Diagnosis of Traumatic Brain Injury (TBI) at Texas Brain Institute

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, advanced brain imaging known as DTI, and other diagnostic tests.

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 over 30 separate brain locations. See examples below of injury locations:

An injury in the fornix can impair new memory formation;
An injury in the hippocampal cingulum impairs attention;
An injury in the middle cerebellar peduncle can cause vertigo and balance problems;
An injury of the basal forebrain can cause insomnia;
An injury to the “thinking” part of the brain in the frontal lobe;
An injury to long inter-connecting paths in the brain critical to speech formation, and normal conversation.

Click to view lager image

We also analyze multiple DTI metrics including fractional anisotropy (FA), mean diffusity (MD), apparent diffusion coefficient (ADC), and compare it against age and sex matched normals to quantitatively identify brain abnormalities that occurred after the traumatic injury.

We also include a brain volumetrics study which is a 3D-post processing measure which analyzes key brain structure volumes including the hippocampus, ventricles, and other brain structures. These volumes are compared to standardized norms based on age, sex, and cranial volume and includes multiple visual and quantitative reports.

Our DTI analysis is supplemented with analyses of other MR sequences that can help elucidate previous brain injury, if any, or other brain abnormalities.

What are these different MRI sequences?

T1-weighted imaging is used to assess the anatomy and structure of the brain. It provides information and detailed images of the brain’s different tissues and can help detect abnormalities such as tumors, hemorrhages, and infarctions.
T2-weighted imaging is sensitive to changes in tissue water content and can help identify abnormalities like tumors, infections, edema, and demyelination.
Fluid Attenuated Inversion Recovery (FLAIR) imaging is a specific type of T2-weighted imaging that suppresses the signal from cerebrospinal fluid (CSF). This technique can help visualize abnormal areas of high signal intensity like lesions and inflammation, reducing the interference from CSF.
Susceptibility weighted imaging (SWI) is a technique that is helpful to identify microhemmorhages, microbleeds, and vascular malformations.

A brain DTI requires post-processing with specialized software that can take hours to fully process the images. Interpretation by a radiologist can also take several hours as it is not a routine brain MRI.

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.

Our Comprehensive DTI Medical Expert Report includes details on the patient’s brain injury, showing multiple brain images depicting injury (tractography) with clinical interpretation of the DTI scans, correlation of the symptoms with the images and provides a diagnosis of traumatic brain injury when clinically indicated. In addition, we provide a narrated video showing injury locations, causation and biomechanics of injury.

Our Treating Physicians are experienced in depositions and trial testimony and can also provide Medical Expert opinions.

TBI Workup Process:

Step 1 – Our medical staff will collect registration paperwork and capture the details of on-going symptoms post-trauma.

Step 2- Our neurological exam conducted by a board certified neurosurgeon 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 the physician’s order, 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.

Step 3- If recommended, a patient will undergo a DTI Exam to support the TBI clinical findings during the evaluation. (Note: if the patient has an outside treating physician who has already performed the neurological exam, the patient can be referred just for a DTI Exam and skip Steps 1-2).

Step 4- Upon completion of the neurological evaluation and DTI Exam is completed, the patient will have a follow-up with the neurosurgeon to discuss the DTI findings and personalized Treatment Plan aimed to help ameliorate post-trauma symptoms.

Additional Diagnostic Recommendations

In addition to the DTI Exam, the neurosurgeon may also recommend additional diagnostic testing depending on the patient’s unique clinical presentation.

T1-weighted imaging is used to assess the anatomy and structure of the brain. It provides information and detailed images of the brain’s different tissues and can help detect abnormalities such as tumors, hemorrhages, and infarctions.
T2-weighted imaging is sensitive to changes in tissue water content and can help identify abnormalities like tumors, infections, edema, and demyelination.
Fluid Attenuated Inversion Recovery (FLAIR) imaging is a specific type of T2-weighted imaging that suppresses the signal from cerebrospinal fluid (CSF). This technique can help visualize abnormal areas of high signal intensity like lesions and inflammation, reducing the interference from CSF.
Susceptibility weighted imaging (SWI) is a technique that is helpful to identify microhemmorhages, microbleeds, and vascular malformations.

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 a traumatic 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).

Our physician can also refer patients to 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

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. Our DTI Report will include Volumetrics analysis.

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.