Case Title: EASUM v. MILLER

Citation: 

Docket Number: 

State: wyoming

Court: Wyoming Supreme Court

Date: 2004-06-24T00:00:00Z

Document:
EASUM v. MILLER2004 WY 7392 P.3d 794Case Number: 02-242Decided: 06/24/2004
APRIL TERM, A.D. 2004

 

                                                                                                            

 

JEFF 
EASUM and LYNN EASUM,

 

Appellants(Plaintiffs),

 

v.

 

CLAY 
MILLER, d/b/a PRIME POWER

& 
COMMUNICATIONS, LLC,

 

Appellee(Defendant).

 

 

Appeal 
from the District Court of Park County

 

Representing 
Appellant:

John 
R. Hursh of Central Wyoming Law Associates, P.C., Riverton, 
Wyoming

 

Representing 
Appellee:

Judith 
Studer of Schwartz, Bon, Walker & Studer, LLC, Casper, 
Wyoming

 

 

Before 
HILL, C.J., and GOLDEN, LEHMAN, KITE, and VOIGT, JJ.

 

 

 

GOLDEN, 
Justice.

 

[¶1]           
The 
primary issue in this appeal is the reliability of the differential diagnosis 
technique for determining general and specific causation in a general negligence 
action.  Differential diagnosis 
determined that the severe illness suffered by Appellant Jeff Easum (Easum) was 
caused by numerous electrical shocks that he received while working on his 
family-owned dairy.  In a summary 
judgment ruling, the trial court determined that this particular differential 
diagnosis was inadmissible because it was unreliable.

 

[¶2]           
Easum 
began suffering severe illness shortly after Appellee Clay Miller's company, 
Prime Power and Communications, LLC, (Prime Power) replaced a transformer near 
Easum's family-owned dairy.  An 
unconnected neutral line was determined to be the cause of stray voltage found 
throughout the dairy that was administering shocks to Easum as he worked at the 
dairy.  After the neutral line was 
properly connected, the stray voltage and shocks ceased; however, Easum 
continued to suffer from his symptoms and was ultimately diagnosed with reflex 
sympathetic dystrophy (RSD) caused by electrical injury.  Easum and his wife (Easums) brought suit 
against Prime Power for personal injury and property 
damages.

  

[¶3]           
Prime 
Power settled with Easums for property damages; however, it moved for summary 
judgment on other damages.  Easums' 
suit was dismissed by grant of summary judgment based upon a determination that 
their expert's testimony regarding specific causation was inadmissible as 
unreliable.  The trial court ruled 
that the expert's differential diagnosis technique insufficiently satisfied 
reliability standards because the scientific methodology used to 
determine that low level electric current could cause RSD was inadequate.  We reverse and remand for 
trial.

 

 

ISSUES

 

[¶4]           
Easums 
present the following statement of the issues:

 

1.                  
Did 
the trial court err in rejecting the Appellants' treating physician's opinions 
relating to medical causation resulting from their properly performed 
differential diagnosis as insufficient to satisfy the reliable scientific 
methodology requirements of Daubert v. Merrill Dow Pharmaceuticals, 509 U.S. 579, 113 S. Ct. 2786, 125 L. Ed. 2d 469 (1993) (hereinafter Daubert) 
and Bunting v. Jamieson, 984 P.2d 467 (Wy. 1999) (hereinafter 
Bunting).

 

2.                  
Did 
the trial court err by redefining medical causation to require general 
causation based peer reviewed medical literature in addition to the 
medical causation derived from a differential diagnosis before treating 
physician testimony will be allowed?

 

3.                  
 In a case when the Appellants' treating 
physicians' opinions on causation were challenged by the Appellee's forensic 
experts on their credibility and upon the degree or level of electrical 
exposures required to cause neurological injury, was it proper for the Trial 
Court to find that there were no disputed material facts for jury determination 
and enter a Summary Judgment in this matter?

 

Appellees 
Miller and Prime Power state the issues as:

 

1.  Did 
the district court properly grant summary judgment to the defendant on the basis 
that plaintiffs could not prove that defendant's conduct was the proximate cause 
of Plaintiff Jeff Easum's injuries?

 

(a)  Did 
the district court properly find that plaintiffs' expert opinion that exposure 
to low levels of electricity causes reflex sympathetic dystrophy ("RSD"), to be 
based on speculation and contrary to well accepted 
science?

