Brain Flashcards
(174 cards)
1
Q
What is the fx of astrocytes?
A
Metabolic support to the neurons
2
Q
What is the fx of ependymal cells?
A
CSF production
3
Q
What is the fx or microglia?
A
Act as macrophages and phagocytize neuronal debris
4
Q
What is the fx of oligodendrocytes?
A
Form the myelin sheath and increase conduction velocity
5
Q
What forms the myelin sheath in peripheral nerves?
A
Schwann cells
6
Q
What do the cell bodies of neurons form?
A
Grey matter
7
Q
What do the axons form?
A
Form the white matter
8
Q
What are the three types found in the CNS?
A
Multipolar (most CNS neurons)
Pseudounipolar (dorsal root ganglion)
Bipolar (retina, ear)
9
Q
What type of CNS cell is most prone to brain tumors?
A
Glial cell
10
Q
What is the cerebral hemisphere that contains the motor cortex?
A
Frontal
11
Q
Which cerebral hemisphere contains the somatic sensory cortex?
A
Parietal
12
Q
Which cerebral hemisphere contains the vision Cortex?
A
Occipital
13
Q
Which cerebral hemisphere contains the auditory cortex and speech centers?
A
Temporal center
14
Q
Which area helps one understand speech?
A
Wernicke’s area
15
Q
Which area is the motor control of speech?
A
Broca’s area
16
Q
Which area of the brain includes cognition, movement (pre central gurus of the frontal lobe), and sensation
A
Cerebral Cortex
17
Q
Which area of the brain affect memory and learning?
A
Hippocampus
18
Q
Which area of the brain deals with emotion, appetite, responds to pain and stressors
A
Amygdala
19
Q
What part of the brain deals with fine control of movement?
A
Basal ganglia
(Caudate nucleus)
(Globus pallidus)
20
Q
What are parts of the diencephalon?
A
Thalamus (acts as a relay station)
hypothalamus (primary neurohumoral organ)
21
Q
What are parts of the brainstem?
A
Midbrain (auditory and visual tracts)
Pons (autonomic integration)
Reticular activating system (controls consciousness, arousal, sleep)
Medulla (autonomic integration)
22
Q
What are the three types of cerebellum?
A
Archicerebellum
Paleocerebellum
Neocerebellum
23
Q
What is cranial nerve 1?
A
Olfactory (smell)
24
Q
What is cranial nerve 2?
A
Optic (vision)
25
What is cranial nerve 3?
Oculomotor (eye mov. And pupil constriction)
(Extorsion ~ elevation, supraduction, adduction, infraduction)
26
What is cranial nerve 4?
Trochlear (eye mov.)
Superior oblique ~ intorsion
27
What is cranial nerve 5?
Trigeminal (somatic sensation to face, anterior 2/3 of the tongue, and muscles of mastication)
V1
V2
V3
28
What is cranial nerve 6?
Abducens (eye mov.)
***abductuon
29
What is cranial nerve 7?
Facial (facial mov., Eyelid closing, taste to anterior 2/3 tongue)
Branches: temporal, zygomatic, buccal, mandibular, cervical
“The zebra bit my cousin”
30
What is cranial nerve 8?
Vestibulocochlear (hearing and balance)
31
What is cranial nerve 9?
Glossopharyngeal (somatic sensation and taste to posterior 1/3 of tongue)
32
What is cranial nerve 10?
Vagus (soooo much ~ swallowing)
33
What is cranial nerve 11?
Accessory (shoulder shrug)
34
What is cranial nerve 12?
Hypoglossal (tongue movement)
35
What is the mnemonic for the function of all the cranial nerves?
Some Say Marry Money, But My Brother Says Big Boobs Matter More
1. Sensory
2. Sensory
3. Motor
4. Motor
5. Both
6. Motor
7. Both
8. Sensory
9. Both
10. Both
11. Motor
12. Motor
36
Hi
37
Which cranial nerve is not part of the peripheral nervous system?
Optic nerve
38
Which nerve causes Bell’s Palsy?
Facial n.
39
What is tic douloureux?
Trigeminal neuralgia CN (generates excruciating neuropathic pain in the face)
40
What is the site of CSF production?
Choroid plexus
41
What is the site of CSF reabsorption?
Arachnoid villi
42
What is the pathway b/t the lateral and third ventricle?
Foramen of Monro
43
What is the pathway between third and fourth ventricle?
