Brief update:
Last night the headaches caused by the Persantin were the worst headache or pain I've had in my life so I've told the consultant that I can't tolerate it and will not be taking any more. From looking-around there seem to be alternatives without the side effects so if he still judges that I need something I assume he will re-prescribe.
There' still no loss of any function but the sensation in my lips, tongue, teeth and thumb are still not as they should be on the left side.
CFI - thanks for the info. I'm pretty sure that I wouldn't have fallen-off because everything seemed to carry-on as normal, but I'll investigate in that direction
The blood test results came back as "all normal" (with a cholesterol level of 4.5), as did the doppler scan of the carotid arteries - the initial MRI feedback was also OK.
From doing a lot of looking around I'm now strongly suspecting that this was a neurological event, rather than a vascular one. Can anyone suggest how I can educate myself enough (presumably about the CNS) to ask the right questions?
B Rick