1 - Anatomy, Prognosis & ASIA Classification Flashcards
Where is the origin of the corticospinal tract? 🔑🔑
Precentral gyrus of the frontal lobe of the brain (primary motor cortex).
Cuccurollo 4th Edition Chapter 7 SCI pg539
Draw spinal cord termination. 🔑🔑
Gray 39’s Anatomy for Students - 4th Edition (2020) & Google
List 4 signs of corticospinal tract lesion besides loss of voluntary movement and skill. 🔑🔑
UMN syndrome
- Clonus
- Spasticity
- Rigidity
- Hyperreflexia
- Positive Babinski response
Cuccurollo 4th Edition Chapter 12 Spasticity pg853
Identify each tract and its function. 🔑🔑
- Cuneatus tract fibers origins above T7
- Gracilis tract fibers origin below T7
Cuccurollo 4th Edition Chapter 7 SCI pg538
List the major spinal tracts and their function. 🔑🔑
DORSAL COLUMN
- Vibration
- Proprioception
- Light Touch
SPINOCEREBELLAR
- Muscle position and tone
- Unconscious proprioception
SPINOTHALAMIC
- Pain and temperature (lateral)
- Crude touch and pressure (ventral)
Cuccurollo 4th Edition Chapter 7 SCI pg538
Explain Major “Ascending Pathways”. 3 marks.
- Spinocerebellar tracts:
* Unconscious proprioception (muscle proprioceptive, stretch, tension fibers) from the ipsilateral side of the body to the brain - Lateral spinothalamic tracts
- Pain and temperature from the contralateral side of the body to the brain
- One to three vertebral segments → contralateral thalamus → Internal capsule → postcentral gyrus of the cerebral cortex.
- Lesion will affect contralaterally below the level of the lesion
- Dorsal (posterior) columns
- Proprioception, fine touch, and vibration sense from the ipsilateral side of the body
- Up to medulla, at which point they decussate → medial lemniscus → ascends to the postcentral gyrus.
- lesion will be ipsilaterally below the level of the lesion.
Cuccurollo 4th Edition Chapter 7 SCI pg539
List the five major descending tracts from the brain 🔑🔑
Which spina cord tract cross and which does not cross? 🔑
- Spinocerebellar does not cross (ipsilateral, leaning toward lesion side)
- Spinothalamic cross 3 levels above (contralateral)
- Corticospinal (contralateral)
- Dorsal Column (contralateral)
Cuccurollo 4th Edition Chapter 7 SCI pg539 Figure 7-3
Explain Blood Supply of the Spinal Cord. 🔑
What is artery of adamkiewicz? clinical significance?🔑🔑
BLOOD SUPPLY TO SPINAL CORD
- Single anterior spinal artery
- Double posterior spinal artery
ARTERY OF ADAMKIEWICZ
The artery of Adamkiewicz is a major lumbar radicular artery
Origin from the left intercostal or lumbar artery at the levels of T9–L3 providing blood supply to spinal cord between lower third of spinal cord.
The lower thoracic region is referred to as the “watershed area” because there are fewer radicular arteries that supply the mid thoracic region of the spinal cord. This area (T4–T6) is most affected when there is low blood flow to the spinal cord (i.e., clamping of the aorta in surgery).
Cuccurollo 4th Edition Chapter 7 SCI pg540
Explain UMN and LMN pathway for medical student 🔑🔑
Lateral corticospinal tracts:
- Main motor tracts for controlling voluntary muscle activity
- Origin in precentral gyrus of the frontal lobe of the brain → thats why we see apraxia
- Descend through the internal capsule to the medulla oblongata
- 80% to 90% of the axons cross over (decussate) to the contralateral side at the pyramidal decussation in the medulla. Then descend in the lateral white columns of the spinal cord (lateral corticospinal tracts).
- 10% to 20% of axons that do not decussate/travel in the anterior (ventral) corticospinal tracts.
- Synapse first in ventral horn as uninterrupted neurons and are termed upper motor neurons (UMNs), while the secondary neurons that they synapse on are termed lower motor neurons (LMNs).
