Page 1853 - Cote clinical veterinary advisor dogs and cats 4th

930 Spinal Cord Injury

Spinal Cord Injury Client Education
Sheet
VetBooks.ir

BASIC INFORMATION
• Signs can be progressive (e.g., IVDH, unstable
events that perpetuate and exacerbate the
fracture) or nonprogressive (ANNPE, FCE). • Secondary injury: cascade of pathologic
Definition • Discomfort is common with IVDH and primary injury, including hemorrhage,
Any insult to the spinal cord resulting in vertebral column trauma. inflammation, excitotoxicity, free radical
neurologic impairment. Most common causes • Possible history of prior episodes of pain or production, and apoptosis resulting in
of acute spinal cord injury (SCI): neurologic deficits with IVDH. progressive tissue destruction; therapies
• Intervertebral disc herniation (IVDH) • ANNPE and FCE: progression up to 24 are being investigated to address secondary
○ Hansen’s type I hours after onset is possible; pain is described injury.
○ Hansen’s type II but atypical; neurologic deficits frequently
○ Acute noncompressive nucleus pulposus asymmetrical; history of physical activity DIAGNOSIS
extrusion (ANNPE) common; blunt force trauma noted with
• Vertebral column trauma (including fractures, traumatic disc herniation Diagnostic Overview
subluxations, and luxations) • Traumatic event (e.g., being hit by car, falling Thorough neurologic exam is key to accurate
• Fibrocartilaginous embolism (FCE) from a height) may be witnessed or suspected neuroanatomic localization, diagnosis, and
initiation of appropriate therapy. If trauma is
Synonyms PHYSICAL EXAM FINDINGS suspected, complete physical exam is essential
• SCI, spinal cord trauma • Neurologic deficits: paraspinal pain, paresis to evaluate for concurrent injury. The initial
• For ANNPE: missile disc; traumatic disc; (weakness), ataxia (incoordination), paralysis diagnostic plan consists of spinal radiographs
high-velocity, low-volume disc herniation with loss of pain perception and testing to establish general health status
• Specific deficits depend on the neuroanatomic and suitability for general anesthesia. Further
Epidemiology localization. testing includes advanced imaging and possibly
SPECIES, AGE, SEX • With acute, severe thoracolumbar injury, cerebrospinal fluid (CSF) analysis. For more
• Any species, age, or sex, depending on the spinal shock and a Schiff-Sherrington posture severely affected animals (nonambulatory or
underlying cause may be present characterized by flaccid worse), prompt referral to a neurologist or
• IVDH: type I tends to affect middle-aged hindlimbs with reduced spinal reflexes and surgeon is recommended.
(3-7 years) chondrodystrophic dog breeds; increased forelimb extensor tone.
type II predominantly affects slightly • With severe thoracolumbar injury (typically Differential Diagnosis
older (6-8 years), nonchondrodystrophic paraplegia with loss of pain perception • Vertebral neoplasia causing pathologic
dog breeds. IVDH tends to occur in secondary to IVDH), there may be signs fracture
older cats. of progressive ascending/descending myelo- • Meningomyelitis (infectious or immune-
• ANNPE or FCE typically affects middle-aged, malacia. They include decreased trunk and mediated causes)
medium- to large-breed dogs; uncommon abdominal tone, rapidly changing neurologic • Neuromuscular weakness (e.g., neuropathy,
but reported in cats exam findings such as cranial progression junctionopathy, myopathy)
• Vertebral column trauma can occur at or loss of the cutaneous trunci reflex, loss • Orthopedic: bilateral cranial cruciate liga-
any age but is more common in younger of hindlimb spinal reflexes, flaccid bladder, ment rupture (dogs), hip fractures
animals. absent anal tone, progression to forelimb • Non–nervous system: hemoabdomen, aortic
abnormalities and breathing difficulty. thromboembolism (especially cats), severe
GENETICS, BREED PREDISPOSITION • With tetraplegia, hypoventilation is possible. systemic illness or end-stage disease (e.g.,
IVDH: chondrodystrophic dog breeds (e.g., • With trauma, there may be signs of external cancer), abdominal pain
dachshund, basset hound, French and English trauma (abrasions, lacerations or other
bulldog, shih tzu, miniature schnauzer, Peking- wounds). Concurrent injuries are common Initial Database
ese, beagle, Lhasa apso, Bichon frisé, Tibetan with signs referable to the body system • Neurologic exam (p. 1136): neuroanatomic
spaniel, Cavalier King Charles spaniel, Welsh affected. Excessive patient manipulation localization depends on location of SCI
corgi) should be avoided. • CBC and serum biochemical profile: typically
unremarkable; preanesthesia screening test
RISK FACTORS Etiology and Pathophysiology • Urinalysis: can be unremarkable or show
• Breed for IVDH Cause: hematuria, pyuria, or bacteruria
• ANNPE and FCE have been associated with • ANNPE: herniation of relatively normal • Thoracic radiographs, abdominal radiographs,
physical activity. nucleus pulposus material causing a contusive or ultrasound: screening tests considered for
• Free-roaming animals at greater risk of injury to the spinal cord with little or no older animals and trauma cases
trauma residual extradural compression; associated • Spinal radiographs: often unremarkable,
with exercise and can occur secondary to especially for ANNPE or FCE; lack of visible
ASSOCIATED DISORDERS blunt force trauma abnormalities does not rule out IVDH or
Urinary and fecal incontinence: depend on • See chapters on intervertebral disc disease trauma. May reveal: mineralized discs in situ,
injury severity (IVDD [p. 555]), FCE (p. 336), and narrowed disc space, mineralized material
vertebral fractures (p. 369). in the spinal canal, spondylosis, fractures,
Clinical Presentation Pathogenesis: subluxation or luxation
HISTORY, CHIEF COMPLAINT • Primary injury: mechanical insult to the
• Acute SCI is characterized by peracute to spinal cord causing contusion, shearing, Advanced or Confirmatory Testing
acute onset of neurologic deficits affecting laceration, compression, hemorrhage, and • MRI (p. 1132): excellent soft-tissue detail
1 to 4 limbs, ranging from pain (back or ischemia; spinal stabilization and/or decom- allows visualization of the spinal cord; gold
neck), mild paresis and ataxia to paralysis pression prevent further primary injury, if standard for definitive diagnosis of cause of
and loss of pain perception. indicated. the SCI

www.ExpertConsult.com