the use/misuse of spect to diagnose minor brain damage in trauma

THE USE/MISUSE OF
SPECT TO DIAGNOSE
MINOR BRAIN DAMAGE IN
TRAUMA OR
TOXIC EXPOSURE CASES
PRESENTED BY:
JOHN J. SOLTYS
COZEN O’CONNOR
SEATTLE, WASHINGTON
FDCC MID-WINTER MEETING
HAWAII – MARCH 8-13, 2004
REVISED: November 2003
THE USE/MISUSE OF SPECT TO DIAGNOSE MINOR BRAIN DAMAGE
IN TRAUMA OR TOXIC EXPOSURE CASES
By
John J. Soltys
Cozen O’Connor
Seattle, Washington
I. INTRODUCTION
The plaintiff’s use/misuse of nuclear medicine to diagnose mild brain damage resultant
from trauma or toxic exposure is exploding in spite of cautions published by the American
Academy of Neurology warning that SPECT/PET is still primarily experimental and not yet
available for clinical use. We see plaintiffs attempting to introduce SPECT (Single-PhotonEmission Computed Tomography) and PET (Positron Emission Tomography) at trial to diagnose
alleged mild brain damage resultant from a trauma, or from environmental or toxic exposure to
chemicals such as pesticides, glues and solvents, 1 or pharmaceutical or foreign body reactions
such as to breast implants.
While a limited number of articles and publications on the use of SPECT/PET for such
clinical diagnosis of brain damage have been published, the technique has not been accepted by
the medical community for clinical use. 2 Its use should be the subject of a Daubert Challenge.
Daubert v. Merrell Dow Pharmaceuticals, 509 U.S.579, 113 S. Ct. 2786, 125 L.Ed. 2d. 469
(1993). Daubert held that Federal Rules of Evidence 702 provides the standard for admitting
expert scientific testimony, not the Frye test which still seems to be the applicable rule for the
admissibility of expert testimony in criminal cases. Daubert, 113 S. Ct. at 2793. ER 702, which
is the same as Federal Rule of Evidence 702, states:
If scientific, technical, or other specialized knowledge will assist
the trier of fact to understand the evidence or to determine a fact in
issue, a witness qualified as an expert by knowledge, skill,
experience, training, or education may testify thereto in the form of
an opinion or otherwise.
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1
Heuser G., Menard, Thomas C., Alamos F., Cerebral Blood Flow in Patients Exposed to Neurotoxic
Chemicals [Abstract] J. Nucl. Med. 1994; 35 (Suppl. 210 P.).
2
Jchise M. Charg et al., Technetium-99- HMPAO SPECT, CT and MRI in the Evaluation of Patients with
Chronic Traumatic Brain Injury: A Correlation With Neuropsychological Performance. J. Nucl. Med. 1994;
35:217-222. Gray B.G. et al., Technetium-99-HMPAO SPECT in the Evaluation of Patients with a Remote History
of Traumatic Brain Injury: A Comparison with X-ray Computed Tomography, J. Nucl. Med. 1992; 33: 52-58.
ER 702 requires the trial judge to ensure that all scientific material or testimony rests
both on a reliable foundation and is relevant to the task at hand.
Reliability depends on whether the scientific testimony qualifies as scientific knowledge
of a known certainty. Relevancy depends on whether the expert’s testimony will be helpful to
the trier of fact. Helpfulness turns on whether the underlying reasoning or methodology is
scientifically valid and can be applied to the facts at issue. This requires the plaintiffs to
establish by a preponderance of the evidence that the reasoning and methodology underlying the
testimony is scientifically valid and that the proper scientific principles and methodologies were
used in deriving the scientific information.
To assist in this analysis, the Daubert court set forth a non-exclusive list of issues to be
considered.
A.
Courts should examine what methodology or technique was employed by the expert and
whether that methodology or technique is capable of being classified as or actually employs a
“scientific method.” Daubert, 113 S. Ct. at 2796-97.
B.
Courts should consider whether the particular methodology or technology employed by
the expert was subjected to peer review and publication; its potential or known rate of error; and
whether it has gained “general acceptance” within the scientific community. Id., at 2797.
(Emphasis added).
