Radiculopathy

1. Why are sensory complaints more common than motor complaints in radiculopathy?
2. What are the two most common causes of radiculopathy?
3. What are the NCS findings in radiculopathy?
4. When can abnormal spontaneous activity first be seen in the paraspinals? Why might they be normal?
5. When does abnormal spontaneous activity begin in the limbs?
6. When does reinnervation usually occur?

Answers:
1. Sensory fibers are larger and therefore more prone to injury.
2. Disc hernation, which is most common in age <50,>50.
3. SNAPs are normal. CMAP may show reduced amplitude or be normal if the injury is purely demyelinating, incomplete, or reinnervation has occurred. H-reflex is abnormal in S1 radiculopathy. F-waves are not useful as muscles have more than one root innervation.
4. Abnormal spont activity is seen in paraspinals at 1 week, but they can be normal if they become reinnervated or the posterior primary rami are spared. In 10-30% of cases, abnormal paraspinals are the only abnormal finding.
5. 2 weeks.
6. 5-6 weeks.