Thrombolytic Therapy for Acute Bilateral Carotid Artery Occlusion

Context: Acute bilateral internal carotid artery occlusion is a rare condition which is frequently associated with prolonged coma or brain death. There is no consesus on which is the optimal therapy for this condition, although there are reports of clinical improvement after mechanical thrombectomy. We present a case report of a patient treated with intravenous thrombolytic therapy. Case Report: A 82 year-old woman with previous history of hypertension and coronary artery disease presented with seizures, followed by coma. There was no description of focal neurological deficit. On examination, patient was comatous, with decebrate posturing after painful stimulus, bilateral myosis, showed absent oculocephalic reflex and absent corneal reflex on the left eye. CT scan showed diffuse hypodensities on the frontal and parietal lobes and on the superior temporal lobes. CT angiography showed occlusion of the right internal carotid artery and of the left common carotid artery. The patient was treated with 72mg of IV alteplase within 4 hours after symptom onset. There was no improvement after 24 hours. A new CT scan showed infarction of all anterior circulation territory. Diagnosis of brain death was made after 48 hours. Conclusions: Acute bilateral carotid artery occlusion is usually associated with poor outcome despite treatment. Endovenous thrombolytic therapy did not lead to clinical improvement on the presented patient. There is limited data on the efficacy of IV thrombolysis and other recanalization therapies for acute bilateral carotid artery occlusion.

Study ofαB-Crystallin Expression in Gerbil BCAO Model of Transient Global Cerebral Ischemia

αB-crystallin (α-BC), the fifth member of mammalian small heat shock protein family (HspB5), is known to be expressed in many tissues and has a distinctive interaction with cytoskeleton components. In this study, we investigated thatα-BC and microtubule-associated protein-2 (MAP-2), a neuron-specific cytoskeleton protein, were coexpressed in neurons of Gerbil cortex, while in subcortex Gerbil brains, we found that several MAP-2-negative glia cells also expressα-BC. When subjected to 10-minute bilateral carotid artery occlusion (BCAO), an increment was observed inα-BC-positive cells after 6-hour reperfusion and peaked at around 7 days after. In the same circumstances, the number and the staining concentration of MAP-2 positive neurons significantly decreased immediately after 6-hour reperfusion, followed by a slow recovery, which is consistent with the increase ofα-BC. Our results suggested thatα-BC plays an important role in brain ischemia, providing the early protection of neurons by giving intracellular supports through the maintenance of cytoskeleton and extracellular supports through the protection of glia cells.

Rodent Neonatal Bilateral Carotid Artery Occlusion with Hypoxia Mimics Human Hypoxic-Ischemic Injury

We report a new clinically relevant model of neonatal hypoxic-ischemic injury in a 10-day-old rat pup. Bilateral carotid artery occlusion and 8% hypoxia (1 to 15 mins, BCAO-H) was induced with varying degrees of injury (mild, moderate, severe), which was quantified using magnetic resonance imaging including diffusion-weighted and T2-weighted imaging at 24 h and 21/28 days. We developed a magnetic resonance imaging-based rat pup severity score and compared 3D ischemic injury volumes/rat pup severity score with histology and behavioral testing. At 24 h, hypoxic-ischemic injury was observed in 17/27 animals; long-term survival was 81%. Magnetic resonance imaging lesion volumes did not correlate with hypoxia duration but correlated with rat pup severity score, which was used to classify animals into mild ( n = 21), moderate ( n = 6), and severe ( n = 10) groups with average brain lesion volumes of 0.9%, 33.2%, and 56.3%, respectively. Histology confirmed lesion location and histologic scoring correlated with the rat pup severity score. We also found excellent correlation between injury severity and multiple behavioral tasks. Bilateral carotid artery occlusion and hypoxia in the P10 rat pup is an excellent model of neonatal hypoxic-ischemic injury because it induces diffuse global injury similar to the term infant. This model can produce graded injury severity, similar to that seen in human neonates, but manipulation with hypoxia duration is unpredictable.