Page 80 - NNS 2014 Program & Abstract Book

addresses different secondary consequences; combining two or more of
these therapies might have a cumulative effect. Therefore, the present
study was designed to determine if any potential synergistic effects exist
between the three approaches following TBI. Male Long-Evans rats
received either a medial frontal cortex contusion injury or a sham
surgery. After injury, animals were assigned to either an EE or standard
environment (SE). Progesterone (10 mg/kg) or a vehicle was adminis-
tered four hours post-surgery and every 12 hours after, for 72 hours.
Half of the animals received *100K eNSCs or media one week post-
injury. Subjects were evaluated on the Barnes maze (BM), Morris water
maze (MWM), and the rotorod (RR). Following the behavioral portion
of the study, the animals were perfused, extracted, and prepared for
histological investigation. The subjects that received all three thera-
peutic approaches performed significantly better than untreated injured
subjects on all three behavioral tests. Stereological analysis revealed
that animals that received eNSC and EE had greater cortical volume and
the animals that received eNSC, PROG, and EE had a greater average
number of cells in the hippocampus than any other treatment. Confocal
immunofluorescence imaging combined with advanced optical clearing
techniques (SeeDB) confirmed that eNSCs survived, migrated from the
transplantation site, and expressed neural characteristics. These data
suggest that a polytherapeutic approach improves recovery. However,
the direct mechanism (independent or in combination) has yet to be
elucidated. Future research should be focused on understanding how
these approaches act together to improve recovery.
Key words
behavioral recovery, embryonic neural stem cells, enriched environ-
ment, polytherapy, progesterone, SeeDB
B1-11
IDENTIFICATION OF MILITARY OCCUPATIONS MOST
LIKELY TO SUFFER MILD TRAUMATIC BRAIN INJURY
(MTBI) AND RELATED SENSORY INJURIES
Lawson, B.D.1, Kass, S.J.2 , Dhillon, K.3 , Cho, T.H.1, Rupert, A.H.1
1U.S. Army Aeromedical Research Laboratory, Fort Rucker, U.S.A.
2University of West Florida, Pensacola, U.S.A.
322nd Special Tactics Squadron, McChord A.F.B., U.S.A.
Military return-to-duty decisions following mTBI are based on med-
ical screening and physical readiness exams. Improving such deci-
sions requires identifying occupations affected by mTBI and
determining whether occupation-critical skills are disrupted.
This epidemiological study identified the occupations most sus-
ceptible to mTBI and related neurosensory problems. The team nar-
rowed down 1,500 medical injury codes to the 25 most relevant to
acceleration/blast injuries across four categories: head/brain, vision,
auditory, vestibular. (These injuries will be presented since they are of
interest to studies of neurotrauma and sensory disorders.) We identi-
fied the top-ten most-affected jobs in each of the 25 codes using data
from the Defense Medical Epidemiology Database. The 250 most-
affected jobs (with the highest rate of injured-versus-total personnel)
were ranked by how frequently they occurred in the top-ten list for
each injury category. These lists were used to identify the overall top-
three most-affected occupations. Finally, we determined the critical
skills needed to perform each job, to identify job-critical deficits.
The most relevant mTBI-related injury codes and categories were
identified. We confirmed that some jobs are more likely to suffer from
these injuries. The top-three most affected occupations were Infantry,
Cavalry Scout, and Artillery. We determined that certain key injuries
would disrupt job-critical performance of these jobs. Additionally, we
found that Special Forces ranked in the top-ten for head/brain injuries
but not any of the sensory injury categories, while Law Enforcement
ranked in the top ten for sensory injuries but not head/brain.
mTBI and associated sensory disorders disproportionately affect
certain military jobs in ways that make it difficult to perform those
jobs. Certain key injuries disrupt abilities that are job-critical (e.g.,
firearms operation) and job-specific (e.g., Artillery gunnery); these
injuries should be the focus of military neurotrauma research intended
to improve rehabilitation and return-to-duty.
Key words
blast injury, fitness-for-duty, mild traumatic brain injury, military
brain injury, return-to-duty
B1-12
PAIRING VAGUS NERVE STIMULATION WITH RE-
HABILITATIVE TRAINING ENHANCES FUNCTIONAL RE-
COVERY AFTER TRAUMATIC BRAIN INJURY
Pruitt, D., Schmid, A., Choua, C., Kim, L., Trieu, J., Abe, C.,
Danaphongse, T., Kilgard, M., Rennaker, R.L.
University of Texas at Dallas, Dallas, USA
Traumatic Brain Injury (TBI) is one of the largest health problems in the
United States, and affects nearly two million people every year. The
effects of TBI, including weakness and loss of coordination, can be
observed years after the initial injury. We have developed a method by
which we drive cortical plasticity through stimulation of the vagus
nerve during rehabilitative therapy to enhance recovery from TBI. We
trained rats to perform the isometric pull task – a task that measures
volitional pull strength. After animals were proficient at the task they
received a controlled cortical impact in the forelimb area of left motor
cortex, and were then randomized into two treatment groups. The first
group of animals received vagus nerve stimulation (VNS) paired with
rehabilitative therapy, while another group received rehabilitative
therapy alone. We found that animals that received VNS paired with
therapy achieved a full recovery of their forelimb strength, while ani-
mals that received only rehabilitative training did not significantly re-
cover forelimb strength. Our findings indicate that pairing VNS with
rehabilitative therapy enhances functional recovery, and further research
is warranted to investigate how VNS may transfer to clinical settings.
Key words
vagus nerve stimulation
B1-13
WITHDRAWN
A-48