Spinal Cord Injury Flashcards
What type of lesion to the spinal cord causes Brown-Sequard syndrome?
Hemi-cordectomy
Which important tracts would be damaged in Brown-Sequard syndrome and what would the corresponding deficits be?
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
What causes anterior cord syndrome?
Ischemia - due to thrombotic events, aortic aneurysm repairs, etc.
What tracts would be damaged in anterior cord syndrome and what would the corresponding deficits be?
Corticospinal tract damage -> loss of motor function below the lesion
Spinothalamic tract damage -> loss of pain and temp. sensation below the lesion
What tract(s) is/are damaged in posterior cord syndrome and what is/are the corresponding deficit(s)?
Dorsal column/medial lemniscus tract damage -> loss of discriminative touch, proprioception, vibration sense below the lesion
What is conus medullaris syndrome? Describe the possible cause(s) and deficits. How can it be distinguished clinically from cauda equina syndrome?
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.
Describe what cauda equina syndrome is and what symptoms are common.
Damage to the lumbosacral nerve roots (L2 and lower) –> bilateral pain, radiculopathy, urinary and fecal incontinence
What body parts are more severely affected by central cord syndrome and why?
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).
Are patients with a complete injury to spinal cord segments C1-3 able to breathe on their own?
No, phrenic nerve (C3, 4, 5) is cut off
Are patients with a complete injury to spinal cord segments C3-4 able to breathe on their own?
Initially they will need a ventilator but can learn to breathe on their own part-time.
Which spinal cord segment contributes to the ability to flex the arm at the elbow?
C5 (1st root of brachial plexus) -> musculocutaneous nerve!
Along with elbow flexion, what other upper extremity movment(s) are people with a C6 spinal cord injury able to perform?
Wrist extension
At which spinal cord level (or lower) allows for one to have triceps use? What is the significance of this from a functional standpoint?
C7
This allows for patients to be completely independent.
Injuries to which spinal cord injuries allow for the possibility of walking with long leg braces + forearm crutches, and short leg braces + cane, respectively?
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
Describe the autonomic innervation to the heart.
Vagus - parasympathetic
T1-T4 - parasympathetic
Define neurogenic shock and describe its pathophysiology.
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
How is neurogenic shock treated?
IV fluids, atropine (anti-muscarinic), pacemaker if shit is real
Define spinal shock.
Loss of sensory, motor, and reflex function below a spinal cord injury. Pathophysiology is not understood. Can last days to months.
Patients with a spinal cord injury to spinal cord level ____ or higher are susceptible to autonomic dysreflexia.
T6
Describe the pathophysiology and common symptoms of autonomic dysreflexia.
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)
What is a normal BP reading for a patient with a SCI at T6 or above?
100/60 (cuz GI splanchnic vascular beds have greater parasympathetic tone than normal -> vasodilation)
What is the most common trigger for autonomic dysreflexia?
Full bladder
What are the three steps for treatment of autonomic dysreflexia?1
- Sit the patient up and loosen any tight clothing.
- Look for the trigger (usually full bladder).
- Give nitropaste or hydralazine if stimulus can’t be found.
Describe the autonomic innervation to the GI system.
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.
Name and describe the three important bowel reflexes to check in patients with SCI.
- Gastrocolic reflex: food in stomach triggers emptying from the ileum -> colon
- Rectoanal inhibitory reflex: relaxation of anal sphincter in response to rectal distension
- Rectocolic reflex: increased colonic motility in response to rectal distension
Describe the differences between UMN bowel and LMN bowel with regards to reflexes and functional needs.
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.
Describe the autonomic innervation to the bladder.
Parasympathetic: pelvic splanchnic (S2, 3, 4 keeps the piss of the floor)
Sympathetic: T10-L2 (lesser, least, lumbar splanchnic)
What type of injury/at what level causes a spastic bladder?
What about a flaccid bladder?
What are sequelae of each?
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.
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?
Yeah high white cells is normal.
Most common symptom is increased leg spasms.
What is your Dx?
Syringomyelia (formation of a cyst in the center of the spinal cord months to years after an injury)
Name two musculoskeletal complication of spinal cord injury.
- Osteoporosis and fractures
- Heterotopic ossification
Paralysis of accessory muscles of respiration such as the intercostals and abdominal muscles puts patients at risk for…?
Atelectasis and pneumonia
Are DVTs and pressure ulcers bad?
They’re bad, mmkay
