# In the United States Court of Federal Claims

FOR PUBLICATION

No. 16-1494V (Filed: March 13, 2023  )

EBONIE WEAVER

, parent of T.M., a minor

,

Petitioner

,

v.

SECRETARY OF HEALTH
AND HUMAN SERVICES

,

Respondent

. ) ) ) ) ) ) ) ) ) ) ) ) ) Vaccine Act, 42 U.S.C. § 300aa-10 et seq. ; Off-Table Causation-in-Fact & Significant Aggravation Claims; Complex Febrile Seizure; Abnormal Screenings; Epilepsy

Edward Kraus , Kraus Law Group, LLC, Chic ago, IL, for plaintiff.

Meghan R. Murphy , Torts Branch, Civil Division, U.S. Department of Justice, Washington, DC, for defendant, wi th whom on the briefs were Brian M. Boynton, Principal Deputy Assistant Attorney General, C. Salvatore D’Alessio , Director,
Heather L. Pearlman , Deputy Director, and Lara A. Englund , Assistant Director, Torts Branch, Civil Division, U.S. Depa rtment of Justice, Washington, DC.

OPINION AND ORDER

BONILLA, Judge

.

Petitioner Ebonie Weaver, parent of a minor child identified herein as T.M.,
seeks review of a decision of the United States Court of Federal Claims Office of Special Masters (OSM) denying entitlement under the National Childhood Vaccine Injury Act, 42 U.S.C. § 300aa-10 et seq. Ms. Weaver claims a vaccine-induced complex febrile seizure caus ed T.M. to develop a chronic seizure disorder and, concomitantly, significantly aggravated T. M.’s preexisting developmental delay.

 This decision was initially filed under seal on February 24, 2023, in accordance with Rule 18(b) of the Vaccine Rules of the United States Court of Federal Claims, to allow the parties to propose redactions based upon privacy concerns. No proposed redactions were filed.2 For the reasons set forth below, the Court finds the Chief Special Master improperly elevated petitioner’s burden of proof by requiring contemporaneous medical screening evidence documenting brain in jury under a “seizures beget seizures” theory of causation. The legal error furt her extended to petitioner’s significant aggravation claim. Accordingly, Ms. We aver’s motion is G RANTED, the decision
of the OSM is REVERSED-IN-PART and VACATED-IN-PART, and this matter is REMANDED for further proceedings consistent with this opinion.

BACKGROUND

I. Medical History

T.M. was born on March 29, 2013. No complications were reported during delivery (at 391⁄2 weeks) and her Apgar scor es for appearance (skin color), pulse (heart rate), grimace (reflexes), activity (muscle tone), and respiration (breathing rate and effort) totaled 9 out of 10 after one minute and, again, after five minutes. 1 T.M. was discharged from the hospital on March 31, 2013. During her April 3, 2013 follow-up wellness visit, healthcare provid ers found five-day-old T.M. to be in good health.

On July 15, 2013, during her four-month wellness visit, T.M. received the following vaccines: diphtheria, tetanus, and acellular pertussis (DTaP) (1st dose); haemophilus influenzae type b (Hib) (1st dose); hepatitis B (HepB) (2nd dose); inactivated poliovirus (IPV) (1st dose); rota virus (RV) (1st dose); and pneumococcal conjugate (PVC) (1st dose). During T.M. ’s physical examination, the healthcare provider checked the “well child” box under “Assessment” on the medical form but noted “Developmental Delay.” See ECF 7-4 at 8. When asked about T.M.’s developmental progress using the Ages and Stages Questionnaires® (ASQ), 2 Ms. Weaver reported T.M. was not meetin g the following milestones: pushing up to elbows, symmetrical movement, and ro lling and reaching for objects. The healthcare provider documented their impression as “ASQ – Delay but is not 4 mo[nth]s yet.” See ECF 7-4 at 8.

1 See J OHNS H OPKINS A LL C HILDREN ’ S H OSPITAL , https://www.hopkinsallchildrens.org/PatientsFamilies/Health-Library/HealthDocNew/What-Is-t he-Apgar-Score (last visited Feb. 22, 2023) (“A baby who scores a 7 or above on the test is consid ered in good health. . . . Ten is the highest score possible, but few babies get it. That’s because most babies’ hands and feet remain blue until they have warmed up.”).

2 The Ages and Stages Questionnaires® are a screen ing tool used to measure developmental progress in children between the ages of one month and five years. See A GES AND S TAGES Q UESTIONNAIRES

, https://agesandstages.com/products-pricin g/asq3/ (last visited Feb. 22, 2023).3 On December 6 and 10, 2013, nine-m onth-old T.M. returned for her

six-month wellness visit. 3 During the December 10, 2013 visit, Ms. Weaver reported T.M. “was doing everything normal until 4 months and now she is not doing much.” See ECF 7-8 at 4; see also ECF 11-1 at 70. Documenting developmental milestones, the healthcare provider noted T.M. occasionally meets 9 of the 16 milestones, is “babbling – little” and “smiles at mom,” but she does not sit alone, roll from front to back or vice versa, pass a toy from hand to hand, imitate beginning consonant sounds, or say “mama” or “dada.” ECF 7-8 at 4. The healthcare provider referred T.M. to a de velopmental clinic for further evaluation and early intervention treatment. During the December 10, 2013 wellness visit, T.M. received the following vaccines: He pB (3rd dose); DTaP (2nd dose); Hib (2nd dose); IPV (2nd dose); PVC (2nd dose ); and RV (2nd dose). ECF 7-8 at 6. That evening, T.M. developed a fever wh ich Ms. Weaver treated with Tylenol.