 

(b)  Is 
a medical doctor allowed to testify as to causation based on exposure to 
electricity when he lacks a basic understanding of the physiological effect of 
electricity on the human body and such conclusion is not based on sound 
methodology or good science?

 

(c)  Is 
a causation opinion by a medical doctor exempted from the basic requirements of 
Daubert v. Merrell Dow Pharmaceuticals, 509 U.S. 571 (1993) and 
Bunting v. Jamieson, 984 P.2d 467 (Wyo. 1999) when there exists no sound 
scientific or medical basis as to the cause of his differential 
diagnosis?

 

 

 

[¶5]           
As 
required by our standard of review for summary judgment, we view the record, and 
the reasonable factual inferences drawn from it, in the light most favorable to 
the Easums as the non-moving party.  
Roussalis v. Wyoming Medical Center, Inc., 4 P.3d 209, 216 (Wyo. 
2000).  

 

[¶6]           
Easum 
works and lives at his family-owned dairy.  
After the dairy decided to upgrade its electrical service, the utility 
company contracted with Prime Power, a local electrical contractor, to upgrade 
the transformer that serviced the dairy.  
On February 26, 1999, Prime Power performed electrical work and hung a 
transformer on an electrical pole near the ranch.  Prime Power admits failing to connect 
the neutral line to the transformer.  
Before that failure was discovered, however, the dairy cattle were 
observed reacting in a manner consistent with animals receiving electrical 
shocks, such as not eating, not wanting to return to the barn, and not 
cooperating.  Easum also experienced 
numerous shocks.  On March 16, 1999, 
another electrical contracting firm began investigating the problem and 
discovered the failure to connect the neutral wire.  Prime Power returned to the ranch and, 
after that connection was made, no further electrical shocks were experienced by 
Easum or observed to be affecting cattle.  

 

[¶7]           
Easum 
first experienced shocks in the dairy on or about March 1, 1999.  Between that date and March 17, 1999, 
Easum experienced numerous shocks while in the dairy milking stalls, the sinks 
and the tanks.  He received the 
worst shocks when his hands were in water.  
On March 12, 1999, Easum developed symptoms of nausea, tremors, headache, 
and extreme fatigue.  His illness 
caused him to stay home the next day, and his symptoms subsided.  He returned to the dairy on March 15, 
1999, and was again shocked causing his symptoms to reappear immediately.  After the electricians connected the 
neutral wire, the electric shocks were no longer experienced; however, Easum's 
symptoms continued and worsened. 

 

[¶8]           
Before 
receiving the shocks, thirty-year-old Easum's only known health problem was 
slightly elevated blood pressure.  
When his symptoms did not subside, his wife called their family 
physician, Dr. Wurzel, on March 26, 1999, to discuss whether the effects of 
electrical shock might be long-term or even permanent.  Easum saw Dr. Wurzel on May 21, 1999, 
and the doctor noted numerous symptoms including fatigue, lack of ambition, 
tremors, difficulties with fine motor skills, vision blurring, lack of libido, 
weakness, and increased blood pressure.  
Later, Easum returned with these symptoms and headaches and swollen, 
painful hands.  Laboratory tests 
were conducted which indicated some abnormalities.  Dr. Wurzel referred Easum to Dr. Norris, 
a board certified rehabilitative medicine physician and 
psychiatrist.

 

[¶9]           
Dr. 
Norris noted that these many symptoms occurred after repeated low voltage 
electrical shocking over a twenty-day period and prepared an extensive medical 
report.  He ordered an EMG and 
MRI.  The EMG returned abnormal, and 
the MRI indicated a brain cyst.  
Easum was referred to another specialist who determined that the brain 
cyst was not causing his symptoms.  
This specialist 
also noted that the onset of symptoms occurred soon after exposure to low level 
electric shocks.

            
       

[¶10]      Easum 
was then referred to a rheumatologist, who again did extensive diagnostic 
testing and was able to rule out rheumatoid arthritis, which had been suspected 
as the cause of the laboratory test abnormalities.  After the extensive reports of these 
specialists were discussed with the Easums by Dr. Norris and Dr. Wurzel, Easum 
was referred to Dr. Hooshmand, a neurologist in Florida, specializing in 
electrical injury type cases.  Dr. 
Hooshmand has identified electrical injury in thirteen other dairy farmers from 
different parts of the country suffering similar symptoms as Easum and concluded 
in all that "stray voltage" was the cause of their medical condition.  

