A careful neurologic examination in patients with a herniated disc often yields objective evidence of nerve root compression. A patient with a far-lateral L5-S1 disc herniation would have involvement of the exiting L5 nerve root, while a L5-S1 posterolateral herniated disc would involve the traversing S1 nerve root. S1 nerve root involvement would result in foot plantar flexion weakness and an absent Achilles reflex. Quadriceps weakness with an absent patella reflex is associated with L4 nerve root compression, and great toe extension would be more consistent with the motor supply from L5 nerve root. There is no consistent reflex associated with the L5 nerve root.
- Foot plantar flexion weakness with absent Achilles reflex.
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Seminars in Medical Practice
Hospital Physician Board Review Manuals
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