Page 57 - NNS 2014 Program & Abstract Book

through immunohistochemical (IHC) analysis of myelin basic pro-
tein (MBP) and neurofilament (NF200) and observed a down-
regulation of MBP and NF200 as early as 2 hours post-injury. Our
results demonstrate proof-of-concept of optical biomarker identifi-
cation after mTBI and suggest PS-OCT as a promising diagnostic
method for detecting changes in tissue dynamics in the clinical
setting.
Key words
meylin, mild traumatic brain injury, neurofilament, optical coherence
tomography
A2-02
WHITE MATTER INJURY IN A RODENT MODEL OF BLAST
INJURY
Wong, Y.C.1, Ng, K.C.1, Kan, E.M.1, Tan, M.H.1, Verma, S.K.2,
Prakesh, B.K.2, Saramani, S.2, Velan, S.S.2, Lu, J.1
1DSO National Laboratories, Singapore, Singapore
2Agency for Science Technology and Research, Singapore, Singapore
Exposure to explosive blast devices accounts for almost two thirds of
the casualties substained by the US military in Iraqi and Afghanistan.
The mechanism of primary blast injury to the central nervous system
is less well characterized. This study aims to investigate the effect of a
low level blast exposure on white matter injury in an experimental
rodent model of blast exposure.
Briefly, male Sprague Dawley rats were exposed to a single blast at
*180kPa. The animal subjects were evaluated on the 5-choice serial
reaction time and subjected to longitudinal diffuse tensor imaging
(DTI). In addition, TUNEL assay for apoptotic cells and black gold
myelin immunostaining was carried out on brain slices at - 3.8 mm
bregma at stipulated post-blast sacrifice timepoints (Day 1, 3, 5, 14, 28
post-blast).
There was an increase in TUNEL-positive apoptotic cells in the
corpus callosum from 24 h to 1 month post-injury after blast. Fur-
thermore, fractional anisotropy (FA) of the corpus callosum using DTI
was found to be suppressed after low blast injury with recovery at 28
days. This suggests that the white fibre tracts are affected transiently
after low blast injury. Furthermore, demyelination was also observed
at the thalamus region using the Black-Gold staining. This disrupted
myelination of the thalamus is corresponded by a transient decrease in
substained attention in the 5CSRTT test from 3–6 days post-injury.
Further investigations into the thalamus post-blast can be made to
evaluate the role of the thalamus in funcational outcome post-blast.
Key words
blast injury, diffuse tensor imaging, fractional anisotropy, rodent
model
A2-03
USING PET TO DETECT CHANGES IN BRAIN BLOOD
FLOW AND METABOLISM AFTER CONTROLLED COR-
TICAL IMPACT IN MICE
Yoder, K.K., Liu, N., Riley, A.A., McCarthy, B.P., Persohn, S.,
West, J.D., Dzemidzic, M., Territo, P., Xu, X.
Indiana University School of Medicine, Indianapolis, USA
The use of PET imaging for translational research with rodent models
of traumatic brain injury (TBI) is still a nascent field. To date, no PET
studies have been conducted with the controlled cortical impact (CCI)
model of TBI. We sought to determine the feasibility of [64Cu]PTSM
and [18F]FDG PET for detecting changes in blood flow and metabo-
lism in the CCI model in mice. Twenty-four male C57BL/6 mice
(22.2 – 1.59 g) received either a CCI to the left parietal cortex (n = 14)
or a sham surgery (SHM; craniotomy but no impact; n = 10). Each
animal received one anatomic MRI and one PET scan one week after
surgery. Five SHM and 7 CCI animals received [18 F]FDG (glucose
utilization); 5 SHM and 7 CCI received [64Cu]PTSM (blood flow).
Tracers were administered via tail vein while animals were awake and
lightly restrained. Average doses for [18F]FDG and [64Cu]PTSM were
0.28 – 0.02 and 0.12 – 0.02 mCi, respectively. Average standardized
uptake values (SUV) data were extracted from regions of interest
(ROIs) that included bilateral parietal cortex, hippocampus, thalamus,
and caudate. Paired t-tests were used for within-group comparisons
of SUV between left and right ROIs. In TBI mice, [64Cu]PTSM SUV
was significantly lower in left parietal cortex (CCI lesion) relative to
the non-lesioned side ( - 13%; p < 0.005). No craniotomy effects
were detected in SHM. In TBI mice, [18F]FDG SUV was signifi-
cantly lower in the left parietal cortex ( - 14%, p < 0.02) and left
hippocampus ( - 12%, p < 0.03) relative to the right side. In SHM
mice, [18F]FDG SUV was lower in the left hippocampus ( - 9%,
p < 0.02); higher SUV was found in left thalamus (12%; p < 0.03).
Standard deviations from the [18 F]FDG SHM group were twice that
of the TBI group, indicating that larger sample sizes ( > 5) are needed
to reduce variance. Both [64Cu]PTSM and [ 18F]FDG show promise
for monitoring acute and longitudinal effects of CCI on brain me-
tabolism and blood flow.
Key words
blood flow, controlled cortical impact, glucose metabolism, mouse,
positron emission tomography
A2-04
ACUTE AND 1 YEAR FOLLOW-UP MRI OF TRAUMATIC
HEMORRHAGIC BRAIN LESIONS AFTER MODERATE/
SEVERE PEDIATRIC TBI
Tong, K.A., Al-Ramadhani, R., Rundquist, M., Holshouser, B.A.,
Ghosh, N., Ashwal, S.
Loma Linda University Medical Center, Loma Linda, USA
We present findings on acute and 1 year follow-up of hemorrhagic
brain injury in pediatric TBI patients, studied with MRI susceptibility-
weighted imaging (SWI).
Pediatric patients (4 to 18 y), with moderate/severe TBI (GCS
score < 13 or hemorrhagic intracranial injury on CT) underwent MRI
(3T), acutely (6–17 d), and at 1 year post injury. Number/volume of
hemorrhagic lesions were compared with initial GCS and at the 2 time
points.
Fifty-two children (38M/14F, mean age 12.3 years), were injured in
vehicle/bike accidents (31), falls (12), sports-related injuries (7), or
assaulted (1). Lesions numbered from 0–977/patient, and hemorrhagic
volume ranged from 0–135 cc/patient. Extent of hemorrhages nega-
tively correlated with initial GCS. Significant differences in hemor-
rhages were seen between GCS groups. Ten patients (GCS of 6–15)
had no lesions, whereas 13/18 patients with GCS of 15 had lesions.
Most lesions (80% of total number, 87% of total volume) occurred in
the cerebral cortex and subcortical white matter. Frontal lobe lesions
were most frequent (34% of total number, 65% of total volume),
followed by temporal lobe lesions (29% of total number, 17% of total
volume). Only 1 patient (with minimal lesions) showed 100% reso-
lution at 1 year. In the remaining patients, the degree of reduction in
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