http://www.cosmosmagazine.com/news/2428/sarcasm-useful-detecting-dementia
This honestly explains a lot. Ive always wondered why some people in the PD section behave so oddly in certain posts. There are more than one or two well along the road to dementia that post in that section so this article makes soooooooooo much sense.
There's a battery of tests available to test psycho-cognitive function.
The most basic one, used by non-neuro-psychiatrists, geriatricians, psychiatrists or
neurologists is the Mini-Mental State Exam. It's very basic and guides the clinican along whether early cognitive malfunction is present, which may need referral for a more specialised accessment and care.
http://www.patient.co.uk/showdoc/40000152/
As for 'sarcasm', it may have problematic usage in SA because of cultural, educational and language barriers. So what is needed is a standardised test (that's how medicine works), testing for sarcasm would have to be adapted for poorer blacks who speak Black languages, poorer coloureds who speak Afrikaans, white Afrikaaners, Indians, English speaking whites and so on. Australia is quite homogenous in many parts - they have aboriginies in their reservations and have Asian (Chinese) immigrants in other parts but
overall it's much of this, as an ex-gf told me who's specialising in Melbourne is that it's usually old white women,
80 year old (who's half demented and has a nasty attitude) brings in her 99 year old mother. Application in such a setting would be more appropriate and less laborious.
Of course enthusiastic wannabe geriatricians and neuro-psychiatrists can always enter med school and become that.