94 / 198
analyzed using a generalized estimating equation. Statistical analysis
of the response categories revealed that time affected the VFH re-
sponse (Wald Chi-Square
=
11.146, p
=
0.004). Further the 5 body
locations assessed behaved differently over time (time*location ef-
fect; Wald Chi-Square
=
2.197*10
13
, p
<
0.0001). Post-hoc analysis
indicated that the animals were particularly responsive to stimulations
at the thorax at the intermediate time-point (Chi-Square
=
9.750,
p
=
0.008). Overall, these data suggest differences across sites in re-
sponsivity, and that changes in responses were distinct at the thorax in
the intermediate post-op period. The VFH testing provided a means of
evaluating potential changes in sensation as reflected by tactile sen-
sitivity. The long term goal of these efforts is to pave the way for
improved cross-species sensory testing, and accelerate translational
research.
Funding: VA, NIH (NS042291, NS088475, NS067092, NS079030),
Wings for Life and Craig H. Neilsen.
Keywords: Spinal cord injury, Sensory system, von Frey hair,
translational research
B5-03
OUTPATIENT CARE REFERRAL AT 3-MONTHS IS ASSO-
CIATED WITH 6-MONTH SYMPTOMATOLOGY FOLLOW-
ING MILD TRAUMATIC BRAIN INJURY
Sourabh Sharma
1
, John Yue
1
, Ethan Winkler
1
, Caitlin Robinson
1
,
Jonathan Ratcliff
2
, Opeolu Adeoye
2
, Adam Ferguson
1
, Jonathan
Rick
1
, Frederick Korley
3
, Mary Vassar
1
, Esther Yuh
1
, Pratik
Mukherjee
1
, Thomas McAllister
4
, Ramon Diaz-Arrastia
5
, Alex
Valadka
6
, Wayne Gordon
7
, David Okonkwo
8
, Geoffrey Manley
1
1
UCSF, Neurosurgery, San Francisco, USA
2
Univ. Cincinnati, Emergency Medicine, Cincinnati, USA
3
Johns Hopkins Univ., Emergency Medicine, Baltimore, USA
4
Univ. Indiana, Psychiatry, Indiana, USA
5
USUHS, Neurology, Bethesda, USA
6
Seton Brain & Spine Institute, Neurosurgery, Austin, USA
7
Mount Sinai Hospital, Rehabilitation, New York, USA
8
Univ. Pittsburgh, Neurology, Bethesda, USA
Current guidelines for mild traumatic brain injury (mTBI) are not
clearly defined, and the relationship between referral of care and
chronic symptoms after mTBI needs better characterization. We
utilized the Transforming Research and Clinical Knowledge in TBI
(TRACK-TBI) Pilot study to investigate whether referral of care
influences 6-month functional outcome on the Glasgow Outcome
Scale-Extended (GOSE) and post-concussive syndrome (PCS) do-
mains on the Acute Concussion Evaluation (ACE). Of 168 mTBI
patients (age 45
–
18 years, 69% male), 22% received referral by
3-months post-injury. Education years (OR 0.85, 95% CI [0.76–
0.96],
p
=
0.011), psychiatric history (2.73, [1.30–5.75],
p
=
0.008)
and GCS
<
15 (2.71, [1.17–6.25],
p
=
0.020) emerged as predictors of
6-month functional disability after adjusting for age, CT pathology
and 3-month referral. Referral was not a predictor of GOSE. Re-
garding PCS, patients with 3-month referral reported a higher inci-
dence of 6-month cognitive and physical symptoms (78%/58%,
p
=
0.024; 89%/70%,
p
=
0.020, respectively). On multivariable re-
gression, 3-month referral (OR 3.15, [1.25–7.92],
p
=
0.015), less
education years and psychiatric history predicted the presence of 6-
month cognitive symptoms, while referral (OR 3.31, [1.05–10.38],
p
=
0.040) and psychiatric history predicted physical symptoms.