 

[¶11]      Under 
the direction of Dr. Hooshmand, Easum underwent fourteen days of extensive 
diagnostic testing, including qualitative sensory testing, infrared thermography 
imaging on two occasions, electroencephlography tests, visual evolved response 
tests, brain mapping tests, brain stem evoke response tests and 
neuropsychometric testing.  The 
electroencephlogram test was abnormal, and another specialist, Dr. Weise, 
reported it to be consistent with electrical injury.  The thermography test was also abnormal 
and determined consistent with tissue responses to electrical injury.  From the use of differential diagnosis 
technique, Dr. Hooshmand concluded that Easum was suffering from Reflex 
Sympathetic Dystrophy (RSD) and an immune system dysfunction.  Doctors Norris and Wurzel concurred in 
that diagnosis.  Easum was 
prescribed treatment that is administered and monitored by the latter two 
doctors and, while he has shown improvement, continues to be afflicted by many 
of his symptoms.  

 

[¶12]      Dr. 
Hooshmand concluded that the cause of Easum's RSD was his exposure to low levels 
of electrical current; however, RSD has no known etiology other than heredity 
and repetitive strain injury.  
Easum, nevertheless, filed suit against Appellees and presented Dr. 
Hooshmand as his expert on causation.  
Appellees moved for summary judgment on the basis that the technique of 
differential diagnosis is unreliable for determining general causation and 
contended that this technique was too unreliable to admit regarding the specific 
causation because it has not been scientifically proved that RSD can result from 
low levels of electrical current. 

 

[¶13]      The 
trial court determined that the technique of differential diagnosis is reliable 
only if the remaining cause is one that is scientifically established and then 
concluded that the basic research had not been conducted in this case.  The trial court stated:  

 

The 
scientific method consists of 4 steps: gathering information, classifying those 
data, forming a theory or prediction of behavior, and testing that theory.  Dr. Hooshmand skipped the first two 
steps and arrived at a conclusion based upon the common fallacy in reasoning 
known as "after this, therefore, because of this."

Dr. 
Hooshmand has treated 13 dairy farmers with similar symptoms.  Even with this limited sample, there has 
been no rigorous collection of data.  
We are not told the medical histories of the patients, the durations and 
intensities of electrical exposure, the reactions of others who were exposed, 
and the incidence of this condition among the general population compared to the 
incidence among dairy farmers or some other group exposed to low levels of 
electricity.

 

[¶14]      The 
trial court dismissed Easums' case authority supporting the differential 
diagnosis as distinguishable either because causation was not an issue in those 
cases or because the causation diagnosis was supported by medical literature, 
peer-reviewed articles, clinical trials, and product studies.  The trial court concluded that the claim 
of injury from exposure to low levels of electrical current was not based upon 
science but was only a matter of speculation.  Summary judgment was granted for 
Appellees, and this appeal followed.

 

 

DISCUSSION

 

 

[¶15]      Summary 
judgment is appropriate when "the pleadings, depositions, answers to 
interrogatories, and admissions on file, together with the affidavits, if any, 
show that there is no genuine issue as to any material fact and that the moving 
party is entitled to a judgment as a matter of law."  Roussalis, 4 P.3d  at 228.  In reviewing a summary judgment, we do 
not accord any deference to the district court's decisions on issues of law, and 
we examine de novo the entire record--the parties' submissions of evidence--in 
the light most favorable to the parties who opposed the motion. Id. at 
229. We give the Easums "the benefit of every reasonable inference and every 
doubt," which may be drawn from the materials either supporting or opposing the 
motion. Id. (quoting Fiscus v. Atlantic Richfield, 773 P.2d 158, 
161 (Wyo. 1989)).

 

 

Standard 
for Admission of Expert Opinion

 

[¶16]      A 
qualified expert witness may testify about scientific, technical, or specialized 
knowledge if such testimony will help the jury understand the case.   W.R.E. 702.  When determining the admissibility of 
expert testimony, the district court's gatekeeping function requires it to 
determine whether the methodology or technique used by the expert to reach his 
conclusions is reliable and, if so, the court must then determine whether the 
proposed testimony "fits" the facts of the particular case.  Bunting v. Jamieson, 984 P.2d 467, 471-72 (Wyo. 1999) (citing Daubert v. Merrell Dow Pharmaceuticals, 
Inc., 509 U.S. 579, 591-93, 113 S. Ct. 2786, 2796, 125 L. Ed. 2d 469 
(1993)).  

