OFFICE OF SPECIAL MASTERS

No. V

(Filed: December 22, 1998)

Timothy B. Saylor, Canton, Ohio, for petitioners.

Mark W. Rogers, U.S. Department of Justice, Washington, D.C., for respondent.

DECISION ON ENTITLEMENT

GOLKIEWICZ, Special Master.

Petitioners, Michael Gruber and Lana Baker, filed a petition for compensation under the National Vaccine Injury Compensation Program on January 13, 1995.⁽¹⁾ Petitioners allege that their daughter, Irene Baker Gruber ("Irene") suffered a significant aggravation of an underlying neurologic disorder as the result of a diphtheria-pertussis-tetanus ("DPT") vaccination she received on January 16, 1992. Transcript of Hearing ("Tr.") at 11-12. On April 12, 1995, respondent filed a report recommending that the court dismiss this case based on the lack of evidence to support a finding that Irene's condition is vaccine-related.

An evidentiary hearing was held on December 11, 1997, in Florence, Kentucky. At that time, petitioners presented the testimony of Michael Gruber, Irene's father, and Dr. Tracy Glauser. Testifying for respondent was Dr. Mary Anne Guggenheim. Petitioners filed a post-hearing brief on April 6, 1998, to which respondent filed a responsive brief on June 18, 1998. This case is now ripe for decision.

FACTS

The pertinent facts are not in dispute. Irene was born on July 23, 1991, at Grant Medical Center in Columbus, Ohio, following a pregnancy remarkable only for borderline gestational diabetes. Petitioners ("P.") exhibit ("ex.") 1 at 6. At birth, Irene weighed 7 pounds, 14.8 ounces and measured 20 inches in length. Her APGAR scores were eight and nine.⁽²⁾ P. ex. 1 at 20.

Irene was noted by her pediatrician, Dr. Roach, to be a well baby at her first few appointments. P. ex. 2 at 4-5. She received her first set of immunizations on September 18, 1991, and her second set on November 20, 1991. P. ex. 2 at 5. Michael Gruber, Irene's father, testified that in late November or early December 1991, he and his wife noticed that Irene was experiencing very subtle episodes of eye fluttering. Tr. at 14-15; see also P. ex. 2 at 7 (pediatrician's records confirm time of onset of episodes). Mr. Gruber described these episodes as "just a brief double blink of the eyes" that did not occur on a daily basis but could be seen most frequently when Irene was just waking from a nap. Tr. at 15. Mr. Gruber did not believe the episodes to be unusual because they were infrequent and subtle. Tr. at 38. By early January 1992, Mr. Gruber testified, he and his wife noticed an increase in the frequency of the episodes, which were no longer associated only with waking. However, petitioners were still not concerned for Irene's health at that time. Tr. at 16.

Mr. Gruber testified that on January 16, 1992, when Irene was taken to Dr. Roach for her third DPT vaccination, petitioners mentioned the eye-fluttering episodes to Dr. Roach. Tr. at 19-20. According to Mr. Gruber, Dr. Roach observed several of the episodes at that time, but felt that they were startles, a normal response to Irene's environmental stimuli. Tr. at 20. Dr. Roach's notes indicate Irene was a well baby at that appointment and she received her third DPT shot that afternoon. Tr. at 20-21; P. ex. 2 at 5.