Virtually every jurisdiction has adopted Daubert into its own case law. Competent
physicians, certified in Nuclear Medicine by the American Board of Nuclear Medicine, and
aware of the work of the American College of Neurology and the National Society of Nuclear
Medicine and its Brain Imaging Council will provide you with declarations which will advise the
court of the lack of all of the requirements which the plaintiff must prove in order to defeat a
Daubert challenge.
Regardless of the lack of acceptance of SPECT/PET to diagnose minor brain damage, in
the medical community, many plaintiff’s attorneys utilize such testimony from various medical
doctors who apparently believe in, and/or are willing to testify regarding, the efficacy of this
untried methodology to diagnose minor brain damage. Just as we have encountered, met, and
defeated the short lived use of thermography and computerized electroencephalographic brain
mapping (BEAM) we must also prepare ourselves to understand and meet SPECT/PET when it
is inappropriately used.
II. WHAT IS IT
A.
Description of SPECT/PET.
SPECT has been around since the early 1980s and is a process in which a computer
evaluates cerebral perfusion (blood flow) after a radionuclide or a radioactive tracer is
intravenously injected into a patient’s blood stream. The radioactive tracer is built as a fat loving
material capable of crossing from the blood into the brain where it becomes hydrophilic, which
means that it is no longer fat loving. A hydrogen atom replaces an organic molecule and then
becomes trapped in the neuron in the brain. The brain’s neurons include various chemicals
2
including glutathione. This chemical is more prominent in the gray matter which is why the
radiopharmaceutical “sticks” primarily in that matter. It accumulates in different areas of the
brain depending on the rate of delivery of nutrients (blood flow) being supplied to that volume of
brain tissue. 3 After the tracer sets in the brain, a rotating gamma camera using the techniques of
CT is able to “view” the distribution of the radiopharmaceutical within the brain. (See Fig. A
and B.) The camera essentially counts the photons for a computer to analyze. These
radiopharmaceuticals concentrate primarily in the brain’s gray matter in a ratio of
FIGURE A
Typical Multi-detector camera apparatus used
in SPECT
Figure B
Multi-detector camera demonstrating the
patient position during data acquisition
approximately 4 to 1 when compared with the white matter. The cameras are able to identify the
cerebral perfusion in a patient’s brain such that it can then be compared with the expected
patterns in a normal brain or even to the average cerebral activity in the same slide of the same
brain. Computers are then able to examine and display the results in a convincing and colorful
(even three dimensional) manner. (See Fig. C and D.) The SPECT picture which is presented at
trial looks like a photograph but is actually a computer generated presentation.
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3
Special Article. Assessment of brain SPECT. Report of the Therapeutics and Technology Assessment
Subcommittee of the American Academy of Neurology, Neurology 1996; 46: 278-285.
3
FIGURE C
A portion of a Brain SPECT Scan
in Color (axial slices)
FIGURE D
A normal 3 dimensional SPECT Brain
(Surface Rendered Study)
Although this paper deals with SPECT, the concepts apply equally to PET which utilizes
positron emitting radiopharmaceuticals which are incorporated into biologically active
compounds which in turn are also injected into the blood stream. 4 Unlike SPECT, PET can
measure regional cerebral metabolism. PET has been available since the 1970s and was
traditionally believed to be complimentary of and superior to EEG. EEG provides information
about events occurring only at the surface of the brain in proximity to the electrodes. PET
measures the metabolism and substrate utilization of volumes of tissues in three dimensions
throughout the complete volume of the brain tissue. Both PET and SPECT are safe procedures
in that the radiation exposure in absorbed dose is generally approximately equal to that received
in a routine radio diagnostic medical procedure. 5 It is not recommended that an independent
defense SPECT or PET be obtained because to do so might suggest some credibility in the
clinical use of the procedure in the first instance. Nonetheless, if you should decide that you do
need such an independent study, the plaintiff should not be heard to refuse due to the alleged risk
of being over-exposed to radiation.
III. CLINICAL USE OF SPECT
A.
Some Accepted Uses of SPECT.
Before exploring what SPECT cannot be used for, it is important to recognize the
importance of and the accepted clinical uses of the procedure in nuclear medicine. Essentially
SPECT maps the distribution of brain perfusion or blood flow. Any disease process which alters
cerebral perfusion will show a deviation from normal on SPECT. There are various conditions
and diseases which display distinctive patterns of abnormal cerebral metabolism which can be
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4
Mazziotta, J.C., Phelps, M.C.; Positron Emission Tomography Studies of the Brain, etc., New York: Raven
Press 1986; 493-580.