On December 11, 2013 at approximately 2:00 a.m.–less than 24 hours after receiving the vaccines–T.M. was taken by ambulance to the emergency room and treated for a complex febrile seizure lasting 35 minutes. Ms. Weaver reported the following symptoms to the paramedics and hospital staff: grunting, body shakes, clenched hands, curled toes, pulsating limbs, heavy drooling, and eyes rolled upward. 4 When examined at 4:00 a.m., T.M. presented with fever and shaking and “seizure-like activity.” See ECF 11-1 at 8. Showing signs of respiratory distress, T.M. was intubated and placed on a vent ilator. T.M.’s bloodwork showed an abnormally high white blood cell count ; a flu panel, Computed Tomography (CT or CAT) brain scan, and chest x-ray yiel ded negative results. T.M. was given
antibiotics and transferred to another ho spital for treatment in the facility’s pediatric intensive care unit. Following her hospital transfer, T.M.’s fever broke

and she was extubated with no further seizure activity. An electroencephalogram (EEG) of T.M.’s brain activity performe d that afternoon was interpreted to be normal. During evening rounds, a treating physician documented the likely diagnosis as complex febrile seizure. T. M. was discharged the following day.

Six days later, on December 18, 2013, T.M. returned to the emergency room after experiencing three episodes of vomi ting and diarrhea, but no reported fever or additional seizures. By this time, Ms . Weaver had filed a Vaccine Adverse Event Reporting System (VAERS) report suggestin g a link between T.M.’s febrile seizure

3 The December 10, 2013 follow-up visit was necessa ry after healthcare providers were unable to verify T.M.’s vaccine history on December 6, 2013; consequently, no vaccines could be administered during the initial check-up.

4 T.M.’s father also reported that T.M.’s tong ue was swollen and confirmed the excess drooling.4 and her recent vaccinations. 5 T.M. was prescribed a naus ea medication, instructed to stay hydrated, and discharged. Du ring a January 14, 2014 wellness visit, the treating physician documented their assessment of T.M.’s December 11, 2013 episode as a “DTaP induced versus febrile seizure.” See ECF 7-4 at 5.

On March 18, 2014, T.M. returned to the emergency room after suffering a second febrile seizure and remained hospita lized overnight for observation. Medical staff flagged T.M.’s “significant developmen tal delay” and urged Ms. Weaver to seek early intervention for T.M. through prescribed physical and occupational therapy.
See ECF 7-7 at 241; accord id. at 239–40. In early April 2014, healthcare providers
continued to raise concerns that T.M. wa s not meeting developmental milestones.

On May 1, 2014, T.M. suffered a third febrile seizure while at daycare and again transported by ambulance to the em ergency room. According to her daycare provider, T.M. “began to shake, foam at th e mouth, and her eyes rolled into the back of her head while [the te acher] was holding her.” See ECF 7-1 at 2. Prior to her discharge later that day, T.M.’s body temperature measured 102.2 degrees. Over the following week, T.M. was evaluated by the Illinois Bureau of Early Intervention and a pediatric neurologist. She was di agnosed as suffering from “[e]pileptic seizures, [f]ebrile seizures, [s]taring spell, and [d]evelopmental delay.” See ECF 7-2 at 10. T.M. was prescribed a low dose of the anti-epileptic drug Keppra.

During a May 13, 2014 wellness visit, Ms. Weaver reluctantly authorized
the administration of three more vacci nes: measles, mumps, and rubella (MMR) (1st dose); varicella/chickenpox (1st dose); and hepatitis A (HepA) (1st dose). Two months later, on July 3, 2014, T.M. underwent a two-hour EEG. The results were found “within normal limits and ap propriate for [the] patient[’s] age”; however, the entry under “[a]bnormalities” reads: “slow wave activity was present throughout the recording and was unrespons ive to stimulation.” ECF 7-2 at 43.

Through the fall of 2014, T.M.’s over all development showed few signs of improvement. During a September 4, 2014 wellness visit, 17-month-old T.M.

did not meet any of the 11 evaluated developmental milestones. 6 Concerned the vaccinations were causing or contributing to T.M.’s continuing health issues,
Ms. Weaver declined to authorize additi onal scheduled vaccinations for T.M.

5 Co-managed by the Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA), VAERS “is a national early wa rning system to detect possible safety problems
in U.S.-licensed vaccines.” See VAERS, https://vaers.hhs.gov/about.html (last visited Feb. 22, 2023).

