The effects of blast-related traumatic brain injury on

Neuropsychological Assessment of Blast Injuries
Chair: Antonio E. Puente, Ph.D.
Presenters: Michael A. Francis, Angie C. Sekely,
Marlee A. Cadwell, John W. Capps, Jacob S. Wisnoski
University of North Carolina Wilmington
UNCW Neuropsychology Lab
Session ID: 4132
The Effects of Blast-Related Traumatic Brain Injury
on Executive Functions in a Large Veteran Sample
Professor Antonio E. Puente
By: Jacob Wisnoski
What Constitutes a TBI in the Military?
–  Mild TBI in military operational settings is defined as an injury to the brain
resulting from an external force and/or acceleration/deceleration mechanism from
an event such as a blast, fall, direct impact, or motor vehicle accident which
causes an alteration in mental status
–  Typically resulting in the temporally related onset of symptoms such as:
•  headache
•  nausea
•  vomiting
•  dizziness/balance problems
•  fatigue
•  insomnia/sleep disturbances
•  drowsiness
•  sensitivity to light/ noise
•  blurred vision
•  difficulty remembering
•  difficulty concentrating
–  (Defense and Veterans Brain Injury Center , 2006)
Blast-Related TBIs Today (cont.)
•  T h e i n c r e a s e d u s e o f
improvised explosive devices
and advances in medicine and
protective equipment have
contributed to this high
prevalence of TBI (McCrea
et al., 2011; Taber et al.,
2007).
•  While more U.S. warfighters
are surviving blast injuries,
these same individuals are
now dealing with a host of
neuropsychological problems
Blast-Related TBIs Today
•  Since 2000, the Department of Defense estimates that 294,172 new
diagnoses of TBI have occurred.
What are Executive Functions?
•  While there is no singularly agreed upon definition of the term ‘executive
function’ (EF), it is often thought as an umbrella term which is thought to include
the following variables:
– 
– 
– 
– 
– 
– 
– 
– 
– 
– 
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planning
cognitive flexibility
inhibition of behavior
creating goals/goal-oriented behavior
problem solving
verbal fluency/reasoning
adapting to novel situations and stimuli
decision-making
multitasking
switching between tasks
filtering out interference
•  (Banich, 2009; Chan, Shum, Toulopoulou, & Chen, 2008; Gilbert & Burgess, 2008;
Jurado & Rosselli, 2007; Lezak, 1982)
The Effects of TBI on EF: A Historical
Example
•  “He is fitful, irreverent,
indulging at times in the
grossest profanity…
impatient of restraint or
advice when it conflicts with
his desires…devising many
plans of future operation,
which are no sooner
arranged than they are
abandoned in turn for others
appearing more
feasible.” (Harlow, 1868, p.
340-341)
The Purpose of the Present Study
•  The purpose of the present study is to understand
the effects of blast-related TBIs have on EF
performance.
•  Specific attention will be paid to the role that
mechanism of injury plays on EF performance.
Hypothesis
•  Research literature suggest that mechanism of injury
should have no significant effect on EF performance
(Belanger, Kretzmer, Yoash-Gantz, Pickett, &
Tupler, 2009).
–  However, these data use a relatively small n (102)
compared to the present study.
•  Therefore, the following is predicted:
–  HO: Blast-related TBI = Non blast-related TBI = No TBI
–  H1: Blast-related TBI < Non blast-related TBI < No TBI
The Present Study
Methods: Participants
•  The present study will analyze data from 568 Marines
and sailors from a pre-existing dataset.
•  The following exclusion criteria were be applied to
these data:
–  Unspecified demographic information
–  Sub-optimal performance (score of <45) on the Test of
Memory Malingering
–  Not completing all four measures of executive function
–  Unspecified mechanism of injury
Methods: Materials
•  The Hayling and Brixton Tests (Burgess & Shallice,
1997)
–  EFs measured: initiation speed, response suppression, and rule
attainment
•  The Controlled Oral Word Association (COWA) Test
–  “Evaluates the spontaneous production of words under restricted
search conditions (verbal association fluency).” (Strauss,
Sherman, & Spreen, 2006, p.499)
•  The Trail Making Test (Reitan & Wolfson, 1993)
–  EFs measured: attention, speed, and mental flexibility
•  The Stroop Test (Stroop, 1935)
–  EFs measured: goal-oriented behavior and behavior inhibition
Methods: Procedures
•  The present will consist of three groups:
–  Those with a blast-related TBI (M1), n= 439
–  Those with a non blast-related TBI (M2), n= 107
–  Those with no TBI (M3), n= 22
•  Data will be taken from the original Excel file and
input into IBM SPSS for analysis.
•  Three factor one-way ANOVAs will be conducted
to compare the three groups.
•  A Tukey’s Post-Hoc analysis will also be conducted
to correct for Type II error inflation.
Results: Demographics
Age: 25.85 years (5.6 SD)
Years of Education: 12.5 (1.1 SD)
Gender: 563 Males, 5 Females
Ethnicity:
Caucasian (486)
African American (28)
Hispanic (38)
Asian American (2)
American Indian (5)
Pacific Islander (2)
Other (7)
Results: Omnibus
•  Overall, none of the ANOVAs conducted for any
of the EF tests yielded statistically significant
results. Thus, we fail to reject the null
hypothesis.
