Bored of the Cord: Spinal Cord Syndromes

Saved_by_the_Bell_logo zackphone

Listen up, Preppy.

It’s 1990 and Bayside High is where it’s at. Mr. Belding may be breathing down your back, but you have Zack Morris and the gang to kick it with. Surely you remember Zack’s state-of-the-art, cooler-than-school cordless phone, right?

Well, with all of the Saved By the Bell shenanigans pulled by Zack, it may leave you and your high school sweetheart “cord-less” as well!

Check out some totally gnarly cord syndromes in this episode of Bored Review!

Screech may be the nerdy one now, but he’ll end up being that gunner in med school- just you wait. Let’s get on his good side now by answering some basic questions:

What runs through the dorsal columns, the spinothalamic tract, and the corticospinal tract, respectively?

Dorsal columns: ascending vibration and proprioception sensation
Spinothalamic: ascending pain and temperature sensation
Corticospinal: descending motor pathway

Zack Morris may have a fancy cordless phone, but after AC Slater wrestles him for this hot '90s prize, he ends up with an anterior cord injury! (And no phone!!) What are his clinical findings?

Complete loss of motor, pain, and temperature distal to the lesion from spinothalamic and corticospinal pathway damage which run–you guessed it–anteriorly in the cord. This injury can occur traumatically with cervical spine flexion or direct anterior cord compression or non traumatically with thrombosis of the anterior spinal artery.

Patients with anterior cord syndrome will have crude sensation to touch. Why is this? What would need to happen to have complete loss of sensation?

Dorsal columns are still intact in anterior cord syndrome, and therefore vibration sense and position sense are still intact. Patients will still have basic sensation to touch, so when you simply rub their extremity and say, “Can you feel that?” you are not testing this properly. Two-point discrimination will be lost in anterior cord and should be accurately tested if there is true concern for this injury, otherwise crude touch sensation will take over and give you false reassurance.

Remember that episode when Jessie Spano is hooked on caffeine pills? (I’m so excited! I’m so excited! I’m so… scared!) Well, what you may not know is in Jessie’s caffeinated rage she actually beasts out and stabs Kelly Kapowski in the back! Kelly loses complete motor function, vibration, and proprioception on her right side, along with loss of pain and temperature sensation on the left side.

What cord syndrome is this?

Brown-Séquard Syndrome – hemisection of the spinal cord:

ipsilateral loss of motor (corticospinal tract which decussates in the medulla)
ipsilateral loss of vibration + proprioception (dorsal columns; doesn’t cross midline until the medulla)
contralateral loss of pain and temperature (spinothalamic tract, fibers cross midline 1-2 levels above where they enter the spine).

Cell phone driving laws are not yet in effect. Lisa Turtle is driving to the mall while talking on her cordless cell phone and doesn’t see the taco truck making a turn. The resulting scene is a mess–guacamole and salsa everywhere!–and poor Lisa has central cord syndrome after neck hyperextension from whiplash. What extremities are most affected and why?

She will have UPPER EXTREMITY paralysis and likely loss of upper extremity pain and temperature. Lower extremities may also be affected depending on the extent of the central cord lesion (upper extremity fibers lay more medial/central with the lower extremities more lateral).

Which of these lesions has the best prognosis for recovery?

Brown-Séquard Syndrome

Which of these has the worst prognosis?

Anterior Cord Syndrome. Sorry Zack…

Pop Quiz! Name the anatomy affected, clinical deficits, and mechanism of the top 4 incomplete cord syndromes.

Syndrome	Anatomy	Clinical Deficits	Mechanism
Anterior Cord	Bilateral spinothalamic & corticospinal	Bilateral: pain/temp, motor below lesion	Flexion injury, spinal artery occlusion
Central Cord	Bilateral upper extremity spinothalamic & corticospinal	Upper extremity motor, pain/temp loss > lower extremity loss	Hyperextension injury, cervical stenosis
Brown Sequard	Unilateral (R or L) spinothalamic, corticospinal, & dorsal column	Ipsilateral motor, vibration/proprioception Contralateral pain/temp	Trauma / hemisection, unilateral cord compression
Cauda Equina	Often bilateral, nerve root compression	Lower extremity motor and sensory, bowel/bladder, saddle anesthesia	Tumor, disc herniation, abscess

References

Baron BJ, McSherry KJ, Larson JL, Jr., Scalea TM. Chapter 255. Spine and Spinal Cord Trauma. In: Tintinalli JE, Stapczynski J, Ma O, Cline DM, Cydulka RK, Meckler GD, T. eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7e. New York, NY: McGraw-Hill; 2011.

Special thanks to Dr. Willis!