 

[¶17]      
Daubert 
provided a non-exclusive list of four criteria to be used to guide the trial 
court's assessment of reliability: 

 

1) 
whether the theory or technique in question can be and has been tested;  

2) 
whether it has been subjected to peer review and publication; 

3) 
its known or potential rate of error along with the existence and maintenance of 
standards controlling the technique's operation;  and 

4) 
the degree of acceptance within the relevant scientific community. 

 

Bunting, 
984 P.2d  at 472.  Because these 
criteria cannot be applied in every case, "[t]he initial step in reviewing the 
admissibility of expert testimony is the determination whether the Daubert 
factors apply to the specific testimony at issue.  Where they are reasonable measures of 
reliability, these factors should be considered."  Id. at 475.   

 

[¶18]      It 
cannot be overemphasized that methodology should be distinguished from the 
conclusion of the expert.  A trial 
judge need not and should not determine the scientific validity of the 
conclusions offered by an expert witness.  
Rather, to decide admissibility, the trial judge should only consider the 
soundness of the general scientific principles or reasoning on which the expert 
relies and the propriety of the methodology applying those principles to the 
specific facts of the case.  
Id. at 472-73.

 

[¶19]      In 
Kumho Tire Co., Ltd. v. Carmichael, 526 U.S. 137, 119 S. Ct. 1167, 143 L. Ed. 2d 238 (1999), the United States Supreme Court further clarified the scope 
of Daubert and discussed additional factors that may be used by a trial 
court in fulfilling its gatekeeping function.  Bunting, 984 P.2d  at 471.  Bunting then considered specific 
factors, including:

 

1) 
The experience and specialized expertise of the proffered 
expert;

2) 
Whether or not that expert is testifying about matters occurring "naturally and 
directly" out of research conducted independent of litigation; 
and

3) 
Any "non-judicial" utilization of the expert methodology in 
question.

 

Id. 
at 
472 (citing Ambrosini v. Labarraque, 101 F.3d 129, 140 (D.C. Cir. 1996); 
Daubert, 43 F.3d 1311, 1317 (9th Cir.) (on remand), cert. 
denied, 516 U.S. 869 (1995); and In re Paoli R.R. Yard PCB 
Litigation, 35 F.3d 717, 742 n.8 (3d Cir. 1994)).

 

[¶20]      The 
United States Supreme Court favored admission of evidence on the borderline. 
"Vigorous cross-examination, presentation of contrary evidence, and careful 
instruction on the burden of proof are the traditional, and appropriate means of 
attacking shaky but admissible evidence."  
Daubert, 509 U.S.  at 596, 113 S. Ct.  at 2798.  At the same time, the Court recognized 
the significant difference between "the quest for truth in the courtroom and the 
quest for truth in the laboratory."  
Id. at 596-97, 113 S. Ct.  at 2798.  Scientific inquiry must necessarily be 
broad and far-reaching, with the reliability of theories under continuous study 
and revision. Resolution of a legal dispute, on the other hand, involves 
binding, final judgments that cannot be based on conjecture. Consequently, there 
may well be "authentic insights and innovations" of science that are nonetheless 
inadmissible in a court of law.  
Id. at 597, 113 S. Ct.  at 2798-99.

 

[¶21]      We 
review de novo the question whether the district court performed its gatekeeper 
role and applied the proper legal standard in admitting or excluding an expert's 
testimony.  We then review for an 
abuse of discretion a district court's decision to admit or reject expert 
testimony. Seivewright v. State, 7 P.3d 24, 29 (Wyo. 2000); 
Springfield v. State, 860 P.2d 435, 438-39 (Wyo. 1993); Betzle v. 
State, 847 P.2d 1010, 1022 (Wyo. 1993).  We agree with Kumho Tire Co. that 
the trial court's broad discretion applies both in deciding how to assess an 
expert's reliability, including what procedures to use in making that 
assessment, as well as in making the ultimate determination of reliability. 
Kumho Tire Co., 526 U.S.  at 152, 119 S. Ct.  at 1176.  Accordingly, we will not disturb the 
district court's ruling unless it has failed to exercise sound judgment with 
regard to what is right under the circumstances or has acted arbitrarily or 
capriciously.  Vaughn v. 
State, 962 P.2d 149, 151 (Wyo. 1998).   

