Spinal Injuries and Intracranial Disease Flashcards
why is it important for nurses to be able to understand spinal injuries?
so that best nursing care can be provided
what is involved in the veterinary nurses role in the care of a spinal injury patient?
identify disease progression
understand how to assess and monitor
report accurately to the VS
how may some spinal injuries present?
as an emergency and so are time critical
what forms the extracranial part of the CNS?
spinal cord
what structure encases and protects the spinal cord and nerves?
spinal column
what is involved in the patient assessment of a neuro patient?
history physical exam neurological exam differential diagnosis based on previous findings diagnostic tests diagnosis / prognosis treatment
when will a neurological exam be performed?
seizures
behavioural changes
gait abnormalities
change in posture / positioning
why is a neurological exam so important?
identify if nervous system is involved
identify specific location / localisation of injury
aid diagnosis and prognosis
continuous assessment of condition
what is neurolocalisation?
identification of which part of the spinal cord is affected by injury
what types of motor neurons are there?
upper
lower
what are the signs of upper motor neurone injury?
loss of motor function
paresis
reflexes are normal or increased
chronic atrophy
what are the signs of lower motor neurone injury?
reduced muscle tone
reflexes reduced or absent
atrophy
where are upper motor neurones located?
between the cerebral cortex and the spinal cord
what is the role of upper motor neurons?
send signals to lower motor neurons
what is the role of lower motor neurons?
connect the CNS to the effector organ (often muscles) and send signals to make them contract
what can neurologic signs help with?
localisation of lesion
what is involved in neurological examination?
mentation gait and posture cranial nerves postural reactions spinal reflexes sensory evaluation palpation
what is assessed about mentation during a neurological exam?
is the patient alert, obtunded, stuporous or comatose
what is assessed about gait and posture during a neurological exam?
is it normal for the individual
how can cranial nerves be assessed during a neurological examination?
reflexes: menace PLR gag palpebral vestibuloccular
what is assessed about postural reactions during a neurological exam?
propreoception
what is assessed about spinal reflexes during a neurological exam?
thoracic and pelvic limb assessment
what is assessed about deep pain during a neurological exam?
panniculus
deep pain
what areas of the body are palpated during a neurological exam?
head, spine, limbs
what is one of the most common presentations of spinal cord injuries?
gait abnormalities
what is assessed about gait during a neurological exam?
can the animals generate and make coordinated movements
is there normal limb use
how is gait assessed in a neurological exam?
owner / nurse walks animal up and down
what should be done if the animal makes no attempt to walk during a gait assessment in a neurological exam?
sling or support should be used
define ataxia
uncoordinated gait (may have normal strength in limbs)
define paresis / paretic
weakness
decreased voluntary movement
define paralysis / plegic
no voluntary movement
animal cannot move limbs at all
define mono paretic/plegic
one limb affected
define hemi paretic/plegic
both limbs on one side (L or R) affected
define para paretic/plegic
both pelvic limbs affected
define quadra or tetra paretic / plegic
all four limbs affected
why is a quadra/tetra plegic animal very rare?
will affect respiratory function as well as limbs so liely to die
what posture changes may indicate spinal cord injury?
head tilt - one ear below the other head turn - nose turned towards body ventroflexion of the neck curling of the spine decerebrate rigidity decerebrate rigidity wide based stance - wider limb placement than normal
what is ventroflexion of the neck?
low head carriage - head is lower than normal
what are the 3 main altered curvatures of the spine?
scoliosis
lordosis
kyphotisis
what is scoliosis?
lateral curve in spine
what is lordosis?
abnormal ventral curve in spine
what is kyphosis?
abnormal dorsal curve in spine
define decerebrate rigidity
extension of all limbs, head and neck and unable to move
define decerebellate rigidity
extension of thoracic limbs, head and neck
pelvic limbs are flexed or normal
how can postural reactions be tested?
propreoceptive positioning hopping visual placing tactile placing hemi-walking wheelbarrwoing
how is propreoceptive positioning performed during a neurological exam?
tuck paw under with dorsal surface on floor - animal should correct this
how is hopping performed during a neurological exam?
one leg is lifted and the patient encouraged to move on other 3
how is visual placing performed during a neurological exam?
hold limb towards a table and then place paw on it - animal should reach out towards table
how is tactile placing performed during a neurological exam?
