DALE THOMAS, Employee, v. AUTO GLASS SPECIALISTS and ST. PAUL COS., Employer-Insurer/Appellants, and BLUE CROSS/BLUE SHIELD OF MINN., Intervenor.

 

WORKERS= COMPENSATION COURT OF APPEALS

SEPTEMBER 15, 2000

 

HEADNOTES

 

CAUSATION - SUBSTANTIAL EVIDENCE; EVIDENCE - EXPERT MEDICAL OPINION; EVIDENCE - CREDIBILITY.  Where the medical expert with whose opinion the judge agreed assumed no facts that were unsupported by the evidence, where the judge=s decision was clearly based more importantly on the credibility of the employee=s testimony as to the continuity of his symptoms during a twenty-month post-injury period during which he received no treatment, and where there was no evidence that earlier injuries were causally related to the employee=s current condition, the compensation judge=s conclusion that the employee=s admitted work injury was causally related to his condition twenty months later was not clearly erroneous and unsupported by substantial evidence.

 

Affirmed.

 

Determined by Pederson, J., Rykken, J. and Johnson, J.

Compensation Judge:  Gary P. Mesna

 

OPINION

 

WILLIAM R. PEDERSON, Judge

 

The employer and insurer appeal from the compensation judge's award of benefits in partial reliance on medical opinions of challenged foundation.  We affirm.

 

BACKGROUND

 

On June 17, 1996, Dale Thomas injured his neck while removing a windshield in the course of his employment as service center manager with Auto Glass Specialists.  Mr. Thomas [the employee] was twenty-nine years old at the time and was earning a weekly wage of $600.  Prior to this work injury, the employee had sustained an injury also to his neck while playing broomball in 1989,  for which he apparently obtained follow-up treatment in 1990, and a second injury to his neck in 1994, while weightlifting.  Immediately subsequent to his 1996 work injury, the employee saw chiropractor Dr. Robert Thiry, who treated him on June 19 and June 21, 1996, under a diagnosis of acute cervical thoracic myofacial ligamentous strain syndrome with multiple cervical subluxations and neck pain.  The employer and insurer admitted liability and paid workers= compensation benefits.

 

On February 10, 1998, about twenty months after his admitted work injury, the employee saw chiropractor Dr. Albert Hoff with complaints of Aconstant nagging pain@ in his neck, head, and upper back for A2 years.@  X-rays indicated subluxations at C7-8, and Dr. Hoff diagnosed acute recurrent cervical/thoracic strain with headaches and radiculitis, noting that the employee had been Aliving with it@Aongoing since injury,@ which the doctor identified as June 17, 1996.  The employee received apparently about a dozen treatments from Dr. Hoff in February of 1998 and then returned again in November of 1998 for a second regimen of treatment.  On November 5, 1998, Dr. Hoff completed a Physician=s Report, indicating that the employee=s Acervical and thoracic strain with radiculitis and headaches@ were Aa direct result of the 6/17/96 work injury.@  On January 20, 1999, Dr. Hoff completed a Health Care Provider Report, on which he concluded that the employee had reached maximum medical improvement [MMI] on December 22, 1998, from his June 17, 1996, work injury, which the doctor indicated had resulted in a permanent partial disability to 12% of his whole body.

 

On February 3, 1999, the employee filed a Claim Petition, alleging entitlement to certain medical and chiropractic benefits and to permanent partial disability benefits for an impairment to a total of 12% of his whole body, all consequent to his admitted work injury of June 17, 1996.  The employer and insurer denied the claim, affirmatively alleging in part that any current disability or need for medical care was solely the result of significant disease processes not related to the admitted 1996 work injury and/or were the result of superseding/intervening injuries and/or nonwork-related activities.

 

The employee received further treatment from Dr. Hoff in February of 1999 and was eventually referred to neurologist Dr. Steven Lebow.  Dr. Lebow saw the employee on February 22, 1999, and, noting a history of a work injury on June 17, 1996, ordered an MRI scan of the employee=s cervical spine.  The scan, conducted the following day, was read to reveal a small lateral disc herniation on the left at C6-7, apparently impinging the exiting left C7 nerve.  A mild posterior disc bulge at the C5-6 level was also noted.  On February 24, 1999, Nurse Practitioner Charlotte Farmer at the Noran Clinic diagnosed left cervical radiculitis and imposed certain restrictions on the employee=s work activities.  On March 25, 1999, the employee was seen, on referral from Dr. Lebow, by neurosurgeon Dr. Walt Galicich, who reported a history of Aleft arm pain on and off for the last three years@ but recommended trying a course in physical therapy, including gentle cervical traction, rather than surgery.

