neuro past exam Qs Flashcards
What is the most common signalment for FCE?
Young to middle age, large breed dogs
Any dog can be affected.
What are the presenting signs of FCE? (5)
- Acute onset paresis/plegia
- Initially painful but non-painful after 24hrs
- Signs relate to the location of the embolus
- Usually lateralized to one side
- Non-progressive after 24hrs
Most common in thoracolumbar and lumbosacral areas
Larger emboli affect both sides
What imaging techniques are used for FCE and what you would see using those techniques? (2)
- Myelography: focal enlargement of spinal cord changes
- CT Myelogram: absence of compressive lesion, focal enlargement of spinal cord
What clinical signs indicate a poor prognosis for FCE? (4)
- Presence of LMN signs
- Symmetrical/bilateral signs
- No improvement in 14 days
- Loss of deep pain
What is the cranial nerve that branches into the recurrent laryngeal nerves?
Vagus nerve (CN10)
What is the function of the caudal laryngeal nerve?
Stimulates the Cricoarytenoid muscle (CAD) to contract and abduct the arytenoids during inspiration
What is the most common surgical approach for lateral tie back?
Unilateral procedure focusing on the left side
What are the possible complications of the lateral tie back surgery? (5)
- Aspiration pneumonia
- Hoarse bark
- Seroma formation
- Infection
- Suture breakdown
What are the expected findings for Hansen type 1 at T13-L1 lesion relating to limb muscle tone and reflexes?
Hindlimbs- Increased tone and Exaggerated reflexes
Forelimbs - normal tone and normal reflexes
What is the grading system for scoring neurological dysfunction?
Modified Frankel Scale
* Grade 0: complete loss deep pain, quadriplegia/tetraplegia
* Grade 1: loss of superficial pain, quadriplegia/tetraplegia
* Grade 2: pain sensation, tetra/paraplegia
* Grade 3: paraparesis/tetraparesis, non-ambulatory
* Grade 4: paraparesis/tetraparesis, ambulatory, GP ataxia
* Grade 5: normal, just painful
What are the pros and cons of radiographs as an imaging modality?
- Pros: Easy, accessible, affordable, good for ruling out fractures/bony changes
- Cons: Superimposition of structures, lacks soft tissue detail
What indicates the need for surgical intervention in neurological cases?
- Severe unresponsive pain/Failed conservative treatment
- Progressive neuro deficits
- Toileting issues
- Within 48hrs if thoracolumbar
- High grade 2, grade 3-5
What is the main determinant of prognosis in spinal injuries?
Presence or absence of deep pain
What is the most common signalment for Idiopathic Laryngeal Paralysis in dogs?
- Older larger breed dogs
- Sometimes medium and small breeds
What are typical clinical signs of Idiopathic Laryngeal Paralysis? (4)
- Coughing
- Gagging
- Noisy labored breathing
- Decreased exercise intolerance
What is the surgical treatment of choice for Laryngeal Paralysis?
Lateral arytenoid tie back
What are the postoperative complications to monitor for after lateral tie back surgery? (6)
- Aspiration pneumonia
- Respiratory distress
- Suture failure- return of clinical signs
- Fragmentation of arytenoid cartilage
- infection
- seroma formation
What distinguishes Hansen type 1 from type 2 intervertebral disc disease?
Type 1 involves chondroid metaplasia and acute extrusion of disc material;
type 2 involves fibrous metaplasia, chronic degenerative changes and protrusion of the disc (bulging)
What is the role of the hypogastric nerve in urinary function?
- Relaxation of the detrusor muscle to facilitate storage
- Stimulates the internal urinary sphincter to CLOSE during STORAGE
What happens to the bladder in a T-L lesion?
Upper motor bladder: large and firm, difficult to express
What are the neuro exam findings for a C1-C5 lesion?
Mentation - normal
Cranial nerves - normal
Gait - abnormal
Postural reactions - increased limb tone
Spinal reflexes - increased spinal reflexes, UMN limbs/bladder
Pain - cervical pain, variable sensation limbs depending on severity
What are the possible differential diagnoses for a C1-C5 lesion? (7)
- Atlantoaxial subluxation
- Cervical IVVD
- Cervical spondylomyelopathy
- Traumatic injury
- Neoplasia (meningiomas)
- Steroid responsive meningitis
- Discospondylitis
What are the strengths and weaknesses of CT imaging?
- Strengths: good for identifying epidural lesions, more available than MRI, better spatial resolution
- Weaknesses: not good for showing parenchymal changes of CNS, expensive, radiation exposure
What are the primary stabilizers of the Atlanto-axial joint? (4)
- Transverse ligament
- Apical ligament of the Dens
- Alar ligaments
- Dorsal atlantoaxial ligament
What conservative management is indicated for Atlantoaxial Subluxation?
- Strict crate rest for 6 weeks
- Analgesia
- External coaptation with a rigid cervical brace
What do the bilateral alar ligaments attach to?
Occipital condyles to the apex of the dens
What is the function of the dorsal atlantoaxial ligament?