Aqueduct of Sylvius
44
What are the locations the CSF in the brain/spine?
Ventricles (left lateral, right lateral, third, fourth)
Cisterns around the brain
Subarachnoid space in the brain and spinal cord
45
What are some traits about the BBB?
Tight junctions to restrict access
Does not have carrier proteins
Is poorly developed in the neonate
46
Where are the 5 parts the BBB is not at?
Chemoreceptor trigger zone, posterior pituitary gland, pineal gland, choroid plexus, and parts of the hypothalamus.
47
What is the total CSF volume?
150 mL
48
What is CSF’s specific gravity?
1.002 - 1.009
49
At what rate is CSF produced at?
30 mL/hr
50
What is normal CSF pressure?
5-15 mmHg
51
Where is the site of production of CSF?
Choroid plexus in the cerebral ventricles
52
Where is the site of reabsorption?
Arachnoid villi in the superior Sagittarius sinus
(Reabsorption is dependent on the pressure gradient b/t CSF and venous circ)
53
What is the Mnemonic for CSF flow?
Love My 3 Silly fierce little Monsters
Love: lateral ventricles
My: monro (foramen)
3: 3rd ventricle
Silly: Sylvius
Fierce: fourth ventricle
Little: Luschka
Monsters: magendie
54
What are some main different b/t CSF and plasma?
CSF = less K+, decreased pH, decreased glucose, and Literally NO PROTEIN
55
What is an excessive accumulation of CSF in the brain called?
Hydrocephalus
56
What are the two types of hydrocephalus?
Obstructive: obstruction of CSF flow
Communicating hydrocephalus: decreased absorption by the arachnoid villi or overproduction of CSF
57
What is the equation for cerebral blood flow?
Cerebral blood flow = cerebral perfusion pressure / cerebral vascular resistance
58
At what CBF will you evidence of ischemia?
~ 20 mL/100g
59
At what cerebral blood flow (CBF) would you have complete cortical suppression?
~ 15 mL/100g
60
At what cerebral blood flow (CBF) will you have membrane failure and cell death?
< 15 mL/100g
61
What are the 5 determinants of cerebral blood flow?
Cerebral metabolic rate for oxygen
Cerebral perfusion pressure
PaCO2
PaO2
Venous pressure
62
Cerebral blood flow is coupled to what?
CMRO2
(The greater the need for oxygen, the more blood flow there will be to satisfy this need)
63
What % or oxygen is used for electrical activity? What % is used for cellular integrity?
Electrical= 60%
Cellular integrity=40%
64
How much does CMRO2 decrease per 1 degree of Celsius decrease in temperature?
7%
65
What things decrease CMRO2?
Hypothermia, halogenated anesthetics, propofol, etomidate, and barbiturates
66
What things increase CMRO2?
Hyperthermia, seizures, ketamine, nitrous oxide
67
At what temperature do proteins denature and neurons become destroyed?
42 degrees Celsius
68
What is the range for cerebral perfusion pressure?
50-150 mmHg
OR
MAP 60-160 mmHg
69
What is the equation for CPP?
CPP = MAP - ICP (or CVP) whichever is higher.
70
What are patients at risk of if there cerebral vessels are maximally dilated? (CPP is < 50)
Cerebral ischemia / hypoperfusion
71
What are patients at risk of if their vessels are maximally constricted?
Cerebral edema/hemorrhage
(I.e. CPP > 150)
72
For every 1 mmHg increase in PaCO2; how much of the CBF will increase?
1-2 mL/100g
73
For every 1 mmHg decrease in PaCO2; how much of the CBF will decrease?
1-2 mL/100g
74
When does max vasodilation occur?
PaCO2 of 80-100 mmHg
75
When does max vasoconstriction occur?
PaCO2 of 25 mmHg
76
What is the steal phenomena?
Administration of a vasodilator (or Hypoventilation, hypercapnia) causes cerebral vasodilation and can potentially “steal” flow from ischemia areas
77
What is inverse steal or the Robin Hood effect?
Concept in which using hyperventilation (for instance) constricts cerebral vessels that supply healthy tissue but redistribute they blood to ischemic areas (they are maximally dilated no matter what)
78
At what PaO2 will there be cerebral vasodilation and increased CBF?
A PaO2 below 50-60 mmHg
(If PaO2 is above 60 mmHg, CBF is unaffected)
79
What is the gold standard of ICP measurement?
