A Connecticut man was arrested for allegedly bludgeoning his wife with a baseball bat inside their mansion Tuesday night in an attack that left the woman brain-damaged, the Greenwich Time reported. 

Greenwich police say Michael De Maio, 55, has been charged with attempted murder and first-degree assault. He was arraigned Wednesday in Stamford Superior Court.

His nutritionist wife, identified as Diane De Maio, remains hospitalized at Stamford Hospital following the attack that left her with massive blood loss and severe head injuries, according to the newspaper. She is listed in critical condition.  

Police said an argument between De Maio and his wife escalated shortly before the assault. Multiple sources told the newspaper that the attack was reported by the victim's mother around 6:30 p.m. When authorities arrived at the scene, the mother, who was on the second floor, reportedly stated, "that monster hit her and she's dying."

De Maio became enraged after his wife said she was leaving him, sources close to the investigation told the newspaper.

While in police custody, DeMaio said to police, "I lost it, I just lost it," the newspaper reported. 

The couple's Greenwich mansion is valued at $7.3 million and owned by Diane De Maio.

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The Associated Press contributed to this report.