Spinal Cord Injury

Question 1

What type of lesion to the spinal cord causes Brown-Sequard syndrome?

Answer 1

Hemi-cordectomy

Question 2

Which important tracts would be damaged in Brown-Sequard syndrome and what would the corresponding deficits be?

Answer 2

Damage to corticospinal tract -> ipsilateral motor loss

Damage to dorsal column/medial lemniscus tract -> ipsilateral loss of discriminative touch, pressure, proprioception

Damage to spinothalamic tract -> loss of contralateral pain and temp. sensation

Question 3

What causes anterior cord syndrome?

Answer 3

Ischemia - due to thrombotic events, aortic aneurysm repairs, etc.

Question 4

What tracts would be damaged in anterior cord syndrome and what would the corresponding deficits be?

Answer 4

Corticospinal tract damage -> loss of motor function below the lesion

Spinothalamic tract damage -> loss of pain and temp. sensation below the lesion

Question 5

What tract(s) is/are damaged in posterior cord syndrome and what is/are the corresponding deficit(s)?

Answer 5

Dorsal column/medial lemniscus tract damage -> loss of discriminative touch, proprioception, vibration sense below the lesion

Question 6

What is conus medullaris syndrome? Describe the possible cause(s) and deficits. How can it be distinguished clinically from cauda equina syndrome?

Answer 6

Damage to the tip/cone of the spinal cord.

Possible cause is T10-L2 vertebral fractures.

Can damage UMNs, LMNs, or both (variable).

Saddle anesthesia is a common symptom.

Distinguish from cauda equina by a lack of radiculopathy.

Question 7

Describe what cauda equina syndrome is and what symptoms are common.

Answer 7

Damage to the lumbosacral nerve roots (L2 and lower) –> bilateral pain, radiculopathy, urinary and fecal incontinence

Question 8

What body parts are more severely affected by central cord syndrome and why?

Answer 8

Upper body because the corticospinal tract is organized with the tracts to the LMNs to the upper body/arms in a more medial position than the lower extremities (CTLS in the photo means cervical, thoracic, lumbar, sacral).

Question 9

Are patients with a complete injury to spinal cord segments C1-3 able to breathe on their own?

Answer 9

No, phrenic nerve (C3, 4, 5) is cut off

Question 10

Are patients with a complete injury to spinal cord segments C3-4 able to breathe on their own?

Answer 10

Initially they will need a ventilator but can learn to breathe on their own part-time.

Question 11

Which spinal cord segment contributes to the ability to flex the arm at the elbow?

Answer 11

C5 (1st root of brachial plexus) -> musculocutaneous nerve!

Question 12

Along with elbow flexion, what other upper extremity movment(s) are people with a C6 spinal cord injury able to perform?

Answer 12

Wrist extension

Question 13

At which spinal cord level (or lower) allows for one to have triceps use? What is the significance of this from a functional standpoint?

Answer 13

C7

This allows for patients to be completely independent.

Question 14

Injuries to which spinal cord injuries allow for the possibility of walking with long leg braces + forearm crutches, and short leg braces + cane, respectively?

Answer 14

L2 - can rehab to walking with long leg braces and forearm crutches

L3-4 - can rehab to walking with short leg braces and a cane

Question 15

Describe the autonomic innervation to the heart.

Answer 15

Vagus - parasympathetic

T1-T4 - parasympathetic

Question 16

Define neurogenic shock and describe its pathophysiology.

Answer 16

Definition: hypotension, bradycardia, hypothermia due to loss of autonomic innervation.

An acute loss of sympathetic innervation to the heart and GI system results in unopposed parasympathetic tone: bradycardia, splanchnic vasodilation -> decreased effective circulating blood volume

Question 17

How is neurogenic shock treated?

Answer 17

IV fluids, atropine (anti-muscarinic), pacemaker if shit is real

Question 18

Define spinal shock.

Answer 18

Loss of sensory, motor, and reflex function below a spinal cord injury. Pathophysiology is not understood. Can last days to months.

