Week 4 - Neuro Flashcards
IVDD Type I
nucleus pulposus extrusion
chondroid metaplasia/degeneration with nuclear mineralization
TL>cervical>LS
–less in thoracic region due to intercapital ligament (adds more structure to vertebrae)
Typical Signalment: Chondrodystrophic (short legged) dogs only + Frenchies
Typical Age: Young adults (1-6yo)
Typical Onset/Presentation: Acute
Progressive: Both, potentially progressive
Painful: Yes
Pathophysiology: disc degerantes, nucleus pulposus loses water content and becomes dry, is extruded
Comments: Could be symmetric/asymmetric
Surgical referral: anytime when they are non-ambulatory (Grade 3) or more (ex. Grade 2,1,0)
IVDD Type II
Typical Signalment: LARGER breed dogs
Typical Age: Middle age to older (5-12yo)
Type of onset/presentation: Chronic (>2 weeks)
Progressive: Yes, slowly
Painful: Yes, but usually bigger dogs that can hide pain better (less pain expression)
Pathology: Annulus fibrosis protrusion due to fibroid metaplasia/degernation
-common at L7-S1
ANNPE (Acute Non-compressive Nucleus Pulposus Extrusion)
Typical Signalment: any breed
Typical Age: Young enough to still have healthy discs
Type of Onset/Presentation: Acute/peracute, inability to walk
Progressive? Both, depends on if animal continues to extrude disc (most of the time if it is just the one episode)
Painful? Can be both – acuteness will be less pain…?
Pathophysiology: High traumatic force to a normal hydrated disc (different from IVDD Type I/Type II) - extrusion of NORMAL nucleus pulposus
AAI (Atlantoaxial Instability)
Typical Signalment: Small toy breeds (YORKIE, Pomeranian, Chihuahua, Miniature Poodle)
Typical Age: Juvenile to young, hx of neck pain
Type of Onset/Presentation: Acute via some sort of event (tripping, playing frisbee, etc)
Progressive: Usually progressive/recurring
Painful: Yes
Pathology: Instability of the C1-C2 joint -> leads to brain injury of cranial cervical spinal cord (ex. ligament issues), can be traumatic event
DA-CSM (Disc-Associated Cervical Spondylomyelopathy)
Typical Signalment: Large dogs (Dobermans), Large/Giant breeds
Typical Age: Middle-aged
Type of Onset/Presentation: Chronic, takes time
Progressive: Yes
Painful: Yes
Pathology: congenital
Comments:
-Localization – C5-C6-C7
-mostly ventral compression
-symmetrical/asymmetrical signs
FCE (Fibrocartilaginous embolism)
Typical Signalment: ACTIVE large breed breeds (but can be Miniature Schnauzer, Min. Pin., Sheltie)
Typical Age: Young to middle aged (any age)
Type of Onset/Presentation: Peracute onset, during exercise (dog was playing then freezes then falls)
Progressive: No
Painful: No
Pathology:
Comments: Similar to ANNPE, hard to discern the two, usually asymmetric (lateralized)
Localization: can happen anywhere where there is vessels and discs
DM (Degenerative Myelopathy)
Typical Signalment: GSD, Corgi, Boxer
Typical Age: Older (esp. for corgis)
Type of Onset/Presentation: Chronic, slowly progressive
Progressive: Yes, slowly
Painful: No
Pathology:
Location: ALWAYS starts with T3-L3 localization, could be asymmetric, Gene - SOD-1 (homozygous mutated SOD-1 = at risk, but doesn’t mean they have it at that time)
Diagnosis: Exam, definitely usually post-mortem
GME (Granulomatous meningo-encephalitis/myelitis
Typical Signalment: small breeds (purse dogs)
Typical Age: 1-8 years old… young to middle aged
Type of Onset: Acute
Progressive: Yes without treatments
Painful: Yes
Diagnosis: Definitive dx = pathology
-MRI
-CSF: pleocytosis, increased macs and lymphocytes (mononuclear cells)
Localization: Anywhere - can affect brain and spinal cord, most commonly encephalitis
