Lumbo-Sacral Disc Disease Flashcards
clinical signs most commonly encountered in cases of lumbo-sacral dx. (5)
- Pain with spontaneous yelping/vocalisation usually when jumping or standing up
- Ipsilateral lameness with possible associated nerve root signature
- Pain on palpation and mobilisation of the affected limb
- Paraesthesia with excessive grooming/licking of the affected limb
- Lower motor neuron signs of the affected limb.
In severe cases of lumbo-sacral dx. What signs may be seen? (2)
Paresis/paralysis of the tail
Urinary and/or faecal incontinence
In cases of lumbo-sacral disease the most common abnormalities on neurological examination are (6)
1 Proprioceptive deficits
2 Reduced hock flexion
3 Pseudo hyperreflexia patellar reflex
4 Muscle atrophy especially of the tibial cranial muscle can be present.
5 Reduced perineal reflex / anal tone
6 Low tail carriage.
Benefits of advanced imaging for LS dx (4)
- Investigate foraminal stenosis
- Good visual of vertebral foramen
- Identify bone proliferations
- Identify disc calacification extrusion
With lumbo-sacral dx. On the xrays what other dx should be ruled out? (3)
- Discospondylitits
- Neoplasia
- Hip dysplasia
What might be seen on survey radiographs of lumbar-sacral dx? (5)
- Foraminal opacification (in cases of lateralised calcified disc extrusion),
- Sclerosis of the endplates,
- Reduced disc space size as well
- Osteoproliferative changes around the articular facets
- Spondylosis deformans
What is a CT scan poor at identifying with LS dx? (2)
- Soft tissue
- Nerve root compression
What study is the imaging modality of choice to investigate associated enlargement of the affected spinal nerve proximal to the level of stenosis, especially on STIR sequences?
MRI
What can enable confirmation of the neurological lameness and confirmed the suspicion of LS disease over an orthopaedic disease?
Electromyography
What neurological deficits would you expect on examination with a LS subluxation (4)
Reduced / absent perineal reflex
Reduced / absent perineal nociception
Absent tail nociception
Reduced to absent withdrawal reflex
With a LS luxation; which of the following would you expect to see?
Urinary incontinence
Faecal incontinence
Flaccid tail
Paraplegia
Muscle wastage
Urinary incontinence
Faecal incontinence
Flaccid tail
Muscle wastage
Medical management of lumbo-sacral disc herniation encompasses the use of medication and associated extended periods of rest, for how long?
4-8 weeks
The lumbosacral region of the dog’s spine is normally approached using which approach?
dorsal approach with bilateral elevation of the paraspinal muscles from the dorsal spinous processes and the dorsal lamina of the vertebra
In which position should the patient be placed for dorsal laminectomy surgery?
Ventral with the pelvic limbs directed cranially
Dorsal laminectomy; why are the pelvic limbs directed cranially?
Opening of L7-S1 disc space.
Dorsal laminectomy at L7-S1;
Skin is incsed with a number 10 blade; where?
L5-S3
Dorsal laminectomy at L7-S1
Incise the fascia on both sides of the spinous process with what?
Number 11 scalpel
Dorsal laminectomy at L7-S1
Periosteal elevator is used to elevate which muscles?
Paraspinal m.
Dorsal laminectomy at L7-S1;
Expose the L7 and S1 spinous processes and dorsal lamina. How?
Gelpi retractor
Dorsal laminectomy at L7-S1; what is removed of L7 and S1?
Spinous processes
Dorsal laminectomy at L7-S1;
A) What is burred for L7 and S1?
B) What is left in tact?
A) Dorsal laminae
B) Articular facets
Dorsal laminectomy at L7-S1;
What is used to remove cortical bone? (3)
Rongeurs
Curettes
Kerrison bone punch
Dorsal laminectomy at L7-S1;
Explore vertebral canal and foramen ; why?
Remove disc material if present
Dorsal laminectomy at L7-S1;
What is retracted before both the disc cranial and caudal to surgical site is fenestrated?
Cauda equina
Dorsal laminectomy at L7-S1;
Before closure; check what? what is performed?
Check - haemorrhage
FLUSH
Dorsal laminectomy at L7-S1;
A) Suture material for fat and fascia?
B) Material for S/C
C) Material for skin?
A) PDS
B) Monocryl
B) Staple/ethilon
cases of very lateralised foraminal disc extrusion/protrusion at L7-S1, what can be performed to allow decompression of the nerve root?
foraminotomy
What are the most common complications following a lumbo-sacral dorsal laminectomy? (5)
Venous sinus haemorrhage
Trauma to the cauda equina
Redistribution of disc material
Incomplete decompression
Articular facet fracture or subluxation.
What can be applied on the cauda equina before closure to reduce post-operative pain?
Morphine splash
A high standard of nursing care is essential in order to prevent what (2) in incontinent animals?
bladder distension
urinary tract infections
How many times a day should the urinary bladder be emptied?
3
What drugs may be beneficial post op; in terms of assisting urination? (2)
bethanechol
prazosin
Which patients is placing an indwelling Foley urinary catheter in a recumbent patient particularly important in?
No obvious voluntary movement
+/- nociception
What should be ecouraged post op to promote limb use and reduce muscle atrophy? (2)
- Physio
- Hydro
What aids should be used in patients that are unable to ambulate? (3)
Belly band (sling),
Chest harness
Hoist.
When can physio, massage and passive range of motion be started post op?
36-48 hours
Post op - when should physio be delayed? (Noticed when going to start)
Significant restraint be applied
Recumbent animals should be turned regularly, why? (2)
- Reduce decubital ulcers
- Reduce pneumonia
Antimicrobial agents, if considered necessary, should be used when?
peri-operatively
Faeces should be monitored for evidence of melaena; why?
Gastrointestinal ulceration can occur in spinal injury patients treated with anti-inflammatory drugs.
The risk of complications associated with recumbency can also be reduced by (4)
Keep patients clean and dry
Non-retentive, well-padded bedding
Checking regularly for urine or faecal scald
Check for decubital ulcers over pressure points.
A multimodal analgesic regimen should ideally be used. Which combinations would you use?
opioids,
non-steroidal anti-inflammatory drugs
Paracetamol
Gabapentin
Which opioid is V+ common?
Morphine
If usign methadone or morphine ; what is the effect of a high dose?
Dysphoria
Why should opioids be avoided (or strongly considered) in pregnant animals?
Cross the placenta
Receptor of action for morphine?
Mu agonist
Receptor of action for methadone?
Mu agonist
NMDA receptor
Effects of methadone if given IV?
Panting
Buprenorphine:
A) Receptor?
B) What is inhibited? (2)
A) Partial mu agonist
B) Reuptake of noradrenaline and serotonin
What to change about giving gabapentin if renal dx?
Lower dose
Where does methocarbamol act?
Central acting skeletal muscle relaxant
Not known receptor wise
Where does gabapentin act?
GABA ergic
Voltage-dependent Calcium channels
Meloxicam, robenacoxib and carprofen; COX 1 or 2 preferential?
2
Meloxicam:
a) Contraindicated when? (4)
B) Not advised when? (2)
A) Liver, renal, GI, blood clotting
B) hypovolaemic and dehydrated
Paracetamol receptor?
COX 3 inhibitor
Ketamine receptor.
NMDA receptor antagonist
Amantidine receptor
NMDA receptor antagonist
Amantidine; what pain is it good for?
OA
Cancer
Amitriptyline; contraindications (4)
Glaucoma
Seizing
Urinary retention
Severe liver dx
What can amitriptyline NOT be used with? (2)
cimetidine,
chlorphenamine
