I cannot give you a formal clinical opinion over the internet, as this site is purely educational
Have you addressed this problem with your doctor? If not, I suggest you do.
Its possible that it is a side effect, the only way to tell may be to stop taking the drug for a while - this should only be done with the close supervision of your doctor.
One possibility that should be looked into by your doctor is a seizure disorder, by doing an EEG test. TIAs usually result in abnormalities suchg as loss of vision in one eye, weakness of a limb, clumsiness of a limb etc. Sometimes with TIAs of the posterior brain circulation cause slurred speech, clumsiness, double vision - in this case an MRI and MR angiogram of the posterior circulation may be revealing, alhtough this would be unusual in your age group.
I've been taking Parlodel for more than 9 years but am trying to switch to Dostinex.
Sorry, this statement didn't make sense when I first posted!
Have you had your free t-3 & free t-4 checked? Your TSH is alittle low & could suggest hyperthyroidism in which you can get most of those symptoms mentioned. Although your pulse slowing isn't indicative of high thyroid but it's still not out of the question. I had many of those symptoms with hyperthyroidism. Are you on any thyroid meds?