Which condition is described as involving lower motor neuron signs due to nerve root involvement?

Which condition is described as involving lower motor neuron signs due to nerve root involvement?

• A. Cauda equina syndrome
• B. Central cord syndrome
• C. Brown-Sequard syndrome
• D. Guillain-Barré syndrome

Answer: (A)

Lower motor neuron signs appear when nerve roots or motor neurons themselves are affected. When nerve roots are compressed or irritated, as happens with cauda equina syndrome, the affected roots cause flaccid weakness and reduced reflexes in the muscles they innervate, along with radicular pain and sensory changes in a dermatomal pattern. Cauda equina syndrome specifically involves compression of the lumbar and sacral nerve roots below the conus medullaris, leading to LMN-type weakness in the legs, hyporeflexia, and often saddle anesthesia with bowel or bladder dysfunction. In contrast, central cord syndrome mainly produces upper motor neuron deficits below the level of injury, Brown-Sequard causes a mix of ipsilateral motor and vibration loss with contralateral pain and temperature loss, and Guillain-Barré syndrome is a peripheral nerve demyelinating process that causes ascending LMN weakness not primarily due to nerve root compression. Therefore, the description aligns best with cauda equina syndrome.

Lower motor neuron signs appear when nerve roots or motor neurons themselves are affected. When nerve roots are compressed or irritated, as happens with cauda equina syndrome, the affected roots cause flaccid weakness and reduced reflexes in the muscles they innervate, along with radicular pain and sensory changes in a dermatomal pattern. Cauda equina syndrome specifically involves compression of the lumbar and sacral nerve roots below the conus medullaris, leading to LMN-type weakness in the legs, hyporeflexia, and often saddle anesthesia with bowel or bladder dysfunction.

In contrast, central cord syndrome mainly produces upper motor neuron deficits below the level of injury, Brown-Sequard causes a mix of ipsilateral motor and vibration loss with contralateral pain and temperature loss, and Guillain-Barré syndrome is a peripheral nerve demyelinating process that causes ascending LMN weakness not primarily due to nerve root compression. Therefore, the description aligns best with cauda equina syndrome.