5
Freeman, L. M.; Freeman and Johnson’s Clinical Radionuclide Imaging (3d. ed.), Vol. II, Orlando, Florida:
Grunet & Stratton 1984: 1514-1521.
4
demonstrated and therefore diagnosed with SPECT. In such instances, SPECT is clinically
useful in making a diagnosis. After significant peer review SPECT has become accepted in the
medical community for clinical use in the diagnosis of Alzheimer’s Disease (see Fig. E and F),
Parkinson’s Disease, Huntington's Chorea, Pick’s disease, stroke (see Fig. G), epilepsy (both for
diagnosis and to locate the focal origin thereof), in grading brain tumors (both to evaluate tumor
growth patterns and to differentiate between recurrent high
FIGURE E.
Color SPECT of typical Alzheimer’s patient
FIGURE F
3-D SPECT demonstrating a typical severe
Alzheimer’s pattern.
FIGURE G
SPECT demonstrating major asymmetry resultant from
a left side infarct (stroke).
5
FIGURE H
Black and white SPECT demonstrating marked
asymmetry resultant from an infarct (stroke).
The CT on this patient was normal.
FIGURE I
3-D SPECT showing a significant infarct (stroke)on the right
side
6
FIGURE J
3-D view of a subject with a small left posterior parietal
region of brain ischemia in which no large region of brain
death occurred as evidenced by a normal 4-hour delayed
image. (This is an old technique.)
grade tumors and chemotherapy induced necrosis), HIV encephalopathy, and in the
determination of brain death. 6
B.
Unacceptable Uses of SPECT.
In other areas, the use of SPECT is still experimental. Criminal lawyers have improperly
attempted to use SPECT as objective evidence in support of a criminal defendant’s claim that his
crime was the result of organically based poor judgment, lack of insight, uncontrolled aggression
or impulsivity, or due to an organic brain dysfunction. There are limited functional brain
imaging studies of subjects with criminal behaviors. 7 These studies are seriously flawed in
protocol design and often lead to erroneous conclusions. Likewise in civil cases, the role of
SPECT in the evaluation of brain damage from head trauma or toxic exposure remains
experimental. 8, 9
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6
Assessment of Brain SECT. Report on the Therapeutics and Technology Assessment Subcommittee of the
American Academy of Neurology. Neurology 1996; 46:278-285.
7
Functional Brain Imaging in Forensic Psychiatry: In Clinical Perspective SNM 1994, Helen Mayberg, M.D.
8
American Academy of Neurology, Assessment Positron Emission Tomography (PET) Report of the
Therapeutics and Technology Subcommittee.
9
Waxman Chapter on”Functional Brain Imaging in the Assessment of Multiple Chemical Sensitivities” in
Multiple Chemical Sensitivity/Idiopathic Environmental Intolerance, Occupational Medicine, State of the Art
Review, Editor: Patricia J. Sparks, M.D.
7
IV. REVIEWING THE PLAINTIFFS’ EXPERTS’ THEORIES
There are several ways in which the results of SPECT may be intentionally or
unintentionally manipulated. When confronted with SPECT testimony, defense counsel must
question not only the physician’s interpretation of the results but also the use of improper or
untested acquisition and processing protocols, the use of improper norms, and other factors of a
technical or reporting nature. Although most courts will sustain a Daubert challenge to the
plaintiff’s use of SPECT in making a clinical diagnosis, some will allow the introduction of that
evidence. In such an instance, defense counsel must be prepared to question all the variables
associated with the procedure.
A.
Protocol.
It is imperative that SPECT Brain Studies be administered in a proper manner. The
American Academy of Neurology is in the process of establishing a proper protocol and is
expected to publish same in the near future. Until the publication of such protocol, one must use
the methodology accepted by the Nuclear Medicine Community when administering SPECT. 10
1.
Radiopharmaceutical Preparation.
The FDA has approved radiopharmaceuticals Tc-99mHMPAO and Tc-99mECD for
evaluating brain perfusion in stroke cases. Three others have been FDA approved for other uses.
No other applications have currently been approved by the FDA. This does not mean that other
radiopharmaceuticals are necessarily inappropriate. 11 HMPAO must be injected within 10 to 30
minutes following its preparation. Imaging should start 90 minutes following injection. ECD
must be injected within four hours of its preparation and imaging started 60 minutes after
injection.
