NEUROCOGNITIVE ASSESSMENT & TREATMENT
More than 1.7 million people each year in the United States sustain a traumatic brain injury (TBI).
Seventy - five to 80% of these cases are diagnosed with a mild traumatic brain injury (mTBI) with moderately to severely impaired cases making up the remaining 20%.
More importantly 15 to 30 % of mTBI cases don’t fully recover. They are left with serious and permanent residual neurocognitive deficits and related adverse Psychological Symptoms.
These adverse symptoms are based on post traumatic vascular contusions and diffuse axonal injuries. These are microscopic in nature with no visible structural changes to the brain.
With no visible (macroscopic) structural changes to the brain, CT and MRI Diagnostic Technologies are unable to identify or quantify these microscopic cerebral injuries.
Diffusion Tensor Imaging (DTI) however, has the proven capability for identifying and quantifying the magnitude and location of these microscopic vascular contusions and diffuse axonal injuries.
As such, DTI has been able to document, these microscopic injuries that underlie mTBI. [1]*
This is short of including the additional neuro-metabolic factors that can increase the risk of progressive impairment over time.
As well, Concurrent Neuropsych Testing with DTI, obtains virtually the same results.
This is in terms of the location and magnitude of microscopic cerebral injuries (inferred from the location and magnitude of impaired higher cortical functions indicated in neuropsych testing). See reference in the box immediately below for examples.
*[1] Diffusion Tensor Imaging identifies diffuse axonal injuries when neuronal membrane permeability is compromised by acceleration, deceleration and rotational forces, disturbing Na+ influx and K+ efflux including the sodium pump. This results in the diffusion of water molecules away from their normal; linear alignment down the length of the neuronal membrane indicating neuronal death (e.g. Retraction balls)..
On this basis, neuropsych testing can be considered as a Diagnostic Technology that exceeds the accuracy of CT and MRI Diagnostic Computer Technologies for identifying & quantifying mTBI.
In a manner of speaking, validated neuropsych testing accurately predicts DTI results (e.g., magnitude and location of vascular contusions & diffuse axonal injuries).
This is compared to CT & MRI having no capability in this regard, and with no correlations with Neuropsych Test Results.
This is reflected in the operating characteristics of the Halstead Reitan Neuropsychological Test Battery listed below demonstrating significantly increased accuracy for identifying cases of mTBI relative to CT & MRI.
Through a lot of research and investigation Reitan Labs have established that a Total Brain Injury Impairment Index Score of 26 has the proven capability of identifying 92 mild brain injured individuals out of 100, mistakenly missing only 8 mild brain injury cases. This is a proven Sensitivity of 92% with a False Negative Error rate of 8%
The Total Brain Injury Impairment Index Score of 26 also has the proven capability of identifying 90 no-brain injury cases out of 100, missing only 10 cases by mistakenly identifying them as having a mild brain injury when they don’t. This is a proven Specificity of 90% with a False Positive Error rate of 10%
The Total Brain Injury Impairment Index Score of 26 also has the proven capability for identifying 94% of mild brain injury cases out of a group of brain injury cases and no-brain injury cases in the same proportion that exists in the normal population. This is a proven Positive Predictive Value of 94% with a False Negative Error Rate of 6%
The Total Brain Injury Impairment Index Score of 26 also has the proven capability of identifying 86% of no-brain injury cases out of a group of mild brain injury cases and no-brain injury cases in the same proportion that exists in the normal population. This is a proven Negative Predictive Value of 86% with a False Positive Error Rate of 14%.
As such, The Halstead Reitan Neuropsychological Test Battery (employed by NA&T and recommended in AMA Guide 6, Table 14-III), can qualify as a medically supported Diagnostic Technology capable of identifying and quantifying microscopic cerebral injuries.
As required by the SABS, vascular contusions and diffuse axonal injuries are physical entities underlying mTBI (equivalent to CT & MRI macroscopic intracranial injuries required in Criterion 4).
Accordingly, the HRB is an important Diagnostic Technology for identifying serious and permanent intracranial injuries that underlie neurocognitive impairment following mTBI.
This has been acknowledged in the Official Periodical of the American Board of Independent Medical Examiners “Disability Medicine” Vol. 2, No. 1, Jan. to Mar. 2002. Pages 4 to 10.
Accordingly, NA&T has the capability of identifying and quantifying mTBI necessary to distinguish between individuals with and without cerebral compromise (mTBI), when assessing Catastrophic Impairment.
Neuropsychological Test Batteries without proven and published operating characteristics, (e.g., Sensitivity, Specificity, Positive Predictive Value, and Negative Predictive Value) have no proven capability for identifying or quantifying that 15 to 30 % of unrecovered mTBI cases. This excludes 80% of all individuals with TBI.
Dr. John H. Gilman PhD., C. Psych.