Localized cortical chronic traumatic encephalopathy pathology after single, severe axonal injury in human brain.

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with repetitive mild impact traumatic brain injury from contact sports. Recently, a consensus panel defined the pathognomonic lesion for CTE as accumulations of abnormally hyperphosphorylated tau (p-tau) in neurons (neurofibrillary tangles), astrocytes and cell processes distributed around small blood vessels at sulcal depths in irregular patterns within the cortex. The pathophysiological mechanism for this lesion is unknown. Moreover, a subset of CTE cases harbors cortical ß-amyloid plaques. In this study, we analyzed postmortem brain tissues from five institutionalized patients with schizophrenia and history of surgical leucotomy with subsequent survival of at least another 40 years. Because leucotomy involves severing axons bilaterally in prefrontal cortex, this surgical procedure represents a human model of single traumatic brain injury with severe axonal damage and no external impact. We examined cortical tissues at the leucotomy site and at both prefrontal cortex rostral and frontal cortex caudal to the leucotomy site. For comparison, we analyzed brain tissues at equivalent neuroanatomical sites from non-leucotomized patients with schizophrenia, matched in age and gender. All five leucotomy cases revealed severe white matter damage with dense astrogliosis at the axotomy site and also neurofibrillary tangles and p-tau immunoreactive neurites in the overlying gray matter. Four cases displayed p-tau immunoreactivity in neurons, astrocytes and cell processes encompassing blood vessels at cortical sulcal depths in irregular patterns, similar to CTE. The three cases with apolipoprotein E ε4 haplotype showed scattered ß-amyloid plaques in the overlying gray matter, but not the two cases with apolipoprotein E ε3/3 genotype. Brain tissue samples from prefrontal cortex rostral and frontal cortex caudal to the leucotomy site, and all cortical samples from the non-leucotomized patients, showed minimal p-tau and ß-amyloid pathology. These findings suggest that chronic axonal damage contributes to the unique pathology of CTE over time.

Ultrasound guided percutaneous common carotid artery access in piglets for intracoronary stem cell infusion.

In pigs, the deep location of the common carotid artery and overlying sternomastoideus muscle in the neck has led to the recommendation for a surgical cutdown for common carotid access, as opposed to minimally invasive techniques for vascular access. We sought to determine if direct percutaneous common carotid artery access in piglets is attainable. Seventeen piglets were anesthetized and intubated. Under two-dimensional and color flow Doppler ultrasound guidance, a 21 gauge needle was utilized to access the right common carotid artery. Following arterial puncture, the Seldinger technique was applied to place a 4 or 5 French introducer. Upon completion of cardiac catheterization with intracoronary stem cell infusion the introducer was removed and manual pressure was applied to prevent hematoma development. Successful access with an introducer was achieved in all 17 piglets. The average weight was 8.5 ± 1.7 kg. One piglet developed a hematoma with hemorrhaging from the catheterization site and was euthanized. This piglet was given bivalirudin for the procedure. After this incident, subsequent piglets were not given anticoagulation and no other complications occurred. Ultrasound guided percutaneous common carotid artery access in piglets is attainable in a safe, reliable, and reproducible manner when performed by microvascular experts.