Neurology Flashcards
the different areas of the central nervous system
Forebrain, brainstem, cerebellum, spinal cord and neuromuscular
how is the spine segmented
C1-C5, C6-T2, T3-L3, L4-CAUDAL
8 parts to a neurological exam
1 Mentation, 2 Posture, 3 Gait, 4 Postural Reactions, 5 Spinal Reflexes, 6 Cranial Nerves, 7 Palpation, 8 Nociception
what are you looking for in the first 2 steps of a neurological exam
Mentation: Level (alert/coma), Quality( appropriate or not)
Posture: head tilt (roll) or turn (yaw), stance( wide base) and posture
decerebrate
neck and limbs extended
decerebellate
neck and forelimbs extended but hindlimbs flexed
Schiff-scherrington posture
forelimbs rigid hindlimbs flexed (T3-L3 lesion)
paresis
decreased voluntary movement
LMN ( decreased to absent reflexes in limb effected and reduced muscle tone) or UMN (normal to increased muscle tone and spinal reflexes caudal to lesion)
cause of normal to increased stride length with spastic movements
UMN Paresis
cause of “bunny hopping” (reduced stride length) or collapse
LMN Paresis
Ataxia
Without coordination:
Sensory: wide base, knuckling, increased stride length
Cerebellar: rate+range, intention tremors, hypermetria
Vestibullar: falling, leaning, head tilt,
what does a exaggerated spinal reflex show
A lesion in the UMN cranial to the spinal section tested
what does the patella reflex test
femoral nerve L4-L6
what does the perineal reflex test
Pudendal nerve S1-S3
what does cutaneous trunci test for
thoracic nerves C8-T1
What does the absence of a reflex show
lesion present in the reflex ark or joint/muscle problem
what does the menace response test
optic nerve , forebrain, cerebellum, brainstem and facial nerve
what does PLR test
Optic nerve, brainstem and oculomotor
what are the cranial nerves?
1: Olfactory 2:Optic 3:Occulomotor 4:Trochlear 5:Trigeminal 6:Abducent 7:Facial 8:Vestibulocochlear 9:Glossopharageal 10:Vagus 11;Accessory 12: hypoglossal
cause of drooped eyelid and miosis (constriction)
Horner’s syndrome: sympathetic supply to eye and face (trigeminal)
facial sensation
trigeminal, brainstem and facial nerve
what nerve is effected in nystagmus and strabismus
Vestibulocochlear -> 3,4,+6
circling shows a problem where
Forebrain
spastic or exaggerated movements
cerebella dysfunction
absent or reduced menace
cerebella dysfunction
retractor ocular reflex nerves
trigemninal and abducens
atrophy of masticatory muscles is a problem with what nerve?
trigeminal
how is spinal disease graded
0: normal -> 5 Down
clues of ataxia
Pacing and circumduction
weak limb can be caused my ……
spinal cord damage
hypometria
shorter protraction phase of gait
hypermetria
longer protraction phase to gait
Dysmetria
impaired ability to control the distance, power and speed of movement (combination of hypo/hyper-metria)
abnormal postural reaction and limb paresis
sensory ataxia
head tilt, falling to one side, postural strabismus with normal postural reactions
vestibular ataxia
wide-base stance, tremors, loss of balance, menace deficit
cerebella ataxia
location of lesion in vestibular ataxia
vestibular apparatus or inner ear
tests for vestibular ataxia
occularvestibular reflex (pendulum nystagmus: nystagmus when head is moved)
if mentation if effected where is the lesion
forebrain, brainstem or systemic (hypertension, pyrexia, ECT)
Menace and PLR pathways
Menace: optic, opposite forebrain and cerebella, facial nerve
PLR: optic, optic chiasm, oculomotor
3 nerves involved in eye movement
3,4 and 6
oculomotor, trochlear and abducens
what nerves are responsible for which movement of the eye
oculomotor: up down, medial, clockwise,
Trochlear: anticlockwise
Abducens: lateral and inwards
lesion in Ventrolateral strabismus
Oculomotor
rotation of the globe
Trochlear (cannot see in dog, round pupil)
medial strabismus
abducens
loss of palpebral
trigeminal (afferent) facial (efferent)
change in facial expression
facial nerve
drooping of ear
facial nerve
pendulum nystagmus
nystagmus when head is moved, reduced towards side of lesion
two types of deafness
Sensorineural: failure of sensory organs
