Small core infarct

A simpler approach to identifying a significant penumbra is the combination of a proximal artery occlusion, significant clinical deficit (NIHSS score >10), and small core infarct (<70-100 mL)... 

In our view, the MRI patterns for identifying the ideal candidate for thrombolysis are straightforward. This particularly applies to treatment beyond the 3-h window. A small infarct core identified by DWI and a large perfusion deficit on PI indicate the potential for a major benefit from thrombolysis. This simple, practical mismatch model has, however, been challenged by partial normalisation of... 

Apoptosis is delayed and may be maximal at 24-48 h after an insult. However, apoptotic cells can be seen even within 6 h of an insult, but are not common. Apoptosis involves condensation of the nucleus. Condensation of the cytoplasm occurs with large vacuole formation. Some mitochondria may condense. Very uncommonly, some mitochondria swell in apoptosis. The cell splits up into membrane-bound apoptotic bodies that can be seen in the limit areas surrounding the core of an infarction. Apoptosis is a programmed form of cell death that occurs following a small but sufficient amount of damage to a cell. This initiates a program that eventually kills the cell. 

Fig. 5.9 Prediction of infarct growth. A 65-year-old man, improving clinically at 5 h postictus, was monitored in the Neurology ICU based on his labile blood pressure, a fixed left M2 occlusion on CTA, and a significant core/penumbra mismatch on CTP/MRP. His 24-h follow-up DWI showed a small infarction. However, 24 h after cessation of hypertensive therapy there was infarct growth into the region of penumbra. Admission CTA (top) CTP (CBV/CBF/ MTT) at 4.5 h second row) MR-perfusion weighted imaging (MR-PWI) (CBV/CBF/MTT) at 5.25 h (third row) DWI at 24 h (fourth row) and follow-up DWI at 48 h (bottom). The CTP and MR-PWI demonstrate a mismatch between the CBV (no abnormality) and the CBF/MTT penumbra (arrows). After cessation of hypertensive therapy, the DWI abnormahty grows into the region predicted by the CBF/MTT maps...

As described in the previous chapter on the ischemic penumbra, a patient with significant neurological deficit (NIHSS > 10), the finding of an ICA or proximal MCA occlusion and a small infarct core (<70-100 mL), very likelyhasavolumeofhypoperfused, symptom-producing tissue at risk that is at least 50% greater than the core volume. This concept was initially proposed as the diffusion-clinical mismatch [108, 109], and is based on the fact that the occlusion, core, and penumbra are not independent variables, but are related to each other by the collateral circulation. If one can identify two of the... 

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