 

 

Electrical 
Current

 

[¶22]      Creating 
an electric circuit is a function of force which is measured in voltage, current 
which is measured in amperes, and resistance which is measured in ohms.1  Simply stated, electricity involves the 
flow of energy (electrons) along the path of least resistance toward a natural 
ground. See Schlader v. Interstate Power Co., 591 N.W.2d 10, 12 (Iowa 
1999); see also W.B. Saunders, Nave 
& Nave Physics For the Health Sciences, Electric 
Shock Hazards ch. 
14 
(3d ed. 1985).  All objects are either resistors or 
conductors. The electric current is the most important physiological variable 
for determining the severity of an electric shock.  However, this current is in turn 
determined by the driving voltage and the resistance of the path that the 
current follows through the body.  A 
voltage that produces only a mild tingling sensation under one circumstance can 
be a lethal shock hazard under other conditions.  This uncertainty is caused because 
although the skin acts as a natural resistor to flow, i.e., normal skin 
has a resistance of 25,000 ohms and calloused skin has a resistance of 2,000,000 
ohms, wet skin has a resistance of only 1,500 ohms.  One hundred and twenty volts delivered 
to a calloused finger would probably cause a tingling sensation, that voltage 
delivered to dry skin would cause a painful shock, but that same voltage to wet 
skin could prove to be a lethal shock.  
Id.

 

[¶23]      The 
record shows that when electricians measured voltage in the areas where Easum 
was working, their readings were consistently between thirty and fifty volts, 
with the highest reading at sixty-seven volts.  The resistance is unknown as is the 
level of current; however, Easum stood in water and placed his hands in water so 
presumably resistance was low.  As 
we have already seen, the margin between a minor shock with no effect and 
electrocution is very narrow.  The 
issue of stray voltage in connection with dairies and the effect on dairy herds 
is not new to courts and is explained as follows: 

 

All 
electricity leaving an electrical substation must return to that substation in 
order to complete a circuit. Unless that circuit is completed, electricity will 
not flow. The current leaves the substation on a high voltage line which 
eventually connects to some electrical appliance.' After exiting the 
appliance' that current must return to the substation. The neutral-grounded 
network provides the returning current two choices. Either it can return via the 
neutral line, which accounts for the second wire on our electrical poles, or it 
can return through the ground. These two pathways comprise the grounded-neutral 
network. Electricity flows through the path of lowest resistance. If there 
exists more resistance in the neutral line than in the ground, the current will 
flow through the ground to return to the substation. Neutral-to-earth voltage or 
stray voltage will occur when current moves from either the neutral line to the 
ground or from the ground to the neutral line. It uses a cow as a pathway if 
that animal happens to bridge the gap between the two. A cow's hooves provide an 
excellent contact to the earth while standing on wet concrete or mud, while at 
the same time the cow is contacting the grounded-neutral system consisting of 
items such as metal stanchions, stalls, feeders, milkers, and waterers. The 
current simply uses the cow as a pathway in its eventual return to the 
substation. Apparently very slight voltages can affect cattle. Evidence [has] 
suggested anything greater than one volt can be catastrophic to a dairy 
farm.

 

Kaech 
v. Lewis County Public Util. Dist., 23 P.3d 529, 533 n.3 (Wash. App. 2001).

 

Reflex 
Sympathetic Dystrophy

 

[¶24]      
Reflex 
sympathetic dystrophy was first described by medical authorities in 1864 and, 
until recently, was considered a disorder of the sympathetic nervous system. 
This network of nerves, located alongside the spinal cord, controls certain 
functions in our bodies, such as the opening and closing of blood vessels and 
sweat glands.  The disorder is 
difficult to diagnose because it has many variations, often follows minor 
injury, and evolves and spreads over time. The disorder is unique in that it 
simultaneously affects the nerves, skin, muscles, blood vessels, and bones and 
is characterized by a devastating amount of pain, swelling, discoloration, and 
stiffness.  Robert J. Schwartzman, 
M.D., New Treatments for Reflex Sympathetic Dystrophy, New Eng. J. Med., 
Vol. 343, No. 9 (Aug. 31, 2000).

 

[¶25]      A 
new name, the complex regional pain syndrome, is gaining recognition because the 
role of the sympathetic nervous system in many aspects of the illness is not 
clear, and dystrophy may not occur in all patients. The two types of complex 
regional pain syndrome are distinguished by whether a definable nerve injury is 
present.  In the early stages of 
reflex sympathetic dystrophy, the pain is more severe than would be expected for 
the degree of tissue damage, and the pain spreads progressively from a nerve to 
a regional distribution. The cause of RSD is unknown. As the illness evolves, 
pain becomes intense and chronic; nails, hair, skin and bone change; and 
weakness, swelling, tremors, sleep disruptions, anxiety and depression may be 
experienced.  
Id.