SRMA (Steroid Responsive Meningitis Arteritis)
Inflammatory dz
Typical Signalment: Beagles, Burmese Mt. Dogs, Boxers
Typical Age: Younger than GME dogs (1-2 years old), rarely >2yo
Localization:
Type of Onset: Acute, waxing and waning
Progressive: Yes, without treatment
Painful: Yes, cervical pain
Comment: No neuro deficits
CSF: Neutrophilic pleocytosis - dilemma is if it’s bacterial infxn
Neoplasia of Spinal Cord
Typical Signalment: Any breed
Typical Age: Usually older
Localization: Anywhere depending on type
Discospondylitis
Infectious dz
Signalment: GSD (fungal), bacterial – any, large/giant dog breeds
Type of Onset: Usually chronic, but can be acute if fracture/lux
Painful: Yes, extremely
Localization: L7 - S1, but can be seen anywhere
Tx: if you can’t get confirmation of bacterial agent – use the 4Bs with abx – 1. crosses BBB, 2. bactericidal, 3. beta-lactams, 4. broad spectrum
Fracture-Lux
Type of Signalment:
Painful: Yes, IMMOBILIZE
What does AMBULATORY mean?
at least 3 limbs are able to move/support the animal’s weight
What is a myelopathy?
myelo - spinal cord/marrow
dz/disorder affecting the spinal cord:
-dura
-vertebrae
-epidural space
-neuro parenchyma
What are the 3 different types of myelopathies, relative to the DURA?
Lecture 22, Slide 8
- Extradural
- Intradural, extramedullary
- Intramedullary
What are the 2 types of myelopathies, relative to the SPINAL CORD?
Lecture 21, Slide 9
- intrinsic – affecting the neuro parenchyma
- extrinsic – everything else (outside of spinal cord parenchyma)
-also, in terms of dura, includes extradural and intradural, extrameduallary
What are the 4 NAL classifications of myelopathies?
- C1-C5
- C6-T2
- T3-L3
- L4-caudal (S3)
Findings are based on ______ and _______, NOT the underlying cause.
Findings are based on localization and severity, NOT The underlying cause.
If there are LMN and UMN lesions, _____ always wins.
LMN always wins/LMN will mask UMN signs.
Myelopathies have normal: (2)
- normal mentation
- CN function
Describe UMN vs LMN
UMN
1. the boss - “supervises”
2. cell bodies in brain
3. generally “inhibits” LMNs
LMN
1. the worker – “effector”
2. cell bodies in spinal cord and brainstem
3. LMN pools for limbs in intumescences
-TLs - cervical (C6-T2)
-PLs - lumbar (L4-S3)
Describe UMN vs LMN SIGNS/DEFICITS
UMN signs:
-normal to HYPER - reflexes and tonicity
-disuse atrophy (slow, minimal)
-paresis/paralysis
LMN signs:
-normal to HYPO - reflexes and tonicity
-neurogenic atrophy (rapid and severe)
-paresis/paralysis
What are the nerves involved with the Cutaneous Trunci/Panniculus reflex?
-afferent: dermatomes (L6 to rostral)
-efferent: lateral thoracic nerve (C8-T1)
T3-L3 myelopathy – loss of reflex about 2 spinal cord segments caudal to lesion
C6-T2 – loss of reflex regardless of site of stimulation
Schiff-Sherrington (T3-L3) characteristics: (3)
-extension of TLs (+/- neck)
-severe T3-L3 myelopathy
-normal postural reflexes
-NE will be normal – aside from extension of the TLs
-no brain/CN deficits
-thoracic limbs are normal during exam, only postural abnormality (not “postural reflex” abnormality
-lesion of border cells – loss of inhibition
Severity levels from mild to severe (5)
- painfulness
- conscious proprioception
- voluntary movement
- superficial pain sensation
- deep pain perception/sensation
-loss of DPP = loss of the most protected nerve fibers
ex. if you LOSE deep pain sensation, most severe sign/neuro deficit
Decerebellate posture:
-lesion affecting cerebellum
-extended TLs, +/- flexed PLs
-NE consistent with cerebellum lesion
-normal consciousness
What’s the anatomy of a vertebral disc?