6 Although T.M. was reportedly “rolling more frequently” and “up on her knees,” she was not yet crawling. See ECF 7-3 at 71. Moreover, the healthcare provider checked “no” for the following developmental milestones: vocabulary 3 to 6+ words; listens to story; points to one or more body parts; gestures what they want; understands si mple commands; walks, stoops, climbs stairs; stacks blocks; feeds self with fing ers; drinks from a cup; looks for fallen objects; and social play. Id.5 On December 30, 2014, T.M. suffered a breakthrough seizure and returned to the emergency room. The seizure reportedly “last[ed] for about ten minutes [and]
then resolved on its own.” See ECF 7-9 at 5. Hospital st aff attributed the episode to T.M. missing her morning dose of Keppra . By the time T.M. was examined by a doctor two hours after her arrival at the hospital, she had returned to her baseline and discharged. T.M.’s development show ed no documented signs of improvement throughout 2015 and into 2016.

On May 8, 2016, T.M. experienced an ac tive afebrile seizure and was taken to the emergency room. Medical staff attr ibuted the episode to T.M.’s reported congestion, exposure to vi ral illness, and a missed Keppra dose. A continuous-video EEG identified the following abnormalitie s: absent posterior dominant rhythm (PDR); excessive beta activity; and diffuse slowing. The EEG report further noted: “EEG is consistent with a global enceph alopathy and drug-induced fast activity.” 7
See ECF 9-4 at 62. An August 16-17, 2016 follow-up ambulatory (24-hour) EEG revealed the following abnormalities: “reg ional epileptiform discharges involving the posterior quadrant maximal over midline parieto-occipital region.” Id. at 293-
94. The results were deemed “consistent with an active epileptogenic source in the midline parieto-occipital region [of the brain].” Id.

Since then, T.M. has experienced se veral afebrile seizures resulting in additional trips to the emergency room and, in at least one instance, being admitted to the hospital. In diagnosing T.M., healthcare providers generally offer non-vaccine related explanations (e.g., recurrent ear infections, missed Keppra doses, exploring alternative treatments). Her current diagnoses include epilepsy and global encephalopathy (i.e., global developmental delay). Nearing her 10th birthday, T.M.’s global and profo und developmental delays continue. She remains nonverbal, wears diapers, an d continues to experience seizures.

II. Petition and OSM Decision

Ms. Weaver’s petition presents a caus ation claim and significant aggravation claim, asserting the December 10, 2013 vacci nes administered to T.M. caused her seizure disorder and significantly worsened her developmental delays. In support of her causation claim, Ms. Weaver relies upon the “seizures beget seizures” theory, asserting that T.M.s’ initial vaccine-ind uced febrile seizure lowered her seizure threshold, paving the way for her chroni c seizure disorder. The resulting brain damage from the attributable seizures, Ms. Weaver continues, significantly aggravated T.M.’s preexisti ng developmental delays.

7 “Encephalopathy is a term for any disease of the brain that alters brain function or structure.” See

N ATIONAL I NSTITUTE OF N EUROLOGICAL D ISORDERS AND S TROKE

, https://www.ninds.nih.gov/healthinformation/disorders/encephalopathy#:~:text =Encephalopathy%20is%20a%20term%20for,increased %20pressure%20in%20the%20skull (last visited Feb. 22, 2023). Although the parties dispute the import of this diagnosis, the OSM decision unde r review makes no mention of the May 8, 2016 EEG.6 On September 23, 2022, the OSM issued a decision denying entitlement. The Chief Special Master found the December 10, 2013 vaccinations were responsible for T.M.’s ensuing fever and at least contribu ted to her initial febrile seizure. Citing the “absence of evidence that [T.M.’s] br ain was likely damaged by the first febrile seizure,” however, the Chief Special Master concluded T.M.’s subsequent seizures were not likely attributable to the first. Weaver v. Sec’y of He alth & Hum. Servs.

, No. 16-1494V, 2022 WL 12542485, at *1 (Fed. Cl. Spec. Mstr. Sept. 23, 2022). The Chief Special Master also held Ms. Weaver failed to establish that T.M.’s preexisting developmental delays were si gnificantly aggravated by her initial
vaccine-induced febrile seizure.

DISCUSSION

I. Standard of Review

In reviewing a Vaccine Act decision, this Court may

(A) uphold the findings of fact and conclusions of law of the special master and sustain th e special master’s decision,

(B) set aside any findings of fact or conclusion of law of the special master found to be arbi trary, capricious, an abuse of discretion, or otherwise not in accordance with law and issue its own findings of fact and conclusions of law, or

(C) remand the petition to the special master for further action
in accordance with the court’s direction.

42 U.S.C. § 300aa-12(e)(2). The Federal Circuit clarifie d the applicable standards of review as follows: findings of fact are re viewed under the arbitrary and capricious standard; discretionary rulings are reviewed under an abuse of discretion standard; and legal conclusions are reviewed de novo under the “not in accordance with law”

standard. Turner v. Sec’y of He alth & Hum. Servs. , 268 F.3d 1334, 1337 (Fed. Cir. 2001) (citing Munn v. Sec’y of He alth & Hum. Servs. , 970 F.2d 863, 870 n.10 (Fed. Cir. 1992)).