•  Further, none of the post-hoc analyses yielded
any significant differences between any pairs
within the three groups for the EF measures.
Results: Hayling Brixton
•  F (2, 565)= .
884, p= .414
Results: Hayling Brixton
•  F (2,565)=
1.428, p
= .241
Results: Hayling Brixton
•  F (2,
565)= .
424, p = .
655
Results: Hayling Brixton
•  F (2,565) = .
501, p= .606
Results: Stroop
•  F (2,565)
= .264,
p= .768
Results: Stroop
•  F
(2,565)
= 1.402,
p= .247
Results: COWAT
•  F (2,565)
= 1.710,
p= .182
Results: COWAT
•  F (2,565) = .
993, p= .371
Results: Trails A
•  F (2,565)
= 1.417,
p= .243
Results: Trails B
•  F (2,565) =
1.873,
p= .155
Discussion
•  The results of this study support the
findings originally discussed in
Belanger et. al (2009).
•  These findings suggest that
mechanism of injury may not play a
particularly significant role in EF
outcomes of veterans returning from
combat.
Discussion: Limitations
•  The procedures may have been too
exclusionary and data from the rest of the
data set should be added back in for
additional analyses.
•  Despite a more conservative post-hoc
analysis, Type II error may have affected
results due the sheer number of analyses
conducted.
•  EF measures may be affecting one another
and therefore, there may be latent effects on
EF performance that was not previously
considered.
Discussion: Future Directions
•  These data are the beginning of a thesis
project that will be delving deeper into the
effect of bTBIs on EFs. Some of the upcoming
analyses include:
–  Multiple regression and ANOVA analyses looking at
how EF measures affect one another.
–  Moderation/mediation analyses of other variables
(both continuous and categorical) and how they
affect EF performance.
–  A latent variable analyses using structure equation
modeling to investigate if there is a common factor
EF being measured between the four tests.
Questions?
References
• 
Banich, M.T. (2009) Executive function: The search for an integrated account. Current Direction in Psychological Science, 18 (2), 89-94
• 
Belanger, H.G., Kretzmer, T., Yoash-Gantz, R., Pickett, T., & Tupler, L.A. (2009) Cognitive sequelae of blast-related versus other mechanisms of brain trauma. Journal of the
International Neuropsychological Society, 15, 1-8
• 
Burgess, P.W. & Shallice, T. (1997) The hayling and brixton tests. Thurston, Suffolk: Thames Valley Test Company
• 
Chan, R.C.K., Shum, D., Toulopoulou, T., & Chen, E.Y.H. (2008) Assessment of executive functions: Review of instruments and identification of critical issues. Archives of
Clinical Neuropsychology, 23, 201-216
• 
DVBIC (2006) Defense and veterans brain injury center working group on the acute management of mild traumatic brain injury in military operational settings. Washington, DC:
Defense and Veterans Brain Injury Center.
• 
Gilbert, S. J. & Burgess, P. W. (2008) Executive function. Current Biology, 18, R110–R114
• 
Harlow, J.M. (1868) Recovery from the passage of an iron bar through the head. Bulletin of the Massachusetts Medical Society, 2, 327-347
• 
Jones, E., Fear, N.T., & Wessely, S. (2007) Shell shock and mild traumatic brain injury: A historical perspective. The American Journal of Psychiatry, 164, 1641-1645
• 
Jurado, M.B. & Rosselli, M. (2007) The elusive nature of executive functions: A review of our current understanding. Neuropsychological Review, 17 (3), 213-233
• 
Lezak, M.D. (1982) The problem of assessing executive functions. International Journal of Psychology, 17, 281-297
• 
McCrea, M., Pliskin, N., Barth, J., Cox, D., Fink, J., French, L., Hammeke, T., Hess, D., Hopewell, A., Orme, D., Powell, M., Ruff, R., Schrock, B., Terryberry-Spohr, L.,
Vanderploeg, R., & Yoash-Gantz, R. (2008) Official position of the military TBI task force on the role of neuropsychology and rehabilitation psychology in the evaluation,
management, and research of military veterans with traumatic brain injury. The Clinical Neuropsychologist, 22 (1), 10-26
• 
Reitan, R. M., & Wolfson, D. (1993). The Halstead-Reitan Neuropsychologicnl Test Battery: Theory and clinical interpretation (2nd ed.). Tucson, AZ: Neuropsychology Press.
• 
Strauss, E., Sherman, E.M.S., & Spreen, O. (2006) A compendium of neuropsychological tests: Administration, norms, and commentary. (3rd ed.) New York: Oxford University
Press
• 
Stroop, J.R. (1935) Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 18, 643-662
• 
Taber, K.H., Warden, D.L., & Hurley, R.A. (2006) Blast-related traumatic brain injury: What is known? The Journal of Neuropsychiatry and Clinical Neurosciences, 18 (2),
141-145
UNCW Neuropsychology Lab
601 S College Road
Wilmington, NC 28403
[email protected]

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