eyes are covered and foot is brushed towards the edge of a table
the animal should place the paw normally on the table
how is hemi-walking performed during a neurological exam?
paws on one side of the body lifted and animal encouraged to move
how is wheelbarrowing performed during a neurological exam?
hindlimbs are lifted and animal walks on forelimbs
what spinal reflexes can be used to assess nerve function?
thoracic limb
pelvic limb
perineal
panniculus
what are the spinal reflexes that are assessed in the forelimb?
withdrawal reflex
extensor carpi radialis and triceps reflex
what are the spinal reflexes that are assessed in the hindlimb?
patella reflex
cranial tibial and gastrocnemius
how are extensor carpi radialis, biceps, triceps, cranial tibial and gastrocnemius reflexes tested?
muscles are tapped with a hammer and a reaction should be seen
what is the most reliable spinal reflex in the thoracic limb?
withdrawal reflex
what is the perineal spinal reflex?
if area around perineum is touched there will be contraction of sphincter
what is the panniculus reflex?
pinching either side of the spinal column which should result in a twitch that runs down the spine
what can the panniculus reflex help with?
aid localisation of lesion in spinal cord
is the withdrawal reflex an indication of pain?
no
when is pain evaluation performed?
last investigation as it is stressful
why is it important to test deep pain sensation?
deepest tracts in spinal cord are the pain tracts - if these are affected it means there is severe spinal cord damage
how is pain evaluated in patients?
pinching / pressure is applied to digits on each limb and response is noted
what are you looking for during a pain evaluation to show that pain tracts in the spinal cord are undamaged?
reaction from the patient (e.g. turning, vocalising or trying to bite)
what is a negative result on a deep pain evaluation?
no pain sensation (may still see withdrawal)
what are acute causes of spinal injury?
intervertebral disc disease (IVDD)
trauma - fracture/luxation
infarction (fibrocartilaginous embolism FCE)
in waht breed of dogs is IVDD most common?
dachshund
what happens during FCE?
blood vessels supplying the spine becomes blocked by clot / fibrocartilageonous material
what are the chronic causes of spinal injuries?
degenerative disc disease
degenerative myelopathy
cervical stenotic myelopathy (wobblers)
in what breeds are degenerative myelopathy and cervical stenotic myelopathy common?
large breeds
what is happening in a patient with cervical stenotic myelopathy?
narrowing of spinal column in cervical region
what are the other potential causes of spinal injury?
atlanto-occipital subluxation vertebral abnormalities neoplasia inflammatory diseases discospondylitis
what is discospondylitis?
infection within vertebral bodies
how are spinal injuries diagnosed?
imaging (radiographs, CT and MRI) CSF tap (possibly) - cisternal or lumbar
what is the best imaging modality for diagnosis of spinal injuries?
MRI
how may spinal cord injuries be treated?
conservative treatment
surgery
what is involved in conservative treatment of spinal injuries?
6 weeks of strict rest (cage if possible) physiotherapy anti-inflammatory drugs analgesia steroid therapy (occasionally)
what are the surgical options for treatment of spinal cord injury?
hemilaminectomy
ventral slot
dorsal laminectomy
spinal stabilisation / fixation
what area of the spine is operated on during hemilaminectomy surgery?
T3-L3 and L4-S3 regions
where is ventral slot surgery performed?
C1-T2 - ventral approach
when is surgical treatment of spinal injury needed?
negative deep pain test
extreme pain
disc material visualised in spinal column
what makes up a big proportion of nursing care in spinal injury patients?
bladder function
why is bladder function so significant in spinal cord injury patients?
many patients are incontinent
what are the 2 main types of bladder injury/damage seen with spinal cord injury patients?
upper motor neuron bladder
lower motor neuron bladder
describe what an upper motor neuron bladder is like
increased urethral resistance detrusor and urethral sphincter can contract at the same time not able to control bladder function urinary retention kidney damage possible difficult to manually express requires catheterisation intermittent squirting of urine as muscle and sphincter contract
are patients with upper motor neuron injuries able to control bladder function?
no
can upper motor neuron bladders be easily manually expressed?
o
is catheterisation advised for upper motor neuron bladders?
yes
describe the bladder of a patient with a spinal injury which affects lower motor neurons
flaccid bladder
doesn’t contract spontaneously
continues to fill which results in overflow leaking of urine
bladder muscle is overstretched
easy to manually express (will urinate with any pressure on bladder)
how easy to express are lower motor neuron bladders?
