It is my opinion that Drug Recognition Evaluator exams are examinations conducted by a lay person without the appropriate training, experience, skills or licensing necessary to conduct such exams. Drug Recognition Evaluators sometimes call themselves Drug Recognition Experts. However, it is my opinion that they do not have any expertise in this area. The term Drug Recognition Expert or DRE is a misnomer. These individuals are lay people without the required education, training or experience of an “expert”.
Part of the evaluation utilized in these cases includes psychophysical tests and the Standardized Field Sobriety Tests of the National Highway Traffic Administration. However, the Standardized Field Sobriety Tests by the National Highway Traffic Safety Administration has only been studied with respect to alcohol intoxication, not drug intoxication. Significantly, there is considerable disagreement regarding these tests without alcohol intoxication. There is very little in the literature regarding these tests and drug intoxication.
These evaluations can only be described as typical “junk science”. They are merely net opinions. A conclusion is based upon untested and unproven theories that are presented as scientific facts. Therefore, I cannot believe that these examinations indicate anything. For this reason, nothing regarding intoxication can be determined from such examinations.
SFST’s and alcohol intoxication has been studied. However, there is considerable disagreement regarding SFT’s and people with alcohol intoxication. For example, the literature indicates that psychophysical tests, or Standardized Sobriety Tests, are only reliable 70% of the time. Thirty times out of one hundred will be wrong. This is the error rate and it is unacceptably high.
The validity of the National Highway Traffic Safety Administration Standardized Field Sobriety Tests are based upon all three tests, including the one leg stand,m horizontal gaze nystagmus and the walk and turn test. These tests taken individually or two out of the three have not been sufficiently validated. Furthermore, the validity of horizontal gaze nystagmus either alone or in combination is highly suspect.
For example, on the Horizontal Gaze Nystagmus test the angle of onset of the nystagmus is noted as in indication of degree of intoxication. This test has not had adequate validation. The threshold of angle of onset with respect to the degree of intoxication is i dispute by researchers and the studies have unacceptably high error rates.
Many factors can cause nystagmus. These factors vary from atmospheric conditions to changes in biorhythms. Normal medical conditions as well as pathological medical c onditions and medications can cause nystagmus.
Climate changes such as changes i atmospheric pressure including barometric pressure as well as temperature and other weather changes can result in nystagmus. For example, irrigation of the ears with water of varying temperatures is utilized as a diagnostic test by neurologists.
Biorhythms such as circadian rhythm an be associated with nystagmus. Pathological conditions including infections, both bacterial such as streptococcus, or viral, such as measles, influenza, the common cold and other infections such as syphilis, can cause nystagmus. This is primarily due t their effect on the labyrinth associates with the inner ear.
Vitamin deficiency such as Thiamine or Vitamin B2 causes what is known as Wernike’s encephalopathy or Wernicke-Korsakoff syndrome which can include nystagmus.
Neurologic disorders such as multiple sclerosis and epilepsy, as well as psychogenetic factors, are associated with nystagmus.
Cardiovascular diseases such as arteriosclerotic cardiovascular disease (ASCVD) and associates hypertension, arrhythmias and cerebral vascular accidents (CVA) or strokes.
Other pathological conditions include sunstroke, motion sickness, eye strain, Glaucoma ad exposure to relatvely inocuous substances, such as caffeine, incotine and aspirn.
Of course, various eye conditions including strabismus and amblyopia severely and negatively impact upon this test.
All of these conditions and many others can result in HGN which is indistinguishable from that caused by the consumption of alcohol.
Therefore, the appreciation of nystagmus in an individual is not a very specific test. There are a lot of false positives when searching for alcohol intoxication with this test. The test for nystagmus is too non-specific producing a ver high error rate when used for the purpose of determining alcohol.
Therefore, the appreciation of nystagmus in an individual is not a very specific test. There are a lot of false positive when searching for alcohol intoxication with this test. The test for nystagmus is too non-specific producing a very hgh error rate when used for the purpose of determining alcohol intoxication.
Obviously, it is impossible t develop a methodology to reliably ascertain nystagmus short of electronystagmography and even with that, it is not possible to determine the etiology without much, much more information. And even with the additional information the error rate makes the test much too unreliable to provide a specific diagnosis of alcohol intoxication. It is readily apparent why HGN is not generally an accepted test, since it is not conclusive, it is not specific, it is insensitive and the methodology that is commonly used has not been systematically validated.
In addition, without electronystagmography, the test itself and its interpretation can be “fudged” that is, it is subject to fraud.
Similar problems exist with the walk and turn and the one leg stand tests. The other portions of an examination from the vital signs through specific neurologic passive and active observations can only be interpreted by a cliician. Such examination by non-clinical personnel are not accepted in the medical scientific community.
The findings of a psychophysical examination must be applied by a clinician, the criteria in the Diagnostic Statistical Manual (DSM-5).
Such examinations are not accepted in the medical scientific field.