II. Causation-In-Fact

To prove causation-in-fact for an injury not listed in the Vaccine Injury Table, 42 U.S.C. § 300aa–14(a) (“off-Table injury”), a petitioner must demonstrate by preponderant evidence:7 (1) a medical theory causally connecting the vaccination and the injury; (2) a logical sequence of cause and effect showing that the vaccination was the reason for the injury; an d (3) a showing of a proximate temporal relationship between vaccination and injury.

Althen v. Sec’y of Health & Hum. Servs. , 418 F.3d 1274, 1278 (Fed. Cir. 2005). To satisfy this burden, a petitioner need not pr ove their claim to a medical or scientific certainty; rather, they must simply show that it is “more likely than not” that the vaccine caused the injury. Moberly v. Sec’y of Health & Hum. Servs., 592 F.3d 1315, 1322 (Fed. Cir. 2010).

The three Althen prongs comprise an overlapping analysis determining whether a vaccine more likely than not caused injury. Capizzano v. Sec’y of Health
& Hum. Servs. , 440 F.3d 1317, 1326 (Fed. Cir. 2006) (“[T]he statute requires only that the claimant show that it is more likely than not that this claimant’s [injury] was caused by the vaccine.”) (emphasis in original). Under the first prong, petitioner must provide a reputable medi cal or scientific explanation for their theory of causal connection. Boatmon v. Sec’y of Health & Hum. Servs. , 941 F.3d 1351, 1359 (Fed. Cir. 2009) (quoting Moberly , 592 F.3d at 1322). To satisfy the second prong, petitioner must show how the facts of their case align with the medical theory presented and demonstrate a logical connection between the vaccine and the injury (i.e., a logical sequence of cause and effect). See Capizzano , 440 F.3d at 1326 (“[M]edical records and medical op inion testimony are favored in vaccine cases, as treating physicians are likely to be in the best position to determine whether ‘a logical sequence of cause and effect show[s] that the vaccination was the reason for the injury.’”) (quoting Althen , 418 F.3d at 1280) (c iting 42 U.S.C. § 300aa–13(a)(1)). Finally, the third prong requires petiti oner to show the injury occurred within the expected time fr ame of the proposed medical theory. See de Bazan v. Sec’y of Health & Hum. Servs. , 539 F.3d 1347, 1352 (Fed. Cir. 2008).

In this case, the Chief Special Ma ster found Ms. Weaver satisfied Althen prongs one and three. In addressing pr ong one, the Chief Special Master found that Ms. Weaver provided a credible medical theory demonstrating how vaccines can cause a febrile seizure and, in turn, how a febrile seizure can cause a chronic

seizure disorder. See Weaver , 2022 WL 12542485, at *25 (“I can easily determine

herein that almost any vaccine, alone or grouped with others, could cause sufficient inflammation to trigger a single febrile seizure.”) (emphasis in original); id. at *27 (“I emphasize again—the contention th at a vaccine-caused febrile seizure could
constitute the first ‘domino’ in a chronic se izure disorder is scientifically reliable.”) (emphasis in original). Regarding prong three, the Chief Special Master credited testimony demonstrating the requisite timi ng between T.M.’s vaccination and her complex febrile seizure. See id. at *12 (“Finally, Dr. Huq addressed the timeframe
between T.M.’s vaccinations and her first se izure, deeming it consistent with the short interval for initial inflammatory ch anges (which could occur within 24 hours to a few days after vaccination).”). Neithe r of these conclusions are contested here.8 Accordingly, the Court focuses on the dete rmination that Ms. Weaver did not satisfy

the second Althen prong.



### A. Contemporaneous Evidence of Brain Injury

The Chief Special Master improperly el evated Ms. Weaver’s burden of proof

under Althen prong two. In denying compensat ion, the Chief Special Master
focused on the absence of abnormal scr eening results evidencing brain injury contemporaneous with T.M.’s first febrile seizure, finding:

[T]he medical record in this case does not support the conclusion that T.M.’s December 2013 post-vaccination febrile seizure caused her epilepsy.

Specifically, the record does not est ablish that the initial febrile seizure harmed T.M.’s brain sufficiently to co nclude that it likely “explains” what transpired thereafter. On the contrary, persistent testing performed over the next two-plus ye ars, whether in the form of EEGs or [magnetic resonance imaging (MRIs)], did not confirm the presence
of a seizure-induced brain malforma tion or injury that could then (under a “seizures beget seizures” theory) be deemed causal of all subsequent seizures.

See Weaver , 2022 WL 12542485, at *25 (emphasis in original) (citing three EEGs, an MRI, and a CT scan yielding normal results between December 2013 and May 2016). The Chief Special Master note d that it was not until August 2016 that epileptiform activity in T.M.’s brain was corroborated by an EEG yielding abnormal

results. Id. Upon these findings, the Chief Spec ial Master concluded T.M.’s first vaccine-induced seizure could not be deemed responsible for her epilepsy “in the absence of record evidence corroborating the presence of brain injury that could credibly be attributed to the vaccine-induced febrile seizure.” Id. at *27.