 

On July 28, 1999, the employee was examined for the employer and insurer by neurologist Dr. Joel Gedan, to whom the employee reported neck pain with radiation of pain and paresthesia along the posterior left arm and forearm toward the middle three fingers of the left hand, with left arm weakness.  After making a review of the employee=s medical records, taking a detailed history from him, and conducting a physical examination, Dr. Gedan concluded that there was Ano documentation of cervical radiculopathy that can be directly related with any reasonable degree of medical certainty to the accident of June 17, 1996.@  Dr. Gedan=s opinion was based essentially on the absence of any treatment for about twenty months subsequent to shortly after the June 1996 injury.  While conceding that surgery remained an option for decompression of the left C7 nerve root, Dr. Gedan was reluctant to recommend surgery at that time, in view of what he concluded was a generally normal neurologic examination.  He added that any surgery that might be performed would not, at any rate, relate to the work injury of June 17, 1996, which the doctor concluded was Aprobably a cervical strain,@ and he concluded that the employee had no permanent partial disability related to that work injury.

 

The matter came on for hearing on January 11, 2000.  Issues at hearing included the employee=s entitlement to permanent partial disability, medical, and chiropractic benefits, based on his admitted work injury of June 17, 1996.  At the hearing, the employee testified that, on the date of the alleged injury, he felt a popping sensation on the left side of his neck, which radiated through his left shoulder blade and down into his left arm and fingertips.  He testified that, during the twenty-month gap in treatment subsequent to his two chiropractic treatments in June 1996, he experienced daily and often severe symptoms of radicular neck, shoulder, and arm pain, for which he took ibuprophen on a daily basis.  He testified that the shoulder pain Afelt like there was kind of like a knife sticking into it.@  He testified that he endured this pain without obtaining treatment largely because Dr. Thiry=s working hours were extremely difficult to avail himself of, given the work schedule of his new job with the employer.  He testified also that his symptoms during this time varied some during the course of each day, beginning usually as severe neck stiffness early in the morning, which then often moved down into his shoulder and sometimes even down into his arm during the course of the day.

 

By Findings and Order filed February 18, 2000, the compensation judge concluded that the employee was entitled to the benefits claimed, acknowledging in his memorandum that A[i]t is a very close issue whether the employee=s current neck problems are causally related to the 1996 work injury.@  The judge indicated, however, also in that memorandum, that, although the medical and chiropractic record did not contain evidence of neck problems for twenty months after the initial brief treatment immediately after the work injury, Athe Court was persuaded by the testimony of the employee that he did have such complaints.  The Court found his testimony to be credible.@  The judge stated also in his memorandum that, A[e]ven though Dr. Hoff did not specifically record arm pain and tingling in February 1998, he did note radiculitis, and he also noted that the employee=s symptoms had been ongoing since the injury and that he had been >living with it.=@ The judge added finally that, although the employee had received treatment for neck pain on a number of occasions prior to his 1996 work injury, Athere is nothing to show that he had ongoing neck complaints for about two years prior to the work injury, and there is little to show that his current neck problems are related to the earlier incidents.@  The employer and insurer appeal.

 

STANDARD OF REVIEW

 

In reviewing cases on appeal, the Workers= Compensation Court of Appeals must determine whether Athe findings of fact and order [are] clearly erroneous and unsupported by substantial evidence in view of the entire record as submitted.@  Minn. Stat. ' 176.421, subd. 1 (1992).  Substantial evidence supports the findings if, in the context of the entire record, Athey are supported by evidence that a reasonable mind might accept as adequate.@  Hengemuhle v. Long Prairie Jaycees, 358 N.W.2d 54, 59, 37 W.C.D. 235, 239 (Minn. 1984).  Where evidence conflicts or more than one inference may reasonably be drawn from the evidence, the findings are to be affirmed.  Id. at 60, 37 W.C.D. at 240.  Similarly, A[f]actfindings are clearly erroneous only if the reviewing court on the entire evidence is left with a definite and firm conviction that a mistake has been committed.@  Northern States Power Co. v. Lyon Food Prods., Inc., 304 Minn. 196, 201, 229 N.W.2d 521, 524 (1975).  Findings of fact should not be disturbed, even though the reviewing court might disagree with them, Aunless they are clearly erroneous in the sense that they are manifestly contrary to the weight of the evidence or not reasonably supported by the evidence as a whole.@  Id.

 

DECISION

 

In their brief, the employer and insurer assert that A[t]he compensation judge apparently relied on Dr. Hoff=s opinion regarding causation,@ contending that Dr. Hoff=s opinion was without proper foundation with regard to the employee=s preexisting medical care.  They contend also that records from the Noran Neurological Clinic, upon which the judge might also have relied, also lack sufficient foundation to base a causation opinion, in that those records also do not include copies of records from several providers.  The employer and insurer contend that Dr. Gedan=s records were the only records sufficiently founded to base a causation opinion.  We are not persuaded.

