Natasha McShane’s heartbroken mother left a Chicago courtroom in tears after a neurosurgeon described the damage inflicted to her daughter’s brain by baseball bat mugger Heriberto Viramontes.

The Northern Ireland exchange student was beaten by Viramontes in Chicago’s Bucktown neighborhood in 2010.

The 34-year-old attacked McShane and friend Stacy Jurich and robbed them under a Damen Avenue viaduct as they returned home after a night out.

Viramontes is currently on trial on 25 counts of attempted first-degree murder, armed robbery and aggravated battery.

Now Natasha’s primary carer back in Northern Ireland, Sheila McShane cried openly as she left the courtroom after hearing testimony from Dr. Leonard Kranzler.

The Chicago Tribune reports that he testified that the damaged section of her daughter’s brain controls ‘speech, understanding and the ability to move the right arm and leg’.

McShane was a graduate student in urban development at the time of the assault but cannot speak more than a few words or walk unassisted now as a result of her injuries.

Kranzler told the court that he had to remove a three-quarters of an inch section of McShane’s fractured skull to save her life after her brain swelled as a result of the beating.

He also said he found evidence that McShane had suffered a stroke as her brain swelled.

Jurors saw the wooden baseball bat that prosecutors allege Viramontes used in the attack in Friday’s proceedings.

The report says that police found the bat between the front seats of a gray minivan belonging to Marcy Cruz, who was with Viramontes on the night of the beating.

Cruz has already pleaded guilty in return for a 22-year prison sentence and is expected to testify against Viramontes as soon as Monday.

Chicago police Cmdr. Joseph Salemme testified that the bat was found with Viramontes’ black wallet and state ID card in the van.

Prosecution witness Johnny Paige told the court that he was given Jurich’s credit card for jump-starting a minivan that broke down in the East Garfield Park neighborhood in the hours after the robbery.

Paige identified the man as Viramontes in a photo array and police lineup at the time but he was unable to pick out Viramontes in the courtroom on Friday.

The Tribune says Paige’s niece Latoya testified that her aunt gave her Jurich’s credit card and she used it to pay off her Comcast bill of more than $500. She said she destroyed the card after being questioned by police.