2.
Patient Preparation.
Patients should be prepared in a separate quiet, dimly lit room in a comfortable reclining
position with eyes open and with soothing background noise. A hepacath or IV is to be inserted
in the patient at least 15 minutes prior to the injection of the radiopharmaceutical. This allows
the patient to calmly get used to the IV. Some physicians, who frequently testify as SPECT
experts for the plaintiffs, have developed their own procedure which is at variance with accepted
protocol. They often utilize unique protocols which have not been peer reviewed or accepted in
the medical community. By way of example, some physicians will ask that their patients conjure
an image of themselves at a beach. Although such an image might be restful to a large
percentage of patients, that same mental imagery might trigger or stimulate other patient’s
brains. The visual cortex of the brain might not react the same way in the patient who enjoys
Caribbean vacations as it would in a different patient who may have recently lost a loved one
through a drowning, or a shark attack. (On a normal SPECT Brain Scan, the cerebellum will
most often appear brightest and closely related in intensity to the primary visual cortex in the
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10
Juni J, Taking Brain SECT Seriously: Reflections on Recent Clinical Reports in The Journal of Nuclear
Medicine. J. Nucl. Med. 1994; 1891-1895.
11
Waxman, A., A Practical Approach to Brain Image SPECT.
8
occipital lobes. A schizophrenic who is having visual hallucinations may have a brighter visual
cortex than cerebellum). It is generally accepted amongst nuclear medicine physicians that
external stimulus during injection should be avoided. 12
Some physicians have developed their own protocols including “flow” studies which
require them to inject the radiopharmaceutical in a patient while the patient is lying in the
machinery while the data is being acquired. Inappropriate and unproven activation protocols
have been attempted. These unproven activation protocols may result in variable protocols
including results between subjects and may result in different patterns in the same individual if
tested at different times (reproducibility problem) (see Figure K.) which demonstrate the effect
of activation on the human brain. Protocol demands that the patient be placed in a separate room
without distractions. If the patient is being injected while reclining within the confines of the
gamma camera (which resembles CT equipment) (see Fig. A), he is receiving external visual and
auditory stimuli. The camera is rotating about the head (see Fig. B) and making noises which
could cause confusion, tension, claustrophobia, fright, or other cognitive processes. Such
“activation” studies using mental conjuring have not yet been peer reviewed and are not accepted
in the medical community.
FIGURE K
The same slices of normal subject demonstrating the effect
of language and/or music activation on the brain’s
metabolism.
3.
Radiopharmaceutical Intake.
After a patient has been injected, brain uptake is rapid and reaches its maximum in about
10 minutes. The radiopharmaceutical crosses from the blood into the brain where it has been
taken up and becomes hydrophilic. (See Fig. L.)
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12
American Academy of Neurology, Assessment: Positron Emission Tomograph (PET) Report of the
Therapeutics and Technology Subcommittee.
9
FIGURE L.
How it works
The hydrogen atom which replaces the organic molecule is then unable to escape from the brain
tissue where it is trapped in the neuron. The patient needs only be quiet for 10-15 minutes while
the radiopharmaceutical is being injected. The injection should be done slowly taking about 3
minutes. Patient movement during this 10-15 minute period may affect the readings.
After the 10 minute quiet period, and after the injection period has passed, an additional
60 to 90 minutes must elapse before the study is conducted. The patient may be active during
this 60-90 minute period and may move about freely. During this period, any of the blood that
surrounds the brain will clear away leaving only the pharmaceutical that has been trapped in the
brain.
Background ratio improves with time.
Immediately after the injection, the
radiopharmaceutical has also been taken up by the head’s soft tissues including the salivary
glands, the parotid glands, the submandibular glands, nose and the sinuses (especially if the
patient has a cold). The soft tissue blood pool initially is also elevated and the pharmaceutical
needs the 60-90 minute opportunity to clear.
The test should only measure the
radiopharmaceutical which has become hydrophilic in the nerve cells of the brain. Once the
radiopharmaceutical is taken up in the brain, it remains frozen for two to four hours.
4.
Image Acquisition.
