Noncontact Rotational Head Injury Produces Transient Cognitive Deficits but Lasting Neuropathological Changes.

Traumatic brain injury (TBI) caused by improvised explosive devices (IEDs) is a growing problem in military settings, but modeling this disease in rodents to pre-clinically evaluate potential therapeutics has been challenging because of inconsistency between models. Although the effects of primary blast wave injury have been extensively studied, little is known regarding the effects of noncontact rotational TBIs independent of the blast wave. To model this type of injury, we generated an air cannon system that does not produce a blast wave, but generates enough air pressure to cause rotational TBI. Mice exposed to this type of injury showed deficits in cognitive and motor task acquisition within 1-2 weeks post-injury, but mice tested 7-8 weeks post-injury did not retain any deficits. This suggests that the effects of a single, noncontact rotational TBI are not long lasting. Despite the transient nature of the behavioral deficits, increased levels of phosphorylated tau were observed at 2 and 8 weeks post-injury; however, this tau did not adopt typical pathological structures that have been observed in other TBI models that incorporate blast waves. This was possibly attributed to the fact that this injury was insufficient to induce changes in microglial activation, which was not affected at 2 or 8 weeks post-injury. Taken together, these data suggest that exposure to noncontact, rotational head injury only produces transient cognitive anomalies, but elicits some minor lasting neuropathological changes.

Pressure ulcer risk of patient handling sling use.

Patient handling slings and lifts reduce the risk of musculoskeletal injuries for healthcare providers. However, no published evidence exists of their safety with respect to pressure ulceration for vulnerable populations, specifically persons with spinal cord injury, nor do any studies compare slings for pressure distribution. High-resolution interface pressure mapping was used to describe and quantify risks associated with pressure ulceration due to normal forces and identify at-risk anatomical locations. We evaluated 23 patient handling slings with 4 nondisabled adults. Sling-participant interface pressures were recorded while participants lay supine on a hospital bed and while suspended during typical patient transfers. Sling-participant interface pressures were greatest while suspended for all seated and supine slings and exceeded 200 mm Hg for all seated slings. Interface pressures were greatest along the sling seams (edges), regardless of position or sling type. The anatomical areas most at risk while participants were suspended in seated slings were the posterior upper and lower thighs. For supine slings, the perisacral area, ischial tuberosities, and greater trochanters were most at risk. The duration of time spent in slings, especially while suspended, should be limited.

Lesser metatarsophalangeal joints: intra-articular distension, volumetric measurements, and changes of position.

Plantarflexion of the second metatarsophalangeal (MTP) joint with intra-articular injection has previously been observed and commented upon, and the purpose of this study was to determine motion of the lesser toes with direct fluid infusion into the lesser MTP joints. Fluid distension was found to cause variable postural changes in all lesser toes; the most consistent change was plantarflexion of the second metatarsophalangeal joint. Dorsiflexion of the third, fourth, and fifth MTP joints was observed, but less reliable than plantarflexion of the second MTP joint. The average volume in each of the lesser MTP joints was less than 1 cc. Plantarflexion of the second MTP joint was usually, but not always, indicative of intra-articular distention. Aspiration of these joints (given their small volume capacity) may not be a reliable or therapeutically useful technique.