How do you diagnose TBI?
Traumatic brain injury is a complex injury, often resulting in damage to the brain’s connectivity to the white matter of the brain. TBI can be diagnosed through a combination of medical history assessment, a physical and neurological evaluation, and an advanced brain MRI, known as DTI (Diffusion Tensor Imaging).
Other routine imaging modalities like MRI, CT, and SPECT scans are not well-suited identifying the subtleties of traumatic brain injury. Routine brain MRIs can show bleeding in the brain (hemorrhage), blood clots (hematomas), and bruised brain tissue (contusions), and tumors. CT scans can identify bone damage, and are relevant for acute injuries, but often miss TBI. SPECT scans are great at identifying brain metabolic activity, useful for identifying cerebral perfusion disorders and dementia, but require radiation exposure with radioactive isotopes.
Most evidence of TBI is invisible in a routine MRI, that is because routine MRI cannot detect white matter injury. However, the state-of-the-art advanced brain MRI known as DTI can accurately detect and document all the subtle injuries that interfere with the normal functioning of the operating circuits of the brain. DTI can detect white matter tract impairments, making it the best marker for brain injury.
What is DTI?
DTI provides detailed information regarding the integrity of the white matter tracts in the brain, which is not possible with routine, standard imaging. The full analysis of a brain DTI requires specialized software and can take hours to fully process.
We use a proprietary DTI protocol to create tractography, a technique used to visualize the connectivity of white matter tracts in the brain. It measures the diffusion of water molecules in brain tissue to infer the direction and orientation of nerve fiber bundles, or tracts. We can identify any abnormalities or disruptions that may have been caused by TBI. This provides valuable insight into the extent and location of the injury, as there are locations in the brain that when injured correspond to specific, distinct clinical symptoms. We analyze 35 separate brain locations and matches the findings with the patient’s symptoms. See below for examples of injury locations which have been correlated to distinct clinical symptoms:
Click to view lager image
In many instances, our physician will perform fractional anisotropy (FA) measurements to assess the degree of directionality (or anisotropy) of water diffusion within tissues. FA is calculated by considering the magnitude and direction of water diffusion within each voxel. It ranges from 0 to 1, where 0 indicates isotropic or random diffusion (equal diffusion in all directions), and 1 indicates highly anisotropic diffusion (diffusion predominately in one area). Healthy tracts have values closer to 1 (anisotropic) and injured tracts will have values closer to 0 (isotropic), which correlates with decreased efficiency in sending neurological electric signals along the nerves, thus impairing the function that is necessary to accomplish their critical role in the nervous system. These FA values are statistically analyzed and compared against normals.
A serious problem with DTI has been severe under-reading by neuroradiologists. This occurs because a routine brain MRI can be reviewed by a neuroradiologist with no special software in three to seven minutes. However, the full analysis of a brain DTI requires several specialized software and can take hours to fully process.
Can DTI Be Used to Diagnose TBI In Personal Injury Cases?
Personal Injury Cases are varied and encompass a wide range of situations. Some common Personal Injury cases include car accidents, slip and fall accidents, product liability, etc.
Simply put- yes, DTI can be used to diagnose TBI in Personal Injury Cases. DTI is an FDA approved protocol. With more than 20,000 peer-reviewed publications, courts throughout the United States are admitting DTI into evidence and allowing expert testimony based on it. DTI has been ruled admissible under Daubert and similar standards in numerous State and Federal Courts.
At Texas Brain Institute, we rely on the expertise of our neurosurgeon and inventor of DTI, Dr. Aaron G. Filler to interpret your DTI Exam. Our unique post-processing software and protocol, coupled with Dr. Filler’s thorough neurological evaluation and interpretation, results in a report that correlates the symptoms you are experiencing with objective image findings and confirms your brain injury.
If a neuroradiologist does interpret a DTI scan, they can only comment on anatomic findings. They do not see patients and can only warrant a clinical correlation. Dr. Filler is a neurosurgeon and is a treating physician who sees the patient and can comment on clinical correlation between the patient’s reported symptoms at the time of injury symptoms and the findings on a DTI scan.
Our DTI Medical Expert Report includes details on your brain injury, showing multiple brain images depicting injury (tractography) with clinical interpretation of the DTI scans from the details from your evaluation visit, correlation of your symptoms with the images from the DTI scan and provide a diagnosis of traumatic brain injury when clinically indicated. In addition, we provide a 3D rotating video of the fornix, showing impairment to the memory circuit of the brain and measurements of fractional anisotropy (FA) values. The Medical Expert Report includes Causation and Biomechanics of Injury that can help determine causation.