Requiring abnormal screening result s to substantiate T.M.’s initial brain injury contradicts the spirit of th e Vaccine Act and the standard to which petitioners are held. The preponderance of the evidence standard applicable under the Act does not require medical cert ainty. Rather, causation is determined on a case-by-case basis with “no hard and fast per se scientific or medical rules.” Knudsen v. Sec’y of Health & Hum. Servs. , 35 F.3d 543, 548 (Fed. Cir. 1994). Moreover, under the National Vaccine In jury Program, close calls regarding
causation are resolved in fa vor of injured claimants. Althen , 418 F.3d at 1280. The question whether T.M.’s brain was harmed by her initial vaccine-induced complex febrile seizure, leading to her chronic seiz ure disorder, is a close call and, as such,
must be resolved in Ms. Weaver’s favor.9 Under the scientifically sound theory th at a vaccine-caused complex febrile seizure could serve as the proverbial “first domino” to topple culminating in T.M.’s development of a chronic seizure disorder, the second Althen prong required Ms. Weaver to produce only a measure of reliable evidence that her brain was more likely than not harmed by the initial seizure. While a concurrent abnormal EEG or other medical screening may provide such evidence, the absence of an abnormal screening alone is not determinative.

The Federal Circuit has rejected the requirement that a petitioner satisfy the

second Althen prong by presenting specific medica l evidence or scientific proof to establish a logical sequence of cause and effect, concluding that such a requirement “impermissibly raises a claimant’s burden under the Vaccine Act.” See Capizzano

, 440 F.3d at 1325–26. The court highlighted the inherent value of opinions from treating physicians and medical experts. See id. at 1325. Relevant circumstantial evidence may satisfy the preponderance standard. Id. In this case, T.M.’s treating physicians and medical expert opined that T.M.’s regression evid ences the impact of her initial vaccine-induced seizure (and su bsequent seizures) on her development. In contrast, expert witness testimony rega rding the probative value of the initial EEGs and other screening tests were, at best, inconclusive.

1. Treating Physicians

“[Medical opinion] testimony is ‘quite probative’ since ‘treating physicians are likely to be in the best position to de termine whether a logical sequence of cause and effect show[s] that the vaccinatio n was the reason for the injury.’” Andreu v. Sec’y of Health & Hum. Servs. , 569 F.3d 1367

, 1375 (Fed. Cir. 2009) (quoting Capizzano , 440 F.3d at 1326) (additional citations omitted). Indeed, “in certain cases, a petitioner can prove a logical sequence of cause and effect between a vaccination and the injury ( Althen prong two) with a physician’s opinion to that effect where the petitioner has proved th at the vaccination can cause the injury ( Althen prong one) and that the vaccination and injury have a close temporal proximity ( Althen prong three).” Moriarty v. Sec’y of Health & Hum. Servs.

, 844 F.3d 1322, 1333 (Fed. Cir. 2016) (citing Capizzano , 440 F.3d at 1326).

Under Ms. Weaver’s scientifically re liable seizures beget seizures theory of causation, children who experience febrile seizures–particularly complex febrile seizures–are more likely to develop seizure disorders, including epilepsy. The proffered theory is sufficiently born e out by the circumstantial evidence presented. The causal link between T. M.’s December 10, 2013 vaccinations and her initial complex febrile seizure within 24 hours is well documented in T.M.’s contemporaneous emergency room records. Further, the medical opinions of T.M.’s pediatric neurologist connected T.M.’s initial febrile seizure and her currently diagnosed seizure disorder. Contemporaneous medical records prepared by other healthcare professionals further document T.M.’s developmental regression and10 substantiate a causal connection between T.M.’s initial febrile seizure and her current diagnosis.

In the days and months following T.M.’s third febrile seizure over the course of five months, pediatric neurology specialist Lubov Romantseva, MD, noted T.M.’s developmental plateaus and regressions occurred contemporaneously with T.M.’s
vaccinations and the onset of her febrile seizures. See, e.g. , ECF 7-2 at 15, 16, 76. To this point, the frequency of T.M.’s febr ile seizures and the possible impact of the antiseizure medication prescribed immediately following T.M.’s third febrile seizure proves corroborative. Prior to taking a daily dose of Keppra, T.M. suffered febrile seizures on December 11, 2013, March 18, 2014, and May 1, 2014. Her subsequent December 30, 2014, and May 8, 2016 febrile seizures occurred on days when T.M. did not take her medication. Dr. Romantseva continues to treat T.M. and, based on the record presented, her opinions supply substantiated evidence of causation. See Mondello v. Sec’y of Health & Hum. Servs. , 132 Fed. Cl. 316, 323 (2017) (“Medical records ‘warrant consideration as trustworthy evidence’ because these records are ‘generally contemporaneous to medica l events,’ and ‘accuracy has an extra premium.’”) (citing Cucuras v. Sec’y of Health & Hum. Servs. , 993 F.2d 1525, 1528 (Fed. Cir. 1993)).