Intraventricular catheter
80
When is ICP measurement indicated?
Glasgow coma scale score < 7
81
What are the S&S of intracranial HTN?
HOP to CVS
Headache
Optic nerve swelling (papilledema)
Pupil dilation
To
Coma
Vomiting (nausea)
Seizure
82
What are the 3 components of the Brain?
“BBC”
Brain tissue
Blood
CSF
83
What is the Monroe-Kellie Doctrine?
Describes the pressure-volume equilibrium b/t the blood, brain, and CSF within the confines of the skull
(an increase in 1 must be countered by a decrease in another)
84
What is Cushing triad?
HTN
Bradycardia
Irregular Respirations
85
Where is the most common site of transtentorial herniation?
Temporal uncus “uncal herniation”
Puts pressure on midbrain and optic nerve (resulting in a fixed and dilated pupil)
86
What are the 4 methods to reduce ICP?
CBV reduction
CSF reduction
Cerebral edema reduction
Cerebral mass reduction
87
What are some ways to reduce cerebral blood flow?
“HAHA”
Hyperventilation (PaCO2 30-35 mmHg)
Avoid hypoxemia (PaO2 < 60 has huge effect on CBF)
Hemodynamics (must maintain CPP ~ Neo)
Avoid drugs that vasodilate (nitro) chose drugs that vasoconstrict (prop)
88
What are some ways to increase venous drainage?
“PP”
Position (head elevation)
PEEP is bad (high peeps increase intrathoracic pressure and reduce venous drainage)
89
What are some ways to reduce CSF?
Drain and Drugs
Drain: place a drain in the lateral ventricles or intrathecal space to improve ICP
Drugs: acetazolamide and furosemide reduce CSF production
90
What are some ways to reduce cerebral mass?
Debulk
Diuretics (mannitol) ~reduce intra cerebral mass
91
How do loop diuretics reduce cerebral edema?
Diuretics and decrease rate of CSF production
92
How do osmotic diuretics decrease cerebral edema?
Pull water across BBB
***if BBB is disrupted, mannitol can enter the brain and increase cerebral edema
93
Which diuretic must you be cautious with in a failing heart?
Mannitol ~ this is because mannitol transiently increases blood volume and can stress heart
94
What should not be used for traumatic brain injury or pituitary adenoma?
Steroids!!
95
What supplies the anterior circulation of the brain?
The internal carotid arteries.
Aorta > carotid > internal carotid > circle of Willis > cerebral hemispheres
96
What supplies the posterior circulation of the brain?
Vertebral arteries
Aorta > subclavian > vertebral arteries > basilar artery
97
For patients suffering from an ISCHEMIC stroke, within how many hours must tPa be given?
4.5
“4.5 to keep that brain alive”
98
What is the most important risk factor for stroke?
HTN
99
What are some of the risk factors to stroke?
“aH SHEED”
aH: HTN
S: smoking
H: HLD
E: excessive ETOH
E: elevated homocysteine level
D: DM
100
What should a patient receive prior to any CVA treatment? What should be done FIRST!?
Emergent non-contrast CT
101
What is the first therapy for patient in ischemia stroke?
ASA
102
Within what hour limit should patients with a large vessel occlusion undergo embolectomy?
Within 6 hours of symptom onset
103
What should the target BP be maintained under?
185/110 mmHg
104
What is the leading cause of morbidity and mortality after a subarachnoid hemorrhage?
Vasospasm
105
What is triple H therapy?
Hemodilution
Hypertension
Hypervolemia
106
What is the ONLY calcium channel blocker that reduces morbidity and mortality associated with vasospasm?
Nimodipine
***it does not actually relieve spasm, but increases collateral flow
107
What is the most common cause of subarachnoid bleeding?
Aneurysm rupture
(Usually in circle of Willis)
108
What is the most common sign of a subarachnoid hemorrhage?
Intense headache
“Worse headache in my life”
109
When should surgical repair take place after the initial bleed of a SAH?
24-48 hours
110
If an aneurysm ruptures during the procedure (due to the loss of ICP pressure tamponading the aneurysm ~ I.e opening the dura), what should the anesthetic provider do?
Reverse heparin
Lower MAP (low/normal range)
Adenosine to temporarily arrest heart
111
What range should intraoperative BP be controlled at?
120-150 mmHg
**this is especially during intubation and induction
112
When will a vasospasm most likely occur?
