Overview Snapshot A 26-year-old male presents with lower back pain that radiates down the side of his right leg and into his right foot. The pain started after he was recently lifting furniture into his new home. On physical exam, there is notable weakness on dorsiflexion of the foot and extension of the toe. Sensory loss is noted between the first and second digit of the foot. Knee and ankle reflexes are normal. There is no saddle anesthesia, and anal wink is appreciated. When raising the extended leg while in the supine position, pain radiates from the lower back, down the leg, and into the foot. (L5 radiculopathy due to disc herniation) Introduction Spinal nerves 31 pairs 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal vertebral exit C1-C7 exit via intervertebral foramina above corresponding vertebra all other nerves exit via intervertebral foramina below corresponding vertebra Spinal cord termination adults spinal cord ends at L1-L2 becomes cauda equina subarachnoid space extends to lower border of S2 see Lumbar puncture topic Pathology vertebral disk herniation nucleus pulposus herniates posteriolaterally through annulus fibrosis most commonly occurs between L5 and S1 cauda equina affects S2-S5 nerve roots spinal cord syndromes anterior cord syndrome ischemia affecting region supplied by anterior spinal artery (anterior 2/3 of spinal cord) Spinal Cord Pathways Sensory pathways dorsal columns function ascending pressure, vibration, discriminative touch, and proprioceptive sensation subdivisions fasciculus cuneatus upper body and extremities fasciculus gracilis lower body and extremities pathway 1st order neuron sensory nerve ending → dorsal root ganglion (location of cell body) → spinal cord → ipsilateral ascent in dorsal column → synapse in ipsilateral nucleus in medulla (cuneatus or gracilis) 2nd order neuron ipsilateral nucleus in medulla → decussates in medulla → contralateral ascent in medial lemniscus → synapse in VPL of thalamus 3rd order neuron VPL of thalamus → sensory cortex Spinothalamic tract function ascending pain and temperature sensation pathway 1st order neuron sensory nerve ending → dorsal root ganglion (location of cell body) → spinal cord → synapse in ipsilateral gray matter of spinal cord 2nd order neuron ipsilateral gray matter of spinal cord → decussates at anterior white commissure → contralateral ascent in spinothalamic tract → synapse in VPL of thalamus 3rd order neuron VPL of thalamus → sensory cortex Motor pathways lateral corticospinal tract function descending voluntary motor control of contralateral limbs pathway 1st order neuron (upper motor neuron) cell body in primary motor cortex → ipsilateral descent through internal capsule → decussation at caudal medulla (pyramidal decussation) → contralateral descent in lateral corticospinal tract → synapse at cell body of anterior horn in spinal cord 2nd order neuron (lower motor neuron) leaves anterior horn of spinal cord → synapses at neuromuscular junction anterior spinal artery strokes leads to loss of deep tendon reflexes and flaccid weakness acutely after the stroke hyperreflexia and spascity days to weeks following a stroke
QUESTIONS 1 of 7 1 2 3 4 5 6 7 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.NE.14.77) A patient with a known spinal cord ependymoma presents to his neurologist for a check up. He complains that he has had difficulty walking, which he attributes to left leg weakness. On exam, he is noted to have 1/5 strength in his left lower extremity, as well as decreased vibration and position sensation in the left lower extremity and decreased pain and temperature sensation in the right lower extremity. Which of the following spinal cord lesions is most consistent with his presentation? QID: 106882 Type & Select Correct Answer 1 Left-sided Brown-Sequard (hemisection) 74% (138/187) 2 Right-sided Brown-Sequard (hemisection) 13% (24/187) 3 Anterior cord syndrome 1% (2/187) 4 Posterior cord syndrome 5% (10/187) 5 Syringomelia 3% (6/187) M 2 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK
All Videos (4) Login to View Community Videos Login to View Community Videos Lateral Coriticospinal Tract Moises Dominguez Neurology - Spinal Cord D 12/1/2017 345 views 4.5 (10) Login to View Community Videos Login to View Community Videos Spinal Cord Organisation Keshav Mudgal Neurology - Spinal Cord D 9/30/2015 123 views 5.0 (3) Login to View Community Videos Login to View Community Videos Spinal Tracts Gio Sabal Neurology - Spinal Cord D 9/21/2015 149 views 5.0 (1) Neurology | Spinal Cord Neurology - Spinal Cord Listen Now 21:6 min 6/18/2021 59 plays 5.0 (1) See More See Less