The Grubers did not notice anything unusual about Irene on the evening of January 16. Tr. at 21. However, Mr. Gruber testified that the next morning his wife was changing Irene's diaper when Irene's body began to jerk. Id. Mr. Gruber did not observe the first part of the episode, but did witness the rest of it. He described Irene as "somewhat rigid and had -- had jerking motions. She was, you know, sort of gazing off at that point." Tr. at 23. He continued, "I believe it was her right arm was basically, you know, stiff, and her -- the hand pumping, as I recall. And her legs seemed somewhat stiffened." Tr. at 24. Mr. Gruber testified that was the first such episode he and his wife witnessed. Tr. at 24, 32. Petitioners suspected the jerking was a seizure and consulted a child medical book. The book instructed that a seizure lasting less than five minutes was not a medical emergency, so petitioners did not call 911. They did call Dr. Roach's office, however, and were instructed to bring Irene to the office. Tr. at 21-22. Petitioners arrived at the medical office at about 8:45 a.m., and Irene was examined by Dr. Royhans. According to Mr. Gruber, Dr. Royhans believed the episode to be a seizure and scheduled an EEG for Irene for February 4. Tr. at 22-23.

Dr. Royhans' records of January 17, 1992, are as follows:

PC [(present complaint)] Mom [des]cribes jerking movements [started] in one leg -- to rest of body lasting 5 min. Dad tried to hold leg still but it cont. to jerk. Eyes remained open --- baby was drowsy after & slept for short time. Irritable & fussy now.

No temp. noted 98.5 Ax [(axillary)] after seizure[.] Mom changed diaper at 7:30 A -- started jerking as above[,] no cyanosis[,] started on leg ® jerking then [indecipherable] body to arms (both) stopped on own.

P. ex. 2 at 6. The doctor's impression was "seizure - time related to DPT." Id. Another notation instructs that no further "P" (pertussis) is to be given and that MMR is to be withheld as well. Id. A Vaccine Adverse Events Reporting System (VAERS) form was completed on January 17, 1992, reporting the events as described above. P. ex. 11 at 1.

Mr. Gruber referred to notes made by petitioners contemporaneously with Irene's birth and development (P. ex. AA, filed at hearing) to confirm that Irene had other seizures on January 29 and February 2. Tr. at 25. The handwritten notes report the following:

1st seizure - Day after DPT 1-17-92 During diaper change right leg began to jerk

2nd 1-29-92 incident last approx. 40 sec. on back playing with toys. Walked over [and] saw arm jerking it seemed to dissipate after I held onto it. Only in arm on R side. Had been awake from nap 15-20 mins. Had hiccups during seizure. Eyes open, quiet but seemed aware.

Overall appears to jerk and startle more easily

3rd 2-2-92 5:53pm5:57p.m. Irene had been up from her nap about ½ hour. She had been sitting up on my lap. I laid her down to change her and her right arm tightened up and was jerking. Her head seemed to stiffen [and] pull up to left. Duration of approx 3 min.

P. ex. AA at 29. Mr. Gruber testified that his wife made the entries describing the first and second seizures and he made the entry regarding the third seizure. Tr. at 26. Irene's pediatrician's notes report those seizures as well. P. ex. 2 at 6. There are also handwritten records of seizures occurring on February 13, and March 14, 1992. P. ex. AA at 30.

Mr. Gruber recalled the change in Irene's seizure activity following the January 16th vaccination, describing it as sudden rather than a consistent increase or smooth continuum. Tr. at 41-42, 46. "The -- both the frequency increased dramatically, as well as her head would start jerking. You know, she would jerk her head back. It would -- and she would throw her arms back, which it never occurred prior to that time." Tr. at 27. He continued:

Where -- where I referred to as the November through January 16th time period where I would say things were subtle and barely noticeable, after January 16th, it basically came right at you and hit you squarely between the eyes. There was no question as far as that she was, you know, having -- having a problem.

Tr. at 41.

An EEG was performed on February 4, 1992, recording activity during waking and sleep states, and was reported to be abnormal. "Generalized spike and wave discharges appeared during the waking state, appeared to be further increased during photic stimulation, and were also seen during sleep." P. ex. 12 at 2-3. An extended EEG with video monitoring was performed on February 18, 1992. That EEG was also abnormal. P. ex. 12 at 38-39. A prolonged 24-hour EEG telemetry recording was also conducted that same day, following the EEG. The results were as follows:

[T]he patient had a very large number of clinical episodes identified by the parent as the typical clinical episodes of concern. These occupied much of the waking recording especially for the hour or so following awakening from sleep. These were generalized myoclonic seizures. They were associated with a generalized atypical spike and wave discharge. Apparently this was one of the two types of clinical episodes of concern as possible seizures. The other type was not recorded.

