Dear Cyndy,

I don't scold, but I do worry. 
Falls such as you describe are sometimes in consequence
of a form of epilepsy which used to be called "petit mal".
I'm not sure whether that's the currently fashionable name.
The classical description is of a person
during a meal, inexplicably dropping a spoon.
Usually there is no premonitory aura.
When patients of our age are so afflicted,
they frequently fall, for no apparent reason,
e.g. "their knees give way".
The consequences of such a fall can be fatal,
as in the case of our neighbor 83 year old Thomas Naylor,
who to whom it happened two years ago.
He fell backwards, striking his occiput,
spent two years demented from brain injury in a nursing home,
and died only about two months ago.

Diagnosis of petit mal, so far as I know,
and I haven't taken the time to bone up on the Internet,
is not radiological, but by electroencephalogram.
Medication of varying degrees of effectiveness
and with various potential side effects is available.
From what you've written me,
I think you should have an electroencephalogram a.s.a.p.
Please forgive my long-distance meddling.
I can't help it.
More later.

Jochen