Spinal Cord Flashcards
Spinal cord circulation consists of _____ anterior and ______ posterior arteries
2 posterior
1 anterior
The anterior spinal artery perfuses:
The anterior 2/3 of the spine
The posterior spinal arteries perfuse:
The posterior 1/3 of the spine
In the cervical region, spinal arteries are perfused by:
the vertebral arteries
In the thoracic and lumbar regions, spinal arteries are perfused by:
Radicular and lumbar arteries
What is the Artery of Adamkiewicz?
The greatest radicular artery
What is a “watershed” region in the spine?
regions of the spinal cord that only have one blood supply and no collateral, so they’re particularly vulnerable to ischemia
Where does the artery of adamkiewicz typically arise?
On the left side between T11 and T12
An aortic cross clamp ABOVE the artery of adamkiewicz can cause:
Anterior spinal artery syndrome
What is Beck’s syndrome?
Anterior spinal artery syndrome
What are the classic signs and symptoms of Beck’s syndrome?
The corticospinal tract is perfused by:
anterior blood supply
Autonomic nerve fibers are perfused by:
anterior blood supply
The spinothalamic tract is perfused by:
Anterior blood supply
The dorsal column is perfused by:
posterior blood supply
The corticospinal tract is responsible for:
primary motor activity for the somatic system from the neck to the feet
The spinothalamic tract is responsible for:
carrying pain and temperature sensation toward the brain
The dorsal column is responsible for:
Sensory neurons exit the spinal cord via _________
the dorsal nerve root
Motor AND autonomic neurons exit the spinal cord via ______________
the ventral nerve root
Where are laminae located?
In the gray matter of the spinal cord
The white matter of the spinal cord contains:
the axons of the ascending and descending tracts
gray matter is for receiving and modulating. White matter is for travelling.
What is the role of laminae 1-6? Where are they located?
What is the role of laminae 7-10? Where are they located?
How can you figure out the purpose of a tract based on its name?
The first half of the name indicates where the tract begins
The second half indicates where the tract terminates
How does damage to upper motor neurons manifest?
The babinski test assess integrity of which tract?
corticospinal
Is a positive babinski sign present with upper or lower motor neuron injuries?
Upper, not lower
Lower motor neuron injury results in:
Impaired reflexes and flaccid paralysis
SSEPs monitor which tract?
Dorsal column, posterior spinal artery
MEPs monitor which tract?
ventral corticospinal,
anterior spinal artery
What is another name for the corticospinal tract?
pyramidal tract
What is a positive babinski sign?
upward extension of the big toe with fanning of the other toes
Where do upper motor neurons begin and end?
They begin in the cortex and end in the ventral horn of the spinal cord
Where do lower motor neurons begin and end?
They begin in the ventral horn of the spinal cord and terminate at the neuromuscular junction
What is the most common site of spinal cord injury?
C7
What are the symptoms of neurogenic shock?
Bradycardia, hypotension, hypothermia with warm extremities
Are spinal reflexes present with a full spinal cord injury?
Initially, no. They will have flaccidity. But later these reflexes will return, leading to spasticity
Why does spinal shock involve bradycardia?
Knocking out the cardioaccelerators leads to unopposed vagal tone
Can you use Succinylcholine in a patient with a spinal cord injury?
Technically you can for the first 24 hours, but forcing fasciculations may worsen outcomes. Best to not.
When are patients at risk for autonomic hyperreflexia?
Once spinal shock ends (about 1-3 weeks out) BECAUSE spinal sympathetic reflexes return BELOW the level of injury
Which patients develop autonomic hyperreflexia?
86% of patients with a lesion above t6 will develop it
Which situations have the highest risk for triggering autonomic hyperreflexia?
Bladder Cath
Cysto, Colonoscopy
bowel movement
childbirth
How is autonomic hyperreflexia treated?
Removing the stimulus
Deepening the anesthetic
Administering a rapid-acting vasdilator
How is bradycardia from autonomic hyperreflexia best treated?
With an anticholinergic
If a woman with a spinal cord injury is laboring without pain, do they still need analgesia?
YES!! Stimulation can still trigger hyperreflexia. Spinal is better than epidural, which doesn’t as reliably anesthetize the roots
What is ALS?
progressive degeneration of motor neurons in the corticospinal tract, leaving sensation intact
What is another name for the dorsal column?
Medial lemniscal tract
