In this condition one or more of the cervical vertebrae is/are displaced anteriorly, and because of the oblique plane of the facet line is also displaced superiorly. This results in a bulging effect of the cervical disc and causes either excess pressure on the motor nerve root of the brachial plexus or increased pressure on the spinal cord, or both. Additionally, there may be no change in symptoms until the head is either flexed (chin to chest) or rotated towards the affected side.
Tell tale signs of a hidden cervical disc include weakness of the arm, possible weakness of one side of the body, anterior head carriage (head and neck out in front of thorax), tenderness of the affected vertebral segment, and massive hyper-tonicity of the neck. Athletes with this condition will see an sudden dramatic decrease in performance.
The most common causes of this condition are sleeping face down and shoulder checking while driving, but any activity requiring excessive cervical rotation may also contribute. If you live in the Greater Vancouver area and you believe this description may align with your current symptoms, please consider an evaluation at my office.