It is the 10th cranial nerve. It can be compressed or injured a few places between the brainstem and the chest. So, there is at least one way an injury to the neck or brainstem can relate to heart rate, ekg, and breathing.
An injury "above c1" implies a brain injury
. If it is located in the brainstem, it would have to be very small to be survivable. This area controls many functions that are "primitive"--that is to say, common to all animals. That would include heart rate and breathing.
When we talk about brainstem injury, we talk about cranial nerve signs and "long tract" signs, meaning the extremities. By finding the intersection of the involved nerves, the area can be identified.
Injuries above the brainstem can be a bit more difficult to localize. Cerebellar problems can be difficult to diagnose and often involve balance and coordination. The midbrain is a relay area of sensory and motor signals. The cerebral cortices, on the other hand, are reasonably well-mapped and those lesions can be recognized more easily.
A neurologist or neurosurgeon
can help diagnose and treat the problem. Often MRI
is needed to help locate and diagnose the problem. To be useful, though, the images should correspond to the symptoms and exam findings.