Dose-dependent antithrombotic effect of warfarin in rabbits

One-hundred and fifty-one rabbits, divided into controls and animals treated with varying daily doses of warfarin, were subjected to the stasis assay, and the amount of thrombosis quantitated after intravascular coagulation was initiated either by activated factor X or tissue thromboplastin. Following 8-10 days of warfarin administration, there was a significant dose-dependent decrease in the vitamin-K- dependent coagulation factors paralleled by an increase in the prothrombin time ratio. Whether thrombosis was initiated by activated factor X or tissue thromboplastin, there was, with increasing drug dose, a progressive increase in the inhibition of stasis thrombosis. This significant antithrombotic effect occurred even when the vitamin-K- dependent coagulation activities were at a mean value of 50%.     

Effect of co-morbid traumatic brain injury on functional outcome of persons with spinal cord injuries

OBJECTIVE: This study was undertaken to determine if persons who sustain a spinal cord injury (SCI) and co-morbid brain injury (dual diagnosis [DDS]) evidence smaller functional gains and experience significantly longer rehabilitation lengths of stay than persons with only an SCI. DESIGN: This retrospective comparison study was performed at a 100-bed rehabilitation hospital specializing in acute SCI and traumatic brain injury rehabilitation. Summary scale outcome data of persons who sustained an SCI were compared with outcome data of a group of persons with a DDS. Comparisons were established by matching groups principally on level of SCI and admission Motor FIM trade mark score and secondarily on education, sex, and age. Outcome measures included admission Motor and Cognitive FIM score, discharge Motor and Cognitive FIM score, Motor and Cognitive FIM change, length of stay, and rehabilitation charges. RESULTS: Persons with a DDS evidenced a significantly more impaired Cognitive FIM score at admission and discharge from rehabilitation. Persons with a DDS also achieved a significantly lower Motor FIM change than persons with SCI. There were no significant differences between DDS and SCI groups regarding Cognitive FIM change, length of stay, or rehabilitation charges. Injury severity as defined by the Glasgow Coma Scale or intracranial lesions did not predict response to treatment in the DDS group. CONCLUSION: Persons with a DDS achieved smaller functional gains during rehabilitation than peers with SCI. Brain injuries seem to limit functional gains, although the relationship between brain injury severity and functional change is not linear. Prospective studies are needed to identify factors limiting functional gains in rehabilitation and assist in developing specific treatment programs for persons with SCI and brain injury.     

Neurocognitive performance of concussed athletes when symptom free

CONTEXT: Concussed athletes may underreport concussion-related symptoms in order to expedite return to play. Whether neurocognitive impairments persist once concussion-related symptoms resolve has yet to be determined. Reliance on athlete-reported, postconcussion symptoms when making return-to-play decisions may expose athletes to subsequent injury if complete recovery has not occurred. OBJECTIVE: To evaluate the presence of neurocognitive decrements in concussed athletes no longer reporting concussion-related symptoms. DESIGN: Within-groups design. SETTING: University research laboratory. PATIENTS OR OTHER PARTICIPANTS: Twenty-one National Collegiate Athletic Association Division I collegiate athletes (16 men, 5 women). Age = 19.81 +/- 1.25 years, height = 180.95 +/- 10.62 cm, mass = 93.66 +/- 27.60 kg, and previous concussions = 1.76 +/- 2.02. MAIN OUTCOME MEASURE(S): The ImPACT concussion assessment test was administered to concussed athletes at baseline, when symptomatic (within 72 hours of injury), and when asymptomatic. Index scores of verbal memory, visual memory, visual-motor speed, reaction time, and concussion-related symptoms were recorded at each session. The Symptom Assessment Scale was administered daily after injury to establish when the athlete became asymptomatic. RESULTS: When assessed within 72 hours of concussion, 81% of the athletes showed deficits on at least 1 ImPACT variable. At the asymptomatic time point, 38% of the concussed athletes continued to demonstrate neurocognitive impairment on at least 1 ImPACT variable. CONCLUSIONS: Neurocognitive decrements may persist when athletes no longer report concussion-related symptoms. The exclusive use of symptom reports in making a return-to-play decision is not advised. A multifaceted approach to concussion assessment that includes evaluation of a myriad of functions is warranted.