Our physician, a Treating Physician, is an expert in depositions and trial testimony and can also provide Medical Expert opinions.
TBI Workup Process: Evaluation, DTI Exam, and Follow-Up
To familiarize ourselves with your injury, we administer detailed and throughout intake forms which include symptom-based questionnaires and diagrams to fully understand the specifics of your injury. While we realize it is a tedious process to fill out all the questionnaires, diagrams, and intake forms, this is useful, meaningful, and a unique process. These details are necessary for our neurological evaluation. Our neurological exam includes evaluation of thinking, motor function (movement), sensory function, coordination, eye movement, and reflexes.
The evaluation is concluded with a comprehensive assessment and treatment plan that includes recommendations for additional diagnostic tests including DTI, treatments and medications, and follow-up visits. Depending on your physician’s order and your needs, the report can also include an in-depth physical and neurological examination of the patient, review of systems, an overview of the medical records and radiology reports, and detailed cause of injury.
After your DTI Exam and depending on your physician’s orders and your needs, the DTI Exam Report can include details on your brain injury, showing multiple brain images depicting injury (tractography) with clinical interpretation of the DTI scans from the details from your evaluation visit. Our DTI analysis is supplemented with analysis of T1, T2, FLAIR, Routine Brain MRI, and Susceptibility Weighted Imaging (SWI) that can help elucidate previous brain injury, if any, or other brain abnormalities.
What are these different MRI sequences?
We can correlate your symptoms you have been experiencing with the images from the DTI scan and provide a diagnosis of traumatic brain injury when clinically indicated. Additional report options can also include a 3-Dimensional rotating video of the fornix which allows you visualize any injury you have to the memory circuit, measurements of fractional anisotropy (FA) values, and can also include causation and biomechanics of injury. The end of the report details a section that has recommendations for further diagnostic testing and includes a Treatment Plan.
Additional Diagnostic Recommendations
To further investigate any symptoms of Traumatic Brain Injury you may be experiencing, we may recommend the following diagnostic services:
Neuropsychological Testing
With TBI, neuropsychological testing can also assess cognitive functioning after your injury. Typically, this testing includes a battery of testing to evaluate a variety of cognitive ability areas including memory, attention, processing speed, reasoning, judgment, and problem-solving, spatial, and language functions.
Popular tests include the Neuropsychological Assessment Battery with five domain-specific modules: Attention, Language, Memory, Spatial, and Executive Functions. The Wechsler Adult Intelligence Scale 4th Edition (WAIS-IV) measures of learning, memory and processing speed are the neuropsychological domains that are most sensitive to acquired brain impairment in general. Additional neuropsychological testing helpful for TBI can also include ImPACT (measures cognitive function), Apraxia (measures speech function), and AMNART (measures reading comprehension).
We can provide referrals to a team of Board-Certified Neuropsychologists for neuropsychological exams.
Videonystagmography (VNG)
Videonystagmography (VNG) testing is a useful diagnostic to identify vestibular dysfunction – or problems with balance, dizziness, or vertigo. VNG is a technology that does a vestibular assessment which tests the inner ear and central motor functions in the brain by linking it up with certain eye movements. VNG testing uses binocular goggles with infrared cameras that traces bilateral eye movements during visual stimulation (series of lights and moving dots) and changes in position (sitting/laying down). VNG can help determine whether the dizziness experienced is caused by a problem with the inner ear or some other cause.
Volumetrics is used in conjunction with a brain MRI and provides a statistical analysis of the volume of key areas of the brain and compares these volumes to standard norms based on age, sex, and cranial volume. Volumetrics can then generate multiple visual and quantitative reports and provide information about hippocampal asymmetry, general morphology, total intracranial volume, and age-related atrophy. This information helps assess traumatic brain injury and other various neurological conditions and neurodegenerative diseases including Alzheimer’s disease, epilepsy, and multiple sclerosis.
Evoked Potentials
Evoked potentials or evoked-related potential (ERP) measures the electrical activity in certain areas of the brain and spinal cord as a result from specific sensory, cognitive, or motor events. Simply put, it is a non-invasive method to evaluate brain functioning. Evoked potentials test measures in milliseconds the processing speed of the brain in response to sensory or visual stimuli and is useful in TBI to detect changes in processing speed that may be related to cognitive decline.