Could sjogren syndrome causes sever dysphagia and how this appear in upper gi series ?

Yes: Upper GI series will show dysphagia but it wont necessarily show the cause. In sjogrens disease the cause of dysphagia can be due to dry throat, but can also be caused by inflammation in the brain stem. The latter might also cause other symptoms besides just dysphagia.

Dysphagia: Dysphagia in sjogren's syndrome is more apt to be due to decreased salivary secretion. There can be impaired movement which can be noted on a barium swallow.