Cuccurollo 4th Edition Chapter 7 SCI pg539
List 4 Most Common Primary Causes of Death in SCI patients 🔑
💡 Most patient die from cardiorespiratory arrest, plus in SCI we have UTI and septicemia.
- Respiratory disorders, Pneumonia (acute phase)
- Heart diseases
- Septicemia (UTI, Pressure injuries, Pneumonia)
- Suicide (in teens, first years of diagnosis)
Cuccurollo 4th Edition Chapter 7 SCI pg536
List 4 Predictors of mortality post SCI 🔑🔑
- Male gender
- Advanced age
- Ventilator dependent
- Injured by an act of violence
- High injury level (particularly C4 or above)
- Neurological complete injury
- Poor community integration
- Poor economic status indicators
Cuccurollo 4th Edition Chapter 7 pg536
Describe the Manual Muscle Testing Grading System 🔑🔑
Cuccurollo 4th edition Chapter 7 SCI pg553
Explain 5 steps of AIS grading 🔑🔑
1- SENSORY LEVEL OF INJURY (SLI)
Most caudal “inferior” segment of the spinal cord with normal (2/2 score) sensory function on both sides of the body for both pinprick and light touch sensation
Pin Prick of a safety pin
0 = No sensation or unable to differentiate it from dull
1 = Felt but not as sharp as on the face
2 = Felt as sharp as the face
Light touch of cotton tip
0 = No sensation
1 = Felt but different than on the face
2 = Felt as on the face
2- MOTOR LEVEL OF INJURY (MLI)
Most caudal “inferior” key muscle group that is-graded ≥3/5 with all the segments above graded 5/5 in strength.
Motor level can be determined for each side of the body
3- NEUROLOGICAL LVEL OF INJURY (NLI)
Most caudal segment of the spinal cord with both normal sensory and motor function ≥3/5 with cephalad segments graded 5/5 on both sides of the body.
4- ANAL EXAMINATION
Deep anal pressure (DAP)
Inserting a lubricated gloved finger into the anus with pressure applied to the anorectal wall using the thumb to gently squeeze the anus against an inserted index finge.
Patient is asked if he or she can appreciate this digital pressure
Voluntary anal contraction (VAC)
Inserting a lubricated gloved finger into the anus and asking the patient to “squeeze my finger as if to hold back a bowel movement.”
Differentiate volitional contraction from anal spasm when the finger is inserted or anal contraction is triggered by Valsalva.
5- DETERMIN AIS GRADE
Cuccurollo 4th Edition Chapter 7 SCI pg550-556
ASIA definitions, Neurologic Level of Injury, ASIA A to E classification 🔑🔑
ASIA IMPARMENT SCALE
Describes a person‘s functional impairment as a result of their spinal cord injury
ASIA A COMPLETE
No motor or sensory function is prevesed in sacral segment S4-S5
ASIA B SENSORY INCOMPLETE
- Sensory (LT or PP or DAP)
- No motor function in S4-S5 (VAC)
- No motor function > 3 levels below NLI on either side
ASIA C MOTOR INCOMPLETE
- Motor function in S4-S5 (VAC)
“OR”
- Sensory (LT or PP or DAP)
Motor function > 3 levels below NLI on either side (it’s not B)
Less half key muscles grade ≥ 3 (so it’s not D)
ASIA D MOTOR INCOMLPETE
- Motor function in S4-S5 (VAC)
“OR”
- Sensory (LT or PP or DAP)
Motor function > 3 levels below NLI on either side (it’s not B)
Half or more key muscles grade ≥ 3 (it’s D)
NEUROLOGICAL LEVEKL OF INJURY (NLI)
Most caudal “inferior” segment of the cord with
- Intact sensation (2/2) both pin prick and light touch, with normal sensation above
- Muscle strength ≥3/5 with motor function 5/5 (or sensory) above that segment
Cuccurollo 4th Edition Chapter 7 SCI pg554
💡 ASIA C because of intact motor levels ≥ 3 (C7, C8, T1) below NLI (C6)