Question 19

Patients with a spinal cord injury to spinal cord level ____ or higher are susceptible to autonomic dysreflexia.

Answer 19

T6

Question 20

Describe the pathophysiology and common symptoms of autonomic dysreflexia.

Answer 20

Disconnection of sympathetic innervation to GI, bladder; after a noxious stimulus to any body part below the injury can set off the sympathetics in reflex arcs without ability for the CNS above the injury to turn that shit off.

Symptoms: HTN, flushing and sweating above the injury level, piloerection (goosebumps)

Question 21

What is a normal BP reading for a patient with a SCI at T6 or above?

Answer 21

100/60 (cuz GI splanchnic vascular beds have greater parasympathetic tone than normal -> vasodilation)

Question 22

What is the most common trigger for autonomic dysreflexia?

Answer 22

Full bladder

Question 23

What are the three steps for treatment of autonomic dysreflexia?1

Answer 23

1. Sit the patient up and loosen any tight clothing.
2. Look for the trigger (usually full bladder).
3. Give nitropaste or hydralazine if stimulus can’t be found.

Question 24

Describe the autonomic innervation to the GI system.

Answer 24

Parasympathetic: vagus for foregut and midgut, pelvic splanchnic (S2, 3, 4) for the hindgut.

Sympathetic: greater splanchnic (T5-9) for the foregut, lesser & least splanchnic (T10-12) for the midgut, lumbar splanchnic (L1, 2) for the hindgut.

Question 25

Name and describe the three important bowel reflexes to check in patients with SCI.

Answer 25

1. Gastrocolic reflex: food in stomach triggers emptying from the ileum -> colon
2. Rectoanal inhibitory reflex: relaxation of anal sphincter in response to rectal distension
3. Rectocolic reflex: increased colonic motility in response to rectal distension

Question 26

Describe the differences between UMN bowel and LMN bowel with regards to reflexes and functional needs.

Answer 26

UMN bowel: reflex arcs still work despite there being a lesion above, so while voluntary motor control is lost, patients can trigger a bowel movement with digital rectal stimulation.

LMN bowel: due to cauda equina syndrome or conus medullaris syndrome affecting the LMNs - reflex arc is fucked up so none of the reflexes work; stool needs to be manually removed from the rectum.

Question 27

Describe the autonomic innervation to the bladder.

Answer 27

Parasympathetic: pelvic splanchnic (S2, 3, 4 keeps the piss of the floor)

Sympathetic: T10-L2 (lesser, least, lumbar splanchnic)

Question 28

What type of injury/at what level causes a spastic bladder?

What about a flaccid bladder?

What are sequelae of each?

Answer 28

Spastic bladder occurs when there is UMN damage -> loss of parasympathetic innervation for voluntary bladder voiding. When the bladder fills, the detrusor muscle spasms, but the sphincter muscle might be closed -> vesicoureteral reflux -> hydronephrosis and renal failure

Flaccid bladder occurs when there is LMN injury from cauda equina syndrome or conus medullaris syndrome with LMN involvement. The sphincter is relaxed and the detrusor muscle is areflexic. Result is incontinence or overflow.

Question 29

Are somewhat high WBC counts (~10k) on urinalysis of a patient with a spinal cord injury normal?

What is the most common symptom of UTI in a patient with spinal cord injury?

Answer 29

Yeah high white cells is normal.

Most common symptom is increased leg spasms.

Question 30

What is your Dx?

Answer 30

Syringomyelia (formation of a cyst in the center of the spinal cord months to years after an injury)

Question 31

Name two musculoskeletal complication of spinal cord injury.

Answer 31

1. Osteoporosis and fractures
2. Heterotopic ossification

Question 32

Paralysis of accessory muscles of respiration such as the intercostals and abdominal muscles puts patients at risk for…?

Answer 32

Atelectasis and pneumonia

Question 33

Are DVTs and pressure ulcers bad?

Answer 33

They’re bad, mmkay