cranial nerves Flashcards
1
Q
which cranial nerves originate from the superior orbital fissure?
A
occulomotor, trochlear, abducens
2
Q
which cranial nerves originate from the internal auditory meatus?
A
facial and vestibulocochlear
3
Q
which cranial nerves originate from the jugular foramen?
A
glossopharyngeal, vagus, accessory
4
Q
which of the cranial nerves are parasympathetic?
A
3,7,9,10
3 = pupillary construction 7 = lacrimation and salivation of sublingual and submandibular glands 9 = salivation of parotid gland 10 = input to organs in thorax and abdomen
5
Q
which cranial nerves are special sensory?
A
1,2,7,8,9,10
6
Q
what is the location of the cranial nerve nuclei?
A
3, 4 = midbrain
5, 6, 7 = pons
8 = pontomedullary junction
9, 10, 11, 12 = medulla
7
Q
combinations of cranial nerve signs: in which region would bilateral III be?
A
midbrain
8
Q
combinations of cranial nerve signs: in which region would III, IV, VI be?
A
superior orbital fissure
9
Q
combinations of cranial nerve signs: in which region would VI, VII be?
A
pons
10
Q
combinations of cranial nerve signs: in which region would V and VIII be?
A
cerebellopontine angle
11
Q
what would unusual combinations in reference to cranial nerve lesions make you think of?
A
chronic/malignant meningitis
think about crossing sub arachnoid space
12
Q
what is optic neuritis a sign of?
A
MS
signs of optic neuritis: inflammation of ON, monocular vision loss, pain on eye movement, swollen optic disk
13
Q
dilated pupil because of loss of parasympathetic nerve input is what disease? (think CN)
A
3rd nerve palsy
14
Q
a problem where in the sympathetic pathway can lead to a constricted pupil
A
anywhere
15
Q
what eye drops constrict and dilate pupils?
A
miotic - constrict - remember like my o tic
myDriatic - Dilate
16
Q
in horners syndrome, first order neurons go to with verterbral level?
A
T1.
First-order preganglionic from hypothalamus -> T1, then second-order preganglionic from T1 through to superior cervical ganglion -> 3rd order neuron (postganglionic) up through internal carotid artery to SOF.
external carotid artery from apex of lungs
can be sign of lung tumour or carotid dissection
17
Q
what are the two types of isolated third nerve palsy and what are the symptoms/aetiology?
A
microvascular: painless, pupil spared - seen in hypertension and diabetes
compressive - painful, pupil affected - caused by posterior communicating artery aneurysm or raised ICP. the worst headache ever
18
Q
idiopathic ICP is nerve palsy of which nerve
A
CN VI
19
Q
nystagmus (butterfly eyes) is most commonly caused by?
A
toxins (e.g. alcohol on a friday night)
20
Q
what is trigeminal neuralgia defined as clinically
A
paroxsymal attacks of lancinating face pain
21
Q
what is trigeminal neuralgia commonly caused by and what is the Tx?
A
vascular loop compression in posterior fossa
carbamzepine
22
Q
what medicine is commonly used to treat trigeminal neuralgia?
A
Carbamazepine
23
Q
in bells palsy, if facial weakness unilateral or bilateral? + what is the most common indicator
+ how to treat
A
unilateral
first sign: pain behind ear, eye closure affected, treat with steroid
24
Q
how to tell between UMN or LMN lesion? in terms of wrinkling forehead
A
in UMN, you can wrinkle the whole forehead, in LMN you can only wrinkle on side.
25
a patient presenting with sudden onset, viral neuritis, vomiting and vertigo would make you think of what?
vestibular neuronitis
26
bulbar palsy and pseudobulbar palsy: which one is LMN and which is UMN?]
pseudobulbar palsy is UMN lesion. if bilateral then it is vascular lesions of both internal capsules, indicitave of MND. - brisk jaw jerk and gag reflex.
bulbar palsy = bilateral lesion affects CN 9-12. indicative of MND, syphilis and polio.
