Spinal Cord Syndromes

Question 1

What is Lumbosacral Syndrome?

Answer 1

• Damage to cord at the L4-S3 spinal cord segment
• Flaccid weakness/paralysis of pelvic limbs and tail
• Bladder incontinence
• Proprioceptive deficits
• Decreased or absent reflexes

Question 2

What is Thoracolumbar Syndrome?

Answer 2

• Damage to spinal cord segments T3-L3
• Hyperreflexia (UMN) to rear limbs
• UMN bladder
• Hindlimb paresis/paralysis
• Proprioceptive deficits to pelvic limbs
• +/- Schiff-Sherrington (rare occurrence)

Question 3

What is Cervicothoracic Syndrome?

Answer 3

• Lesion in the C6–T2 spinal cord segment
• Mono-, hemi- or tetraparesis
• LMN signs to thoracic limbs
• UMN signs to pelvic limbs
• Proprioceptive deficits all limbs

Question 4

What is Cervical Syndrome?

Answer 4

• Lesion in C1-C5 spinal cord segments
• UMN to thoracic and pelvic limbs
• Cervical pain and rigidity
• Proprioceptive deficits all limbs
• Abnormal postural reactions in all limbs

Question 5

Why is there imperfect localization?

Answer 5

• anatomic variations within each species
• Cervicothoracic and Lumbosacral lesions can have variable effects on flexors and extensors resulting in confusion
• Understanding that the lesion is “probably cervical” but “possibly cervicothoracic” is sufficient for differential diagnoses and a diagnostic plan

Question 6

How is Spinal Cord Function scored?

Answer 6

• 1 - Pain without deficits (neurologically normal)
• 2 - Ambulatory paresis (mono-, hemi-, para-, tetra-)
• 3 - Non-ambulatory paresis (mono- hemi- para- tetra-)
• 4 - Paralysis (plegia) with intact nociception
• 5 - Paralysis without nociception

Question 7

What are the different Intervertebral Disk Diseases?

Answer 7

• Hansen’s Type I IVDD
• Hansen’s Type II IVDD
• Acute Noncompressive Nucleus Pulposus Extrusion
• Fibrocartilaginous Emboli
• Diskospondylitis

Question 8

What happens with Hansen’s Type I IVDD? Causes?

Answer 8

• Nucleus pulposus degenerates
• Weakened/torn/degenerated dorsal annulus
• Rapid extrusion of nucleus pulposus
• Seen in chondrodystrophic breeds
  
  • Dachshund, beagle, Pekingese, Lhasa (3 - 8 years)
  • Most common type in large breed dogs
  • Also reported in cats (9years)
• Damage created by:
  
  • Compression (duration, amount)
  • Velocity of extrusion

Question 9

What are therapeutic options of Hansen’s Type I IVDD?

Answer 9

• Surgical Decompression
  
  • Improves recovery vs conservative management in grades 1 &2 (mild) 3&4 (moderate) and 5(marked)
  • Hemilaminectomy, fenestration
• Conservative management
  
  • No benefit of corticosteroids
  • Analgesia
  • Strict cage rest

Question 10

How is Hansen’s Type I diagnosed?

Answer 10

• Clinical diagnosis
  
  • Index of suspicion
  • signalment, history, findings
  • What level of diagnostics are needed if conservative management is pursued
• Plain radiographs and Myelography
• CT scan
• MRI scan

Question 11

What is Hansen’s Type II IVDD (Chronic progressive IVDD)

Answer 11

• Progressive thickening of anulus fibrosus
• Seen in older, large breed dogs
  
  • Cervical spondylomyelopthy
  • Degenerative lumbosacral stenosis
• Slow onset (weeks-months)
• Damage results from compression only
  
  • No hemorrhage, no edema
  • Motor, sensory deficit
  • Less painful
• Diagnosis MRI, CT (often with traction)

Question 12

What are the key features of IVDD?