easy - will express with minimal conact
what are the main nursing considerations of patients with spinal injuries?
long term patients
holistic care and enrichment crucial
nutrition - encourage eating
turning and physio for recumbent patients
temperature control to prevent hyper/hypothermia
padded bedding to prevent pressure sores
excretion management (inco sheets, catheter or walked out)
grooming and TLC
hygiene
what is intracranial disease?
a disease or injury which affects the brain
is intracranial disease commonly seen in practice?
yes - head trauma common
is intracranial disease an emergency?
yes, must be triaged and managed quickly as can be life threatening due to involvement of the brain
why is any intracranial swelling or inflammation dangerous?
brain is encased within the skull vault which is a closed, inelastic compartment so there is no additional room
what is contained within the skull vault?
parenchymal tissue (brain)
blood
CSF
what percentage of the skull vault is taken up by parenchymal (brain) tissue?
80%
what percentage of the skull vault is taken up by blood?
10%
what percentage of the skull vault is taken up by CSF?
10%
what does the CNS depend on to function?
blood flow
why does the CNS depend on blood flow to function?
require large amount of O2 and energy via the blood to function
brain has especially high consumption and limited storage of O2 and glucose
neurons respire aerobically
what autoregulatory mechanisms are in place in the normal brain?
those that maintain constant cerebral blood flow (CBF) over a wide range of MAP
what is CBF?
cerebral blood flow
what is the range of MAP that autoregulatory mechanisms can maintain constant cerebral blood flow?
50-150 mmHg
what is intracranial pressure?
pressure exerted between skull and intracranial tissues
what is normal ICP?
5-10 mmHg
What is the name for disruption of normal ICP?
intracranial hypertension (ICH)
what does intracranial hypertension result in?
reduced cerebral perfusion pressure (CPP)
reduced blood flow to the brain leading to secondary changes
what leads to raised ICP?
increase in any volume in the brain without compensatory decrease or the presence of additional volume
what is cerebral perfusion pressure made up of?
MAP - ICP
what happens if autoregulatory mechanisms within teh brain are compromised?
CPP will decrease as MAP decreases and ICP increases leading to overall decrease in CBF
what is CBF?
cerebral blood flow
what causes an overall decrease in CBF if autoregulatory mechanisms are compromised?
CPP will decrease as MAP decreases and ICP increases
how can the body compensate for increased ICP?
reduction of CSF and blood volume in the brain to compensate for raised ICP
what reflex are you monitoring for in patients with intracranial disease?
cushings reflex
what is the cushings reflex triggered by?
severe and acute increase in ICP
what are the signs of cushings reflex?
marked risk in MAP and relfex bradycardia
what is the cushings reflex a sign of?
potentially life threatening increase in ICP and so should be treated immediately
what are the causes of intracranial disease?
trauma inflammatory infectious neoplastic toxins seizures anomalous
what are examples of trauma that may cause intracranial disease?
RTA fall horse kick being stepped on BB gun pellet
what are examples of inflammatory causes of intracranial disease?
meningoencephalitis of unknown origin (MUO)
what are examples of infectious causes of intracranial disease?
viral
protozoal
fungal
bacterial
what are examples of neoplastic causes of intracranial disease?
meningioma
glioma
choroid plexus tumor
what are examples of toxins that may cause intracranial disease?
lead
ivermectin
what are examples of anomalous causes of intracranial disease?
hydrocephalus
what is involved in a neurological exam?
mentation
gait and posture - is it normal
cranial nerves
postural reactions - proprioception
spinal reflexes - thoracic and pelvic limbs
sensory evaluation - panniculus and deep pain
palpation of head, spine and limbs
what are the two key elements of the neurological examination that will show intracranial disease?
mentation
cranial nerves
what are the 4 main categories to assign when assessing mentation?
alert
obtunded
stuporous
comatose
describe alert mentation
normal response to surrundings
describe obtunded mentation
awake but less responsive
will sleep if left
describe stuporous mentation
only responds to noxious or painful stimuli
describe comatose mentation
unconscious
unresponsive to any stimuli
what behaviours may an animal show if they have intracranial disease?
circling in tight circles, one way head pressing pacing head tilt - one ear below the other head turn - nose turned towards the body
what is head pressing a sign of?
increased ICP and pain
what are the ways in which cranial nerve function can be assessed?
menace response palpebral reflex pupillary light reflex (PLR) gag reflex oculocephalic relfex nystagmus
how many cranial nerves are there?
