I've had severe weakness in right leg and some in right arm, and now walk with a cane. 6 months ago I couldn't walk without a walker. MRI, blood tests, EMG all normal. SO I sympathize with you not being diagnosed either. When people ask me why my leg is so weak and trembles when I raise it from a sitting position I just say "I don't know" and "the drs. don't know". Please post if you ever find something out! I'd like to know too!