Joins the dorsal arch of the atlas and craniodorsal spine of the axis
What materials are commonly used for the cervical brace in AA subluxation?
Fibreglass material over bandage material
What head position is recommended when using a cervical brace?
Slight extension
Under what conditions is a conservative approach indicated for AA subluxation? (4)
- Financial limitations
- Signs of neck pain only with no neurological deficits
- Systemic illness
- No radiographic abnormality of the dens
Describe the patella reflex arc?
Sensory fibres in patella tendon (femoral nerve) -> L4-S1 (L4-L6) -> motor nerve quadriceps to extend stifle
What does the withdrawal reflex involve?
Local reflex arc with no cerebral modulation, limbs pulled away/towards the body, no head turn
What is required for nociception?
Conscious reaction
What is a normal reaction to nociception testing?
Head turn/signs of conscious reaction
What does the cutaneous trunci reflex test for?
Spinal cord lesions 1-2 vertebrae cranial to the level of stimulation
What indicates a lack of response in the perineal reflex?
spinal lesions in S1-S3
Pudendal nerve damage
What are the findings in L4-S3 myelopathy?
Mentation - normal
Cranial nerves - normal
Gait - abnormal: hindlimb paresis or plegia
Postural reactions: proprioception wnl FLs, reduced/absent HLs
reduced hindlimb reactions, normal FLs
Spinal reflexes:
- thoracic withdrawal wnl
- cutaneous trunci will cut off at some point
- reduced/absent HL withdrawal
- reduced/absent patella reflex
- reduced/absent perineal reflex
Pain: variable
What is pseudohyperreflexia?
Exaggerated patella reflex due to dysfunctioning sciatic nerve
what would the patella reflex look like with a spinal lesion cranial to L4?
UMN - hyperreflexive patellar reflex
What are the clinical findings of an UMN bladder? (3)
- Increased bladder tone
- Difficult to express
- Overfill incontinence
What is the role of the hypogastric nerve?
Inhibits the detrusor muscle and stimulates the internal urethral sphincter
Facilitates storage of urine
What medications can help a flaccid bladder contract?
vs. an UMN bladder
- Bethanocol- enhances detrusor muscle contraction
______________________________ - Prazosin - decreases internal urethral sphincter tone
- Phenoxybenzamine - decreases internal urethral sphincter tone
What are indications for tail amputation in sacrocaudal luxation? (5)
- Self trauma
- Necrotic skin/degloving
- complete loss of sensation and movement
- urinary incontinence
- intractable pain and discomfort
What is the role of the pelvic nerve?
Stimulates the detrusor muscle to facilitate voiding
What is the normal reaction for the perineal reflex?
Flexion of the tail and contraction of anal sphincter
What is the significance of spinal reflexes in a neurological exam?
Localisation of spinal lesion
FCE etiopathology (4)
- remnant blood vessels
- chronic vascularisation of the disc, with movement of fibrocartilage
- direct penetration of the NP into the spinal cord
- herniation of NP into Bone marrow of the vertebral body
How to assess Gait/Posture (4)
walking/trotting patient
symmetrical,
head position
stride lengths
Cutaneous trunci
Spinal segment and localisation
Extends from iliac wings cranial to C8-T1
Cuts off 2 vertebral segments caudal to lesion.
Signs that indicate worse prognosis for FCE
- LMN signs
- Bilateral signs
- no improvement in 14days
- Loss of deep pain
- Lesion at Pelvic Intumescence (LMN)
- Imaging: lesion >2x adjacent vertebral body
LMN - grey matter deeper in spinal cord that white matter
Deep pain - pain tracts are deeper in the spinal cord
Cranial nerve that is involved in Laryngeal Paralysis (and branches that terminate in larynx)
Vagus nerve
-> L and R recurrent Laryngeal nerve
-> Caudal Laryngeal nerve
- which side is Lateral tie back performed?
- Surgical approach ?
- Which is preferred?
- Left side - patient in R lateral recumbency
- Ventral or Lateral incision
- Lateral
ideal sutures used for Tie back surgery Dogs/cats
non dissolvable monofilamnent such as nylon 2/0 in dogs or Prolene 3/0 in cats.
Grade 0 modified frankel score =
complete loss deep pain
Tetraplegia or Paraplegia
Grade 3 Modified Frankel Score =
non ambulatoy,
Tetraparesis, Paraparesis
Grade 2 MFS
Tetraplegia/paraplegia
with pain
Grade 4 MFS
Ambulatory
tetra/paraparesis
GP Ataxia
Grade 5 MFS
Spinal hyperaesthesia
no ataxia
Grade 1 MFS
Tetra/paraplegia,
No superficial nociception
Pros/cons contrast myelograms
Pros - as per Xrays but more specific information regarding localisation
Cons - risk of reaction to IV contrast, expensive, takes more time
Clinical signs Laryngeal Paralysis
- inspiratory stridor
- inspiratory dyspnoea
- mild cyanosis
- continual panting
- high pitched resp noise, cranial cervical trachea
- possibly other signs peripheral neuropathies
Typical history laryngeal paralysis (4)
- chronic slowly progressive history of coughing, gagging, laboured breething.
