Cervical Spinal Cord Compression

A 55-year-old computer programmer comes to your office worried that he has carpal tunnel syndrome (CTS) because he has been having numbness in his left hand on his thumb, index, and middle finger; these were the same symptoms his coworker had before receiving a diagnosis of CTS. He also has had similar but milder symptoms in the same 3 fingers on the other hand. The numbness and tingling have gradually progressed over the past 2 weeks and now the hand occasionally feels weak. He also mentions that he occasionally gets an electric shock feeling between his shoulder blades when he is chewing or protrudes his jaw. There has been no injury and there are no other complaints. Specifically, he denies chest pain, trouble breathing, fever, swelling, and rash.

On physical examination, vital signs are all normal as are inspections of the head and neck. The lungs are clear and heart sounds are normal. There is no swelling, redness, or tenderness of the extremities. Neurologic examination demonstrates normal strength and sensation but reflexes seem overly brisk and there are 5 beats of clonus in both feet. You note a positive Hoffmann sign: extending the middle finger and flicking down rapidly at the distal interphalangeal (DIP) joint it causes the DIP joint of the adjacent index finger and/or the thumb to spontaneously flex immediately afterward.

• What is the significance of a positive Hoffmann sign? 
• What other special physical examination tests might you perform to confirm or refute this? 
• What type of diagnostic testing will be required?