4-9 days following SAH
113
What is the gold standard for diagnosing a vasospasm?
Cerebral angiography
114
What is the goal for maintain CPP?
Increase MAP 20-30 mmHg above baseline
115
At what hematocrit is hemodilution acceptable for vasospasm and triple H therapy?
27-32%
116
What is cerebral salt-wasting syndrome?
Brain releases natriuretic peptide (like the heart) and this leads to volume contraction, hyponatremia, and sodium wasting by kidneys
Treated with isotonic crystalloids
117
What is Plavix reversed by?
Platelets!
118
A Glasgow of < what is consistent with traumatic brain injury and is an indication for intubation and controlled ventilation?
< 8
119
In the Glasgow coma scale, how is motor response measured?
1 no motor response
2 extension to pain
3 flexion to pain (decorticate)
4 withdrawal to pain
5 localize pain
6 verbalize pain
120
In the Glasgow coma scale, how is verbal response measured?
1 no verbal response
2 incomprehensible sounds
3 inappropriate words
4 confused
5 oriented
121
In the Glasgow coma scale, how is eye opening measured?
1 no eye opening
2 opening to pain
3 opening to sound
4 open spontaneously
122
What can warfarin be reversed with? (If patient comes in with traumatic brain injury)
FFP, prothrombin concentrate, or factor 7a
123
What are the two things you should specifically avoid in a patient with traumatic brain injury?
Prolonged hyperventilation
Steroids
124
For traumatic brain injury, CPP should be maintained at?
70 mmHg
125
What is a grand Mal seizure?
Generalized tonic-clinic activity
Resp arrest due to hypoxia (increase in O2 consumption)
Tx: propofol, diazepam, thiopental
126
What is the tonic phase?
Whole body rigidity
127
What is the clonic phase?
Repetitive jerking motions
128
What is a focal seizure?
Localized to a particular cortical region
(Usually not loss of consciousness)
129
What is a absence seizure? (Aka petit mal)
Temporary loss of consciousness BUT remains awake (more common in children)
130
What is a akinetic seizure?
Temporary loss of consciousness and postural tone
Can result in fall
Common in kiddos
131
What is status epilepticus?
Seizure activity lasting > 30 mins OR two grand mal seizures WITHOUT consciousness.
Resp arrest ~ hypoxia (increased O2 consumption)
Acute tx: phenobarbital, thiopental, phenytoin, benzos, propofol
132
In the adult, new-onset seizures are likes the cause of what?
Structural brain lesion (tumor, CVA, or trauma)
Metabolic cause: hypoglycemia, drugs, withdrawal, toxicity
133
Which iv anesthetic can induce seizure activity?
Ketamine
It’s should be avoided in patients with seizure history
134
Which two NMB produce laudanosine (a proconvulsant)?
Atracurium (more)
Cisatracurium (less)
135
Which anticonvulsant is excreted unchanged by the kidneys?
Gabapentin
136
Which two anticonvulsants INDUCE hepatic enzymes?
“Keep is PC”
Phenytoin and carbamazepine
137
Which anticonvulsant INHIBITS hepatic enzymes?
Valproic acid
138
What is Phenytoin? MOA? And additional info…
Blocks voltage gates Na+ channels
***zero order
Enzyme inducer
SE: purple glove (on extravasation or arterial injection), steven’s Johnson, gingival hyperplasia, dysrhythmias, aplastic anemia
139
What is Valproic acid? MOA? Additional info….
MOA: blocks voltage gated Na+ channels
Info: enzyme inhibition
SE: hepatotoxicity, thrombocytopenia (in kiddos), displaced phenytoin from proteins
140
What is carbamazepine? MOA? Additional info….
MOA: blocks voltage gated Na+ channels
Info: inducer
Useful in Trigeminal neuralgia
SE: aplastic anemia, thrombocytopenia, liver dysfunction, ADH-like effect (hyponatremia)
141
What is gabapentinoid? MOA? Additional info?
MOA: inhibition of alpha 2 subunit of voltage gates Ca channels in CNS > decrease in excitatory (NE) transmitter release
Info: may cause resp depression with opioids
Unchanged in urine
SE: somnolence and dizziness
Must taper if pt has history of seizures (1 wk)
142
What is the most common cause of dementia in patients 65 and older?
Alzheimer’s
143
What is the patho physiology behind Alzheimer’s?