P. ex 12 at 40.

Irene was admitted to Children's Hospital in Columbus, Ohio on March 6, 1992, following a twenty-minute seizure that resolved spontaneously in the emergency room. During the hospitalization, an EEG was performed which recorded a large number of clinical episodes of generalized myoclonic seizures. Irene did well overnight and was discharged on March 8, 1992. P. ex. 12 at 92, 282.

On March 22, 1992, Irene experienced her first episode of status epilepticus. Children's Hospital records note that "generalized clonic seizures lasted for 50 min. before valium and dilantin stopped her seizures." She required intubation following valium-induced apnea. P. ex. 12 at 104. An EEG conducted during that hospitalization on March 25, 1992, was abnormal, showing "moderate to severe generalized slowing of the cerebral activity." P. ex. 12 at 128. Irene was discharged from the hospital on March 30, 1992. P. ex. 12 at 174; Tr. at 32.

Mr. Gruber and his wife noticed that Irene had an increased sensitivity to light sometime after February 1992. According to Mr. Gruber, sometimes just going outside would be enough to trigger a seizure in Irene. They kept cardboard in their windows. "To take her to the doctor's office, we had to put a coat over her head, put cardboard up in the windows of our car." Tr. at 36.

Over the next few months, Irene's seizure activity continued in the form of multiple myoclonic seizures and generalized tonic-clonic seizures. P. ex. 12 at 222; P. ex. 2 at 11-20 (pediatrician records). On August 5, 1992, Dr. Roach's notes indicate Irene's parents reported a "different" type of seizure. She was described as having three to four minutes of continuous eye blinking followed by five minutes of eye deviation to the right, limpness, then 15 minutes of intermittent deviation. Afterward, Irene vomited and became pale. P. ex. 2 at 18.

On July 1, 1992, Irene was reported to be "growing normally, along the 75th percentile for height and weight and 50th percentile for head circumference." P. ex. 7 at 1. On August 27, 1992, she was noted to have cognitive, social, and behavioral skills at an age-appropriate level. Her neurodevelopmental functioning was also thought to be age-appropriate. Her general fine/gross motor skills, however, were equivalent to those of a ten-month old. P. ex. 12 at 302. Pediatrician notes of September 21, 1992, report that Irene could pull to a stand and was cruising. She could say "Ma Ma" and "Da Da" and had words for body parts. P. ex. 2 at 20. An evaluation on October 22, 1992, reports that Irene sat alone at five to six months and started to say words at 11 months. At that time, she could not walk, but was cruising along furniture. P. ex. 6 at 2.

On October 22, 1992, Irene was evaluated by Dr. Blaise Bourgeois of The Cleveland Clinic Foundation. He noted that she was experiencing three different seizure types at the time: 1) "generalized myoclonic seizures . . . [that] occur almost every few minutes"; 2 "generalized, predominantly clonic seizures, occasionally with a tonic phase . . . usually last[ing] less than one minute, but on occasions, have persisted for up to an hour"; and 3) "focal seizures." P. ex. 6 at 1-2. Irene's seizures continued over the next few years, requiring medication and hospitalization.

A momentous event in Irene's clinical history occurred on March 11, 1996, when Irene was admitted to Columbus Children's Hospital for a generalized tonic clonic seizure which progressed to status epilepticus. Irene developed liver failure and was transferred to Children's Hospital Medical Center in Cincinnati, Ohio, for a possible liver transplant, which became unnecessary when her liver enzymes normalized. However, Irene remained hospitalized for nearly two months, until May 5. P. ex. 12 (second P. ex. 12, filed Aug. 14, 1996) at 22; P. ex. 13 at 10-11. Mr. Gruber testified that after her liver failure, Irene lost any developmental gains she had made and became severely mentally retarded. Irene is currently in a wheelchair, unable to stand or walk. She has no upper body control and cannot speak. She cannot control her bowel functions and is entirely dependent upon her parents for care. Tr. at 37-38; P. ex. 15 at 3.

