Valor de mudança multisselect de bootstrap
// select an option
$('#demo').multiselect('select', value);
// deselect an option
$('#demo').multiselect('deselect', value);
// select all options
$('#demo').multiselect('selectAll', justVisible);
// deselect all options
$('#demo').multiselect('deselectAll', justVisible);
TomatenTim