-nucleus pulposus in the center (jelly)
-annulus fibrosis around (dough)
IVDD Type I affects which types of dogs?
Chondrodysplastic! Short legs!
Which area of the spine does IVDD Type I mainly target?
any, BUT:
TL>cervical>LS
CS for IVDD Type I:
variable
-pain
-paresis
-ataxia
-hyperesthesia
-incontinence
-loss of pain sensation
-lameness
How would you diagnose IVDD Type I? (2)
-radiographs (in situ mineralization)
-MRI (T2W - fluid and fat hyperintense)
–loss of disc hydration (dark discs)
–deviation of spinal cord
–loss of CSF/epidural fat
When would you conservatively manage IVDD Type I/Which GRADES would you consider CONSERVATIVE management?
conservative management ONLY with milder signs of IVDD Type I
-pain only (grade 5)
-ambulatory (grade 4)
-nonambulatory with good voluntary motor function (grade 3) – MAYBEEEEeeee conservative management
What does CONSERVATIVE management of IVDD Type I entail? (3)
-CAGE REST
–no walks, jumping, playing
–2-4 weeks (4-6 weeks)
-analgesia
–NSAID, Trama-gaba
–not more than 7 days)
-anti-inflammatory
–NSAID
–not more than 7 days
PROGNOSIS: reoccurrence is common, may progressively decline
When should SURGICAL management of IVDD Type I be considered?
-any grade can be surgical, esp grade 0-3
-rapid progression of IVDD should be considered for sx
-FAILED medical management
-severe pain
What are the BENEFITS of IVDD Type I surgery? (4)
- greater outcome with intact deep pain perception
- lower recurrence rate (esp if fenestrations are done)
- faster resolution of pain
- usually faster recovery
What are the GOALS of surgical treatment of IVDD Type I? (3)
- decompression
- control hemorrhage
- disc fenestration
Techniques:
1. hemilaminectomy
2. ventral slot
3. vacations of above
Post-Op management of IVDD Type I: (6)
Nursing Care
1. bladder management
2. recumbency care
3. pain management
Rehabilitation
1. maximize recovery
2. maintain muscle mass
3. maintain joint movement
How is Myelomalacia (MM) associated with IVDD Type I + any spinal cord injury?
-spinal cord become toothpaste (spinal cord necrosis)
-mostly seen in PARAPLEGIA, DPP negative
-dogs with negative DPP
-can have a peracute decline
-loss of DPP >48hr poorer prognosis
–lack of improvement by 2 weeks = poor prognosis for recovery
-10-15% risk of ascending/descending myelomalacia = FATAL!!!
–spinal cord necrosis secondary to ischemia
–will affect ventilation as MM will necrose the nerves that innervate the muscles that help breathe -> so can lead to respiratory arrest
Progressive myelomalacia CS and Pathophysiology
CS - systemically ill:
-fever
-pain
-inappetence
NE:
-acute onset, transverse myelopathy
-diffuse progressive myelopathy signs
SOMETIMES imaging
Pathophysiology:
-will affect ventilation as MM will necrose the nerves that innervate the muscles that help breathe -> so can lead to respiratory arrest > then will reach cervical area and damage phrenic nerve (which innervates diaphragm) – will breathe more to try and create negative pressure
What happens to the vertebral disc with IVDD Type II?
the annulus fibrosis hypertrophies!
-fibroid metaplasia/degeneration
-protrusion
-can happen with any dog
-results in spinal cord compression > meningeal/nerve root irritation
What is the most common location for IVDD Type II?
