Neuro Exam Flashcards
Six components of neuro exam
- mentation
- gait & posture
- cranial nerves
- postural reactions
- segmental reflexes
- palpation & range of motion
mentation
- alert & appropriate
- obtunded (dull, lethargic but responsive)
- stuporous (responsive to noxious stimuli)
- comatose (not responsive to noxious stimuli)
- dead
gait
- ambulatory vs. non-ambulatory
- ataxia
- paresis or plegia? (mono-, hemi-, para-, tetra-)
- lameness?
ataxia
- lack of coordination
- cerebellar, vestibular, proprioceptive
cerebellar ataxia
wide-based stance, +/- hypermetria, truncal sway
no CP deficits, no weakness
vestibular ataxia
wide-based stance, leaning, listing, “drunken sailor”
proprioceptive ataxia
lack of coordination with a lack of awareness and paresis
“spinal ataxia”
posture
- head
- tilt or turn
- resting or intention tremors
- head held low, neck guarding
- body
- kyphosis, lordosis, scoliosis
- torticollis
- laterally recumbent
- decerebrate vs. decerebellate vs. Schiff-Sherrington
decerebrate
- cerebrum disconnected
- comatose
- rigid extension in all limbs
decerebellate
- acute cerebellar lesions
- extended TLs, flexed PLs
Schiff-Sherrington
- severe, acute T3-L3 lesions-plegia +/- pain perception
- not prognostic
- when placed on side: TLs rigid, HLs weak
- extensor hypertonia of TLs
- due to loss of ascending inhibition
- distinguish from decerebrate and decerebellate posutres (mentation and CNs)
what do decerebrate, decerebellate and Schiff-Sherrington have in common?
oposthotonus (star gazing), extended neck and rigid thoracic limbs
menace
afferent: CN II
efferent: CN VII
PLR
afferent: CN II
efferent: PS CN III
palpebral
- medial canthus:
- afferent: V (ophth)
- efferent: VII
- lateral canthus
- afferent: V (max)
- efferent: VII
facial symmetry
CN VII
physiologic nystagmus
afferent: CN VIII
efferent: CN III, IV, VI
- MLF
- strabismus, positional nystagmus
gag
afferent: CN IX, X
efferent: IX
tongue function
CN XII
(lesions here are not as common in dogs and cats as horses)
postural reactions
- placing/knuckling (CP)
- hopping
- hemistanding & hemiwalking
- wheelbarrow
- visual & tactile placing
- extensor postural thrust
hemistanding & hemiwalking
walk laterally slowly- don’t have musculature to hop medially
should be 1:1 thoracic:pelvic limb steps
segmental reflexes: thoracic limb
-
withdrawal (reliable)
- biceps, musculocutaneous n., C6-C8, triceps, radial n., C8-T2
- biceps & triceps
segmental reflexes: pelvic limb
-
patellar (reliable)
- femoral n., L4-L6
- gastrocnemius
- cranial tibial
-
withdrawal (reliable)
- mostly sciatic n.
- L6-S1
segmental reflexes: cutaneous trunci
- lateral thoracic n.
- C8-T1
- not a simple reflex
segmental reflexes: perineal reflex
tail tuck and anal sphincter
neurolocalization
- normal vs. abnormal
- brain vs spine vs LMN vs multifocal
- 1: brain
- 2: C1-C5
- 3: C6-T2
- 4: T3-L3
- 5: L4-S3
- 6: motor unit (LMN)
brain and cranial nerves
- forebrain
- cerebrum: I
- diencephalon: II
- cerebellum
- brainstem
- midbrain: III-IV
- pons: V
- medulla oblongata: VI-XII
forebrain lesions-clinical signs
- seizures
- circling
- compulsive
- behavior changes (inapp, getting stuck in corners)
- blindness, non-ocular (amaurosis)
- postural reaction deficits
- gait should be normal (no paresis)
idiopathic head tremors
“head bobbing”
labs
try feeding PB and will stop
cerebellar lesions-clinical signs
- head tilt
- nystagmus
- loss of menace
- intention tremors
- truncal sway
- ataxia
- hypermetria“spastic”
- DO NOT have: paresis, behavior changes, CP deficits
brainstem lesions-clinical signs
- decreased mentation (ARAS)
- obtunded to stuporous to comatose
- CN deficits: III-XII
- usually some CN VIII involvement
- check for physiologic nystagmus
- vestibular or proprioceptive ataxia (if ambulatory)
- may seem cerebellar depending on lesion
vestibular: central vs peripheral
- central
- CP deficits
- paresis
- ataxia
- hypermetria
- mentation changes
- +/- other CN
- peripheral
- head tilt
- nystagmus
- other CN deficits (VII)
- ataxia
spinal cord lesion
- postural reactions = there is a lesion
- segmental reflexes = where it is
muscle tone
- extended, difficult to flex limb
- implies UMN lesion
- normal, resting tone
- flaccid, unable to support any weight
- implies LMN involvement
- consider spinal shock
C1-C5
- +/- ambulatory (knuckling, stumbling, “face-planting”
- tetraparesis
- ataxia (PL>TL)
- reflexes: N to increased in all limbs
- +/- muscle fasiculations
- +/- pain
C6-T2
- +/- ambulatory
- knuckling, stumbling, “face-planting”
- “two-engine” gait
- tetraparesis
- ataxia
- reflexes
- TL: N to decreased
- PL: N to increased
- +/- muscle fasiculations
- +/- pain
T3-L3
- +/- ambulatory
- paraparesis (increased PL tone!)
- PL ataxia
- +/- kyphosis
- reflexes:
- TL: N
- PL: N to increased
- +/- panniculus cut-off
- +/- pain
spinal shock
- T3-L3
- physiologic or anatomic transection of the spinal cord that results in temporary loss or depression of all or most muscle tone and spinal reflex activity below the level of injury
- acute injury
- patellars return within hours in dogs
- withdrawal reflexes can take days
- not prognostic
L4-S3
- +/- ambulatory
- PL ataxia
- +/- pain
- paraparesis-decreased PL muscle tone
- reflexes:
- TL: N
- PL: decreased to absent
- +/- panniculus cut off
LMN
- +/- ambulatory
- no ataxia
- no pain
- +/- CN weakness (facial, gag)
- paresis: decreased muscle tone all over
- reflexes:
- decreased to absent
- panniculus may or may not be affected
- exercise intolerance
