Ben Carson has been running his campaign for the White House as an outsider, heavily relying on his stellar reputation as a brain surgeon, but the National Enquirer has revealed that a string of malpractice lawsuits dating back to the 1980s suggests that the Republican presidential candidate’s medical career was far from flawless.

Carson, 64, who according to the latest Quinnipiac University poll was in second place with 23 percent behind fellow political neophyte Donald Trump, who polled 28 percent in several early-voting states, stepped down in 2013 as a surgeon at the prestigious Johns Hopkins Hospital in Maryland.

Announcing his retirement in March of that year, Carson stated: ‘I'd much rather quit when I'm at the top of my game.'

Imperfect track record: Award-winning surgeon-turned presidential candidate Dr Ben Carson (left) had been sued at least a half-dozen times, including by his former patient Karly Bailey, pictured here as a young girl

Paging Dr Carson: Bailey is pictured as a 9-year-old following a surgery on her brain performed by Carson which, according to her lawsuit, left her with a permanent facial droop

A graduate of Yale University and University of Michigan School of Medicine, at 33 Carson was named director of pediatric neurosurgery at Johns Hopkins, thus becoming the youngest major division chief in the hospital's history.

One of his claims to fame is that in 1987 Carson became the first surgeon to successfully separate twins conjoined at the head.

But as court records indicate, over the course of Carson's distinguished 35-year career in the medical field he had been sued for malpractice no fewer than six times.

In one case, Carson was accused of bungling a surgery to replace a shunt in the brain of an ailing 9-year-old girl, leaving her disfigured for life and for a time partially paralyzed.

In another case, the well-regarded surgeon allegedly punctured his patient's eardrums during an operation and forgot a sponge in her skull, which he later claimed was a tumor.

I'd much rather quit when I'm at the top of my game. Dr Ben Carson on his retirement

Others claims against Carson outlined in a heap of legal documents include improperly putting in a shunt, performing an unnecessary surgery on a woman suffering from multiple sclerosis, and leaving a teenage boy with dwarfism paralyzed from the waist down.

One of Carson's most vocal critics has been 27-year-old Karly Bailey, who in 2009 filed a lawsuit against the former brain surgeon and John Hopkins Hospital claiming medical malpractice involving the alleged failure to properly perform surgery to replace a shunt and remove a tumor.

At age seven, Bailey, from Florida, was diagnosed with a brain tumor and underwent her first surgery at All Children's Hospital in St Petersburg to remove as much of the malignant growth as her surgeon deemed safe and have a shunt placed in her brain.

Two years later, then-9-year-old Karly began experiencing headaches again, and subsequent tests showed that her tumor had regrown, according to her lawsuit.

Her surgeon at All Children's Hospital told Karly's parents that the growth did not require immediate surgery, but they decided to seek a second opinion.

As they were meeting with doctors, Karly went into medical distress and was rushed to Johns Hopkins Hospital, where the family met Dr Ben Carson for the first time.

According to the suit, Carson recommended to the parents that he remove additional sections of Karly's tumor at the same time as replacing her shunt.

On her personal website dedicated to her medical case, Bailey writes that Carson established a pre-surgery contract with her and her parents that prohibited him from removing any tumor from her brain stem or attempting the total resection of her brain stem tumor.

Bailey, seen here with her late mother, is one of at least six patients who have filed medical malpractice lawsuits against Dr Carson since 1986

Happier times: Karly, seen as a happy child posing with her dad, was diagnosed with a benign brain tumor at age 7 and her the first of several surgeries in 1995

Bailey, who is now 27 years old (pictured), claims that Carson bungled a surgery on her brain in 1997, leaving her permanently disfigured and suffering from a host of other complications

But according to Bailey's legal claim, Carson 'attempted to remove all visible tumor' on a portion of the brainstem, in the process destroying 'multiple neuronal circuits controlling the patient’s facial motor functions.'

The court documents go on to say that Bailey was left with a right-side facial droop, lost the ability to write with her right hand, and has problems maintaining her balance, among a host of other medical complications.

In a 2011 sworn affidavit cited by the National Enquirer, Carson called Bailey's post-operation problems 'unavoidable' and denied violating the pre-surgery contract.

Speaking to the tabloid, a furious Ms Bailey blasted Carson as 'totally untrustworthy.'

In an earlier medical malpractice lawsuit against Carson, patient John Sparco claimed that the surgeon and three of his colleagues operated on him to remove what they claimed was a deadly tumor, but which later turned out to be a small benign growth.

During the surgery, Sparco claimed he suffered 'irreversible' injuries, including partial deafness, dizziness and slurred speech.

Talking to the Enquirer, his lawyer said that to strangers his client 'appears drunk.'

Medical luminary: Announcing his retirement from surgery in March 2013, Carson stated: ‘I'd much rather quit when I'm at the top of my game'

Then there is the case of Mary Perna, a multiple sclerosis sufferer who underwent a surgery on her brain in 1994 at Carson's suggestion to relieve her pain.

The operation was a failure, and afterwards Carson admitted, according to Perna's lawsuit, that he had not reviewed her most recent MRI results prior to operating on her.

Carson and Johns Hopkins eventually reached a settlement with the patient. Two decades on, however, Perna said she still has a positive view of the doctor and would vote for him for president, The Guardian reported earlier this year.

Another malpractice lawsuit from 1999 accused Dr Carson of putting in a shunt in a girl's brain 'upside down,' which caused her severe pain.

In 2011, Darlene King, a resident of Venice, Florida, sued Carson, his hospital and three other doctors for allegedly perforating both her eardrums during a 2008 surgery to address facial pain.

Following the operation, documents state, the 69-year-old patient was told by Carson that she might have a brain tumor. But a second surgery later revealed that the mass in her brain was actually a sponge that the award-winning doctor had left in there during the previous operation, according to the plaintiff's suit.

Race for the White House: According to the latest Quinnipiac University poll, Dr Carson was in second place with 23 per cent behind fellow political neophyte Donald Trump in several early-voting states

In yet another legal case, which however does not name Carson as a defendant, Merryl Reynolds claimed the Johns Hopkins medical luminary performed a surgery on her son's spine in 2010, which left 15-year-old Austin Reynolds, who was born with short-limbed dwarfism, paralyzed from the waist down and incontinent.

Several of the cases against Carson are still ongoing, while others have been either settled or dismissed.