The blood flow in the surrounding less-severely ischemic boundary ("penumbral" or "
perifocal" tissue) is ~ 7 to 17 mL/100g/min.
After the administration of clonazepam and levetiracetam, the patient was stable and a new brain CT scan revealed a large intracerebral haemorrhagic site on the left temporal lobe with
perifocal oedema and multiple smaller bleeding sites (Figure 3).
Both abscess and tumor have
perifocal (surrounding) edema, but the former tends to have ring enhancement on CT and MRI images while the latter can be solid or cystic with thick, irregular wall.
However, a new tumefactive lesion with
perifocal edema, which demonstrated ring-like gadolinium enhancement on T1-weighted images and peripheral restriction on DWI, was observed in the right frontal area (Figure 2).
This tumor was located at the left temporal lobe with upward extension to the left basal ganglion and periventricular region, causing
perifocal edema and midline shift (Figure 1).
Nidus is the weak spot, due to abrupt transition from arterial to the venous system, from high to low pressure vessels, and may result in hemorrhage,
perifocal edema and/or subsequent irritation of the surrounding brain tissue [2, 3].
The integrated optical density (IOD) in the
perifocal region was analyzed under 400 x magnification.
The stage of inflammation was considered to be finished once
perifocal edema around the wound disappeared.
In addition, LGG usually shows no necrosis,
perifocal edema, or hemorrhagic foci.
Following cerebral ischemia induced by middle cerebral artery occlusion, Trx1 was reduced in ischemic areas and increased in
perifocal ischemic regions [13].
Not surprisingly some authors reported adverse events, which might be dose dependent, such as occurrence of an rtPA induced delayed cytotoxic
perifocal edema.