Multi-detector cameras (see Fig. A) and ring-type systems are the most desirable for use
in that they generate higher resolution images in a reasonable time frame. Single detector
systems may still be used but require more time and produce a suboptimal (fuzzy) image which
some physicians feel is inadequate to produce valid results. (See Fig. M.) The cost of this
equipment is still high and the number of qualified facilities remains low. While a single
detector head system costs around $250,000, a multi detector system can cost considerably more.
Patients must remain still in the equipment while data is being acquired. Motion artifact
should be evaluated in all subjects by reviewing the raw data (cine images) following
10
FIGURE M
Cloudy result from a single detector system
acquisition. Adequate time should be allowed to acquire sufficient information (counts) for data
processing to be effective. Twenty to thirty minutes of data acquisition is usually sufficient for a
three detector system. A single detector system may require one hour of acquisition time for
adequate results.
5.
Image Processing.
The result and studies should be processed in all three dimensions. The raw data
obtained is processed through digital filters prior to interpretation. The type of filter used is
critical. It is important to ensure that one uses a filter which eliminates artifacts but still allows
the passage of data without distorting image contrast or magnifying minimal irregularities. Noncontrast enhancing or spatially enhancing filters, or low pass filters such as the Butterworth filter
or combined low pass/ramp filters are recommended by the Brain Imaging Council of the
Society of Nuclear Medicine. Spatially varying filters or resolution recovery filters such as the
Metz or Weiner filters are often undesirable because they may distort the shape of images. They
may also increase the image contrast and produce artifacts. One can see that if an inappropriate
filter is used it can eliminate certain levels of emissions from the SPECT while magnifying other
insignificant elements. With incorrect filtering, one might inappropriately conclude that there
was inadequate blood flow to the area of the brain where the filter had eliminated emissions of a
certain level when in fact the filter was the actual cause of the irregularity. (See Fig. N.)
11
FIGURE N.
The same normal brain using 4 different filters and
the same threshold of 60.
FIGURE O.
The same normal brain as shown in Figure N, but using a
higher threshold of 65.
The cutoffs or upper and lower window settings (cutoffs) input to the computer are also
critical. Readings above or below the cutoffs will not be recorded at all. The background cutoffs
chosen for the display are also important. When high background cutoffs (above 20%) are used,
subtle or minor acceptable irregularities are emphasized. (See Fig. O.)
It is important that the entire brain be reconstructed from vertex through cerebellum.
Although one might not suspect injury or damage to a certain portion of the brain, its SPECT
comparison with other portions of the brain is useful.
SPECT data should be reconstructed at one pixel thickness with attenuation correction.
The data is then reformatted into transaxial, coronal, and sagittal views.
6.
Data Display
Volume and surface displays should be generated when possible along with the axial,
coronal and sagittal views. The gamma camera measures emissions and the computer formats
and displays the data. These emissions have no color. It is the operator using a computer who
assigns various colors to various numbers of emissions. For example, a brilliant yellow color
may be used to demonstrate a high level of emissions while a less brilliant level indicates lower
emissions (counts).
A brilliant color is generally believed by the populous to be the color of radioactive
emissions. Any other color could just as easily be used. Great care must be given in establishing
the cut-offs for each of the various colors. Black and white studies should be reviewed with
color studies. (See Fig. P.) Black and white studies refuse to acknowledge what might
otherwise appear to be a glaring contrast in a color presentation because the black and white
study shows gradual gradations of brightness while color presentations may not. With
inappropriate color cutoffs, a color study may appear to show significant differences between
levels of emissions which are actually quite close together.
12
FIGURE P
A normal black and white SPECT (top of slide are the
slices taken from the bottom of the brain)
FIGURE Q
SPECTS of the same normal brain demonstrating the
problem associated with lower counts obtained from a single
detector unit. (The lower count SPECTS were read as
abnormal.)
Ensure that an adequate number of counts are obtained before a SPECT is read. The
older single head system not only produces a noisy, difficult to read picture, but also often
produces too few counts to properly fill in the picture. (See Fig. Q.) The same brain which
would show normal with adequate counts, shows asymmetry with limited counts.
The background settings and cutoffs are also critical. A background of 0-10% is
generally accepted. A normal brain reviewed as normal at 0% (see Fig. R) is read as borderline
abnormal at 20% (see Fig. S) and is read as abnormal with a background of 40%. (See Fig. T.)