 

 

 

[¶26]      Dr. 
Hooshmand presented a medical opinion that Easum's condition was caused by 
receiving a significant number of electrical shocks over a sustained period of 
time.  Dr. Hooshmand's research in 
this case was not "conducted independent of the litigation," and was developed 
"expressly for purposes of testifying."  
Also, his research was not "subjected to normal scientific scrutiny 
through peer review and publication."  
Ordinarily, these Daubert factors would indicate unreliability 
unless good reason existed to explain the absence of independence, peer review 
and publication.  Clausen v. M/V 
New Carissa, 339 F.3d 1049, 1056 (9th Cir. 2003).  In the case of Dr. Hooshmand, the trial 
court found it significant that his causation diagnosis was unsupported by 
medical literature, peer-reviewed articles, clinical trials, and product 
studies.

 

[¶27]      Here, 
medical ethical rules do not permit conducting clinical testing that administers 
low levels of sustained electrical current to humans to see if RSD results.  Dr. Hooshmand examined and treated a 
patient complaining of symptoms consistent with RSD following sustained exposure 
to electric shock and, later, that patient filed suit.  Similarly, there may exist good reason 
why an expert's research may not have been published.  Id.  In this case, the apparent reason is 
that Dr. Hooshmand's research involving the phenomenon of electrical injury to 
dairy farmers is both recent and singular.  

 

[¶28]      In 
the absence of these reliability factors, an expert may use an objective source 
to show that the scientific evidence method has been followed by at least a 
recognized minority of experts in their field.  Id. Objective sources may include 
"a learned treatise, the policy statement of a professional association, a 
published article in a reputable scientific journal or the like."  Id.  Here, Dr. Hooshmand followed a 
differential diagnosis method to determine the cause of Easum's 
condition.

 

[¶29]      
"Differential diagnosis' refers to the process by which a physician 
rules in' all scientifically plausible causes of the plaintiff's injury.  The physician then rules out' the least 
plausible causes of injury until the most likely cause remains.  The remaining cause is the expert's conclusion."2 Hollander v. Sandoz Pharmaceuticals, 289 F.3d 1193, 1209 (10th Cir. 2002) 
(citation omitted).  The Fourth 
Circuit describes it this way:

 

Differential 
diagnosis, or differential etiology, is a standard scientific technique of 
identifying the cause of a medical problem by eliminating the likely causes 
until the most probable one is isolated.  
A reliable differential diagnosis typically, though not invariably, is 
performed after physical examinations, the taking of medical histories, and the 
review of clinical tests, including laboratory tests, and generally is 
accomplished by determining the possible causes for the patient's symptoms and 
then eliminating each of these potential causes until reaching one that cannot 
be ruled out or determining which of those that cannot be excluded is the most 
likely.

 

Westberry 
v. Gislaved Gummi AB, 178 F.3d 257, 262 (4th Cir. 1999) (internal quotation marks 
omitted).  Most physicians use the 
term differential diagnosis to describe the process of determining which of 
several diseases is causing a patient's symptoms while courts use the term more 
generally to describe the process by which causes of the patient's condition are 
identified.  Clausen, 339 F.3d  at 1057 n.4; see, e.g., Westberry, 178 F.3d  at 
262.

 

[¶30]      In 
general terms, the reliability of differential diagnoses is easily 
resolved.   "Most circuits have 
held that a reliable differential diagnosis satisfies Daubert and 
provides a valid foundation for admitting an expert opinion.  The circuits reason that a differential 
diagnosis is a tested methodology, has been subjected to peer 
review/publication, does not frequently lead to incorrect results, and is 
generally accepted in the medical community."  Turner v. Iowa Fire Equip. Co., 
229 F.3d 1202, 1208 (8th Cir. 2000); 
see Westberry, 178 F.3d  at 262-63.  
Physicians routinely determine medical causation by this technique, and 
we have previously determined that the technique of differential diagnosis for 
establishing causation can be reliable under Daubert.  See Reichert v. Phipps, 2004 WY 7, 
¶18, 84 P.3d 353, ¶18 (Wyo. 2004).

