Case Notes
History
36 year old male diabetic who was found down. Patient initially was unresponsive, and later exhibited a markedly depressed level of consciousness. Patient was uncooperative on presentation and aphasic.Exam
CTA of the Head
This part of the stroke protocol CTA is performed after the 1st bolus of contrast and is referred to as the initial post contrast head CTA exam. Since there is no recirculation of contrast, it has the advantage of identifying stenoses and short segment occlusions without obscuration by pial collateral. On the other hand, it may underfilling patent, more distal, arteries, which, of course, also reduces the CT-density in the venocapillary pool within brain parenchyma. Thus, the initial post contrast head CTA tends to overestimate the depth of injury in the apparent stroke-zone.
Purpose
1. To define sites of afferent supratentorial arterial thrombosis or flow-limiting high-grade stenosis or lesser but tandem stenoses, or stenosis plus incomplete circle of Willis with isolated arterial circuit;
2. To define sites of afferent infratentorial arterial thrombosis or flow-limiting high-grade stenosis;
3. To determine features of vessel wall and intimal status;
4. To assess presence of tandem stenosis or stenosis plus incompetent circle of Willis;
5. In case of ICA stenosis/occlusion is there effective EC-IC collateral;
6. Is there a watershed stroke zone affecting the usual anastomotic arterial boundary zones;
7. in case of afferent arterial block, plus an incomplete circle of Willis, is there a potential end-of the-line type of watershed stroke;
8. To assess status of retrograde pial collateral and asses for any pial collateral gap between proximal thrombus & retrograde pial collateral;
9. To assess for delayed venous egress (need to prove on post contrast CT head whether it is just delayed or is actually persistently reduced or absent).
This part of the stroke protocol CTA is performed after the 1st bolus of contrast and is referred to as the initial post contrast head CTA exam. Since there is no recirculation of contrast, it has the advantage of identifying stenoses and short segment occlusions without obscuration by pial collateral. On the other hand, it may underfilling patent, more distal, arteries, which, of course, also reduces the CT-density in the venocapillary pool within brain parenchyma. Thus, the initial post contrast head CTA tends to overestimate the depth of injury in the apparent stroke-zone.
Purpose
1. To define sites of afferent supratentorial arterial thrombosis or flow-limiting high-grade stenosis or lesser but tandem stenoses, or stenosis plus incomplete circle of Willis with isolated arterial circuit;
2. To define sites of afferent infratentorial arterial thrombosis or flow-limiting high-grade stenosis;
3. To determine features of vessel wall and intimal status;
4. To assess presence of tandem stenosis or stenosis plus incompetent circle of Willis;
5. In case of ICA stenosis/occlusion is there effective EC-IC collateral;
6. Is there a watershed stroke zone affecting the usual anastomotic arterial boundary zones;
7. in case of afferent arterial block, plus an incomplete circle of Willis, is there a potential end-of the-line type of watershed stroke;
8. To assess status of retrograde pial collateral and asses for any pial collateral gap between proximal thrombus & retrograde pial collateral;
9. To assess for delayed venous egress (need to prove on post contrast CT head whether it is just delayed or is actually persistently reduced or absent).
Prior Study
Non-Contrast Head CT1. Acute thrombus in Lt. intracranial primary and secondary stem components of the Lt. ICA
2. Early cytogenic edema in both Lt. ACA & MCA territories, likely stroke-age is in the 3-6 hour range.
CT Perfusion
CT perfusion was not obtained.
CTA of the Neck
There were no flow limiting stenoses in the lower and mid cervical major afferent arteries.
There is unexplained reduced lumen size of the upper Lt. cervical ICA likely secondary to downstream obstruction. However, the neck CTA did not include any of the intracranial/extradural parts of the left ICA.
No venous egress obstruction was evident.