Even the identification of a defect is the subject of some dispute. Trained human
observers found that a defect of approximately 10% of surrounding brain counts was required for
recognition in clinical practice. It was felt that the sensitivity of scanning in mild disease was
quite poor. 13
FIGURE R
FIGURE S
––––––––––––––––––
A normal brain(read as normal) with
an appropriate –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
The same normal brain as Figure R (read as borderline) ––
with a background of 40%
background setting of 0%.
13
Juni, J., supra.
13
FIGURE T
The same normal brain as Figures R and S (read as
abnormal) with a background of 40%. (Figures R,
Seattle, WA and T all used the same filter.)
7.
Interpretation and Reporting.
Database. In order for SPECT to be of any assistance it must be compared with a
database of SPECTs from normal subjects who were tested using the same techniques. It should
be understood that there is a great deal of acceptable variability present in normals. 14 The extent
of anatomic variability amongst normals must also be recognized and accounted for. Few truly
normal scans or studies of normal patients have, as yet, been conducted. In the past, patients
were not imaged unless they were suspected of, or had signs or symptoms of some
neuropathology. Only now are various research centers acquiring scans from volunteers without
any known neurological deficit, history of head trauma, drug abuse, or psychiatric or
psychological disorder. Some physicians are developing a database made up from average
composites of a number of brains which, when averaged, yields a uniform “norm”. In many
instances, the individual SPECTs of the various “normal” volunteers, when compared with the
averaged composite, would appear abnormal. Further, not all brains are the same size and shape.
To prepare composites using different size or shaped brains, without careful modification, tends
to wash out acceptable variations from one normal SPECT to another normal SPECT. Even
amongst norms, there are differences. There are clear age-related changes in cortical perfusion.
A comparison of a given plaintiff should be to a “norm” of persons in the same age group, i.e.,
within 10 years of the plaintiff’s age. Further, no true studies have been done comparing the
perfusion in men and women. 15 Dr. Levin found significant differences in perfusion deficits
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14
Juni, J., supra.
15
Dr. Levin (Levin J.M., Holman B.L., Mendelson J.H., et al., Gender Differences in Cerebral Profusion in
Cocaine Abuse, 99 MTc-HMPAO SECT Study of Drug Abusing Women. J. Nucl. Med. 1994; 35:1902-1909.
14
when he compared healthy male vs. healthy female cocaine users. Most of the abnormalities
occurred in the frontal and temporal lobes and the basal ganglia. When non-cocaine drug users
were excluded, eight of nine male users had defects compared with only one of nine female
users. In fact, the female group of exclusive cocaine users was indistinguishable from a matched
group of normal women.
Even some asymmetry, such as temporal lobe asymmetry, is an accepted normal
variability in patients. 16 Normal variations are also expected in SPECTs taken of the same
patient on different days. Alcohol or during usage, emotional status, cigarette smoking, coffee
drinking and even diseases like atherosclerosis, depression or hypertension can affect blood flow
to the brain. (See Fig. K.)
When trying to evaluate the SPECT, images should first be reviewed in cinematic format
in order to evaluate the potential for motion artifacts, target to background ratios, or other artifact
production which may become apparent in this format. Hard copy information is acceptable for
record keeping but interpretation should be done using a computer screen to allow adjustments of
contrast, color selection and other display parameters.
SPECTs should rarely be used by physicians to assign a specific pattern of abnormality to
a specific disorder or to a specific origin. SPECT brain studies which do show defects are often
nonspecific because there are so many injuries, ailments, and diseases which can cause SPECT
defects in the brain. Further, even if a defect is observed, SPECT is incapable of determining
when the defect occurred, i.e., in the accident which is the subject of your lawsuit or in a prior
traumatic event. In few instances are SPECT patterns of defects so well known that one can
identify a given ailment by that pattern. Patients suffering from chronic fatigue syndrome (see
Fig. U and V) (an ailment which in itself is a subject of controversy in the
neurological/psychiatric /neuropsychological community) may demonstrate SPECT similarities
to a person suffering from unipolar depression (see Fig. W) or AIDS Dementia Complex (ADC).
Indeed, even when one is suspected of chronic fatigue syndrome, experts question whether it is
the result of a viral infection by a novel (as yet undiscovered) infectious agent or an
unrecognized and untreated underlying primary psychiatric disorder similar to unipolar
depression. Likewise, studies suggest that the Epstein Barr virus, enteroviruses, retroviruses, or
the human herpesvirus 6, alone or in concert, may play a role in chronic fatigue syndrome. 17
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16
Marcus, et al. Alterations in Regional Cerebral Blood Flow with Increased Temporal Interhemispheric
Asymmetric in the Normal Elderly. Nuclear Medicine Communications 1993, Vol. 14, pgs. 628-633.
