Here is perlbrew(0.58) help, section "install":

COMMAND: INSTALL
    install options perl-<version>
    install options <version>
        Build and install the given version of perl.

        Version numbers usually look like "5.x.xx", or "perl-5.xx.x-RCx" for
        release candidates.

        The specified perl is downloaded from the offical CPAN website or
        from the mirror site configured before.

        To configure mirror site, invoke `mirror` command.

    install options perl-blead
    install options blead
        A special way to install the blead version of perl, which is
        downloaded from this specific URL regardless of mirror settings:

            http://perl5.git.perl.org/perl.git/snapshot/blead.tar.gz

    install options /path/to/perl/git/checkout/dir
        Build and install from the given git checkout dir.

    install options /path/to/perl-5.14.0.tar.gz
        Build and install from the given archive file.

    install options http://example.com/mirror/perl-5.12.3.tar.gz
        Build and install from the given URL. Supported URL schemes are
        "http://", "https://", "ftp://" and "file://".

    Options for "install" command:

        -f --force     Force installation
        -j $n          Parallel buildng and testing. ex. C<perlbrew install -j 5 perl-5.14.2>
        -n --notest    Skip testing

           --as        Install the given version of perl by a name.
                       ex. C<perlbrew install perl-5.6.2 --as legacy-perl>

        -D,-U,-A       Switches passed to perl Configure script.
                       ex. C<perlbrew install perl-5.10.1 -D usemymalloc -U uselargefiles>

        --sitecustomize $filename
                       Specify a file to be installed as sitecustomize.pl

    By default, all installations are configured after their name like this:

        sh Configure -de -Dprefix=$PERLBREW_ROOT/perls/<name>

Therefore, the command to install perl 5.16.0 with thread support and to give that perl the name "perl-5.16.0t" should be this:

$ perlbrew install --as perl-5.16.0t -Dusethreads perl-5.16.0
[download]

And in fact, I tried that command on Mac OSX 10.6.8, and I was able to successfully install a perl named perl-5.16.0t:

$ perlbrew list
* perl-5.16.0       #this perl was already installed
  perl-5.16.0t      #this is the new install

$perlbrew use perl-5.16.0t
$perlbrew list
  perl-5.16.0
* perl-5.16.0t
[download]

And here's a test program:

use strict; 
use warnings; 
use 5.012;

use threads;
use threads::shared;

my $counter :shared;
$counter = 1;

my $name = 'Joe';

sub do_stuff {
    my $thread_id = shift;
    sleep rand 10;

    say "thread number $thread_id";

    say "count: $counter";
    $counter++;

    say $name;
    $name = "Cathy";
}

my @threads;

for my $thread_number (1..10) {
    push @threads, threads->create('do_stuff', $thread_number);
}

for (@threads) {
    $_->join;
}


--output:--
thread number 5
count: 1
Joe
thread number 9
count: 2
Joe
thread number 3
count: 3
Joe
thread number 7
count: 4
Joe
thread number 10
count: 5
Joe
thread number 4
count: 6
Joe
thread number 6
count: 7
Joe
thread number 8
count: 8
Joe
thread number 1
count: 9
Joe
thread number 2
count: 10
Joe
[download]

To set perl-5.16.0t as the default when you start up a shell:

$ perlbrew switch perl-5.16.0t
[download]

It's possible that the -f option for the perlbrew alias command is the same as for the install command. But in any case, options are optional--that is what the brackets around the option mean--so if you don't know what an option does, then don't use that option.

perlbrew help also says this:

   
Generic command options:

        -q --quiet     Be quiet on informative output message.
        -v --verbose   Tell me more about it.
[download]

The -v option isn't used to specify the perl version, so you can omit it.