Common Testing: Will it Help With TBI Diagnosis?
Family members, as well as victims, often learn of various tests purportedly administered following traumatic brain injury. Whether the tests were administered in a given case, and whether positive results were found, may not conclusively establish, nor rule out, the existence of brain injury. Nonetheless, brief description of common tests follows:
(a) Glasgow Coma Scale. Often times administered by EMT personnel or paramedics during ambulance transport from the scene of an accident, the Glasgow Coma Scale rates (1) a patient’s ability to open his/her eyes; (2) motor responses to verbal/painful stimulus; and (3) verbal responses.
The Glasgow Coma Scale is also used to rate coma victims, and an individual’s response, or lack thereof, may correlate, especially in severe cases, to cognitive deficits:
Open spontaneously 4
Open to verbal command 3
Open to pain 2
No response 1
Best Motor Response to Verbal Command
Obeys verbal command 6
Best Motor Response to Painful Stimulus
Localizes pain 5
Flexion - withdrawal 4
Flexion - abnormal 3
No response 1
Best Verbal Response Oriented and converses 5
Disoriented and converses 4
Inappropriate words 3
Incomprehensive sounds 2
No response 1
Remember, modern definitions of mild traumatic brain injury allow for a Glasgow Coma Scale score of between 13 to 15. Under the Scale itself, a person generally thought to be alert and oriented would be rated 15, while an unresponsive comatose individual would rate as low as 3.
(b) Sophisticated Imaging. Various sophisticated imaging tests may have been performed diagnostically in the hospital or radiology setting. These include:
(1) Skull x-rays;
(2) CT Scans;
(3)MRI Scans; and
(4) EEG studies.
Generally speaking, this imaging is extremely helpful in cases involving skull fractures as well as hematomas, or hemorrhages which may occur at a variety of locations in the brain.
Common hematomas include extradural hematomas involving a collection of blood outside the dura between the inner-table of the skull and the dura; subdural hematomas involving a collection of blood beneath the dura; and intra-cerebral hematomas involving a collection of blood within the brain itself.
These imaging tests may reveal no positive findings, however, in cases involving “mild” traumatic brain injury. Often times, “mild” to "moderate" traumatic brain injury involves diffuse axonal injury caused by shearing forces. Indeed, axonal degeneration is only seen in the traumatized brain. Yet, its direct visualization is not presently technologically feasible except when a large number of clustered neurons are interrupted. Following death, however, neuro-pathological investigation clearly evidences diffuse axonal hearing.
Recently, the development of new, highly sophisticated imaging techniques have helped the diagnostic process, but are still far from conclusive. Such tests include:
(3)PET scans; and
While not conclusive, these tests have provided validation for neuropsychological assessments, and in the setting of the courtroom may provide the jurors with a picture of the invisible injury.
(c) The Rancho Los Amigas Cognitive Scale.This scale describes levels of function and is used to evaluate the progress of a patient and rehabilitative development. Victims routinely reflect multiple category symptomology.
(i) No Response. No response to pain, touch, sound or sight. (Patient appears to be in deep sleep.)
(ii) Generalized Response. General reflex response to pain.
(iii)Localized Response. Localized response to pain. (Blinks to strong light, turns toward or away from sound, responds to physical discomfort, inconsistent response to commands.
(iv) Confused/Agitated. Alert, very active, aggressive or bizarre behaviors, performs motor activities, but behavior is non-purposeful, extremely short attention span.
(v) Confused/Non-Agitated. Gross attention to environment, highly distractible, requires continual redirection, difficulty learning new tasks, agitated by too much stimulation. May engage in social conversation but with inappropriate verbalization.
(vi) Confused/Appropriate. Inconsistent orientation to time and place, retention span/recent memory impaired, begins to recall past, consistently follows simple directions, goal-directed behavior with assistance.
(vii) Automatic/Appropriate. Performs daily routine in highly familiar environment in a non-confused but automatic robot-like manner. Skills noticeably deteriorate in unfamiliar environment. Lacks realistic planning for own future.
(viii) Purposeful/Appropriate. Patient is alert and oriented and is able to recall and integrate past and recent events.
(d)Neuropsychological Testing. Neuropsychological testing is the sine qua non for modern diagnostics of brain injury. It is proven reliable, accurate, and unlike other testing and evaluative mechanisms which compare patients with the so-called “normal person”, neuropsychological testing evaluates whether a particular patient has himself/herself changed.
The rationale for this distinction is easily enunciated: As an individual grows and matures, s/he develops and utilizes the most efficient pathways in the brain. When traumatic brain injury occurs, many times those pathways are severed or unable to properly transmit or receive information. Methods of learning and behaving are altered. While this individual may still be within the normal population range, s/he would surely be outside their individual “pre-injury” range.
Neuropsychological testing allows competent professionals to reach the conclusion, to a reasonable degree of scientific probability, that organic brain injury has occurred. It further allows the professionals to pinpoint areas of deficit, be they visual/spacial, memory, recall or other. Simply put, neuropsychological testing is the most important testing most “mild” to "moderate" traumatic brain injury patients will undergo.
Neuropsychological assessment is a method of validation, which measures the ability of the nervous system to perform cognitive functions we minimally need to exist. It measures compromise of functions against pre-morbid capabilities. Neuropsychologists are psychologists with specialized training. Neuropsychological assessment is an interface between science and practice.
Current debate in the field of neuropsychology focuses primarily on approach. Many neuropsychologists advocate the quantitative approach utilizing the so-called “non-flex” Halstead-Reitan battery of testing. Still others advocate the “flexible battery” approach. Statistical accuracy is the issue.
Irrespective of approach, neuropsychological assessment is essential to the proper diagnoses and treatment of most victims of traumatic brain injury.