T.M.’s developmental evaluations timeline further supports the conclusion that T.M. experienced developmental regre ssion as a result of her vaccine-induced December 11, 2013 complex febrile seizure an d subsequent febrile seizures. At her December 10, 2013 wellness visit–during wh ich T.M. received the vaccine regimen at issue–she was reported to meet some (but not all) developmental milestones.

See ECF 7-8 at 4. During a 12-month wellness visit conducted on April 8, 2014–
one month after T.M. suffered a second febrile seizure in three months–Lester Hockenberry, MD, documented that T. M. met only 1 of 13 developmental

milestones. See ECF 7-3 at 85–86. By September 4, 2014, Dr. Hockenberry reported that T.M. did not meet a single developmental milestone. See ECF 7-3 at 71. The Court finds the contemporan eous medical opinions regarding T.M.’s developmental regression probative in determining T.M. suffered a brain injury
after her first vaccine-induced febrile seizure.

Relevant here, the Chief Special Ma ster seemingly conflated T.M.’s pre-seizure developmental concerns with he r post-seizure developmental regression.
See Weaver , 2022 WL 12542485, at *26 (“The fact th at T.M.’s seizures occurred in the context of established developmental co ncerns also weighs against a conclusion
that her first seizure caused what followed. ”). As expert witnesses for both parties explained, there is a significant difference between developmental delay and regression. Pediatric Neurologist John Zempel, MD, for example, distinguished between the “many kids who have development delay,” and the “uncommon” phenomenon of regression, which requires immediate evaluation and treatment by a neurologist. See ECF 72 at 251. In turn, Pediatric Neurologist Ahm M. Huq, MD,11 explained that a loss of once-mastered skil ls is “unusual” and, in the absence of evidence of illness or degenerative conditio n, is compelling evidence of harm to the

brain. Id. at 105–06. Dr. Huq further noted the adverse impact brain seizures can have on child development, particular ly during their early years of critical development. See id. at 107.

Notwithstanding the negative screenings cited by the Chief Special Master,

discussed infra , the Court finds sufficient eviden ce in the record to support
Ms. Weaver’s contentions that T.M.’s De cember 11, 2013 vaccine-induced complex febrile seizure made her more susceptible to future seizures and that indications of a lowered seizure threshold were partially masked by the prescribed antiseizure medication. The Court notes the plausibility of this explanation for why T.M.’s allegedly lower seizure threshold did not result in significantly more seizures: it would strain credulity to suggest it is mere ly coincidental that on the two reported days T.M. missed a Keppra dosage, she suffer ed additional seizures. T.M.’s ensuing developmental regression further evidence s the brain damage she suffered.

In reaching these conclusions, the Court finds several similar OSM decisions

instructive. See, e.g.

, Silverio v. Sec’y of Health & Hum. Servs. , No. 15-235V, 2019 WL 6694020 (Fed. Cl. Spec. Mstr. Nov. 14. 2019) (complex febrile seizure triggered propensity for additional seizures; Althen prong two satisfied by treating physician’s testimony despite normal EEG , MRI, and CT scans; first abnormal reading occurred two years after initial complex febrile seizure using a continuous EEG); Fuller v. Sec’y of Health & Hum. Servs. , No. 15-1470V, 2019 WL 7576382 (Fed. Cl. Spec. Mstr. Dec. 17, 2019) (co mplex febrile seizure increased risk of developing epilepsy under seizures beget seizures theory; Althen prong two satisfied in part by expert testimony; first conclusively abnormal EEG was conducted three years after the initial seizure); Ginn v. Sec’y of Health & Hum. Servs.

, No. 16-1466V, 2021 WL 1558342 (Fed. Cl. Spec. Mstr. Mar. 26, 2021) (considering

normal MRI results as evidence ru ling out alternative causes under Althen prong two, but not ruling out vaccinations as the potential cause). Put simply, requiring contemporaneous abnormal screening evidence to prove brain injury under a “seizures beget seizures” theory of causat ion improperly elevates a petitioner’s

burden under the second Althen prong.

2. EEGs and Other Screenings

As noted in the Chief Special Master’s decision, medical experts for both parties testified to the limitations of EEGs and other screening tests in detecting brain injury or abnormality. See, e.g. , ECF 72 at 250 (Dr. Zempel: “If you have epileptiform abnormalities, that makes it more likely that you have a diagnosis of epilepsy. A normal EEG does not ru le out that you have epilepsy.”); id. at 44–45, 148–49 (Dr. Huq: “a short-term EEG has a 30 percent chance of capturing the abnormal. A long-term EEG usually have [sic] 60 percent, 60 or 70 percent. So a12 positive EEG is helpful, and negative EEG cannot rule out the diagnosis. It’s always a clinical diagnosis.”). Moreover, in re viewing T.M.’s abnormal August 2016 EEG results, Dr. Zempel reiterated:

I think that this is the first time we’ve seen evidence of epileptiform activity on an EEG. Again, I think that means it’s more likely in the future that there could be recurrent unprovoked seizures, but there
are children out there who have these abnormalities and don’t have epilepsy, and there are children who have epilepsy and don’t have any abnormalities

.

