Addressing Ecuador's president, Lenin Moreno, she tweeted: "Shame on you @Lenin £Moreno! May the Ecuadorean people seek vengeance upon you, you dirty, deceitful, rotten traitor!
"May the face of my suffering son haunt your sleepless nights.. And may your soul writhe forever in torturous Purgatory as you have tortured my beloved son!""
Assange was taken to Westminster Magistrates' Court after his removal from the embassy on Thursday.
District Judge Michael Snow described his behaviour as "that of a narcissist who cannot get beyond his own selfish interests".
His mother tweeted: "UK judge should NOT be making statements like this! This is (a) rubbish Legal process!"
Earlier today, Mrs Assange issued a plea to police, prison officers and court staff in another tweet.
She said her son had been "detained without charge", "deprived of fresh air, exercise and sun" and "denied proper medical/dental care" for several years.
She also claimed he had been "isolated/tortured" for a year.
"Please be patient, gentle & kind to him," she tweeted.