12
how can the menace response be tested?
cover one eye and move hand towards face in menacing gesture - patient should draw away from hand
how is the palpebral reflex tested?
touch on medial canthus of eye - blink should be shown
what is the pupillary light reflex?
constriction of one or both pupils in response to bright light
how is the gag reflex assessed?
touch larynx
what is the oculocephalic reflex?
physiological nystagmus which corrects with movement
what is physiological nystagmus?
flicking of eyes in response to fast movement which will stop once patient isn’t moving
how is the oculocephalic reflex tested?
patient is moved quickly through room or spun and response of eyes watched
what does an absence of oculocephalic reflex indicate?
poor prognosis
severe brainstem damage
is nystagmus when patient is still normal?
no
what is a miosis / miotic pupil?
constricted
what is a mydriasis / mydriatic pupil?
dilated
what is anisocoria?
asymmetric pupils
what about patients pupils will indicate neurological deterioration?
if patients pupil goes from miotic to mydratic
what must be monitored and recorded about pupil size?
any changes
what is indicated by mid sized, fixed pupils that are unresponsive to light?
grave prognosis - patient is likely dead
what are the clinical signs of intracranial disease?
circling ataxia blindness altered mentation loss of consciousness seizures Cheyne-stokes respiration head tilt head turn coma loss of gag reflex loss of oculocephalic reflex strabismus non-responsive pupils apneustic or ataxic respiratory pattern (sign of deterioration) decerebrate posture decerebellate posture nystagmus
what are the 3 domains of the modified glasgow coma score?
motor activity
brainstem reflexes
level of conciousness
what score is possible in each domain of the modified glasgow coma scale?
1-6
what is the final score possible on the glasgow coma score?
between 3 and 18
what score indicates more severe neurological deficits and grave prognosis?
lower score
what prognosis is indicated by a MGCS of 3-8?
grave
what prognosis is indicated by a MGCS of 9-14?
guarded - potential for deterioration
what prognosis is indicated by a MGCS of 15-18?
good
how is raised intracranial pressure treated?
Mannitol infusion
hypertonic saline IVFT
what is the action of Mannitol?
hyperosmolar
reduces cerebral oedema
increases CPP and cerebral blood flow
how rapid is the onset of action of Mannitol?
rapid - can see improvement in clinical signs within minutes
how long do the ffects of Mannitol last?
1.5-6 hours
how is Mannitol given?
boluses of 0.5-1.5 g/kg every 1.5-6 hours
what is the most significant side effect of Mannitol?
profound diuretic
how can the side effects of Mannitol be managed?
isotonic fluids to follow up
maintain vasuclar volume
what must happen to Mannitol before it is administered?
must be warmed
how does hypertonic saline work to treat raised ICP?
similar osmolarity to Mannitol
improves haemodynamic status
what is the preferred method o treatment for raised ICP?
Mannitol
what may prove beneficial if patient is not responding to treatment for raised ICP?
switching between Mannitol and hypertonic saline or vice versa
what is indicated by a poor response to Mannitol?
poor prognosis
How is raised ICP treated alongside Mannitol or hypertonic saline?
sedatives - encourage patient rest analgesia anaesthesia if severe mechanical ventilation if comatose CRI may be needed intensive care and monitoring needed
when may CRI be needed to treat a patient with raised ICP?
maintaining sedated state before switching to full anaesthesia (e.g. patient is seizing)
are corticosterioids indicated for use in patients with raised ICP?
no
how should the recumbent patient be managed?
turn every 2-4 hours
padding adequate
physio to prevent muscle wastage and joint stiffness
monitoring and management of excretions to prevent scauld
how must the raised ICP patient be positioned?
cranial part of body elevated (not just head) by 30-40 degrees
why must the cranial part of the body and not just the head be elevated in patients with raised ICP?
avoid compression of the jugular vein which can further increase ICP
what blood sampling method is not appropriate in raised ICP patients?
jugular
by how many degress should the cranial part of an animals body be elevated?
30-40 degrees
what is involved in the occular care of an recumbent patient?
eye drops to prevent drying
wipe eyes to keep clean
what is involved in oral care of the recumbent / comatose patient?
prevent saliva and excretion build up in mouth by clearing with a damp swab
monitor for coughing
how often should oral checks be performed in the recumbent / comatose patient?