Id. at 255 (emphasis added). Regarding T. M.’s normal screening results during the first two years following her initial co mplex febrile seizure, Dr. Huq opined on their limited import because “[t]here are patients who have seizures every day and can have normal EEG[s].” Id. at 148–49. As noted above, Dr. Huq explained that the short-term EEGs performed in the two years following T.M.’s initial complex febrile seizure have only a 30 percent chan ce “of capturing the abnormal[,]” whereas long-term EEGs–like the one performed in May 2016 (and August 2016)–capture abnormalities in 60 to 70 percent of individuals. Id. at 143, 148–49. Overall, both experts agreed that T.M.’s abnorma l August 2016 EEG was consistent with epilepsy, and Dr. Huq, in particular, op ined that her multiple EEGs (including those that were normal) were co nsistent with this diagnosis.

With respect to MRIs, Dr. Huq expl ained they would not likely detect molecular changes in the brain that occu r after status epilepticus or a complex febrile seizure, and that the molecular changes might not be detectable for years.
See id. at 93. In turn, although highlighting an MRI’s ability to detect prolonged seizures and significant brain injuries, Dr . Zempel declined to opine that an MRI would detect all injuries in 100% of cases. See ECF 73 at 7–8. As for CT scans, Dr. Zempel testified he was “much less co nfident that a significant injury would appear on CT scan.” Id. at 6.

Consistent with the Federal Circuit’s decision in Capizzano , the nature and extent of the Chief Special Master’s reliance upon EEG and other screening

evidence was in error. See 440 F.3d at 1325–28. While abnormal screening results may be probative, the law does not requ ire abnormal screening results to prove a particular injury under the Vaccine Act.



### B. Burden to Eliminate Alternative Causes

To the extent the Chief Special Master assigned Ms. Weaver the burden of eliminating alternative independent potentia l causes for T.M.’s injury as part of her prima facie causation claim, the burden shift constitutes legal error. Under the Vaccine Act, once a petitioner has met thei r burden on causation, the burden shifts13 to the Secretary to establish by a preponde rance of the evidence that the injury or

harm was unrelated to the vaccine. See Walther v. Sec’y of Health & Hum. Servs.

, 485 F.3d 1146, 1151 (Fed. Cir. 2007) (citations omitted). As stated by this Court:

The Act only requires a showing of “but for” causation and that the vaccine was a “substantial factor,” not that the vaccine was the only
cause. Thus the coincidence of an other potential causal agent is not fatal to a claim under the Act. If petitioner meets its burden on causation, then it is the government’s burden to prove that some other cause is to blame, not petitioner’s to disprove it.

Mondello , 132 Fed. Cl. at 325.

Importantly, while evidence of other poss ible sources of injury can be relevant in the causation analysis, the Federal Circuit has clarified:

first, that a special master may not require the petitioner to shoulder the burden of eliminating all possible alternative causes in order establish a prima facie case[;] and second, that a special master may find that a factor other than a vaccine caused the injury in question only if that finding is supported by a preponderance of the evidence.

Stone v. Sec’y of Health & Hum. Servs. , 676 F.3d 1373, 1380 (Fed. Cir. 2012) (internal citations omitted). 8

8 The Secretary seeks to apply the holding in Stone to this case. Readily distinguishable from this case, in Stone , the special master concluded that the children’s SCN1A gene mutation was the
sole cause of their severe myoclonic epilepsy of infancy (SMEI) (also known as Dravet syndrome), and that the petitioners failed to establish the existence of any brain damage. See 676 F.3d at 1375, 1377–78, 1385. In affirming the OSM’s decision, the Federal Circuit held: “[t]he special master did not reject the petitioners’ evidence of brain damage on the ground that it was circumstantial; rather, he found that [the expert’s] inference of brain da mage, in the face of clinical records showing no brain damage, was unpersuasive and that it was therefore insufficient to carry the petitioners’
burden on causation.” Id. at 1385. It is also worth noting that in Stone , unlike here, the burden of proof shifted to the respondent to demonstrate by a preponderance of the evidence that the gene mutation “was ‘more likely than not the “but for” and “substantial factor” that caused’ the SMEI in
both children.” Id. at 1377 (citations omitted).