 

[¶31]      
Although 
courts have reached contrasting conclusions about reliability under 
Daubert, the Daubert reliability inquiry is case-specific, and, in 
general terms, the reliability of a proper differential diagnoses need 
not be addressed.  Hollander, 
289 F.3d  at 1210 (citing Kumho Tire Co., 526 U.S.  at 150, 119 
S.Ct. at 1175); see also Carlson v. Okerstrom, 675 N.W.2d 89, 105 (Neb. 
2004).  Our task is only to 
decide whether the trial court abused its discretion by characterizing the 
specific diagnosis at issue here as unreliable.  Hollander, 289 F.3d  at 1210.  "A fundamental assumption underlying 
this method is that the final, suspected cause' remaining after this process 
[differential diagnosis] of elimination must actually be capable of causing 
injury.  That is, the expert must 
rule in' the other suspected cause as well as rule out' other possible 
causes.  And, of course, expert 
opinion on this issue of general causation must be derived from scientifically 
valid methodology."  Id. at 
1211 (quoting Siharath v. Sandoz Pharmaceuticals, 131 F. Supp. 2d 1347, 
1362-63 (N.D. Ga. 2001).

 

[¶32]      
Reliable 
differential diagnosis alone may provide a valid foundation for a causation 
opinion, even when no epidemiological studies, peer-reviewed published studies, 
animal studies, or laboratory data are offered in support of the opinion.  Hollander, 289 F.3d  at 1212 
(citing Westberry, 178 F.3d at 262).  As the Eighth Circuit has 
written:

 

We 
do not believe that a medical expert must always cite published studies on 
general causation in order to reliably conclude that a particular object caused 
a particular illness.  The first 
several victims of a new toxic tort should not be barred from having their day 
in court simply because the medical literature, which will eventually show the 
connection between the victims' condition and the toxic substance, has not yet 
been completed.  If a properly 
qualified medical expert performs a reliable differential diagnosis through 
which to a reasonable degree of medical certainty, all other possible causes of 
the victims' condition can be eliminated, leaving only the toxic substance as 
the cause, a causation opinion based on that differential diagnosis should be 
admitted.

Hollander, 
289 F.3d  at 1212 (quoting Turner, 229 F.3d at 1209).  

 

[¶33]      
"Even 
with all the advances of medical science, the practice of medicine remains an 
art. A properly conducted and explained differential diagnosis is not junk 
science.' If a differential diagnosis provides a sufficient basis on which to 
prescribe medical treatment with potential life-or-death consequences, it should 
be considered reliable enough to assist a fact finder in understanding certain 
evidence or determining certain fact issues."  Coastal Tankships, U.S.A., Inc.. v. 
Anderson, 87 S.W.3d 591, 604-05 (Tex. App. 2002).  Courts that accept the differential 
diagnosis as reliable will permit it to establish legal causation when applied 
to an illness with some unknown causes. "Such a bright-line rule would be unduly 
restrictive in a world in which many things are not or cannot be known with 
absolute certainty."  Id. at 
605 n.25; see Westberry, 178 F.3d  at 265; c.f., Cooper v. Smith 
& Nephew, Inc., 259 F.3d 194, 202 (4th Cir. 2001) (outside toxic-tort 
context, relying on Westberry for same).  "A differential diagnosis that fails to 
take serious account of other potential causes may be so lacking that it cannot 
provide a reliable basis for an opinion on causation.  However, a medical expert's causation 
conclusion [based on a differential diagnosis] should not be excluded because he 
or she has failed to rule out every possible alternative cause of a plaintiff's 
illness.  The alternative causes 
suggested by a defendant affect the weight that the jury should give the 
expert's testimony and not the admissibility of that testimony."  Westberry, 178 F.3d  at 265 
(citation and internal quotation marks omitted); see also Cooper, 259 F.3d  at 202.

 

[¶34]      Depending 
on how the injury occurred, a tort action involves either general negligence, 
product liability or a toxic tort.  
Most of the law that we have recited above involved either product 
liability or toxic tort actions prosecuted in federal courts where federal 
courts require that proof of causation be produced for two components, general 
and specific.3  A. A. White, The Admissibility of 
Differential Diagnosis Testimony to Prove Causation in Toxic Tort Cases: The 
Interplay of Adjective and Substantive Law, 64 Law & Contemp. Probs. 
107, 110 (2001). We have previously held that electricity is not a product and 
plainly this case does not involve toxic tort allegations.  Wyrulec Co. v. Schutt, 866 P.2d 756, 760 (Wyo. 1993).  Easum's 
injuries present a general tort claim; however, we believe that this case 
requires that we determine both general and specific causation.  

