Segmental Spinal Reflexes and Nociception Flashcards
What does proprioception refer to?
The awareness of the position and movement of the head, body and limbs.
What tests can you think of which are useful to assess proprioception? (6)
paw positioning,
hopping,
placing and visual placing,
wheel barrowing,
extensor postural thrust,
hemi-walking and paper-sliding tests
What is proprioception NOT specific for?
Neuro-anatomical location
When testing propriocetpion - what must be supported?
Weight
What are the 4 regions of the spine for neuro-anatomical localisation?
C1-C5 (cranial cervical),
C6-T2 (cervicothoracic intumescence),
T3-L3 (thoracolumbar),
L4-S1 (lumbosacral intumescence)
Upper motor neuron (UMN) neurological deficits are seen when the reflexes are ? in the evaluated limb.
present or increased
Lower motor neuron (LMN) neurological deficits are seen when the reflexes are in the evaluated limb.
absent or decreased
Lesions affecting segments C1-C5 cause what deficits in:
A) Thoracic limb?
B) Pelvic limb?
A) UMN
B) UMN
What segmental spinal reflexes are expected with Lesions of C1-C5?
Normal
Lesions affecting segments C6-T2 cause what deficits in:
A) Thoracic limb?
B) Pelvic limb?
A) LMN (reduced spinal reflexes)
B) UMN
Lesions affecting segments T3-L3 cause what deficits in:
A) Thoracic limb?
B) Pelvic limb?
A) Normal
B) UMN
Lesions affecting segments L4-S3 cause what deficits in:
A) Thoracic limb?
B) Pelvic limb?
A) Normal
B) LMN
It is important to remember that the spinal cord segments do not correspond to the surrounding vertebrae, as most spinal cord segments lie cranially to the vertebra of the same number, except which segments.
C1, C2, L1 and L2
Most spinal nerves exit through ? cranially to the vertebra with the same name
intervertebral foramina
Where does the spinal cord end?
L5-L6
What forms the cauda equina?
The nerves of the caudal lumbar and sacral spinal cord
What does the withdrawal reflex evaluate in the thoracic limb? (2)
Intumescence and brachial plexus nerves
What does the Extensor carpi radialis reflex evaluate in the thoracic limb?
Caudal cervical intumescence (C7-T2 and radial nerve).
What does the withdrawal reflex evaluate in the pelvic limb? (3)
lumbar intumescence, femoral and sciatic nerves.
What does the patellar reflex evaluate in the pelvic limb? (2)
Evaluation of L4-L6 spinal cord segments and femoral nerve.
Reliable reflexes of the thoracic limb? (2)
Withdrawal
Extensor carpi radialis reflex
Reliable reflexes of pelvic limb? (2)
Withdrawal
Patellar
Brain lesion; deficits in:
A) Thoracic limbs?
B) Pelvic limbs?
A) UMN
B) UMN
Peripheral neuropathy, deficits in:
A) Thoracic limbs?
B) Pelvic limbs?
A) LMN
B) LMN
What position must the HL be in for patellar reflex?
Relaxed
How is the cutaneous trunci reflex performed?
forceps to pinch the skin cranial to the wings of the ilium,- both sides
What should the cutaenous trunci reflex result in?
Contraction of the cutaneous trunci muscle on both sides
Which nerve involved in the efferent pathway will trigger contraction of the cutaneous trunci muscle?
Lateral thoracic n.
Cutaenous trunci reflex
The A) pathway includes a sensory stimulation of the B) nerve root of at the level of the dermatome tested and bilateral stimulation of the nuclei of the lateral thoracic nerve located at the level of the C) spinal segment.
A) afferent
B) dorsal
C) C8
The testing of the cutaneous trunci muscle is useful to localise a ?lesion
thoracolumbar
Where will the lesion will be located in relation to the cut-off of the cutaneous trunci if present?
within the four spinal segments cranial
The testing of the cutaneous trunci is also useful for cervicothoracic and brachial plexus lesions as it can be absent due to a lesion of the A) pathway (B) nerve).
A) afferent
B) lateral thoracic
When testing spinal palpation; which part should be tested last?
Suspected painful area
Nociception is evaluated by?
conscious response of the patient to a painful stimulus.
Why is it imperative to differentiate nociception from withdrawal reflexes?
Nociception is important in the assessment of the severity of a spinal lesion and its prognosis.
Define nociception
Ability to feel pain
What are the 4 steps of nociception?
transduction,
transmission,
modulation
perception
Nociception: The noxious stimulus is transduced by the receptor into an A) impulse that is then transmitted by the B) nerve to the spinal cord.
A) electrical
B) peripheral sensory
Nociception: The spinal cord modulates the impulse and sends it to the brain via the ? tract.
spinothalamic
The final step of nociception - what perceives pain?
Brain
In case of lumbo-sacral and sacrococcygeal injury testing of the nociception needs to be performed at the level of?
Tai and perineum
What is the prognostic results with absent nociception with lumbo-sacral and sacrococcygeal injury ?
poor prognostic indicator for recovery of urinary and faecal continence.
What is the important role of testing the presence or absence of nociception?
important prognostic value in case of spinal cord and peripheral nerve injury
Is the nervous system able to regenerate with severe damage of the axon of the neuronal cell.
Yes
How many degrees of axonal injury are there?
3
What are the degrees of axonal injury? (3)
- Neurotmesis
- Axonotmesis
- Neurapraxia
What Neurotmesis the result of?
the complete damage of the nerve, including axon, Schwann cells and surrounding connective tissue.
Prognosis for neurotmesis?
VERY poor ; regeneration of the nerve is almost impossible
What does Axonotmesis refers to?
the damage of the axon with preservation of the endoneurium and the surrounding myelin sheath produced by the Schwann cells.
What are the specific and time for prognosis of axonotmesis
The axon can regenerate if the damaged area is not too extended, however, the regeneration is very slow.
What does Neurapraxia refers to?
interruption of the nerve conduction with no damage to the nerve. It is normally due to demyelination with an undamaged axon, due to compression or transient lack of blood supply
How long does recovery take with neurapraxia?
1-5 weeks
Is it possible for the nerve to regenerate?
Almost impossible