4-6 hours
how can nutrition be provided to recumbent/comatose patients
offer in sternal every 4-6 hours if concious
feeding tube if not
are feeding tubes often used in comatose raised ICP patients?
unlikely as there survival rate is low
what feeding tube must be avoided in patients with raised ICP?
N/O as can cause sneezing
what monitoring form may need to be completed in raised ICP patients?
anaesthetic monitoring
what is hydrocephalus?
excessive accumulation of CSF within the ventricular system
what can hydrocephalus be caused by?
obstruction to CSF outflow
decreased absorption of CSF
increased production of CSF
what are the 2 main types of hydrocephalus?
congenital - present at birth
acquired
what breeds are pre-disposed to congenital hydrocephalus?
chihuahua
what causes acquired hydrocephalus?
tumor
inflammation
haemorrhage
what are the clinical signs of hydrocephalus?
behavioural changes slowness in learning (e.g. toilet training) loss of coordination visual deficits seizures circling depressed / obtunded mentation enlarged and dome shaped skull
what is the most common sign of hydrocephalus?
enlarged and dome-shaped skull
are signs of hydrocephalus consistent?
no - may wax and wane particularly congenital
what are the 2 main methods of treatment of hydrocephalus?
medical
surgical
what are the aims of medical treatment of hydrocephalus?
reduce production of CSF
what are the main drugs used for medical treatment of hydrocephalus?
Prednisolone
Frusemide
Omeprazole
what is the aim of surgical treatment of hydrocephalus?
diverting CSF to another location
what is the main surgery performed to treat hydrocephalus?
ventriculoperitoneal shunt (VP shunt)
what is involved in a ventriculoperitoneal shunt?
tubing placed from ventricle to peritoneal cavity to drain excess CSF
what are the main complications associated with VP shunt to treat hydrocephalus?
blockage
tube dislodged
infection
what is the outcome of hydrocephalus treatment dependent on?
cause and severity of signs
what outcome is suggested by severe hydrocephalus signs?
guarded
when may hydrocephalus be found?
incidental during MRI for another issue
what is the prognosis for hydrocephalus due to infectious cause?
good with treatment for underlying infection and removal of CSF build up
what is the prognosis for hydrocephalus treated with VP shunt?
good
what is the prognosis of hydrocephalus due to obstruction by tumor?
guarded
what type of illness is meningoencephalitis of unknown origin (MUO)?
non-infectious inflammatory disorder of CNS
what are the 3 types of meningoencephalitis of unknown origin (MUO)?
granulomatous ME (GME) necrotising (NME) necrotising leukoencephalitis (NLE)
what does meningoencephalitis of unknown origin (MUO) result in?
brain and spinal cord changes due to autoimmune disease
when can the 3 different types of meningoencephalitis of unknown origin (MUO) be determined?
only PM as only difference seen at a cellular level
what is the signalment of meningoencephalitis of unknown origin (MUO)?
small dog
female more than male
>6 months of age
some breed disposition (e.g. bichon freise)
what are the signs of meningoencephalitis of unknown origin (MUO)?
neurological seizures muscle tremors blindness head tilt altered balance and posture circling
how is meningoencephalitis of unknown origin (MUO) diagnosed?
clinical exam
blood tests
MRI of brain with contrast
CSF analysis for inflammatory signs
how is meningoencephalitis of unknown origin (MUO) managed?
immunosuppressive drugs
antiepileptics if seizing
nursing care
what immunosuppressive drugs may be used to treat meningoencephalitis of unknown origin (MUO)?
steroids
cyclosporine
azathioprine
cytarabine
why must care be taken when administering cytarabine?
is cytotoxic
what is the prognosis of meningoencephalitis of unknown origin (MUO) like?
variable
what is the prognosis of meningoencephalitis of unknown origin (MUO) patients who present with seizures?
poorer
what is the prognosis of meningoencephalitis of unknown origin (MUO) patients who present with focal lesions rather than multifocal?
better with focal lesions
what is the prognosis of meningoencephalitis of unknown origin (MUO) patients who show improvement within 3 months of beginning treatment?
good
can meningoencephalitis of unknown origin (MUO) return in patients who have been successfully treated?
yes and signs may be more severe