Development of beta-amyloid rich plaques and neurofibrillary tangles
(Results In dysfunction of synaptic transmission and apoptosis)
144
What is the treatment of Alzheimer’s?
Palliative
Cholinesterase inhibitors (tacrine or donepezil)
145
What should you avoid intraoperatively with a patient with Alzheimer’s?
Avoid:
MAC and regional
Longer-acting drugs
Preoperative sedation
Anticholinergics that cross BBB (scopolamine and atropine)
146
Which two volatile agents increase beta-amyloid production?
Halothane and isoflurane
147
What are the two most important factors that contribute to the pathophysiology in Parkinson’s disease?
Decreased dopamine in the basal ganglia
Increased gaba in the thalamus
148
What does increased Ach n the basal ganglia stimulate and how does this affect a patient with parkinson’s?
^ Ach > increases GABA ~ GABA is inhibitory > suppression of thalamus
Suppression of thalamus > suppresses cortical motor system
149
What are the 4 cardinal signs to Parkinson’s?
“ROLLING SKATES GO BACKWARDS”
Rolling: pill rolling tremor
Skates: skeletal miscible rigidity
Go: gait instability/loss of balance
Backwards: bradykinesia ~ slow mov
150
What is the greatest risk factor for Parkinson’s?
Old age
151
What is levodopa? What is carbidopa?
Levodopa: precursor for dopamine
Carbidopa: decarboxylase inhibitor ~ prevents levodopa metabolism in blood so more levodopa can enter CNS
152
What is the 1/2 life of levodopa?
6-12 hrs. That is why it MUST be given pre-operatively to prevent rigidity, which can impact ventilation
153
What drugs should be avoided in Parkinson’s?
Antidopaminergic drugs: Reglan, butyrophenones, and phenothiazines
154
what drugs can be used to treat acute exacerbation of Parkinson’s symptoms?
Anticholinergics
155
What is the anesthetic management of a patient going for deep brain stimulation?
Avoid levodopa (may help optimal electrode placement)
Pt must be awake, but slightly sedated (opioids and precedex)
Avoid GABA agonists (they interfere with monitoring)
Sitting increases risk of VAE
Keep SBP < 140 mmHg
156
What is the most common perioperative complication?
Corneal abrasion
157
How do you diagnose corneal abrasion?
Fluorescein stain
With a penlight ~ affect region appears green
158
What is the most effective way to prevent corneal abrasion?
Taping the eye after induction but BEfORE intubation
Horizontal taping is better
159
What is the most common cause of postoperative vision loss?
Ischemic Optic neuropathy (ION)
160
When is ION most common?
24-48 hrs after SPINE surgery in the PRONE position
161
What are some risk factors to ION?
Prone
Wilson frame
Long duration of anesthesia
Large blood loss
Low ratio of colloid to crystalloid
Hypotension
162
What is central retinal artery occlusion? (CRAO)
Vascular problem ~ results from occlusion of the central retinal artery (position)
163
What are the S&S of central retinal artery occlusion?
“Cherry red” macula
Sudden, painless vision less (usually one eye)
164
What is the most common cause of Central retinal artery occlusion?
Horseshoe headrest (improper head position)
165
Which cranial nerve injury results in Bell’s palsy?
7th!
166
Between what two vertebrae does the artery of adamkiewics arise?
T8-T12
167
Occlusion if the artery of adamkiewics during cross-clamp can cause anterior artery syndrome…this means what?
Just think….reasons we don’t like Adam.
He’s flaccid
He smells like pee and poop
Loses his “temper ~ ature)
BUT he’s still touching and ap-propriate/proprioception
Flaccid paralysis
Bowel and bladder dysfunction
Loss of temperature and pain sensation
Preserved touch and proprioception
168
What does the spinal cord’s blood flow consist of?
2 posterior arteries
1 anterior artery
6-8 radicular arteries
169
What percentage do the posterior arteries perfuse?
1/3 of the spinal cord
170
What percentage does the anterior artery perfuse?
2/3 of the spinal cord
171
What is the largest and most important radicular artery?
Artery of adamkiewics
172
What is another name for anterior spinal artery syndrome?
Beck’s SYNDROME (not the be confused with becks triad)
173
What three tracts are perfused by anterior blood supply?
Corticospinal ~ motor
Autonomic ~ bowel and bladder
Spinothalamic ~ pain and temperature
174
What tract is perfused by posterior blood supply?
Dorsal column ~ touch and proprioception