MEDICAL EXPERT EVIDENCE

Dr. Glauser

Dr. Tracy A. Glauser, board certified in pediatrics and neurology, with special competence in child neurology, and one of Irene's treating physicians since July of 1993, testified on behalf of petitioners.⁽³⁾ Dr. Glauser believes that Irene suffered an "abnormal reaction" to her January 16, 1992, DPT vaccination that resulted in a distinct and significant worsening of her seizures. Tr. at 60; P. filings of Aug. 15, 1997, and April 28, 1997 (expert reports of Dr. Glauser).

First, Dr. Glauser testified that Irene has a very rare "syndrome," known as Severe Myoclonic Epilepsy ("SME")--a complex of symptoms, for which the etiology is unknown.⁽⁴⁾ Tr. at 62, 96, 102. In 1992, only 172 cases had been reported and, according to Dr. Glauser, that number is not significantly higher now. Tr. at 65; P. ex. 15. Dr. Glauser describes the prognosis for SME as consistently "catastrophic." Tr. at 84. SME patients are often normal initially but virtually all end up being severely retarded, according to Dr. Glauser. Tr. at 82, 84, 122-23. The condition usually begins with the development of one type of seizure and then other types of seizures develop. Tr. at 85. Typically, the seizures of SME patients are resistant to any kind of treatment during the first years of evolution, requiring numerous hospitalizations. Tr. at 84-85.

While Dr. Glauser believes that the onset of Irene's SME predated her third DPT vaccination, as manifested by the seizures beginning in late November or early December, he argues that the January 16, 1992, DPT vaccination caused a significant worsening of her seizures. Tr. at 96-97; P. filing of Aug. 15, 1997. Dr. Glauser testified that, based on petitioners' videotape of Irene between November 20th and December 1st, Irene was experiencing myoclonic seizures.⁽⁵⁾ Tr. at 53. Based on a videotape of Irene after January 17th, Dr. Glauser believes Irene was still suffering myoclonic seizures, but that they were "much worse" in nature, dramatically increased in frequency and in duration. Tr. at 54-56, 59, 68-69. Dr. Glauser testified that the post-vaccinal tape shows a child who was having almost continual brief seizures. Tr. at 114-15. He found it "very hard to watch those videotapes, because I saw that she was having so many seizures, and I knew Mom didn't recognize them at the time." Tr. at 61. According to Dr. Glauser, on January 17th, Irene suffered a "partial onset seizure" and thereafter her condition became substantially worse to the point where she was unable to function because of the continuous nature of the seizures. Tr. at 68, 68-69.

Dr. Glauser testified that it is difficult to say with specificity what course or progression is characteristic of SME because there are so few cases. While it is typical for an SME patient's seizures to increase in severity and frequency, Dr. Glauser does not know within what time frame the deterioration occurs or whether the deterioration is very quick, or slow and steady.⁽⁶⁾ Tr. at 82, 86, 94, 104-05. While the course of SME is far from established, Dr. Glauser testified, "I still think that the intensity and the frequency of the seizures that we saw in the video is more than I would have expected [for SME], having read the literature about it." He attributes that markedly increased severity in Irene's condition to the vaccination. Tr. at 117, 120. In addition, Dr. Glauser believes DPT can aggravate SME, based on a medical article that suggests a temporal relationship may exist between vaccination and afebrile seizures.⁽⁷⁾ P. ex. 15 at court-numbered p. 8 (Charlotte Dravet, et al., "Severe Myoclonic Epilepsy in Infants", chpt. 8, Epileptic Syndromes in Infancy, Childhood and Adolescence, 75, 77 (2nd ed. 1992) (hereafter "SME in Infants")); Tr. at 64.

