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PLAINTIFF’S MOTION IN LIMINE NO. 1 TO EXCLUDE DR. THOMAS MAMPALAM’S OPINIONS 

REGARDING PURPORTED PSYCHIATRIC AND PSYCHOLOGICAL DIAGNOSES 

MIRIAM KIM (State Bar No. 238230) 

miriam.kim@mto.com 

EMILY C. CURRAN-HUBERTY (State Bar No. 293065) 

emily.curran-huberty@mto.com 

SKYLAR D. BROOKS (State Bar No. 310707) 

skylar.brooks@mto.com 

MUNGER, TOLLES & OLSON LLP 

560 Mission Street 

Twenty-Seventh Floor 

San Francisco, California 94105-2907 

Telephone: (415) 512-4000 

Facsimile: (415) 512-4077 

Attorneys for Plaintiff 

RENEE LEPAGE 

UNITED STATES DISTRICT COURT 

NORTHERN DISTRICT OF CALIFORNIA, SAN FRANCISCO DIVISION 

RENEE LEPAGE, an individual, 

Plaintiff, 

vs. 

COUNTY OF NAPA; COUNTY OF NAPA 

SHERIFF’S DEPARTMENT; AND DEPUTY 

TIMOTHY REID, 

Defendants. 

 Case No. 3:17-cv-00600-LB 

PLAINTIFF’S MOTION IN LIMINE NO. 1 

TO EXCLUDE DR. THOMAS 

MAMPALAM’S OPINIONS REGARDING 

PURPORTED PSYCHIATRIC AND 

PSYCHOLOGICAL DIAGNOSES 

Judge: Hon. Laurel Beeler 

Date: September 26, 2019 

Time: 1:30 p.m. 

Crtrm.: B – 15th Floor 

Trial Date.: October 15, 2019 

Case 3:17-cv-00600-LB Document 115 Filed 09/06/19 Page 1 of 8
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 -1- 17-cv-00600-LB

PLAINTIFF’S MOTION IN LIMINE NO. 1 TO EXCLUDE DR. THOMAS MAMPALAM’S OPINIONS 

REGARDING PURPORTED PSYCHIATRIC AND PSYCHOLOGICAL DIAGNOSES 

I. INTRODUCTION 

Defendants intend to have neurosurgeon Dr. Thomas Mampalam offer speculative 

opinions that Plaintiff Renee LePage likely has psychological or psychiatric disorders, among 

other testimony. Ms. LePage acknowledges that Dr. Mampalam is generally qualified to testify 

regarding her physical spinal conditions and neurosurgical issues, but he lacks sufficient 

knowledge and experience, as well as reliable bases, to diagnose Ms. LePage with psychological 

or psychiatric disorders. Moreover, any probative value of such speculative opinions is greatly 

outweighed by the danger of undue prejudice, confusing the issues, and misleading the jury. Dr. 

Mampalam therefore should be precluded from offering opinions that suggest that Ms. LePage 

likely has a psychological or psychiatric condition. 

Dr. Mampalam is a neurosurgeon who focuses on spinal surgery. Brooks Decl. Ex. A 

(“Mampalam CV”); id. Ex. B (Mampalam Dep. (“Dep.”)) 12:23-13:7, 15:25-16:3. He 

acknowledges that he is “not a psychiatrist or a psychologist.” Dep. 15:25-16:3. In Defendants’ 

expert disclosures, they disclosed Dr. Mampalam as a “retained neurosurgeon and IME 

physician,” not as an expert in psychiatry or psychology. Id. Ex. C (“Defs.’ Expert Disclosure”) at 

1. Likewise, when Dr. Mampalam was asked at his deposition what areas of expertise he has that 

are relevant to his opinions in his case, he identified only that he is a board-certified neurosurgeon 

and has experience practicing as a neurosurgeon. Dep. 12:23-13:7. Dr. Mampalam has no 

specialized training in psychiatry or psychology, Mampalam CV & Dep. 12:20-13:7, 55:17-20; he 

is not board-certified in psychiatry or psychology, Mampalam CV & Dep. 17:9-13; he is not 

qualified to treat psychiatric conditions, Dep. 55:6-8; and he has not published any research that 

bears on his opinions in this case, id. at 18:11-20. 

