Numbness, Dizziness, Heavy Head, Relieved by Muscle Relaxer

My husband has been having pain in his neck and upper back; but nothing has shown up on his tests and MRIs other than "minor" narrowing of the canal in his neck. And the doctors don't seem to think it's a problem.

Toward the end of last year, he starting having spells every now and then where he would have a lot of pain in the middle of his upper back and would start feeling dizzy, lightheaded, having feelings of a "heavy head", and "brain tingling". This was accompanied by numbness in the hands, lips, and sometimes the arms, legs, and feet. The two worst spells he had included blurred vision and slurred speech; and his body would go completely limp. He had to go to the ER in an ambulance twice over this in November and December; but nothing was found.

The spells usually start after he gets out of bed, either from a nap or a night's sleep. And he has a habit of sleeping on his side, leaned over toward his stomach with his arm under his head.

A mild case of this (i.e. not including blurred vision, slurred speech, and limpness) occurred yesterday when he got out of bed. He finally decided to take some Soma that had been prescribed to him, despite worries that its effects would worsen his dizziness.

To our surprise, it helped him greatly and kept us from having to go to the ER.

So, I'm wondering, what does the horrible symptoms, the timing of the symptoms, and the relief from Soma imply diagnosis-wise? Whenever we tell his doctors, they don't seem to believe us; and all they care about are the test results. So, they have given us no help in finding a diagnosis or treatment. What can we do to seek better treatment based on likely causes and to be taken more seriously?

Thank you!