From the witness stand Thursday, Dr. Jurriaan Peters recounted his version of Justina Pelletier's treatment at Boston Children's Hospital. The patient, who was 14 at the time, was committed to a psychiatric ward and given limited access to her parents. Her family is now suing the hospital alleging their civil rights were violated.

Peters is a key defendant in the case. A pediatric neurologist, he was the first specialist to evaluate Pelletier after she left the Boston Children’s Hospital emergency department on Feb. 10, 2013. When he saw her, Peters testified, Pelletier was in bad shape.

“She had altered mental status," Peters told the jury. "She had slurred, unclear articulation. Pain, headaches, could not walk properly."

What stood out the most, he said, was that her condition seemed to change from moment to moment?

“She would actually fluctuate within the exam,” Peters said. “For example, she was unable to lift her arm off the bed. But if you distract her, she would wipe her hair away.”

Peters said he knew that doctors at Tufts Medical Center thought Pelletier might have mitochondrial disease, a chronic condition that affects how the body's cells generate energy, but their diagnosis had not been confirmed.

He ran a battery of neurological tests on Pelletier and couldn’t find any underlying medical reason for her symptoms.

“ I found that to be concerning,” Peters told the jury.

“Did you think Justina was faking her symptoms?” Ellen Cohen, one of Peters’ lawyers, asked him.

“Not at all. We’re not dismissing them. They’re very real,” he replied. “It means there are other reasons – and those are often psychological.”

One possibility he considered, Peters said, was that Pelletier might be suffering from somatoform disorder, a medical term for when a psychological condition exacerbates or creates physical symptoms in a patient.

Peters said records he’d requested from Pelletier’s previous doctors, his conversations with those doctors and his own observations caused him to suspect that Pelletier’s parents might be playing a role.

In his medical notes at the time, Peters wrote that some of the doctors who’d treated Pelletier suspected “factitious disorder by proxy,” a form of medical abuse involving excessive medical care or symptoms caused by the parent or guardian.

“She had multiple diagnoses, a very patchy network of providers. Those are all classic red flags,” Peters said. “And that there were Child Protective Services involved [suggested] there was some form of over-medicalization going on.”

Peters said other doctors told him that Pelletier’s parents tended to obsess over potential medical problems. They took her to many different doctors, which increased the likelihood of multiple diagnoses and medications.

“When people have a multitude of medications, it becomes very hard to manage," Peters told the jury. “And it’s a feedback loop where every time someone says you’re sick, it gets endorsed and validated.”

Peters began pulling in specialists from all over Boston Children’s to coordinate Pelletier’s care, as well as some of her former doctors at Tufts Medical Center. They created a treatment plan that they believed would help Pelletier heal. Part of it involved intensive, in-hospital psychological treatment and limiting the parents’ involvement in managing Pelletier's care.

“We wanted to de-medicalize the situation, and we wanted the parents not to encourage the ‘sick role,’ but rather, encourage her about positive things and to be independent and a teenager,” Peters said.

At first, Peters said Linda Pelletier, Justina’s mother, agreed to the plan. But in the morning, “something had changed.”

“Dad was on the phone, expressing frustration with our proposal and not wanting any major psychological intervention," Peters said. "I knew from Tufts that there was push back for a similar plan in 2011. And we were thinking how we can try to make this a productive relationship [with the parents] in the interest of Justina.”

But the next day, Peters got an emergency call.

“The father was at the front desk, trying to urgently discharge Justina from the hospital,” he recalled. “I literally ran to the hospital.”

Peters said he was afraid that if Pelletier left the hospital with her parents, she could get much worse.

“At that point, she was not walking. She was not eating. She was not drinking. She had this fluctuating mental status – it was very severe,” he said. “Mom had already indicated to many people that she was unable to take care of Justina at home.”

Believing their patient was in danger, Peters said he and other doctors at Boston Children's filed what's known as a 51A report. The paperwork is used to alert child welfare authorities to suspected child abuse or neglect. The doctors then met with the family to explain the situation.

“ I was very scared,” Peters said. “Father was red, kind of towering close to our faces. He was screaming or yelling. We had to stop [the meeting] because it escalated dramatically.”

In his testimony, Lou Pelletier said he believed Boston Children’s was trying to kidnap his daughter. Both parents testified that the doctors threatened them, saying they could take Justina away if the Pelletiers didn’t agree to the new treatment plan.

The 51A report that Peters and his colleagues filed led to the Department of Children and Families taking custody of Justina Pelletier. The family says that was a violation of their civil rights. Justina, who is now 21 and living with her parents, testified tearfully last week about her anguish at being separated from her family.

But Peters said he never threatened the Pelletier family and maintained that the 51A report was a last resort to protect Justina Pelletier’s health.

“[Lou Pelletier] forced my hand," he said. "I had no option but to file.”