Dr. Guggenheim

Dr. Mary Anne Guggenheim, board-certified in pediatrics and neurology, with special competence in child neurology, testified on behalf of respondent.⁽⁸⁾ Dr. Guggenheim believes that Irene's course was not significantly aggravated by her third DPT vaccination but, rather, that her course reflects a progression consistent with SME.⁽⁹⁾ Tr. at 139; R. ex. A at 3.

Based on petitioners' videotapes of Irene, Dr. Guggenheim believes, retrospectively, that the first symptom of Irene's SME appeared around Thanksgiving as myoclonic seizures. Tr. at 129, 133. Subsequently, in the beginning of January, Irene developed, in addition to the rapid eye fluttering, some "funny mouth movements" and "a little bit of a body jerk." Tr. at 133. The duration of the seizures also increased, according to Dr. Guggenheim, from a half a second to a couple of seconds at that time. Tr. at 134. According to Dr. Guggenheim, the seizure Irene suffered after her third DPT vaccination was simply the first episode of a second type of seizure, and since the nature of SME is to have three to five different types of seizures, that episode cannot be considered a significant deterioration of Irene's condition. Tr. at 139, 144.

Dr. Guggenheim does not believe the progression of Irene's course was atypical for SME. While the literature provides little data about a typical time course for the progression of SME, Dr. Guggenheim believes that over the period of one year, SME becomes apparent. Tr. at 132. By late January or early February, Dr. Guggenheim testified, Irene's seizures were much more obvious because they were much more frequent and clinically much worse. Tr. at 136-38. However, that increase in noticeability of Irene's seizures was an indication to Dr. Guggenheim that Irene's underlying disorder, SME, was becoming more obvious, not that it had worsened. Tr. at 135.

STATUTORY REQUIREMENTS

Petitioners may establish causation in one of two ways. First, petitioners may demonstrate what is commonly referred to as a Table case. The Vaccine Injury Table lists vaccines covered by the Act and certain injuries and conditions that may stem from those vaccines. §14. If the special master finds that a person received a vaccine listed on the Table and suffered the onset or significant aggravation of an injury listed on the Table within the time period prescribed by the Table, then the petitioners are entitled to a presumption that the vaccine caused the injury. §13(a)(1)(A). The respondent may rebut the presumption of causation with a preponderance of the evidence that the injury or condition was due to a factor unrelated to the administration of the vaccine.⁽¹⁰⁾ §13(a)(1)(B).

Second, petitioners may establish causation by proving, by a preponderance of the evidence, that the vaccine actually caused the alleged injury. Actual causation requires proof of a "logical sequence of cause and effect," using a medical or scientific theory to causally connect the vaccination and the injury. Strother v. Secretary of HHS, 21 Cl. Ct. 356, 370 (1990) (citing Hasler v. United States, 718 F.2d 202, 205-06 (6th Cir. 1983)), aff'd without opinion, 950 F.2d 731 (Fed. Cir. 1991).

Petitioners' theory of recovery in this case is that Irene suffered a Table injury, namely, the significant aggravation of a seizure disorder. Petitioners' burden in a significant aggravation case is to prove that the vaccine recipient:

sustained, or had significantly aggravated, any illness, disability, injury, or condition set forth in the Vaccine Injury Table in association with [a Table vaccine] . . ., and the first symptom or manifestation of the onset or of the significant aggravation of any such illness, disability, injury, or condition . . . occurred within the time period after vaccine administration set forth in the Vaccine Injury Table . . . .

Section 11(c)(1)(C)(i). In this case, petitioners must prove that the first symptom or manifestation of the alleged significant aggravation of Irene's seizure disorder occurred within 72 hours of the DPT vaccination in issue. §14(a)(I).

