Hi David

You may find this link useful. When someone tests negative for Sjogren's but has the dry eyes/mouth etc it is sometimes referred to as sicca syndrome.

http://info.sjogrens.org/conquering-...Sicca-Syndrome

This next one is a rather technical article on autonomic conditions:

http://jnnp.bmj.com/content/74/suppl_3/iii31.full

Hope this gives you some clarification - and hope it's not too heavy reading.