Spinal disease Flashcards
Contents - grey matter
nn cell bodies
Contents - white matter
AXONS (‘tracts’):
- dorsal funiculus
- lateral funiculi
- ventral funiculus
Function - dorsal and lateral funiculi
sensory and proprioceptive tracts. Dysfunction –> ataxia
Function - ventral and lateral funiculi
motor (or UMN) tracts ). Dysfunction –> (UMN) paresis.
Function - LMN cell bodies
Ventral horn grey matter. Dysfunction –> (LMN) paresis
Name the 4 functional segments of SC
- C1-5
- C6-T2
- T3-L3
- L4-S3
(localising SC problem is essential for determining ddx)
T/F: spinal cord segments = vertebral bodies
false
What is the tapered termination of the spinal cord called?
conus medullaris
What is the cauda equina?
bundle of spinal nn and roots which originate in the conus medullaris of the SC
Define myelopathy. Categories?
= disorder of SC
- EXTRINSIC: extradural or intradural
- INTRINSIC: intramedullary (diffuse or focal)
Synonym - ataxia
incoordination
Define ataxia
loss of sense of awareness of body/limb position in space
What is ataxia? What type do you get in spinal disease?
- sensory phenomenon
- sensory or proprioceptive ataxia in spinal dz
Define paresis
- decreased voluntary mvt
- motor phenomenom
- UMN or LMN types
Define plegia
= complete loss of voluntary movement
Distinguish mono, para, tetra
- Mono = one limb affected
- Para = both HL affected
- Tetra = all 4 limbs affected
Define urinary/ faecal continence
ability to ‘fill’ and empty bladder/intestines voluntarily
Define urinary/faecal incontinence. Where is the problem?
- loss of ability to fill and empty bladder/intestines voluntarily
- UMN (CATS L2-5, DOGS L1-4) or LMN (S1-3)
How do you recognise animal with spinal disease?
CS and neuro exam
Why perform a neuro exam with suspected spinal dz?
- confirms neuro nature of CS
- determine neuro-anatomical localisation
- determine prognosis (selected cases)
WHich parts of the neuro exam are important for spinal dz ddx?
- posture
- gait
- postural reactions
- spinal reflexes
- palpation
- nociception
Define kyphosis
spine curvature
What should you determine with gait in a neuro exam with a suspicion of spinal disease? 3 What might this mean?
- only paresis - neuromuscular or lumbosacral problem
- only ataxia - cerebellar or vestibular problem
- ataxia and paresis - spinal or brainstem problem
What is proprioception a reliable indicator for?
the presence of neurological disease. Not always useful for assessment of neuro-anatomical localisation
How do CS of extrinsic (compressive myelopathies) correlate with progression?
EARLY: proprioception deficits movment problems nociception problems LATE (improvement occurs in reverse order to progression - i.e. proprioception will come back last)
Name 3 spinal reflexes
- patella
- withdrawal
- cutaneous trunci / panniculus
- important to ID which SC segment affected
What do decreased spinal reflexes suggest?
- LMN signs
- lesion located in reflex arc
- C6-T2 or L4-S3
What do exaggereated spinl reflexes suggest?
- UMN sign
- lesion located cranial from reflex arc
- C1-5 or T3-L3
Function - motor (UMN) tracts
- UMN ‘tells’ LMN what to do
- synapse on LMN in ventral horn grey matter
Function - UMN system
facilitates and to a greater extent inhibits mm goups. Net effect: inhibition of mm tone and reflexes
CS - UMN lesions
= disinhibition –> increased mm tone and reflexes
What part of the neuro exam should be done last?
palpation as can be painful (aggression etc). Start gently.
Outline use of nociception for spinal dz
- not always necessary
- can assist in determining prognosis
- do NOT confuse with withdrawal reflex
- positive reflex when there is conscious perception of pinch (head turn, pinch)
What does prognosis depend on?
- diagnosis
2. function (neuro exam)
What is the msot important prognostic indicator?