Common at L7-S1, BUT can occur anywhere
CS for IVDD Type II
-paraparesis/tetraparesis
-ataxia
-pain with palpation
-+/- lameness, incontinence
How would you diagnose IVDD Type II? (4)
- radiography
-narrowed disc space
-end-plate sclerosis
-osteophyte production
-spondylosis - myelography
- CT
- MRI - GOLD STANDARD – see picture Lecture 24, Slide 12
When would CONSERVATIVE treatment be indicated for IVDD Type II? (4)
- mild dz
- very slowly progressive
- non-painful
- continent
PROGNOSIS: variable, exercise and physiotherapy effective
What is the treatment for CONSERVATIVE management of IVDD Type II? (3)
- anti-inflammatories
- physical rehab (some movement is good – different than IVDD Type I)
- supportive care
When is SURGICAL treatment indicated for IVDD Type II? (5)
- moderate to severe myelopathy
- short hx or ACUTE onset
- incontinence
- deteriorating
- chronic pain
PROGNOSIS:
GUARDED
-prolonged hx
-multiple discs
-possible other underlying dz
-LMN signs present
-owner expectation
GOOD
-short hx - weeks to months
-focal lesion - 1 compression
-pain is a significant finding
-no other underlying dz
-owner expectation
What are the GOALS for SURGICAL treatment for IVDD Type II? (2)
- decompression without destabilization
- halt progression of dz
via hemilanimectomy vs pediculectomy
What does ANNPE stand for?
Acute Non-compressive Nucleus Pulposus Extrusion
aka Traumatic Disc Extrusion
ANNPE Pathophysiology?
high force/trauma – tears annulus fibrosis and causes ASYMMETRICAL extrusion of NORMAL nucleus pulposus
-can cause compression, but very minimal
CS with ANNPE
-paresis/paralysis
-ataxia
-+/- LMN signs
-+/- hyperesthesia
How to diagnose ANNPE (1)
-MRI
What is the MEDICAL/supportive care treatment for ANNPE? (3)
- crate rest
- time
- PT (once wound is healed)
When should SURGERY be indicated for ANNPE?
-if compressive
PROGNOSIS - good if intact nociception
Congenital spinal malformations are usually _______ findings.
Congenital malformations are usually INCIDENTAL findings.
Malformations of the vertebral body/vertebral disc are: (3)
-usually incidental findings
-mostly treatable
-neuro signs occur secondary to trauma or compression
Malformations of the vertebral arch/spinal cord are: (3)
-maybe incidental
-less treatable
-neuro signs from result of spinal cord malformation
What does AAI stand for?
Atlantoaxial instability
What is the definition of AAI?
instability of the C1-C1 joint – leading to injury of the cranial cervical spinal cord and +/- caudal brainstem
can happen via malformation or trauma
What MALFORMATIONS can lead to AAI? (3)
- malformation of C1 and C2
- malformation of dens
- ligament abnormalities
What TRAUMA can lead to AAI? (2)
- dens fracture
- ligamentous rupture
CS of AAI? (4)
- cervical pain – STIFF neck
- tetraparesis/plegia
- brainstem signs
- seizure -like episodes
True/False: You must NOT FLEX the neck of a patient with AAI
TRUE – you should NOT FLEX the neck – this causes more compression of the spinal cord.
What kind of imaging is needed for AAI? (4)
IMMOBILIZE the patient before imaging
-rads (neutral, dynamic, ventrodorsal, oblique)
-CT
-myelography
-MRI
What does MEDICAL treatment of AAI entail?
INDICATIONS
-immature bones
-very small patient
-mild signs that are resolving
-cost concerns
TREATMENT
-splinting/bandaging (months)
-medication - NSAIDS
-cage confinement/rest
What does SURGICAL treatment of AAI entail?
INDICATIONS (usually indicated)
-moderate to severe neuro deficits/pain
-recurrent episodes of cervical pain
-unresponsive to medical treatment
-angulation of dens
METHODS
-dorsal – BUT DO VENTRAL
PROGNOSIS for sx
-good
What does CSM stand for?
