Montgomeryshire AM Mick Bates has been found guilty of assaulting medical staff and public order offences.
Bates, 63, had denied three counts of common assault and public order offences in Cardiff on 20 January.
But he was found guilty at Cardiff Magistrates’ Court on Friday.
He was ordered to pay a total of £5,490 in fines, costs and compensation.
District Judge Bodfan Jenkins rejected Bates’ defence of suffering from a rare condition at the time which meant he was not aware or responsible for what he was doing.
Paramedics were called to a Cardiff restaurant in January after Bates apparently fell down a set of stairs.
He was found slumped, smelling strongly of alcohol and with a bleeding head at Charleston’s Steakhouse in Caroline Street.
The court was told the AM became increasingly aggressive and abusive when paramedics tried to treat him.
Paramedic Carl Jones told the court the politician did not want to go to hospital and punched him in the chest when he tried to check his blood pressure.
Later, after being taken to hospital, the court heard that he threatened hospital staff.
Bates’ defence team said he had been briefly suffering from a rare condition called automatism at the time of the incident which meant he was not aware or responsible for what he was doing.
The defence’s expert witness, neurologist Dr Christopher Gardner-Thorpe, said Bates had suffered a severe head injury after falling head over heels down the stairs outside the restaurant.
“Mr Bates could have been functioning without being aware of his actions. It is highly likely that [the head injuries] modified his behaviour,” he said.
Speaking after the conviction, a spokesperson for the Crown Prosecution Service said: “The CPS takes attacks on health professionals very seriously.
“Health service workers have challenging duties and they should be able to carry out their roles without fear of violence and abuse.
“A national agreement is in place between the CPS and NHS to ensure health workers do not accept this kind of abuse as an occupational hazard.
“The message must go out that crimes of this nature will not be tolerated and we will do everything we can to make sure offenders are brought to justice.”
A Welsh Ambulance Service spokesperson said: “We are satisfied with the outcome of this case. The Welsh Ambulance Service has a policy of zero tolerance regarding violence and aggression towards its staff and will not tolerate any such acts.
“We will continue to support our staff, who face a difficult job on a daily basis, and where appropriate we will prosecute assailants and abusers without hesitation.”
The Montgomeryshire AM now faces expulsion from the Liberal Democrat party, he had been suspended pending the verdict of the court case. Kirsty Williams, leader of the Welsh Liberal Democrats said;
“Mick Bates has been a dedicated and effective voice for Montgomeryshire over many years. This judgement is a personal tragedy for him and his family but it is one we must respect.
“The Welsh Liberal Democrats are clear that this conviction for a public order offence is incompatible with the high standards we expect of our elected representatives. Proceedings have begun to terminate his membership of the party.”