- deep pain perception
- use an unequivocally noxious stimuli (haemostats on periosteum)
CS - C1-C5 lesion
- tetraparesis and ataxia all limbs
- proprioceptive deficits all limbs
- intact or increased spinal reflexes all limbs
- normal or increased mm tone all limbs
- horner’s possible
- urinary dysfunction possible, uncommon
- tetraplegia uncommon (respiratory dysfunction - phrenic nn - occurs before plegia)
CS - lesion in C6-T2
- tetraparesis and ataxia all limbs
- proprioceptive deficits all limbs
- intact or decreased spinal reflexes in TL, intact or increased in HL*
- intact/decreased mm tone TL, intact/increased mm tone HL
- ‘two-engine’ or disconnected gait possible
- horner’s possible
- urinary dysfunction possible, uncommon
- tetraplegia uncommon - respiratory dysfunction - phrenic nn - before plegia
Describe a ‘two-engine gait in animals with C6-T2 myelopathy
- wide based ataxic HL
- short stilted TL
- TL and HL have different rhythm/engine
CS - lesion of T3-L3
- normal TL
- paraparesis and HL ataxia
- paraplegia possible
- intact/increased spinal reflexes pelvic limbs
- intact/ increased mm tone pelvic limbs
- urinary dysfunction common (‘UMN bladder’)
- Schiff-Scherrington posture (sometimes)
Describe the Schiff-Sherrington posture
- acute T3-L3 spinal injuries
- Borders cells affected (L1-L7): project to cervical intumescence, provide inhibition to extensor mm TL –> disinhibition with dysfunction –> paraplegia with increased extensor tone in TL
- ddx cervical lesion (TL neurologically normal)
- Indicates localisation, NOT prognosis
Where are border cells?
- dorsolateral border of ventral grey column of lumbar SC
- when affected –> Schiff-Scherrington posture
CS - lesion of L4-S3
- TL normal
- paraparesis and ataxia HL
- paraplegia possible
- intact/decreased spinal reflexes
- intact/decreased mm tone to HL
- urinary dysfunction uncommon (‘LMN bladder’)
- possible flaccid tail
- possible decreased perianal reflex
Which spinal cord segment(s) are affected if all 4 limbs affected?
C1-5 or C6-T2
Which spinal cord segment(s) are affected if only HL affected?
T3-L3 or L4-S3
If only HLs are affected or all 4 limbs are, how do you differentiate the cause?
look at spinal reflexes:
INCREASED: C1-5 or T3-L3 problem
DECREASED: C6-T2 or L4-S3
Where is the lesion in a two-engine gait?
C6-T2
Components of 5/6 finger rule
- localisation
- signalment
- onset
- progression
- symmetry
- pain
T/F: presence of pain excludes several problems
True
T/F: not many disorders are truly asymmetrical
True
Ddx - common spinal diseases in dogs
- IVDD (Type 1 and 2)
- Ischaemic myelopathy (IM)
- neoplasia
- syringomyelia (SM)
- immune-mediated
- inflammatory
Ddx - common spinal diseases in CATS
- Infectious/inflammatory - FIP
- Trauma: fracture/ luxation
- Neoplasia: lymphoma (young), meningioma (old)
Define CSM
Cervical spondylomyelopathy
Define CM/SM
Chiari-like malformation/ syringomyelia
Define IVDE
Intervertebral disc extrusion
Which spinal diseases have pain only (no neurological deficits)? 2
- CM/SM
- SRMA
Define SRMA
Steroid responsive Meningitis and Arteritis
Which spinal diseases have neuro deficits +/- pain? 6
- IM or HVLV
- IVDE
- IVDP
- CSM
- Neoplasia
Define HVLV
High velocity low volume disc extrusion
How many disease account for 91% spinal disease cases?
91%
Outline CSM
- younger dogs
- chronic onset
Outine spinal neoplasia
- older, larger
- chronic onset
- localised
- deteriorating
Outline IVDD
- older
- chronic onset
- often stable
- painful
Outline IVDE
- middle aged and older
- smaller
- acute
- non-lateralised
- deteriorating
- painful
Outline IM / HVLV
- medium/large breed
- peracute onset
- stable or improving
- lateralised
- often non-painful
Outline CM/ SM
- CKCS
What age does SRMA affect?
usually