Assuming the SGB was safely performed by an experienced provider such as the ones we perform in our clinic, we expect and want to see the Horner’s syndrome.  This is a constellation of signs that show up almost immediately after the block is completed.  You may also feel a lump in your throat, hoarseness, loss of voice, or difficulty swallowing for the duration of the effects of the block.  This is not caused by the SGB, but by the inadvertent numbing of one of the vocal cord nerves called the recurrent laryngeal nerve.  This is not dangerous as long as both sides of your neck are numbed at the same time.