Answer 12

• The result of extrusion is hemorrhage, edema, and necrosis
• Fatal consequences is myelomalacia (progressive hemorrhagic myelomalacia)
• _Cervical IVDD (t_ype I)
  
  • results in severe neck pain and rigidity
• Cervical IVDD (type II)
  
  • results in less pain
  • pelvic limb signs are first
• T-L IVDD (type I)
  
  • T1-T11 lesions are rare
  • T11-L3 lesions are most common
  • neurological deficits with pain are common
• The absence of deep pain is the most significant negative prognostic factor, reducing likelihood of recovery to less than 5%

Question 13

How should Spinal cord trauma be managed?

Answer 13

• Patient stabilization
  
  • IV fluids
  • Pain control with opioids
  • Maintain normoxia, normocapnia
• Prognostication (radiographs, neuro exam)
• Surgical stabilization or decompression
• Unknowns (not recommended)
  
  • High dose methylprednisolone sodium succinate
  • Oscillating field stimulation
  • Polyethylene glycol
  • Hypothermia

Question 14

What is acute Noncompressive Nucleus Pulposus Extrusion (ANNPE)

Answer 14

• High velocity extrusion of very small amount of NP (Type III)
• Results in concussive injury
• Rapid onset - instantaneous, momentary pain
  
  • Less painful due to lack of compression
• Usually improves w/in 24-48 hours without treatment
• Variable distribution (most common in thoracolumbar spinal cord)
• Dx with MRI or clinical suscpicion
• Main DDx: Fibrocartilaginous emboli

Question 15

What is a Fibrocartilaginous Emboli (FCE)?

Answer 15

• Ischemic Myelopathy
  
  • Disc-like material obstructs a vertebral artery branch
    
    • Acute cord ischemia (“lights-on, Lights-off”)
• Not noticeably progressive
• Non-painful
• Variable distribution (most commonly thoracolumbar)
• Diagnosed with MRI
• Usually younger than dogs with ANNPE; any size dog

Question 16

How well do dogs recover from FCE or ANNPE?

Answer 16

• Ambulatory at discharge:
  
  • 73% of ANNPE
  • 48% of FCE
• Long-term recovery:
  
  • Normal - 19% ANNPE, 15% FCE
  • Mild Deficits - ~75% of both
• Long-term problems
  
  • Urinary incontinence (mild) - 19-30%
  • Fecal incontinence (mild) - 3-33%
• Perceived Successful Outcome:
  
  • 81% ANNPE
  • 67% FCE

Question 17

What are the general practice guidelines of FCE and ANNPE?

Answer 17

• Clinically indistinguishable
  
  • FCE is never reported in the cervical spinal cord
  • ANNPE is not reported in the lumbosacral spinal cord
• Conditions are nonpainful and non-progressive
• No difference in the treatment
  
  • supportive care/conservative management are an accepted level of care
• Clinical suspicion may be sufficient for a diagnosis and management
  
  • MRI is not always needed
• 100% recovery is slow and often not achieved

Question 18

What is Diskospondylitis? Signs? causes?

Answer 18

• Infection of intervertebral disk
  
  • if multiple disk spaces are affected it may be fungal
• Signs:
  
  • Concurrent osteomyelitis
  • Spinal Pain: reluctant to jump, climb, play
  • Fever depression anorexia
  • Neurologic deficits are common
• Causes:
  
  • Grass awns
  • UTI
  • Prostatitis
  • Pyoderma
• Affects medium to large breeds commonly

Question 19

How is Diskospondylitis diagnosed and treated?

Answer 19

• Dx:
  
  • CBC/Chem - usually normal
  • Radiographs: end-plate lysis and erosion, disk space collapse, sclerosis, proliferation
  • Culture - blood, urine, bone, disk
  • Brucella testing
• Tx:
  
  • Long term antibiotics (8-12+ weeks)
    
    • cephalexin - good choice in the absence of an isolate

Question 20

What is Atlantoaxial Subluxation?

Answer 20

• Common in Toy breeds
• Variable in progression Signs range form mild pain to tetraparesis/plegia
• Support the neck during radiographs, handling

Question 21

What is Cervical Spondylomyelopathy?

