Blast Injury Outcome Study in Armed Forces Personnel

1. Aim of this presentation
The team:
Major David Baxter
BIOSAP: Blast Injury Outcome Study in Dr David Sharp (IC)
Armed forces Personnel
Dr Tony Goldstone (IC)
Dr Richard Greenwood (UCL)
Mr Neil Kitchen (UCL)
Location:
Computional, Clinical & Cognitive Neuroimaging Lab (C3NL) –
The Hammersmith Hospital (IC)
The Robert Steiner MRI Center – The Hammersmith Hospital (IC)
Major David Baxter RAMC
SSNP Conference Defence Medical Rehabilitation Centre - Headley Court
September 2012
Blast wave physics Blast wave physics
Primary, secondary, tertiary and quaternary injury Background
Background:
Civilian TBI – outcome is poorly understood. Because pathophysiology is
not well understood.
This is true (more so) for blast. Nevertheless…
Cernak et al Traumatic brain injury: an overview of pathobiology with emphasis on military populations. Journal of
Cerebral Blood Flow & Metabolism (2010) 30, 255–266
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2. Improvements in diagnosis of non-penetrating brain
injury Focal injury and white matter damage
Contusion location Diffuse axonal injury
Conventional MRI; T1, T2, Flair DTI, SWI, Gradient Echo
imaging
i.e. xray and CT
Grade 2: lesions in corpus callosum
Grade 3: lesions also in brainstem
Adams et al ‘85
Hypothesis and Impact What is the BIOSAP project and what are its aims
Aim:
1. To characterize the neuropsychological and endocrine
consequences of blast traumatic brain injury.
ADMEM database
2. To compare this to civilian traumatic brain injury.
Imaging Imaging
DMRC Headley
Court studies studies
Hypothesis:
Endocrine Endocrine
1. Blast causes a specific pattern of white matter damage, B’ham hospitals assessment assessment
that can be assessed using MRI. Blas
t TBI Psychologica Psychologica
l assessment l assessment
Clinician referral
Impact:
1. Gives the capability of screening blast injured soldiers
2. Provide evidence about the mechanism of blast injury.
MRI assessment
Criteria
Inclusion Exclusion Structural MRI
• Moderate to severe traumatic brain injury • Cognitive impairment such that the subject will
• GCS <14 be unable to cooperate.
• LOC >30mins T1
• PTA >24hrs • Significant language or visuo-spatial T2 Flair
impairments..
T2 FFE – Gradient Echo
• History of Blast injury.
• Penetrating head injury or neurosurgery. Diffusion tensor imaging - DTI
• Persistent cognitive impairment. Susceptibility Weighted Imaging – SWI
• Overt bleeding visible on CT (excluding the
presence of microbleeds – a marker of diffuse
• No significant premorbid neurological or axonal injury).
psychiatric illness. Functional MRI
• Able to give informed consent.
• Ability to perform the scanning paradigm.
• Clinically stable.
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3. Neuropsychological & Psychiatric Test Battery Endocrine Assessment
Cognitive: (developed with Professor Jane Powell - Goldsmiths) • Traumatic brain injury produces significant dysfunction in the
hypothalamic-pituitary axis in a significant number of patients
Intellectual function - WASI similarities, WASI Matrix reasoning [Schneider et al., 2007]
Executive function - Trail Making Test, Inhibition/switching, Letter fluency • Impairments persisting in 15-50% of patients. E.g. severe growth
hormone deficiency is seen in 10-20% of patients following traumatic
Memory function and learning - People Test immediate recall brain injury.
Information processing speed - Colour naming (s), Word reading (s)
• Limits brain recovery.
Psychiatric:
• Important therapeutic opportunity.
Including: AGHDA, Beck Depression Inventory, Epworth Sleepiness, Nottingham
Health Profile, SF-36
PTSD
Mood disturbance
Anxiety
Case 1: History
Case 1: Structural imaging findings
28yo male T2Flair Gradient Echo
Top cover
Wearing Helmet and eye protection
50 Kg IED.
Multiple fractures. Superficial lacerations. Left sided pneumothorax.
Initial GCS 12/15
2 weeks of retrograde amnesia
6 weeks of post-traumatic amnesia
On neuropsychological assessment;
Impaired executive function, memory and processing speed
Case 1: Outcome Case 2: History
27yo. Male
Returned to work in a limited capacity but struggling… Passenger in vehicle
Wearing body armour and Helmet
IED of unknown size
Multiple fractures and lacerations. Left sided pneumothorax.
Initial GCS 13/15
1 day retrograde amnesia
4 days post traumatic amnesia
On neuropsychological assessment;
Impaired memory
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4. Case 2: Outcome
Case 2: Structural imaging findings
T2Flair Gradient Echo
Currently studying for Msc.
Case summary Results
Conventional imaging
• 20 blast injured soldiers
1. Gradient echo imaging is more sensitive than standard T1 and Flair to
the changes associated with diffuse axonal injury
• 40 age matched civilians with moderate
to severe TBI
2. But…the presence of microbleeds can still be associated with very
variable clinical outcome. • 40 uninjured civilian controls
Study participant demograhics Diffusion tensor imaging
Controls Military Civilian Difference Cortex
Age 30.6 yrs (SD 29.4 yrs (SD 30.3 yrs (SD No
6.7) 5.8) 7.6) difference
Time since n/a 14.6 mnths 12 mnths No
injury (SD 5.9) (SD 12.7) difference White matter - TBI
Contusion n/a 9 (45%) 10 (50%) No
difference
Microbleeds n/a 5 (25%) 5 (25%) No
difference Low fractional anisotropy
Mori et al Neur
& High mean diffusivity
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5. DTI Results TBSS Pattern analysis
Pattern analysis results Now focus on the bTBI group
Endocrine assessment results Region of Interest analysis
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6. Neuropsychological and QoL assessment results Summary
1. MRI changes following blast traumatic brain injury are associated with,
neuropsychological, neuropsychiatric and endocrine changes.
2. Blast traumatic brain injury produces a hetreogenous white matter
injury pattern, however some regions appear to particularly vulnerable
to injury from blast.
3. We will attempt to use this research to identify patients who will go on
to have a poor clinical outcome, and provide information about the
mechanism of blast.
BIOSAP
Thanks to;
DPMD Prof M Midwinter
Dr A K Samra
Mjr C Lethbridge
DMRC Col Etherington
Wng Cmdr A Bennett
Kit Malia
Doreen Rowland
Ronel Terblanche
Alison Lutte-Elliott
Goldsmiths Prof Jane Powell
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