Is there a drug which can be taken along with Risperdal to stop the muscle spasms?
I suppose the first and most apparent question to you would be, have you discussed the severe neck spasms with your caregiver? If not, it would be most advisable to make an appointment as soon as possible to discuss one of your side-effects to the medication. In some instances the spasms can be dose related while in other cases it's the drug itself that's producing the spasm and altering the dose won't have much of an improvement.
I've known people who've had symptomatic relief from acupuncture treatments while still others have benefited somewhat from massage therapy. These might be two good options for you to explore while waiting to see your psychiatrist, but, as I said - the most important person to speak with is the person that did the prescribing in the first instance. Good luck and best wishes.