how to parse an xml string in mysql?

Question

in ms sql I have the following code:

ALTER PROCEDURE [dbo].[xmlDictamen_Alta]
  @Xml text
as begin

declare @Id            integer
declare @DocumentoId   numeric(18,0)
declare @Descripcion   varchar(300)

begin

    set nocount on
    exec dbo.sp_xml_preparedocument @Id output, @Xml

    select 
        @DocumentId  = DocumentId,
        @Description = IsNull( Description, ''),
    from 
    OpenXml( @IdXml, '/Parameter', 2) with (
    DocumentId       numeric(18,0),
    Description      varchar(300)
    )

    exec dbo.sp_xml_removedocument @IdXml


/*
execute xmlDictamen_Alta
'
    <Parameter>
      <DocumentId>1328</DocumentId>
      <Description>Descripcion</Description>
    </Parameter>
'
*/

How would you port these stored procedure to mysql???