Neuro Flashcards
pneumonic for alt LOC
AEIOUTIPS
A in AEIOUTIPS
acidosis, alcohol
E in AEIOUTIPS
Epilepsy
I in AEIOUTIPS
Insulin reaction
O in AEIOUTIPS
overdose
U in AEIOUTIPS
Uremia, underdose
T in AEIOUTIPS
Trauma, Tumor
I in AEIOUTIPS
Infection
P in AEIOUTIPS
Psychosis
S in AEIOUTIPS
Stroke
CVA
sudden loss of brain fx, neuro deficits that last 24h or more
what are the main risks with decreased LOC
Aspiration, inability to protect airway, seizure, death
what is ICP
pressure exerted on ventricles by CSF
Equation for CPP
Map-ICP
% of brain matter
80
% of CSF
10
% of blood in brain
10
Monro Kellie hypothesis
Postulates there is reciprocal compensation between intracranial compartments. Increase in one means decrease in other
What happens first when ICP increases
CSF moves down spinal cord
CSF production decreased/ reabsorption increased
Small amount of distension in dura mater
what happens second in increased ICP
Pressure builds, venous system is compressed. ICP rises as brain is compressed
What happens last in increased ICP
compensation fails. Increased CO2 causes cerebral vasodilation, increasing blood flow and increasing ICP
what does CO2 do in brain vasculature
Causes increased ICP by increasing perfusion to brain
Why does the venous system fail when ICP increases
it is compressed, outflow of blood is blocked and beings to accumulate
Clinical symptoms of increased ICP
headache
Nausea/vomitting
Alt LOC
Clinical signs of impending brain herniation
Significant pupillary asymmetry
Unilateral or bilateral fixed and dilated pupils
Decorticate or decebrate posturing
Resp depression
What are signs of impending brain herniation (cushings triad)
HTN with widening pulse pressure, Bradycardia, irregular respirations
Normal ICP
5-15mmhg
when is cerebral autoregulation lost
MAP <50, >100 or ICP >35 for 20-30m
why is maintaining MAP important in neuro patients
to ensure CBF and prevent ischemia
how to maintain MAP to ensure CBF
Inotropes, vaspressors
monitoring/treatments for patients with increased ICP
- Ventilation status
- Drainage of CSF with ICP monitoring system
- Maintain MAP >90
- IV bolus or albumin
- Pressors to maintain MAP
- Sedation/analgesia to decrease workload
- Maintain Sats
nursing interventions for increased ICP
- Dim lights
- Decompress stomach to reduce gastric pressure
- Hyperventilate to blow off Co2
- Mannitol
- Avoid hip flexion (increases P in abd cavity)
- Manage BP
- Increase HOB to drain jugular veins
3 layers of meninges
Dura mater
Arachnoid mater
Pia mater
Outmost layer of brain
dura mater
middle layer of brain
arachnoid mater
which layer of brain is deepest
pia mater
characteristic of dura mater
thick spongey layer, protects
characteristics of arachnoid mater
thin and delicate, weblike and semitransparent
Where is the subaarachnoid space
between arachnoid mater and pia matter
Characteristics of pia mater
attached to brain
occipital lobe
visual cortex
parietal lobe
somatosensory cortex
temporal lobe
hearing, equilibrium, emotion, memory
frontal lobe
motor cortex and association areas, complex thought, ethical behaviour
limbic structures
emotions, short term memory, smell
basal ganglia
initiation and planning of learned motor activities
what is RAS
reticulatar activating system
what does RAS do
maintains consciousness, vital regulation for CV, Resp
how do brain injuries manifest
LOC, cranial nerve reflexes, GCS, brain hemodynamics
where is an epidrual hematoma
epidural space-between skull surface and dura mater (extradural)
what injury increases risk of epidural hematoma
skull fracture
source of most epidural bleeds (art or venous)
arterial
where do subdural hematoma form
between dura and outer arachnoid membrane
what type of blood is in subdural hematoma
venous
why may symptoms of a venous bleed appear later
slower bleeding
where does CSF live
subarachnoid space
where does a subarachnoid bleed occur
between pia mater and outer arachnoid membrane
what type of bleed is subarachnoid
venous (like subdural) or arterial (anyerusm rupture)
what happens when blood is in the CSF
meningial irritation
bloody spinal tap
sever headache
Common stroke symptoms
numbness and weakness on one side of body
confusion, trouble speaking/understanding
visual disturbance
Dizziness, loss of balance
Severe headache
characteristic of TIA
clot is lysed before permanent tissue. damage occurs
how long can a TIA last
minutes to hours
goals of care for ischemic stroke
minimize infarct size and perserve function. Aspirin stat or thrombolytic therapy
goals of care for hemorrhagic stroke
manage increased ICP
Origins of meningitis
viral, fungal, bacterial
why does meningitis move quickly in CNS
present in subarachnoid space, moves through CSF
S/S meningitis
headache
fever stiff neck, alt LOC. Occasionally, Increased HR, seizures
Encephalitis
inflammation of the brain
common causes of encephalitis
HSV, Equine virus, West nile virus
S/S encephalitis
fever, headache, seizure, confusion, stupor, coma, hallucinations, personality changes
characteristics of concussion
alteration or loss of consciousness with no brain damage on CT. Symtpoms present immediatly and resolve quickly