I have stiffness in neck from 8months. Sometimes there is neck pain too. The back of the neck, below neck area and shoulders also feel stiff. Arms and legs sometimes feel weak.  Also find difficulty to balance at times. Not able to balance while turning neck to one side and walk. I had sinusitis in the past and during my last ENT visit, doctor said that my sinuses are ok now and there is no problem with ears. Which doctor should I consult for this issue.