The interpretation of the term "significant aggravation" has been the subject of numerous cases arising under the Program. The Vaccine Act provides that the term "significant aggravation" means "any change for the worse in a preexisting condition which results in markedly greater disability, pain, or illness accompanied by substantial deterioration of health." § 33(4). The legal interpretation of the term has changed significantly since the first attempts to define and apply it to Program cases. The Court of Appeals for the Federal Circuit, recognizing the difficulty with which the term has been construed and applied, enunciated a test for evaluating whether a petitioner has successfully demonstrated a prima facie Table significant aggravation claim under the Act. Whitecotton v. Secretary of HHS, 81 F.3d 1099 (Fed. Cir. 1996). The test is not a stringent one, requiring only that the special master:

(1) assess the person's condition prior to administration of the vaccine, (2) assess the person's current condition, and (3) determine if the person's current condition constitutes a "significant aggravation" of the person's condition prior to vaccination within the meaning of the statute. If the special master concludes that the person has suffered a significant aggravation, the special master must then . . . (4) determine whether the first symptom or manifestation of the significant aggravation occurred within the time period prescribed by the Table.

Id. at 1107. This case is measured against the above criteria.

DISCUSSION

There are a number of points upon which both medical experts agree regarding Irene's condition, including the nature of SME and the role it played in Irene's circumstances. First, the experts believe that the eye-fluttering episodes Irene experienced beginning around Thanksgiving of 1991 were myoclonic seizures. There is also no dispute that the onset of a second type of seizure, partial onset, appeared in Irene the day after her third DPT vaccination.

The experts both testified that the myoclonic seizures appearing in 1991 represent the onset of SME, which, according to the doctors, could not possibly have been diagnosed prior to Irene's third DPT vaccination.⁽¹¹⁾ The experts agree that the prognosis for SME is very bad and that the clinical outcome is always poor. Finally, the experts do not dispute that Irene's current condition was caused by her SME. Tr. at 96-97 (Dr. Glauser); R. ex. A at 3, Tr. at 139 (Dr. Guggenheim).

Where the experts differ in opinion concerns the role of the January 16, 1992, DPT vaccination in Irene's seizure disorder. Dr. Glauser believes the DPT vaccination significantly worsened Irene's seizures. Dr. Guggenheim believes the vaccination had no effect on Irene's course and that the course of her illness is attributable only to the SME which progressed as Dr. Guggenheim would expect. That disagreement essentially encompasses the issues before the court--whether Irene's third DPT vaccination significantly aggravated her preexisting condition within the meaning of the Act and, if so, whether SME is a "factor unrelated" to the administration of the vaccination so as to defeat petitioners' claim.

From the outset, it may seem incredible that petitioners' expert advances the following two concepts in support of petitioners' attempt to gain compensation for a vaccine-related injury--that the DPT vaccination significantly aggravated Irene's underlying seizure disorder, but that Irene's medical course did not deviate from the expected course of SME. If the court accepts Dr. Glauser's suggestions, it would seem, intuitively, that petitioners could not prevail. Yet, strangely enough, those two seemingly irreconcilable propositions do not hinder petitioners' claim given the facts of this particular case as analyzed under the current state of the law, as will be explained. In fact, the court concludes that petitioners are entitled to compensation under the Program and provides its reasoning below.

Table Injury

The Court must first resolve whether Irene suffered a significant aggravation of her underlying seizure disorder within the Table time period following her January 16, 1992, DPT vaccination. The court makes this determination using the Whitecotton test, set forth infra, p. 9. The Whitecotton test requires the court to first assess Irene's condition prior to the vaccination and then to assess her current condition.

