trembling

I am experiencing internal tremors in my legs and trunk of body during any type of sleep, whether nap or during night timefor the past 6 months.Tremors do not occur during the day. The tremors cannot be seen but they awaken me and can easily be felt by my wife. Once they awaken me, they will only last another 10-15 seconds. This will happen many times throughout the night. Cat scan, EEG, other medical test are normal. My neurologist seems stumped and believes this is a rare form of RLS. He prescribed Klonipin .75mg and it has truly allowed me to sleep. However I am not convinced this is in any way a form of RLS. Does anyone else have these type syptoms and any idea of cause. Thanks in advance for any responses!