Cervical SpondyloMyelopathy
aka Cervical Stenotic Myelopathy
Etiology of CSM (cervical spondylomyelopathy)
-genetic/congenital
-conformation
-nutritional - Ca?
-trauma (exercise)
What are the two types of CSM?
- DA-CSM - disc-associated CSM (think doberman)
- OA-CSM - osseous-associated CSM (think great dane)
ALL CSM dogs have stenosis (absolute vs. relative) - static and/or dynamic compression
How to DIAGNOSE DA-CSM? (3)
-rads
-MRI
-myelography
When is MEDICAL treatment of DA-CSM indicated? (and OA)
-milder cases only
–pain only
–mild deficits
-cost constraints
-high risk patients (anesthetic and surgical risks)
When is SURGICAL treatment of DA-CSM indicated?
-controversial
-moderate/severe deficits
-acute deterioration
-focal lesion
-unresponsive to medical tx
What does MEDICAL treatment of DA-CSM entail? (4)
-rest
-analgesics (trama-gaba)
-anti-inflammatories (NSAIDs vs steroids)
-physical rehabilitation
PROGNOSIS: guarded
What does SURGICAL treatment of DA-CSM entail? (3)
-decompression - bc stenosis
–direct
–indirect with fusion
-motion preserving techniques
-also physical rehab
PROGNOSIS: Good
CS of CSM (6)
-difficulty walking (tetraparesis)
-ataxia
-neck pain
-hypermetria
-CP deficits
-reflex deficits
-if DA-CSM > due to C5-6-7 favored localization, TLs can present LMN and PLs as UMN
-OA-CSM – PLs often worse than TLs
OA
-chronic progressive cervical myelopathy
-PLs signs seen first
-often acute decline
What does OA-CSM stand for?
Osseous-associated cervical spondylomyelopathy
aka wobbler syndrome
think young giant breeds (and some large breeds) — GREAT DANE
Pathology of OA-CSM
-hypertrophy of bony structure, NOT disc related like DA-CSM – hypertrophy causes stenosis/compression of spinal cord
-bony proliferation of vertebrae around articulations (typically dorsolateral compression)
OA-CSM Imaging
-rads (+/- myelogram)
-CT (+/- myelogram)
-MRI - GOLD STANDARD
–evaluates spinal cord parenchyma (increased intensity with spinal cord)
–guides treatment options
–identifies most severely affected sites
When is SURGICAL treatment for OA-CSM indicated?
-severe pain
-moderate/severe deficits
-focal lesion
-acute deterioration
Spinal Stenosis
-narrowed vertebral column
-congenital, developmental or acquired
-osseous and or soft tissues
Congenital Scoliosis
-lateral angulation of the spine
-congenital forms often progress
-causes:
–vertebral/ligamentous anomalies
–cystic spinal cord lesions
–abnormal muscular support
-neuro signs may occur
Spina Bifida
-presence of midline cleft due to failure of vertebral arch fusion
-size of cleft related to amount of spina cord anomaly present
-one or multiple vertebrae affected
-diagnose - rads, MRI
–bulldogs, manx cats - heritable
Arachnoid Diverticulum
-fluid filled structures within the arachnoid
-congenital or acquired
-slowly progressive, non-painful myelopathy
-may be incidental
How would you DIAGNOSE GME (Granulomatous Meningoencephalomyelitis)?
-MRI
-CSF
–pleocytosis
–rule out infection
–mostly lymphocytes and macrophages
-definitive diagnosis: HISTOPATHOLOGY
What kind of dogs get GME?
-primarily small breeds – toy breeds – purse dogs
-but any breed can be affected
-usually young to middle aged
How do you treat GME?
-immune suppression
–steroids
–cyclosporine
–cytosine
-monitor CS
-recheck CSF
What’s the prognosis for GME?
-if short term > good/fair
-if long term > guarded