Answer 21

• Wobbler Syndrome (Cervical malformation-malarticulation)
• Vertebral canal stenosis (congital) is the most important factor in disease development
• Osseous-associated compression
  
  • Young, adult Giant breed dogs (Great Danes)
  • Bony proliferation is more dorsal and lateral (congenital and arthritic changes)
• Disc-associated compression
  
  • Middle-aged to older dogs (Doberman pinschers)
  • Ventral spinal cord compression
• C5-6 and C6-7 disk spaces are most commonly affected (static and dynamic compression)
• Gradually progressive pelvic limb ataxia, wide-based crouching, and mild thoracic limb abnormalities (later onset)
• Diagnosis is best achieved with myelography using traction or stressed radiographs

Question 22

How is Cervical Spondylomyelopathy managed/treated?

Answer 22

• Medical management:
  
  • Conservative may result in a favorable outcome in 81% of dogs
  • Exercise restriction to minimize dynamic component of compression
  • Body harness and not a neck collar
  • Corticosteroids at anti-inflammatory doses, NSAIDS (preferred)
• Surgical treatment
  
  • Disc-associated CSM: ventral slot, distraction-stabilization, hemilaminectomy
  • Osseous-associated: dorsal laminectomy or cervical hemilaminectomy

Question 23

What is Cauda Equina Syndrome?

Answer 23

• AKA lumbrosacral vertebral canal stenosis
• Chronic instability results in
  
  • Type II disk protrusion
  • Hypertrophy of interarcuate ligament
  • Thickening of vertebral arches/articular facets
• Large breed dogs, especially German Shepherd
• Middle-aged
• Clinical signs
  
  • Pain on palpation, extension of limbs, tial elevation
  • Difficulty rising
  • Tail paresis
  • Urinary, fecal incontinence
  • Pelvic limb weakness/lameness/atrophy (root signature pain)
• Depressed conscious proprioception
• Possible 3+ patellars; depressed flexion respone
• Decreased anal tone; atonic bladder

Question 24

How is Cauda Equina Syndrome dignosed?

Answer 24

• Radiographs: spondylosis, sclerosis, wedging
• Myelogram, epidurography, diskography
• CT, MRI

Question 25

How is Cuada Equina Syndrome Treated?

Answer 25

• Change in exercise (but not rest), weight reduction, NSAIDs
• Lumbosacral epidural corticosteroid injections
• Surgery for moderate to severe pain and in dogs with neurological deficits
  
  • Decompressive laminectomy
  • lumbosacral fusion

Question 26

What is the common etiology of spinal cord neoplasias?

Answer 26

• Older, large breed dogs more common
• spinal lymphoma in young cats
• signs related to location

Question 27

What are some Extradural/extramadullary tumors that effect the spinal cord?

Answer 27

• Osteosarcoma
• Fibrosarcoma
• Chondrosarcoma
• Hemagiosarcoma
• Multiple myeloma/plasma cell tumor
• Lymphosarcoma

Question 28

What are some Intradural/extramedullary tumors

Answer 28

• Meningioma
• Nerve sheath tumor

Question 29

What are some intramedullary tumors?

Answer 29

• Astrocytoma
• Oligodendroglioma
• Ependymoma

Question 30

How are Spinal cord neoplasias diagnosed

Answer 30

• Radiographs
• CSF
• myelography

Question 31

What is Degenerative Myelopathy

Answer 31

• Demyelination and axonal degeneration of the spinal cord
  
  • Amyotrophic lateral sclerosis
  • SOD-1 gene mutation
• Slowly progressive, nonpainful ataxia and paresis of pelvic limbs
  
  • Mild signs see most on slick surfaces ⇢ marked paresis (3-12 months)
  • Worn pelvic limb toenails
  • Usually a T3-L3 lesion initially: no bladder or bowel dysfunction
  • Marked muscle atrophy late in course
• Very common in German shepherd
  
  • Boxer, Great Dane, Chesapeake, Labrador retriever, Corgi
  • older dogs
• Superficial pain remains intact
• May see apparent LMN signs to pelvic limbs late in dsease

Question 32

How is Degenerative myelopathy diagnosed?

Answer 32

• Dx:
  
  • Radiographs, myelography: no specific findings
  • CSF: increased protein content
  • SOD1 gene testing (U of Missouri)
• DDx:
  
  • Chronic IVDD
  • Degenerative lumbosacral stenosis
  • neoplasia
  • Cysts