17
Schwartz, R., Komaroff, A. Gordada, B., Gleit, M., Doolittle, T., Bates, D., Vasile, R. Holman, B., SPECT
Imaging of the Brain. Comparison of Findings in Patients with Chronic Fatigue Syndrome, AIDS, Dementia
Complex, and Major Unipolar Depression, AJR 1994; 162:943-951.
15
FIGURE U
Patient suffering from Chronic Fatigue Syndrome
FIGURE V
Patient suffering, by history, from Chronic Fatigue
Syndrome
FIGURE W
Color SPECT using an older camera with a different color
scale. This demonstrates the effect of a psychological
disorder (depression) on the blood flow.
FIGURE X
The SPECT of a patient suffering from Multiple Infarct
Dementia (multiple small strokes). Symptoms include
problems with language, reasoning, concentration.
16
FIGURE Y
Patient with a posterior cerebral infarct.
Systemic lupus erythematosus, cocaine abuse, and multiple infarct dementia likewise
demonstrate nonspecific multi-regional perfusion abnormalities on SPECT. (See Fig. X and Y.)
Correlating neuropsychological test performance with SPECT has both been promising
and disappointing. The correlation between neuropsychological test results and some SPECT
findings seemed predictive in one study while a contrasting study by Dr. Goldenberg. 18
Dr. Goldenberg revealed a loose correlation between the two. It was found that the ratio of
anterior to posterior activity in the brain generally correlated with the degree of
neuropsychological deficit. On the other hand, the ventricle to brain ratio associated with
traumatic brain injury correlated poorly with neuropsychological testing. 19
A patient with a history of head trauma might demonstrate a SPECT pattern similar to a
patient with unipolar depression. (See Fig. Z.) The same type of pattern has been demonstrated
in a Manganese toxicity case as well as in cases involving AIDS encephalopathy, chronic fatigue
syndrome, and drug abuse. 20 The controversy continues in that some clinicians have testified
that exposure to chemicals such as pesticides, solvents, and glues result in specific and readily
identifiable patterns on brain SPECT. 21 Some clinicians wittingly or unwittingly have overstated
the specificity of various SPECT patterns. Having observed a defect, they have then been
willing to diagnose a specific illness, disease or injury (specifically brain damage) which they
then attribute to a specific insult or event. In some instances, the SPECT patterns can be used to
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18
Goldenberg, Oder W., Spratt, J., Podrenka, I., Cerebral Correlates of Disturbed Executive Function and
Memory in Survivors of Severe Closed Head Injury: A SPECT Study. J. Neurol. Neurosurg. Psych. 1992, 55:362368.
19
Juni, J., supra.
20
Reiman, E.M., Fusselman, M.J., P.T., Raichele, M.E.: Neuro Anatomical Correlates of Anticipatory Anxiety.
Science 243:1071-1074, 1989. Thornton J.I.; Courts of Law vs. Courts of Science: A Forensic Scientist’s Reaction
to Daubert Shephard’s Expert and Scientific Evidence Quarterly 1:475:486, 1944.
21
Huser, G., Editorial: Diagnostic Markers in Clinical Immunotoxicology and Neurotoxicology. J. Occ. Med.
& Tox. 1:V-X, 1992.
17
diagnose certain disease entities whereas in other instances the patterns do nothing more than
identify a defect which could be the result of a host of injuries, insults or exposures, unrelated in
time or origin to the subject of the lawsuit.
FIGURE Z.
SPECT of a patient, in suit, who was depressed and who
sustained a very mild impact to the skull without L.O.C. but
demonstrating an inability, in subsequent weeks, to
adequately perform his high skill, high stress job.
V. CONCLUSION
When confronted with SPECT testimony in a brain damage case, the defense attorney
must first attempt to exclude the testimony through a Daubert challenge. If the defense motion
in limine is not granted, the defense must be prepared to question the protocol used to administer
the test and then to challenge not only the techniques used but also the physician’s evaluation of
the results.
CC[C&O1]407227\099995.000
18