What Could Cause Left-sided Arm And Facial Numbness Along With Tingling Sensation?
Neck ultrasound may not be enough.
Detailed Answer:
Hello and welcome to HealthcareMagic.
I agree with the fact that your doctors are looking into two main directions, a heart or a brain origin. I would add to that a basic metabolic panel (glucose, liver and kidney function, electrolyte panel) but I imagine that that has probably been done.
As for the specific tests, regarding the heart I would say that those tests are the appropriate ones, I wouldn't ask for other additional tests.
When it comes to brain related origin I am not sure that a neck vessel ultrasound is enough. While it is fine as an initial screening test for the carotid arteries, if other tests are normal I think other investigations should be sought as possibility of seizures or insufficient blood supply in the vertebral arteries could be the cause. MRI imaging of the brain and blood vessels would be required. The purpose would be to search for brain lesions like small strokes, tumor etc and for blood vessel changes. The purpose of the ultrasound is to look for such vessel changes as well, but it doesn't visualize that well the posterior vertebral blood vessels, more suitable for the carotid arteries.
I hope my opinion covers what you needed to know (you do not seem to make a specific question). If you have other questions please let me know.