Education, psychiatric history, GCS
<
15 and CT were adjusted
predictors of sleep symptoms, and only psychiatric history predicted
emotional symptoms. Hence, patients seeking subacute referral post-
mTBI may indicate a population at risk for residual cognitive and
physical PCS symptomatology. More granular information regarding
the incidence of outpatient services should be collected to better
triage and allocate resources to this population.
Keywords: Clinical Trial, Human Studies, Mild TBI, Outcomes,
Outpatient Care
B6 Poster Session IV - Group B: Imaging
B6-01
IS DTI A NEUROIMAGING MARKER FOR MTBI WITH
LOSS OF CONSCIOUSNESS?
Harvey Levin
1
, Lisa Wilde
1
, Brian Biekman
1
, Brian Biekman
1
, Xiaoqi
Li
1
, Khader Hasan
3
, Ponnada Narayana
3
, Emmy Miller
4
, Stephen
McCauley
1
, Jill Hunter
5
, James McCarthy
2
, Claudia Robertson
4
1
Baylor College of Medicine, Dept of PM&R, Houston, USA
2
University of Texas Health Science Center at Houston, Dept of
Emergency Medicine, Houston, USA
3
University of Texas Health Science Center at Houston, Radiology,
Houston, USA
4
Baylor College of Medicine, Neurosurgery, Houston, USA
5
Baylor College of Medicine, Radiology, Houston, USA
Objectives:
To study whether loss of consciousness (LOC) in mTBI
is associated with injury to white matter (WM) tracts in patients with
normal CT scans.
Methods:
Seventy-nine patients with mTBI and 64 orthopedic in-
jury (OI) controls had diffusion tensor imaging (DTI) at the initial
study visit (mTBI mean
=
25.9 hrs post-injury, SD
=
12.3 hrs; OI
mean
=
29.8 hrs, SD13.7) and 3 months (mTBI mean
=
94.4 days,
SD
=
8.7; OI mean
=
96.7 days, SD
=
9.0) post-injury. LOC was de-
termined from EMS records, witnesses, and self-report. DTI was
performed on a 3T Philips scanner using a 32 direction protocol.
Fractional anisotropy (FA) and mean diffusivity (MD) were measured
using tractography for the uncinate fasciculi (UF) and inferior frontal
occipital fasciculi (IFOF).
Results:
Forty-nine (62.03%) mTBI patients had LOC (mean
=
3.84 min, SD
=
4.8), whereas 30 (37.97%) did not. On the initial DTI,
mTBI patients with LOC had significantly higher MD (right
UF
=
.773, left UF
=
.782, right IFOF
=
.764, left IFOF
=
.783) than OI
patients (right UF
=
.761, left UF
=
.770, right IFOF
=
.755, left
IFOF
=
.772), p
<
0.05 for all four tracts, effect sizes, Cohen’s d were
0.54, 0.48, 0.44, and 0.45, respectively). However, MD in the mTBI
subgroup without LOC (right UF
=
.761, left UF
=
.778, right IFOF
=
.762, left IFOF
=
.779) did not differ from the OI group and effect
sizes were 0.22, 0.08, 0.13, and 0.30 respectively). LOC in mTBI
group had a positive relation to MD in right UF (slope
=
0.002,
p
<
0.0001) and left UF (slope
=
0.0016, p
=
0.0034) and the slope did
not significantly change between initial and 3 month occasions. LOC
duration was also significantly related to MD in right IFOF (slope
=
0.0012, p
=
0.0243) and left IFOF (slope
=
0.0011, p
=
0.0118). LOC
had no significant relation to FA.
Conclusion:
LOC in mTBI patients with normal CT is related to
diffusivity measured
&
24 hours post-injury in WM tracts connecting
prefrontal with temporal and posterior cortical regions. Diffusivity
at
&
24 hours post- mTBI with LOC is greater than in OI patients,
whereas MD after mTBI without LOC does not differ from OI. High
MD may be useful as a biomarker for mTBI with brief LOC and
normal CT.
Keywords: mTBI, DTI, Consciousness, Subacute
A-58