric sites of laminar cortical necrosis are expected features of CNS vasculitis.

1. There is abnormal distal end-artery stenoses in cerebral vessels consistent with the vasculopathy associated with the known clinical diagnosis of SLE

2. There is a focal area of acute ischemic cytogenic edema in the left retrosylvian area involving both cortex and subcortical parenchyma. There is evidence of a small area of cortical laminar necrosis in cortex in the same area consistent with sequestered infarctions associated with end-artery ischemia with no recanalization of the venocapillary pool.

3. The follow-up MR T1-w sequence demonstrated regional laminar necrosis in the retrosylvian area, which is often the result of infarction affecting end-arteries, as is the case with inflammatory arteritis (SLE in this case).

1. Autoimmune disorders are not uncommon. Many are associated with inflammatory angiitis. When it involves the brain, it is referred to as secondary CNS angiitis; note there is a also a primary CNS angiitis. Both are included in this Transcapillary Stroke Module. Systemic autoimmune angiopathy tends to present in adolescents and younger adults patients and not uncommonly, as in this case, exhibit transient, often recurrent, neurologic deficits. Many are transient, but some are fixed. Most of these immune-based angiopathies involve small arteries and arterioles. As a result, they produce end-artery ischemia at the metarteriole-capillary bed anatomic level. Ischemia at this levelcan result in transcapillary form of stroke. Transcapillary stroke do not generally exhibit recognizable arterial or venous perfusion zone abnormalities. The imaging changes tend to follow the Virchow-Robin spaces, the strokes are in distribution of the terminal end-artery sites. Ishemic events in angiitis tend to be muliticentric and of differing stroke-age; they often exhibit varying degrees of regional brain atrophy. End-artery, metarteriole level ischemia is beyond pial reperfusion collateral help; there is no collateral reflow.  Therefore, the stroke-zones tend to follow terminal arteries. Since they lack reflow, they often proceed to sequestered stroke (i.e. laminar necrsosis or focal sequestered infarcts, they occur in young and middle age patients. They typically have no macroarterial stenoses (excluding diabetic vasculopathy and CADASIL patients with accellerated atherosclerosis). The findings listed above of are characteristic features of secondary small vessel CNS angiitis, which result in transcapillary parenchymal ischemic injuries.

2. Imaging features of small vessel inflammatory angiitis are often subtle, but must be sought, because even biopsy can be nondiagnostic in which case, the imaging may be the only way to confirm secondary CNS angiitis.

Watch the included summary video for this instructional case.