- Decreased exercise tolerance.
- sometimes lethargy/depression.
- Occ vomiting/regurg.
Invesigating Laryngeal paralysis
- GA for Laryngeal exam - very light sedation:
- Chest xrays (normal)
- baseline bloods including T4, TSH, +/- ACTH stim test
Signs on Laryngeal exam you would expect to see for LP
- looking for paradoxical adduction of 1 or both cartilages during inspiration (narrowing)
- inflamed tonsils
- inflamed arytenoids/epiglottis
main surgical aim of Tie back surgery
Anchor the muscular process of arytenoid cartilage to caudodorsal aspect cricoid cartilage.
post op care after Tie back surgery
- Withold food/water until fully awake.
- Avoid over sedating to maintain swallowing reflex.
- limit to 2-3 meatballs in 24hrs post op, and only water.
possible immediate post op complications Tie Back
- aspiration pneumonia
- respiratory distress
- suture failure
- fragmentation of arytenoid cartilage
- coughing/gaggin
- seroma
- hemorrhage
Typical age/breeds Type 1 Hansen disc
- Young
- Chondrodystrophoid breeds
- Dacshund, Brachys, Pekingese, Cockers,
- Pathophysiology Type 1 discs
- type of disc injury
Chondroid metaplasia of NP, causing mineralisaation and increasing rigidity. Tears develope in AF and the NP extrudes through.
CONTUSIVE INJURIES.
Pathophysiology Type 2 disc disease
&
Type of injury
Chronic degeneration and fibroid metaplasia of nucleus pulposus and annulus fibrosis. Slow weakening of annulus fibrosis leads to PROTRUSION of nucleus through weakened annulus.
COMPRESSIVE INJURIES
how does Pudendal nerve act in micturition control
Spinal segment it comes from -
innervates the external urethral sphincter (striated muscle), involved in conscious control and constriction to facilitate storage of urine.
S1-S3
What kind of injury would result in a LMN bladder?
&
Typical features
S1-S3 injury
large, flaccid, leaking continuously, overflow incontinence
Incomplete voiding
Eventual detrusor atony
Pelvic nerve function, and spinal segment
- stimulates detrusor muscle of bladder to contract to VOID the bladder
- S1-S3
What kind of injury results in an UMN bladder
&
typical signs
Thoracolumbar spinal injuries (T3-L3) or higher
large, FIRM, difficult to express, Sphincters tight and difficult to relax,
Overflow incontinence,
Loss of conscious control
Medication that can help with UMN bladder (increase sphincter tone) vs. LMN
UMN - Prazosin (alpha blocker)
Diazepam - Inhibits EUS (striated muscle)
Dantrolene - inhibits EUS (striated muscle)
Phenoxybenzamine to inhibit IUS
+ indwelling catheter
LMN bladder -
Bethanecol (parasympathomimetic)- stimulates smooth muscle and increases urethral sphincter resistance. +/- Cisapride, Propanolol, Metoclopramide
which spinal segment injury may result in Horners syndrome?
T1-T3 lesion
Vagosympathetic trunk
Differentials for C6-T2 spinal lesion
- IVDD
- Neoplasia
- FCE
- Discospondylitis
- cervical spondylomyelopathy
- osteomyelitis
- Trauma
differentials for T3-L3 lesion
- IVDD (type 1 or 2)
- Degenerative myelopathy
- spinal trauma
- neoplasia
- FCE
- discospondylitis
- hemivertebrae
Differentials L4-S3 disease
- IVDD
- Trauma
- neoplasia
- FCE
Differentials L6, L7
- Musculoskeletal disorders
- Degenerative Lumbosacral stenosis
- Discospondylitis
- neoplasia
- Extradural synovial cysts
Differentials C1-C5 disease
- Atlantoaxial subluxation
- Cervival IVDD
- Trauma
- Neoplasia
- Granulomatous meningoencephalomyelitis
- Discospondylitis
- Syringomyelia
CT Strengths (neuro disease) (6)
and
Weaknesses
- Good for identifying extradural lesions/masses
- more easily accessible than MRI
- no summation of parts like Xray
- Can make a 3D model
- can be manipulated digitally
- Dont have to put patient in different positions
- Wont show parenchymal changes within spinal cord
- expensive
- poss reaction to IV contrast
- exposure to radiation
Radiographic signs of Atlantoaxial subluxation (4)
- increased space between dorsal laminae of atlas and spinous process of axis
- Malalignment of the bodies of atlas/axis on lateral view
- Angle of less than 162 degrees (not 180)
- Abnormal/absent Dens
what are features of type 3 Hansen Disc injuries? (5)
- Subtype of Type 1 (extrusion)
- High velocity, low volume
- non compressive
- Contusive injury
- Often traumatic, healthy disc
