Recrudescence of Focal Stroke Symptoms during Pain Management with Hydromorphone.

Patients who have recovered from a prior stroke may experience a reemergence of their original stroke syndrome secondary to metabolic derangements, sedation, infection, and/or fatigue. Critically, the molecular/cellular mechanisms mediating symptom recurrence after exposure to analgesic agents remain unknown. Accordingly, herein, we report a unique case of a patient with hydromorphone-induced recrudescence 30 years after her initial stroke event(s) and in so doing propose a putative mechanism related to post-infarction functional neuroplasticity.

Effects of tibial intraosseous and IV administration of vasopressin on kinetics and survivability in cardiac arrest.

PURPOSE: Purposes of this study were to compare tibial intraosseous (TIO) and intravenous (IV) administration of vasopressin relative to return of spontaneous circulation (ROSC) and time to ROSC in an adult swine cardiac arrest model. In addition, the purposes were to compare the concentration maximum (Cmax), time to maximum concentration (Tmax), and odds of ROSC. METHODS: This was a between-subjects, prospective experimental study. Yorkshire swine (N = 21) were randomly assigned to 1 of 3 groups: TIO, IV, or control groups. The swine were anesthetized and instrumented, and then cardiac arrest was induced and sustained for 2 minutes. Cardiopulmonary resuscitation was initiated and continued for 2 minutes. Vasopressin was then administered via the TIO or IV route. Blood samples were collected for 4 minutes to determine the Cmax and Tmax of vasopressin. Concentration maximum and Tmax were calculated by use of liquid chromatography with mass spectrometry. RESULTS: There was no difference in ROSC between the TIO and IV groups (P = .63). The Cmax of vasopressin was significantly higher in the IV group compared to the TIO group (P = .017). However, there was no significant difference in ROSC, time to ROSC, or Tmax between groups (P > .05). All subjects had ROSC in both the IV and TIO groups, and none had ROSC in the control group. There was 225 times greater chance of survival for both the IV and TIO groups compared to the control group. CONCLUSION: The data support that the TIO is an effective route for vasopressin in a cardiac arrest model.

Application of high-intensity focused ultrasound to the study of mild traumatic brain injury.

Though intrinsically of much higher frequency than open-field blast overpressures, high-intensity focused ultrasound (HIFU) pulse trains can be frequency modulated to produce a radiation pressure having a similar form. In this study, 1.5-MHz HIFU pulse trains of 1-ms duration were applied to intact skulls of mice in vivo and resulted in blood-brain barrier disruption and immune responses (astrocyte reactivity and microglial activation). Analyses of variance indicated that 24 h after HIFU exposure, staining density for glial fibrillary acidic protein was elevated in the parietal and temporal regions of the cerebral cortex, corpus callosum and hippocampus, and staining density for the microglial marker, ionized calcium binding adaptor molecule, was elevated 2 and 24 h after exposure in the corpus callosum and hippocampus (all statistical test results, p < 0.05). HIFU shows promise for the study of some bio-effect aspects of blast-related, non-impact mild traumatic brain injuries in animals.

Short and long-term motor and behavioral effects of diazoxide and dimethyl sulfoxide administration in the mouse after traumatic brain injury.

Traumatic brain injury (TBI) is a worldwide phenomenon that affects all ages and socioeconomic classes and results in varying degrees of immediate and delayed motor, cognitive, and emotional deficiencies. A plethora of pharmacologic interventions that target recognized initiators and propagators of pathology are being investigated in an attempt to ameliorate secondary injury processes that follow primary injury. Diazoxide (DZ), a K(ATP) channel activator, has been shown to provide short- and long-term protective effects in a variety of in vitro and in vivo cerebral ischemia models. However, the effects of DZ on behavioral outcome following TBI have not been investigated. TBI was induced in male C57BL/6J mice by controlled cortical impact (CCI) and followed by intraperitoneal administration of either normal saline, dimethyl sulfoxide (DMSO), or 2.5 mg/kg DZ in DMSO, 30 min post-injury and daily for three days. Open field and beam walk performances were used to assess motor and behavioral function 1, 7, and 14 days following injury. Spatial learning and memory were assessed three weeks following injury using the Morris water maze. Injured mice were significantly impaired on the beam-walk and Morris water maze tasks, and were hyperactive and anxious in an open field environment. On post-injury days 1 and 14, mice treated with DMSO exhibited an increase in the amount of time required to perform the beam walk task. In addition, animals exposed to DMSO or DZ+DMSO exhibited slower swimming speed in the Morris water maze on the final day of testing. There was no therapeutic effect, however, of the treatment or vehicle on open field behavior or learning and memory function in the Morris water maze. In summary, CCI produced significant long-term impairment of motor, memory, and behavioral performance measures, and DZ administration, under the conditions used, provided no functional benefits following injury.

Mouse brain PSA-NCAM levels are altered by graded-controlled cortical impact injury.

Traumatic brain injury (TBI) is a worldwide endemic that results in unacceptably high morbidity and mortality. Secondary injury processes following primary injury are composed of intricate interactions between assorted molecules that ultimately dictate the degree of longer-term neurological deficits. One comparatively unexplored molecule that may contribute to exacerbation of injury or enhancement of recovery is the posttranslationally modified polysialic acid form of neural cell adhesion molecule, PSA-NCAM. This molecule is a critical modulator of central nervous system plasticity and reorganization after injury. In this study, we used controlled cortical impact (CCI) to produce moderate or severe TBI in the mouse. Immunoblotting and immunohistochemical analysis were used to track the early (2, 24, and 48 hour) and late (1 and 3 week) time course and location of changes in the levels of PSA-NCAM after TBI. Variable and heterogeneous short- and long-term increases or decreases in expression were found. In general, alterations in PSA-NCAM levels were seen in the cerebral cortex immediately after injury, and these reductions persisted in brain regions distal to the primary injury site, especially after severe injury. This information provides a starting point to dissect the role of PSA-NCAM in TBI-related pathology and recovery.

The most frequently requested precombat refresher training by the Special Forces medics during Operation Enduring Freedom.

The tactical environment and the mission given the Special Operations Forces in Afghanistan during the initial phases of Operation Enduring Freedom placed the Special Operations Forces medics (18Ds) in a position of significant medical responsibility. The 18Ds became the primary care providers for the indigenous anti-Taliban fighters as well as U.S. military personnel; the care of the latter was further complicated by long evacuation times. Because of these issues and several events that occurred in the combat zone, the 18Ds requested their supporting forward surgical team (FST) (274th FST) to provide specific refresher training before combat deployment into Afghanistan. The areas of greatest interest and concern were orthopedics, field transfusions, and field-expedient anesthesia. It is hoped that the training prepared and given to the 18Ds by the personnel of the 274th FST and presented in this article not only was useful to them but also will be of benefit to 18Ds who find themselves in similar situations in the future.