 

We would note initially that there is no express finding or memorandum statement to the effect that the compensation judge relied in any dispositive way on any causational opinion expressed or implied in Dr. Hoff=s records.  Even were there such a finding or statement, however, we conclude that the judge would not have exceeded his discretion.  It is the employer and insurer=s argument that Dr. Hoff=s opinion lacked foundation Abecause [Dr. Hoff] was without material evidence relating to the Employee=s 1994 weight-lifting injury for which he treated with a chiropractor, and also received prescription medication and physical therapy.@  Moreover, they contend, Anowhere in [Dr. Hoff=s] records are there references to the broomball injury to the neck in 1989, 1990 treatment at Cedarvale Chiropractic Clinic for cervicalgia and cervico-cranial syndrome, or the 1994 weight-lifting injury,@Anor did [Dr. Hoff] have the treatment records of Robert Thiry, D.C., when he rendered his opinion.@  Under our case law precedents, however, a medical expert need not have been aware of every relevant fact in order for his opinion to have evidentiary value.  See Bossey v. Parker Hannifin, slip op. (W.C.C.A. Mar. 14, 1994).  In this case, Dr. Hoff=s opinion is sufficiently founded to have at least some evidentiary value by the fact that the doctor was aware of the activities that the employee performed on his job at the time of his admitted work injury and that he credited the employee=s account of continuous pain since the time of that injury.

 

Dr. Hoff=s opinion is at the very least valuable as expert medical evidence that the employee=s work activities in June 1996 could have resulted in the symptoms he was exhibiting in February 1998.  In the end, it appears clear to us that the critical basis for the judge=s causation decision, granting Dr. Hoff=s opinion at least that minimum value, was not Dr. Hoff=s opinion but the employee=s testimony that his symptoms persisted for the twenty months after his initial treatment.  The judge made clear in his memorandum that his decision on causation vis-a-vis the employee=s preexisting neck injuries was based on a combination of the absence of evidence connecting those injuries to the employee=s current condition and the presence of evidence, in the form of the employee=s own testimony, connecting the work injury to that current condition.  While medical opinion evidence as to causation is desirable, it is not essential where there is other reliable evidence on the issue.  See Reimer v. Minnit Tool/M.I.T. Tool Corp., 520 N.W.2d 397, 51 W.C.D. 153 (Minn. 1994).  Moreover, it is unnecessary to show that an injury is the sole cause of disability, only that it is an appreciable or substantial contributing cause.  See Roman v. Minneapolis Street Railway Co., 268 Minn. 367, 129 N.W.2d 550, 23 W.C.D. 573 (1964); see also Salmon v. Wheelbrator Frye, 409 N.W.2d 495, 497-98, 40 W.C.D. 117, 122 (Minn. 1987) (while an employee has the burden of proving that a work-related injury caused disability, it is not necessary that he show that the work-related injury was the sole cause, only that the injury was a legal cause--that is, an appreciable or substantial contributing cause).  Moreover, that an employee has a long history of back trouble does not disqualify a claim if the employment aggravated, accelerated or combined with the infirmity to produce the disability for which compensation is sought.  See Bender v. Dongo Tool Co., 509 N.W.2d 366, 367, 49 W.C.D. 511, 513 (Minn. 1993). 

 

A trier of fact's choice between experts whose testimony conflicts is usually upheld unless the facts assumed by the expert in rendering his opinion are not supported by the evidence.  Nord v. City of Cook, 360 N.W.2d 337, 342-43, 37 W.C.D. 364, 372-73 (Minn. 1985).  In this case, although the facts he assumed were sparse, Dr. Hoff assumed no facts that were unsupported by the evidence.  Moreover, the judge=s decision was clearly based more importantly on the credibility of the employee=s testimony as to the continuity of his symptoms from June 1996 to February 1998.  The employee is the person most familiar with the severity of his or her symptoms, see Brening v. Roto-Press, Inc., 306 Minn. 562, 237 N.W.2d 383, 28 W.C.D. 225, (Minn. 1975), and the judge credited the employee=s testimony.  Assessment of a witness's credibility is the unique function of the trier of fact.  See Brennan v. Joseph G. Brennan, M.D., 425 N.W.2d 837, 839-40, 41 W.C.D. 79, 82 (Minn. 1988) (citing Spillman v. Morey Fish Co., 270 N.W.2d 781, 31 W.C.D. 187 (Minn. 1978)).  Therefore, because it was also not otherwise unreasonable, we affirm the compensation judge=s decision.  See Hengemuhle, 358 N.W.2d at 59, 37 W.C.D. at 239.