Despite his lack of expertise in psychiatry and psychology, Dr. Mampalam offered 

opinions in his expert report and at his deposition that Ms. LePage likely has one or more 

psychiatric or psychological disorders. For example, he opined in his report that Ms. LePage “has 

an abnormal gait that appears unlikely to be due to a cervical myelopathy, but is more likely a 

hysterical gait, a psychiatric disorder such as a conversion reaction, or an extreme case of 

symptom elaboration in the context of possible secondary gain.” Brooks Decl. Ex. D (“IME 

Case 3:17-cv-00600-LB Document 115 Filed 09/06/19 Page 2 of 8
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PLAINTIFF’S MOTION IN LIMINE NO. 1 TO EXCLUDE DR. THOMAS MAMPALAM’S OPINIONS 

REGARDING PURPORTED PSYCHIATRIC AND PSYCHOLOGICAL DIAGNOSES 

Report”) at 12. At his deposition, Dr. Mampalam provided the following definitions of these 

conditions: 

 “[A hysterical gait] means a gait that is abnormal based on a psychiatric or 

psychological condition rather than a physical condition.” Dep. 50:19-51:2. 

 “[A conversion reaction] is a specific type of psychological condition where a 

patient develops a physical abnormality . . . for which physicians can’t find a 

physiological or anatomic basis. And it can . . . be related to some kind of 

emotional or psychological turmoil.” Id. at 51:3-11. 

 “[Symptom elaboration in the context of possible secondary gain can mean] that 

she was making it up . . . either unconsciously or consciously and doing these 

things for the possibility of getting some external motivating factor such as 

financial compensation or time off work or something else like that.” Id. at 51:12-

21. 

The basis Dr. Mampalam provided for his opinion that Ms. LePage more likely has one of these 

three conditions was simply that “[i]f [Ms. LePage’s abnormal gait] was not related to something 

physical, it is likely something psychological or psychiatric.” Id. at 53:5-10. 

In addition, Dr. Mampalam stated in his report and at his deposition that Ms. LePage 

“underwent cervical spine surgery for what is likely mostly a psychological or psychiatric 

condition.” IME Report at 13; Dep. 47:8-21, 67:14-68:6. The basis Dr. Mampalam provided for 

this opinion was that he believed there was a discrepancy between Plaintiff’s complaints and the 

objective findings. See Dep. 67:14-68:23. In his report and during his deposition, Dr. Mampalam 

did not identify any objective bases that support diagnosing Ms. LePage with a specific 

psychological or psychiatric disorder. Dr. Mampalam performed a physical examination of Ms. 

LePage for this case but has never performed a psychiatric evaluation of her. See generally IME 

Report & Dep. 27:22-28:2. 

///// 

Case 3:17-cv-00600-LB Document 115 Filed 09/06/19 Page 3 of 8
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 -3- 17-cv-00600-LB

PLAINTIFF’S MOTION IN LIMINE NO. 1 TO EXCLUDE DR. THOMAS MAMPALAM’S OPINIONS 

REGARDING PURPORTED PSYCHIATRIC AND PSYCHOLOGICAL DIAGNOSES 

II. ARGUMENT 

A. Dr. Mampalam’s Opinions that Purport to Diagnose Ms. LePage with 

Psychological or Psychiatric Disorders Are Inadmissible Under Federal Rule 

of Evidence 702, Because They Are Outside His Expertise and Are Speculative 

and Unreliable 

Rule 702 of the Federal Rules of Evidence permits expert testimony only if a witness “is 

qualified as an expert by knowledge, skill, experience, training, or education,” and only provided 

that: 

(a) the expert’s scientific, technical, or other specialized knowledge will help the 

trier of fact to understand the evidence or to determine a fact in issue; 

(b) the testimony is based on sufficient facts or data; 

(c) the testimony is the product of reliable principles and methods; and 

(d) the expert has reliably applied the principles and methods to the facts of the 

case. 

Fed. R. Evid. 702. “In applying Rule 702, the Court functions as a gatekeeper, determining 

whether proffered expert testimony meets the requirements of Rule 702 by a preponderance of the 

evidence.” In re Countrywide Fin. Corp. Mortg.-Backed Sec. Litig., 984 F. Supp. 2d 1021, 1026 

(C.D. Cal. 2013) (citing Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579, 592 & n.10 (1993)). 

Rule 702 requires, among other things, that “an expert’s testimony has ‘a reliable basis in 

the knowledge and experience of the relevant discipline.’” Estate of Barabin v. AstenJohnson, 

Inc., 740 F.3d 457, 463 (9th Cir. 2014) (quoting Kumho Tire Co., Ltd. v. Carmichael, 526 U.S. 

