Jun.18, 2014 -- A young New York mother who blogged about her sickly son on social media is accused of fatally poisoning him with salt.

Lacey Spears, 26, turned herself in to police on Tuesday and pleaded not guilty to depraved murder and manslaughter charges. Prosecutors say she poisoned her 5-year-old son Garnett-Paul with sodium through a feeding tube in the boy’s stomach.

Spears brought her son into a hospital in Nyack on Jan. 17, telling doctors he was experiencing seizures. Later in the afternoon, Garnett-Paul's sodium levels spiked mysteriously. His mother was sharing his hospital room, ABC News affiliate WABC-TV reported.

"During the afternoon, that child goes from moderate to severe cerebral dysfunction," prosecutor Doreen Lloyd said in court. "And as that is going on, this child's sodium level is going up. It coincides with the actions of this defendant."

Garnett-Paul was transferred to the Westchester County Medical Center where he was pronounced dead on Jan. 23. Authorities believe Spears poisoned her son with salt three times in January.

"This mother was intentionally feeding her child salt at toxic levels," Lloyd said at Spears' arraignment. “This defendant researched, planned and executed her crime against her own son in a wanton and depraved manner.”

Investigators believe Spears had been medically abusing her son for years, and that she documented her son’s illness on social media as a way to gain attention for herself.

Entitled “Garnett’s Journey,” Spears’ blog described her son’s frequent visits to the doctor and life without her deceased husband. Spears also posted repeatedly on Facebook, MySpace, and Twitter.

"My sweet angel is in the hospital for the 23rd time," Spears posted on Twitter in 2009 when the boy was only 1 year old. "Please pray he gets to come home soon," she wrote.

She posted his death on her Facebook page saying her son had "journeyed on."

Garnett had suffered medical problems from an early age and had a feeding tube inserted in his stomach when he was 9 months old because he had trouble gaining weight. Authorities believe his mother may possibly have been suffering from Munchausen syndrome by proxy, a mental disorder in which a parent purposefully sicken a child for attention, the Journal News reported.

Spear’s attorney David R. Sachs did not immediately return an ABC News request for comment.

Spears is currently being held without bail at the Westchester County Department of Correction in Valhalla, N.Y. Her next court date is scheduled for July 2. If convicted, she faces a maximum sentence of 20 years to life in prison.