There is no dispute that prior to her vaccination (step one of the Whitecotton test), Irene suffered myoclonic seizures. When the seizures began in late November or early December of 1991, they were subtle, manifested only as very brief episodes of eye blinking or fluttering. They were never considered to be seizures by Irene's parents or even, initially, by her pediatrician. In the beginning, the episodes did not occur on a daily basis, and they were associated primarily with waking. The petitioners noticed an increase in the frequency of those episodes by early January and Mr. Gruber testified that the eye blinking was no longer associated only with waking. Still, petitioners were not alarmed because the episodes were subtle and, they presumed, innocuous. Aside from those episodes, Irene appeared to be a healthy, normal child prior to vaccination.

Tragically, Irene's current condition is very poor (step two of the Whitecotton test). There is no question that she is severely compromised--profoundly mentally retarded, wheelchair dependent, and completely reliant on others for all of her needs.

Step three of Whitecotton requires petitioners to demonstrate that the current condition is significantly worse than it was before vaccination. The Federal Circuit was clear that step three of the test is a simple comparison of the pre- and post-vaccination conditions of the vaccinee.⁽¹²⁾ In the facts of that case, Maggie Whitecotton was a relatively normal baby prior to vaccination. Aside from difficulty swallowing, she was microcephalic, meaning her head size was smaller than normal. At the time her claim was brought before the court, Maggie was severely disabled both mentally and physically. 81 F.3d at 1101-02. In its application of step three of the test, the Federal Circuit made an uncomplicated comparison. "[W]e can discern from [the special master's] factual findings as a whole that Maggie's present condition certainly constitutes a significant aggravation of her pre-vaccination condition within the meaning of the statute, since she presently suffers from 'greater disability, pain, [and] illness' than she did before her inoculation." Id. at 1108.

The court follows the guidance of the Federal Circuit and, making a simple comparison in this case, concludes that step three has been satisfied. Irene's current condition is strikingly worse than her pre-vaccination condition. Where she once appeared a healthy child, consistently gaining developmental milestones, and at least overtly unaffected by her seizures, she is now profoundly impaired both mentally and physically. Clearly, Irene's current condition constitutes a significant aggravation of her preexisting seizure condition.⁽¹³⁾

The court must next determine whether the first symptom or manifestation of the significant aggravation occurred within the Table time period, i.e., within 72 hours of the DPT vaccination (step four of Whitecotton test). If the first part of the test for significant aggravation appears relatively simple and straightforward, step four is anything but, at least according to respondent. Before the application of step four to the facts of this case, the court will address respondent's arguments and discuss the shift in the law and the resulting implications under Whitecotton.

Respondent argues that several important issues were not addressed by the Federal Circuit in Whitecotton. First, respondent contends that the most important issue left open concerns the standards for determining whether a petitioner has fulfilled the requirements of step four, that is (in respondent's words), "whether a particular sign or symptom following vaccination is the first symptom or manifestation of a significant aggravation of the preexisting disease, or merely a sign of the continued existence of a disease." R. Closing Argument, ("R. Argument") at 4, filed June 18, 1998. Respondent asserts that,

[a] child who suffers a neurological disease such as SME appears normal at first, but, as a matter of course, appears increasingly abnormal after the onset of clinical symptoms. For such diseases, the special master must carefully consider whether a new development is a sign of onset of a 'significant aggravation' of the condition, or, rather, simply one more manifestation of the inexorable downward course of the condition.

Id. at 4-5.

Respondent urges the special master to consider reliable scientific evidence regarding the nature and expected course of the underlying disease because "[i]f the symptom which follows vaccination is consistent with the usual course of the preexisting disease, it is obviously not a sign, first or otherwise, of a deterioration in that condition." Id. at 5, 9. In this case, respondent asserts, Irene's post-vaccinal seizure was simply the next expression of a disease whose clinical course and outcome is predictable, not a change for the worse in her SME. Id. at 10-15.

While respondent's arguments may be logical, they are not meritorious. Respondent attempts to persuade the special master to consider the underlying or preexisting disorder in the court's application of Whitecotton. Intuitively, it does seem reasonable tha