137, 149 (1999) (“Kumho”)). The test of reliability is “flexible,” Kumho, 526 U.S. at 141; “not 

only must the trial court be given broad discretion to decide whether to admit expert testimony, it 

‘must have the same kind of latitude in deciding how to test an expert’s reliability,’” United States 

v. Hankey, 203 F.3d 1160, 1168 (9th Cir. 2000) (quoting Kumho, 526 U.S. at 152). But “Rule 702 

demands that expert testimony relate to scientific, technical or other specialized knowledge, which 

does not include unsubstantiated speculation and subjective beliefs.” Diviero v. Uniroyal 

Goodrich Tire Co., 114 F.3d 851, 853 (9th Cir. 1997). The Advisory Committee Notes to Rule 

702 explain: 

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 -4- 17-cv-00600-LB

PLAINTIFF’S MOTION IN LIMINE NO. 1 TO EXCLUDE DR. THOMAS MAMPALAM’S OPINIONS 

REGARDING PURPORTED PSYCHIATRIC AND PSYCHOLOGICAL DIAGNOSES 

If the witness is relying solely or primarily on experience, then the witness must 

explain how that experience leads to the conclusion reached, why that experience is 

a sufficient basis for the opinion, and how that experience is reliably applied to the 

facts. The trial court’s gatekeeping function requires more than simply “taking the 

expert’s word for it.” 

Advisory Committee Notes to 2000 Amendment to Fed. R. Evid. 702. 

Here, Dr. Mampalam does not have the appropriate “knowledge, skill, experience, training, 

or education” to purport to diagnose Ms. LePage with psychiatric or psychological disorders. See 

Fed. R. Evid. 702. He does not practice as a psychiatrist or a psychologist, he has no specialized 

training in psychiatry or psychology, and he is not qualified to diagnose or treat specific 

psychiatric or psychological conditions. See supra at 1. The only relevant qualification he 

identified was that if he suspects a patient might have a psychiatric or psychological condition, he 

refers them to a psychiatrist before performing surgery on them. See Dep. 53:20-55:20. His 

experience identifying that a patient might have a psychiatric condition upon further evaluation by 

a psychiatrist does not qualify him to personally purport to diagnose Ms. LePage with psychiatric 

or psychological disorders. See id. 

In addition, Dr. Mampalam’s opinions are inadmissible under Rule 702 because they are 

unreliable. Dr. Mampalam’s report and deposition testimony do not indicate that his opinions are 

“the product of reliable principles and methods,” or that he “has applied the principles and 

methods reliably to the facts of the case.” Estate of Barabin, 740 F.3d at 463. Although Dr. 

Mampalam testified at his deposition that in his practice as a neurosurgeon, he considers whether a 

psychological or psychiatric condition might be an alternative explanation for a patient’s reported 

pain or impairment before performing surgery on them, see Dep. 53:11-54:16, his opinions go 

farther than that and conclude that Ms. LePage likely does in fact have a psychological or 

psychiatric disorder in connection with her abnormal gait and her reported symptoms in 

connection with her spine, see IME Report at 12 (“[Ms. LePage] has an abnormal gait that appears 

unlikely to be due to a cervical myelopathy, but is more likely a hysterical gait, a psychiatric 

disorder such as a conversion reaction, or an extreme case of symptom elaboration in the context 

of possible secondary gain.”); id. at 13 (“[Ms. LePage] underwent cervical spine surgery for what 

is likely mostly a psychological or psychiatric condition.”). Dr. Mampalam provides no 

Case 3:17-cv-00600-LB Document 115 Filed 09/06/19 Page 5 of 8
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PLAINTIFF’S MOTION IN LIMINE NO. 1 TO EXCLUDE DR. THOMAS MAMPALAM’S OPINIONS 

REGARDING PURPORTED PSYCHIATRIC AND PSYCHOLOGICAL DIAGNOSES 

methodology or objective basis for this jump in reasoning. He did not testify that he diagnoses 

and treats specific psychiatric or psychological disorders as part of his practice. Dr. Mampalam 

has never performed a psychiatric evaluation of Ms. LePage, nor is he qualified to do so. Neither 

did he rely in his report or at his deposition on any personal observations of specific psychiatric 

symptoms indicated by Ms. LePage or on any psychiatric or psychological records of Ms. LePage. 

The only basis Dr. Mampalam provided for his opinion that Ms. LePage’s abnormal gait 

likely is due to “a hysterical gait, a psychiatric disorder such as a conversion reaction, or an 

extreme case of symptom elaboration in the context of possible secondary gain,” IME Report at 

12, was that “[i]f [Ms. LePage’s abnormal gait] was not related to something physical, it is likely 

something psychological or psychiatric.” Dep. 53:5-10. Likewise, Dr. Mampalam’s claim that 

Ms. LePage “underwent cervical spine surgery for what is likely mostly a psychological or 

psychiatric condition” is unsubstantiated. See, e.g., United States v. Geanakos, No. 2:13-CR0404-GEB, 2017 WL 374351, at *5 (E.D. Cal. Jan. 26, 2017) (excluding expert testimony 

regarding Autism Spectrum Disorder as unreliable where expert used “conclusory terms” to 

describe the support for his opinions and “ma[de] bald statements about [the defendant’s] mental 

state, which are unsupported by a documented reasoning process”). Dr. Mampalam provides no 

documented support for his reasoning process, and “[t]he trial court’s gatekeeping function 

requires more than simply ‘taking the expert’s word for it,’” Advisory Committee Notes to 2000 

Amendment to Fed. R. Evid. 702. Dr. Mampalam’s unsupported opinions that Ms. LePage likely 

has psychiatric or psychological disorders must be excluded because they do not meet the required 

threshold of reliability under Rule 702. 

