Lumbosacral Dz (PKenny)

Question 1

What is lumbosacral disease?

Answer 1

Not specifically a disease, several diseases affect the lumbosacral spine
- several disease may cause cauda equina syndrome

Question 2

What is cauda equina sydnrome?

Answer 2

• dysfunction of tail, urinary and anal sphincters, (pudendal n.) bladder and sciatic n. of pelvic limb
• L7 -> caudal nerve roots affected

Question 3

Which pelvic lib nerves are not affected by cauda equina syndrome?

Answer 3

• femoral as leaves @ L4-L5

Question 4

When localising the lesion within the SC what is the extra segment to remember?

Answer 4

L4-S3 cauda equina

Question 5

Ddx for cauda equina syndrome

Answer 5

• DLSS
• IVDD
• Discospondylitis (another site)
• Myelitits
• Neoplasia
• Iliopsoas muscle injury

Question 6

Which animals is DLSS seen in?

Answer 6

(Degerative lumbosacralstenosis)

• older large breed dogs
• GSD
• active working dogs
• LS malformations

Question 7

What is DLSS? Aetiology?

Answer 7

> multifactorial disorder 
> combination of soft tissue and/or bony changes causing LS vertebral canal stenosis 
- IVD protrusion 
- ligamentous hypertrophy
- articular process hypertrophy
- osteophyte formation 
- vertebral misalongment
- telescoping dorsal lamina
- transitional vertebrae
- lumbosacral osteochondrosis 
> resulting in cauda equina +_ L7 nerve root compression

Question 8

Specific clinical signs of DLSS?

Answer 8

• lumbosacral pain (reluctance to jump, run, stairs, etc)
• paraparesis/ataxia
• pelvic limb lamness (“root signature”)
• flaccid tail and low tail carriage
• urinary and fecal incontinence (LMN signs to penineum)

Question 9

Ddx DLSS?

Answer 9

• hip pain d/t resenting hip extension

Question 10

What do femoral and sciatic n. control?

Answer 10

• femoral = hip flexion [patella reflex]

- sciatic = distal limb [gastroc reflex]

Question 11

Neuro findings with DLSS?

Answer 11

• poor/absent postural reactions

> r/o OA or stifle dz will usually have good postural reactions unless extrememly painful

Question 12

What other factors are commonly associated with lumbosacral dz?

Answer 12

Orthopeadic comorbidities are common

Question 13

How can limbosacral stenosis (cauda equina syndrome) be diagnosed?

Answer 13

• imaging AND clinical signs +- electrodiagnostics

Question 14

Does spondylosis deformans correlate with clinical signs?

Answer 14

NO

Question 15

What may predispose to cauda equina syndrome in the dog?

Answer 15

Lumbosacral transitional vertebra

Question 16

What is myelography? Is myelography useful in diagnosing cauda equina syndrome?

Answer 16

• injection radiopaque contrast into subarachnoid space
• thecal sac generally arrows and ends near LS
• may see attenuation of contrast over LS if severe midline compression
  > Rarely

Question 17

IS CT useful for dx of cauda equina syndrome?

Answer 17

> yes (??)

• epidural fat surrounds cauda equina nerv and thecal sac, providing natural source of soft tissue contrast
• in DLSS epidural fat is displaced
• confuses differentiation compressive soft tissues and adjecent neural structures

Question 18

Gold standard diagnostics for dx of cauda equina syndrome?

Answer 18

MRI

+- electrodiagnostics

Question 19

Tx of DLSS?

Answer 19

> medical 
- activity restriction 
\+- NSAIDs
\+- analgesia
\+- neuromodulatory drugs eg. Gabapentin for nerve root pain
- topical coritcosteroids (epidural) 
> Surgical 
- decompressive laminectomy most common 
\+- discectomy (excision of protruding annulus fibrosis) 
- foraminotomy
- stabilization 
- distraction + stabilisation

Question 20

Prognositc indicator for decompressive laminectomy?

Answer 20

Urinary continence prior to surgery

Question 21

Signs of cauda equina syndrome in horses?

Answer 21

• tail paralysis
• dilated anus
• loss of perineal sensation
• feacal retention

Question 22

Ddx for cauda equina syndrome in horses ? FURTHER READING

Answer 22

> trauma
- sacral fx (common)
> infectious
- EHV1 myeloencephalopathy (highly infectious and fatal) 
> inflammatory 
- polyneuritis equi