Conductive: failure of passage of sound
what provides motor innervation of the pharyngeal muscles
9
glossopharyngeal
causes of megaosophagus
Addison’s (Hypoadrencortisism), myasthenia gravis, oesophagitis, botulism or brainstem disease
main difference between ataxia and paresis
Ataxia is loss of sensory pathway (proprioeception) and paresis is loss of motor innervation (UMN or LMN)
what does a spinal reflex test
sensory, central(spine) and Motor(LMN, muscle and NMJ)
UMN indirectly because shows as exaggerated reflex
difference between tetraplegia and paraplegia
tetraplegia: absence of movement in all limbs
paraplegia: absence of movement in hind limbs
what are LMN signs
muscle atrophy and reduced spinal reflex
where is lesion if paraplegia, loss of muscle mass in hindlimbs
L4-S3
where is lesion if paraplegia with exaggerated reflexes in hind limbs
T3-L3
location of lesion if tetraplegia with increased muscle tone and exaggerated reflexes in all limbs
C1-C5 or brainstem
location of lesion if tetraparesis, exaggerated reflexes in hind limbs and reduced reflexes in forelimbs
C6-T2
how do you know the severity of spinal lesions based on clinical signs
loss of proprioception then movement then nociception
most important prognostic indicator for spinal lesions
deep pain perception (REMEBER limb withdrawal does not mean pain perception!!)
cause of muscle pain that occurs during or just after exercise
equine rhabdomyolysis syndrome ( Monday morning disease or tying up)
how is equine rhabdomyolysis diagnosed
a >100% increase in CK after a lungs test (take blood CK levels pre and 6 hours post a 20 minute lunge)
cause of equine rhabdomyolysis
overexertion, electrolyte imbalance, inherited
treatment for equine rhabdomyolysis
analgesia, fluids, rest and electrolytes (sodium and potassium)
prevention of regular exercise rhabdomyolysis in TB
oral dantrolene, high fat/low carb diet and regular exercise.
cause and treatment of a limp tail (rudder tail)
coccygeal muscle injury, treatment: rest and NSAIDs
horse with funny kick out placement of hind limb on one side
fibrotic myopathy: rest, ice and NSAIDs
what does the patella reflex test
femoral nerve (L4-L5)
what does the withdrawal reflex test
sciatic (L6-L7)
what does the perianal reflex test
Pudendal nerve (S1-S3)
clinical signs of lumbrosacral syndrome
pain at hips, low tail carriage reluctant to sit/jump, crouched posture
GSD with bladder dysfunction and pain at back
lumbosacral stenosis
horse with tail paresis, dilated anus and perineal loss of sensation
Trauma(sacral fracture) or EHV-1
what are the three muscle involved in bladder voiding
detrusor, urethral muscle (smooth muscle) and external sphincter muscle (skeletal muscle)
type of innervation for storage and voiding phases of the bladder.
Storage: sympathetic
Voiding: parasympathetic
drugs used to stimulate bladder emptying
Prazosin and Diazepam
difference between a T1 and T2 MRI
T1w: fluid is dark
T2w: fluid is white
what is a cross extension reflex and what does it suggest
when doing withdrawal reflex on one limb the opposite one extends (a UMN sign)
if all 4 limbs are effected where must the lesion be cranial to …..
T2
reduced reflex in thoracic limbs, where is lesion?
C6-T2
what does scuffing on the thoracic feet indicate
sensory loss, chronic nature of disease
typical CS of Neuromuscular disease
weakness, muscle loss, ataxia, reduced spinal reflexes and altered breathing
if paresis without ataxia likely to be
neuromuscular
common causes of neuromuscular disease
myasthenia gravis, hypothyroidism, hyperadrenocorticism, neospora, toxoplasma or neoplasia
normal result of a EMG (electromyogram)
silent
regurgitation with exercise intolerance
myasthenia gravis (causing megaoesopagus and blocked Ach receptors on muscles)
treatment and diagnosis of myasthenia gravis
Ach inhibitor test and serology, treat with pyridostgymine and immunotherapy drugs.
cause of dysphagia, loss of tail, tongue and eyelid tone, general weakness, ileus and pupil dilation in a horse
Botulism: antiserum, broad spectrum antibiotics and fluids
