My Husband Has Numbness In His Extremities And Now His

My husband has numbness in his extremities and now his face seems to be getting numb. He went to the dr today. They did lab work and said they would refer him to a neurologist in the next day or two, but he has an abnormal gait with the numbness. He's having difficulty drinking without it running out of his mouth now. We're not sure if we should go to the ER or not or try and wait until morning to get in to see the doctor again. Could this be symptoms of something very serious?