 

 

Reliability 
of Dr. Hooshmand's Differential Diagnosis

 

[¶35]      Dr. 
Hooshmand's conclusions established both general and specific causation.  He established general causation with 
evidence that electrical shock can cause harm to humans receiving them and 
established specific causation by evidence that the electrical shocks received 
by Easum did in fact cause the onset of his RSD.  As our previous discussion indicates, 
the harm produced on dairy farms by stray voltage is well-established.  For many years, Dr. Hooshmand has 
studied the effects of electrical injury on human patients and concluded that 
electrical injury can produce disease or disorders in patients.  Among his patients were a number of 
dairy farmers, all of whom received electrical shocks of varying degrees and 
later suffered illnesses.  Dr. 
Hooshmand believed that the shocks caused the illnesses in those particular 
patients.  Studies show that 
electric shock can cause trauma to nerve and tissue, and animal studies, usually 
involving dairy herds, show that very low voltages can have devastating physical 
effects upon cattle.  Dr. Hooshmand 
properly relied upon studies finding that electrical voltage can seriously harm 
dairy herds and his own studies as support for the general proposition that 
electricity, even at low levels, can harm humans.  Whether his conclusion is sound presents 
a jury question; however, reliance upon these studies is not an improper 
methodology.

 

[¶36]      Dr. 
Hooshmand determined that Easum had suffered illness as the result of harm 
caused by sustained incidences of electric shock and further concluded that 
Easum suffered from RSD.  From this 
conclusion, the district court determined that no reliable scientific 
methodology established that low levels of electric current will cause RSD.  These last two conclusions, however 
shaky, present jury questions.  The 
district court's proper focus should have been the reliability of Dr. 
Hooshmand's opinion that Easum's condition was caused by sustained incidences of 
electric shock.  To make that 
determination, the focus must be on whether Dr. Hooshmand properly used the 
technique of differential diagnosis to decide that sustained electric shocks 
produced illness in Easum.

 

[¶37]      A 
differential diagnosis is properly performed when objective tests are used to 
rule out as many causes as possible. Easum's medical history indicated that he 
had no symptoms before experiencing shocks and began experiencing symptoms while 
receiving shocks over a sustained period.  
Several doctors and Dr. Hooshmand performed numerous objective tests that 
ruled out other causes of injury and confirmed physical injury consistent with 
electrical shock.  Dr. Hooshmand 
reviewed Easum's medical history, conducted days of physical examination and 
testing, relied upon this testing and that of other specialists to eliminate 
other possible diagnoses, and reviewed electrical injury information and medical 
studies.  Dr. Hooshmand properly 
evaluated and diagnosed Easum using standard medical procedure and his 
methodology was based upon valid scientific method.  Although the district court believed 
that the timing between Easum's electrical shocks and the onset of his symptoms 
discredited Dr. Hooshmand's diagnosis, a temporal relationship remains a factor 
that can support Dr. Hooshmand's conclusion.  

 

[¶38]      Even 
though science remains unsure how RSD develops, Dr. Hooshmand has personally 
conducted research in this area and has had numerous patients with this 
condition.  Dr. Hooshmand does not 
believe that Easum's condition is unique to dairy farmers and has researched 
this particular injury to this particular group of patients.  Dr. Hooshmand's conclusions may indeed 
be wrong; however, his methodology is reliable and the accuracy of his 
conclusions presents a jury question that must be presented at 
trial.

 

[¶39]      
The 
district court's order is reversed, and this case is remanded for 
trial.

 

FOOTNOTES

1"The word amp' is a household word. A French physicist named Andre 
Ampere (1775-1836) is credited with describing the flow of electrical current; 
his name became attached to the description of electrical flow and the word 
ampere' is the standard measure of electric current everywhere. An ampere is 
equivalent to a flow of one coulomb per second or to the steady current produced 
by one volt applied across a 
resistance of one ohm (Webster's 7th 
New Collegiate Dictionary, 1967)."  
Amp, Inc. v. Foy, 379 F. Supp. 105, 108 
(W.D.N.C. 1974) (emphasis added).

       
 

2This definition was provided in the context of a product liability 
claim.  The federal courts appear to 
be in dispute whether the "rule in before rule out" method applies in all types 
of claims and some apply the rule differently depending on whether the claim is 
products liability, toxic torts, or general negligence.  Hollander, 289 F.3d  at 1210.

    
 

3General causation deals with whether the substance at issue, e.g., 
silicone, can cause diseases or disorders in people in general. Specific 
causation focuses upon whether the substance, e.g., silicone, was in fact 
the cause of the ailments or symptoms in the particular patient.  Claims must provide admissible evidence 
of both general and specific causation for these two types of claims.  White, supra, at 
110.