Here, it is undisputed–and confirmed by both parties’ experts–that T.M.’s August 2016 EEG was abnormal, demonstrated global encephalop athy, and is consistent with T.M.’s epilepsy diagnosis. Compare ECF 9-4 at 293–94 and ECF 72 at 145–46, 254–55 with Stone , 676 F.3d at 1382 n.2, 1385 (finding EEG evidence “questionable” ; petitioner’s expert witness unpersuasive). Additionally, the Court finds T.M.’s medical records—particularly the medical opinions of her pediatric neurologist and contemporaneous de velopmental assessments—amply support the conclusion that T.M. experienced developmental regression, which is probative circumstantial evidence of brain injury in this case.14 In this case, rather than hold the Secre tary to their shifted burden of proof, the Chief Special Master faulted Ms. We aver for not refuting or otherwise addressing the notion that T.M.’s developmental delay could have caused or increased her risk or propensity for seizures. See Weaver , 2022 WL 12542485, at *26 (“Although I do not purport to find that T.M.’s developmental issues explain her subsequent seizure activity and epilepsy, Pe titioner did not persuasively rebut this kind of evidence, and it therefore further diminishes the possibility that the initial
febrile seizure alone explained why T.M. continued to experience seizures afterward.”) (emphasis added); id. (“ [T]he record in this case paints a picture of a child likely susceptible to seizure activity generally, but whose course could not be
deemed inevitable once the first febrile seizure occurred. T.M.’s initial febrile seizure was likely vaccine-caused—but that seizure in turn was not the cause of what followed.”) (emphasis in original). The law is clear: Ms. Weaver is not required to prove that T.M.’s initial vacci ne-induced complex febrile seizure was the sole or predominant cause of her epilepsy. See Shyface v. Sec’y of Health & Hum.
Servs. , 165 F.3d 1344, 1352–53 (Fed. Cir. 1999) (petitioners must demonstrate

vaccine was a but-for cause of and a substantial factor in the resulting injury; petitioners are not required to establish the vaccine was the only or predominate cause of the injury).

III. Significant Aggravation

Under the Vaccine Act, claimants ma y seek compensation for preexisting injuries that were “significantly aggr avated” by vaccination. 42 U.S.C. § 300aa11(c)(1)(C)(i-ii). To prove an off-Table significant aggravation claim, petitioners must satisfy the six-prong test adopted in Loving v. Sec’y of Health & Hum. Servs.

, 86 Fed. Cl. 135, 143–44 (2009). Under the Loving framework, a petitioner must establish by a preponderance of the evidence:

(1) the person’s condition prior to a dministration of the vaccine, (2) the person’s current condition (or the condition following the vaccination if that is also pertinent), (3) wh ether the person’s current condition constitutes a “significant aggravation” of the person’s condition prior to vaccination, (4) a medical theory causally connecting such a significantly worsened condition to the vaccination, (5) a logical sequence of cause and effect showing that the vaccination was the reason for the significant aggrav ation, and (6) a showing of a proximate temporal relationship between the vaccination and the significant aggravation.

Id. at 144. Here, Ms. Weaver argues T.M.’s vaccine-induced complex febrile seizure and resulting seizure disorder exacerbated her preexisting developmental delay.15 In addressing the significant aggravat ion claim, the Chief Special Master found that T.M.’s contemporaneously documented pre-vaccine developmental issues

“ literally worsened” and became “more pronounc ed” in the months and years after she was vaccinated, thereby satisfying the first three Loving factors. See Weaver

, 2022 WL 12542485, at *27 & n.21 (emphasis in original). Turning to the fourth factor, the Chief Special Master “assum[ed ] that a vaccine-induced febrile seizure could cause sufficient brain injury to worsen preexisting developmental issues.” 9
See id. at *27.

In assessing the fifth Loving factor, the Chief Special Master relied upon his findings under the second Althen prong, concluding that T.M.’s initial vaccineinduced complex febrile seizur e was similarly not “the source of worsening” for her developmental delay. See Weaver , 2022 WL 12542485, at *27

. The Chief Special Master explained: “My finding with respect to a lack of sufficient ‘did cause’ proof that the first, vaccine-caused febrile seiz ure T.M. experienced was causal of her overall epilepsy also bears on Petitioner’s claim that her pre-existing developmental delays were exacerbated by th e December 2013 vaccinations.” See id. ; accord id. at *28 (“[T]he initial, undoubtedly vaccine-related febrile seizure has not been shown to be the ‘linchpin’ to what followed.”). Given the Court’s conclusion reversing the

causation determination under Althen prong two, the extension of the erroneous finding in analyzing the Loving factors necessitates a reeval uation on remand. 10

CONCLUSION

For the foregoing reasons, Petitioner’s Motion for Review (ECF 83) is
GRANTED , the Decision Denying Entitlement issued by the Office of Special Masters (ECF 77 & 81) is REVERSED-IN-PART and VACATED-IN-PART

, and this case is REMANDED for further proceedings cons istent with this opinion.

It is so ORDERED

.

___________________ Armando O. Bonilla Judge

9 The assumption is presumably based on the Chief Special Master’s findings regarding Althen prong one (i.e., the counterpart to the third Loving factor).

10 On remand, the Chief Special Mast er must also address the sixth Loving factor (i.e., proximate temporal relationship between the vaccination an d the significant aggravation)–the counterpart

to the third Althen prong–as his initial decision is silent on that issue. The Court declines to make these factual findings in the first instance on petitioner’s motion for review. See, e.g.

, Mondello

, 132 Fed. Cl. at 325.