Top 10 Canine Neuro Part 1

husky

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Neurologic diseases can present in a variety of scary ways.


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Contrary to popular belief, you don’t just pop them with steroids!

Zuku’s Top 10 canine neuro to know part 1

  1. Intervertebral disc disease

                    A Dachshund - a common breed affected by intervertebral disc disease

                    MRI showing herniated disc

    • Classic case:
      • PAIN in neck or back – arched back or head held down
      • Ataxia, paraparesis/paraplegia, tetraparesis
      • Any breed, but chondrodystrophoid most common
    • Dx: MRI is safe, fast, and best quality; CT is safe and faster than MRI, but lower quality; myelography is invasive and seizures may occur during recovery
    • Rx:
      • If pain only (no neuro signs) – strict cage rest and analgesia with opiates or NSAIDs
      • Nonambulatory or unresponsive to conservative treatment – surgical decompression by experienced surgeon or neurologist
        • Hemilaminectory for thoracolumbar disks
        • Ventral slot for cervical disks
      • Steroids are increasingly unpopular for pain control
        • Falling out of favor with surgeons and neurologists because of numerous adverse effects and poor efficacy
        • Better results with NSAIDs
    • Pearls: Hansen Type I occur in chondrodystrophoid breeds and the nucleus pulposus extrudes through the annulus; Hansen type II are usually nonchondrodystrophoid breeds and there is hypertrophy or bulging of the annulus; prognosis guarded to excellent

  2. Epilepsy

                    Dachshund having a seizure

    • Classic case: 1- to 5-year-old with history of seizure activity; normal presentation
    • Dx: Rule out other causes of seizures using CBC, biochemistry profile, bile acids, cholinesterase, lead level, MRI, CSF analysis
    • Rx: Anticonvulsants (phenobarbital, levetiracetam, zonisamide, etc.) to prevent/reduce seizures; spay females
    • Pearls: Monitor anticonvulsant blood levels and bile acids if on phenobarbital
    • Click here to see list of anticonvulsant drugs from the Merck Manual



  3. Traumatic CNS injury

                      Lateral radiograph showing bullet at L5-6

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    • Classic case: History of trauma, contusions, lacerations; paraparesis, paraplegia, tetraparesis, pain, altered consciousness, seizures
    • Dx: Survey spinal radiographs, CT, +/- MRI
    • Rx:
      • Check airway, breathing, circulation
      • Administer fluids and O2
      • Surgical decompression and/or stabilization
      • Cage rest, external splint
      • STEROIDS are highly controversial and detrimental to traumatic brain injury
    • See also “Steroids in head trauma: indicated or contraindicated?” from VetGirl

  4. Brain tumor

                    MRI of brain tumor in left temporal lobe

    • Classic case: > 5-year-old with any of these signs – depends on location of tumor:
      • Seizures, altered consciousness, pacing, head pressing, turns only toward side of lesion, loss of conscious proprioception
      • Hypermetria, head bobbing, ataxia, intention tremors
      • Head tilt, nystagmus, facial nerve paralysis, tongue paralysis, strabismus, poor swallowing
    • Dx:
      • MRI - safe, fast, best quality
      • CT - safe and fast
      • CSF may show elevated protein but tumor cells rarely found; risk of brain herniation
    • Rx:
      • Definitive: surgical resection, radiation, chemotherapy
      • Supportive: prednisolone, anticonvulsants
    • Pearls:
      • Meningiomas most common, and usually seen in dolicocephalic breeds
      • Gliomas seen more frequently in brachycephalic breeds, esp boxers
      • Brain tumors are #1 cause of seizures in dogs > 5 years of age

  5. Geriatric vestibular disease

                    Pomeranian with left head tilt

    • Classic case: Geriatric dog with acute onset head tilt (toward lesion), horizontal nystagmus (fast phase away from lesion), ataxia, circling (toward lesion), +/- rolling in direction of head tilt; no loss of conscious proprioception; normal mentation
    • Dx: All tests negative; rule out other causes of peripheral vestibular disease using thyroid testing, otoscopy, MRI or CT, +/- CSF analysis
    • Rx: Nursing care
      • Well-padded bedding
      • Physical therapy
      • Sedatives if flailing
    • Pearls: Excellent prognosis, resolves within a few days to weeks; may have persistent head tilt; can relapse; cerebellar strokes are far less common but have a similar appear appearance - acute onset, paradoxical head tilt (away from lesion), nystagmus, circling or rolling, ipsilateral loss of conscious proprioception, normal mentation
    • Click here for more information on evaluation of the neurologic system from the Merck Manual online

Images courtesy of Christine Zenino (dog sledding), Dr. Shirley Scott (dachshund in cage, dachshund with seizure, MRIs of spine and brain tumor), Dr. Debra Quiles (bullet in spine), Jonjoy Pascua (Pomeranian with head tilt), 0894Leanne (funny Japanese Spitz), and Adam.J.W.C (licking the staffy pup).