B. Dr. Mampalam’s Speculative Opinions that Purport to Diagnose Plaintiff with 

Psychological or Psychiatric Disorders Are Also Inadmissible Under Rule 

403’s Balancing Test 

Dr. Mampalam’s opinions relating to Ms. LePage likely having psychological or 

psychiatric disorders are also independently inadmissible under Rule 403. Rogers v. Raymark 

Indus., Inc., 922 F.2d 1426, 1430 (9th Cir. 1991) (“Even if the court finds a witness qualified 

under Rule 702, it may still exclude testimony under Rule 403.”). Under Rule 403, evidence may 

be excluded if its probative value is substantially outweighed by the danger of “unfair prejudice, 

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PLAINTIFF’S MOTION IN LIMINE NO. 1 TO EXCLUDE DR. THOMAS MAMPALAM’S OPINIONS 

REGARDING PURPORTED PSYCHIATRIC AND PSYCHOLOGICAL DIAGNOSES 

confusing the issues, misleading the jury, undue delay, wasting time, or needlessly presenting 

cumulative evidence.” Fed. R. Evid. 403. 

The probative value of the opinions at issue is very low. Dr. Mampalam has never 

performed a psychiatric evaluation of Ms. LePage, and there is no evidence in the record that 

Plaintiff does in fact have a psychological or psychiatric disorder. Instead, Dr. Mampalam simply 

speculates that Ms. LePage might have one of several psychological or psychiatric conditions in 

connection with her abnormal gait, IME Report at 12 & Dep. 50:19-53:10, and that she likely has 

an undefined “psychological or psychiatric condition” that led to her surgery, IME Report at 13 & 

Dep. 47:8-21. Such statements add very little to his other opinions—that the objective findings do 

not appear to account for Ms. LePage’s abnormal gait or reported symptoms, that the incident with 

Deputy Reid did not injure Ms. LePage’s spine, and that Ms. LePage’s second surgery was 

medically unnecessary. See IME Report at 12-13. Moreover, Dr. Mampalam could offer 

testimony generally regarding potential alternative explanations for an abnormal gait based on his 

experience, without elaborating on specific psychological or psychiatric conditions or offering the 

unsupported opinion that Ms. LePage likely has one of them. 

On the other hand, Dr. Mampalam’s opinions that Ms. LePage likely has psychiatric or 

psychological disorders have a high risk of unduly prejudicing the jury to disregard Ms. LePage’s 

account both of the incident with Deputy Reid and of her symptoms and limitations. Not only are 

his opinions likely to evoke general biases against people with mental health conditions, but also, 

his suggestion that Ms. LePage might have a “hysterical gait,” be suffering from emotional or 

psychological turmoil, or be making up her symptoms for secondary gain is highly prejudicial. 

Once Dr. Mampalam suggests these ideas to the jury, especially with an aura of authority as a 

medical doctor, Ms. LePage cannot fully remedy their prejudicial effect through crossexamination or other evidence. Dr. Mampalam’s opinions also pose the risk of creating a minitrial on Ms. LePage’s psychiatric and psychological health, and of misleading the jury to believe 

that Ms. LePage has in fact been determined to have the psychiatric and psychological disorders of 

which Dr. Mampalam speculates. Dr. Mampalam’s opinions that Ms. LePage likely has 

Case 3:17-cv-00600-LB Document 115 Filed 09/06/19 Page 7 of 8
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 -7- 17-cv-00600-LB

PLAINTIFF’S MOTION IN LIMINE NO. 1 TO EXCLUDE DR. THOMAS MAMPALAM’S OPINIONS 

REGARDING PURPORTED PSYCHIATRIC AND PSYCHOLOGICAL DIAGNOSES 

psychiatric or psychological disorders therefore should be excluded under Rule 403’s balancing 

test. 

III. CONCLUSION 

The Court should preclude Dr. Mampalam from offering opinions that suggest that Ms. 

LePage likely has psychiatric or psychological disorders, because such testimony is inadmissible 

under Federal Rules of Evidence 702 and 403. 

DATED: August 20, 2019 Respectfully submitted, 

MUNGER, TOLLES & OLSON LLP 

 MIRIAM KIM 

EMILY C. CURRAN-HUBERTY 

SKYLAR D. BROOKS 

By: /s/ Skylar D. Brooks 

 SKYLAR D. BROOKS 

 

 Attorneys for Plaintiff RENEE LEPAGE 

Case 3:17-cv-00600-LB Document 115 Filed 09/06/19 Page 8 of 8