|
Year |
2002 |
|---|---|
|
Question Number |
17 |
|
Category |
Spine |
Question
A 51-year-old woman has neck and left arm pain. Sagittal and axial MRI scans are shown in Figures 4a and 4b. What is the most likely neurologic abnormality caused by this condition?
1. Left-sided Babinski sign
2. Decreased left brachioradialis reflex
3. Decreased left triceps reflex
4. Weak left wrist extensors
5. Diminished sensation over the left thumb
Figures
Answer (click for answer)
Preferred response: 3
The MRI reveals a left-sided disc herniation at the C6-7 disc. The nerve roots exit above their named vertebral body in the cervical spine (i.e. the C7 root exits above the C7 vertebral body) so that a disc at this level would impinge on the C7 root. The triceps in innervated by the C7 root. Babinski’s sign is for myelopathy; brachioradialis, wrist extensors C6, and thumb sensation are C6 functions.
Reference: Hoppenfeld S: Evaluation of nerve root lesions involving the upper extremity, in Hoppenfeld S (ed): Orthopaedic Neurology; A Diagnostic Guide to Neurologic Levels. Philadelphia, PA, JB Lippincott, 1977, pp 7-44.