27
what should you be sure not to do if you suspect a patient has bulbar palsy
do not feed them!
| wasted fasciltating tongue
28
definition of dementia
a PROGRESSIVE syndrome, impairment of MULTIPLE domains of cognitive function in alert patients, leading to LOSS OF ACQUIRED SKILLS and INTERFERENCE in occupational and social roles
29
treatable causes of dementia are?
B12 deficiency, hypothyroidism, HIV/ syphilis
30
mimics of dementia are?
depression, hypdrocephalus, tumour
31
what are routine tests done to diagnose dementia?
bloods, CT, MRI - MRI is good cause it shows atrophy.
| other tests are CSF if inflam, EEG, FI, genetics
32
screening tests for examination of cognitive function:
Montreal (MOCA) - BEST
Mini-mental (MMSE)
if unsure or patient has high IQ, you can ask for a neuropsychological assesment
33
what is the protein involved in lewybody dementia?
alpha - synonuclein
34
common treatments for Alzheimers and lewybody dementia?
cholinesterase inhibitors - due to inhibition of choline.
NMDA antagonist.
35
which version of dementia is associated with B- amyloid plaques and neurofibrillary tangles (tau)
+
Apoliproptein E (APOE)
alzheimers
| onset is mostly over 70 but 25% of patients have onset before 65 yo
36
what dementia does this describe? :
| visuospatial problems, personality is preserved
tempero-parietal dementia
37
```
what dementia does this describe? :
early personality changes,
tau body plaque,
changed eating habits
hypersexuality
```
fronto-temporal dementia
38
what dementia does this describe? :
early personality changes & parkinsonism
lewy body dementia
39
what protein aggregates in lewy body dementia?
alpha-synonuclein
40
what treatment exists for dementia? (hint: Tx only exists for two types)
only treatments exist for LBD and alzheimers
- cholinesterase inhibitors due to choline inhibition
- NMDA inhibitors
41
diagnosing parkinsons: What signs need to be present
bradykinesia + at least one of:
rigidity, tremor, instability
slow onset (5-10 years), and must have ruled out other causes
42
which type of Parkinsons is most common
idiopathic
43
what part of the body does vascular parkinsons affect?
lower half
44
parkinsons plus syndromes
multiple system atrophy
progressive supranuclear atrophy
corticobasal degeneration
any sort of basal ganglia disease
45
is parkinsons more common in males or female?
1.5 M: F
| 2nd most common neuro disease
46
genetic factors increasing risk of parkinsons:
LRRK2 (late onset), Parkin (young onset), GBA (gauchin disease)
47
most common symptom in parkinsons?
unilateral, asymetrical tremmor at rest, slow onset
ONE SIDED and gets better when not at rest
48
treatment for parkinsons:
1. L-dopa inhibitor - levodopa
2. decarboxylase inhibitor - carbidopa/ benserazide
3. COMT inhibitor - entacapone, tolcapone - COMT
4. dopamine agonist - ropinorole, pramipexole
5. MAO-B inhibitor - selegiline.
If late treatment, try to treat motor symptoms bc effect of levodopa wears off quickly. increase 1/2 life. can use deep brain stimulation or continuous IV if needed
49
what two things does consciousness depend on? (RAS)
1. intact ascending reticular activating system - controls arousal/ wakefulness
2. function cerebral cortex of both hemispheres - awareness
50
low Respiratory rate when patient is in coma is caused by what?
OD/ alcohol/metabolic disturbane
51
high respiratory rate when patient is in coma is caused by what?
hypoxia, hyercapnia, acidosis
52
a fluctuating respiratory rate when patient is in coma is caused by what?
brainstem lesion
53
coma: if there is no meningism or cerebral signs, what sort of causes would you think of?
metabolic/toxins/ epilepsy
54
meningism but no laterising cerebral signs in coma make you think of what?
subarachnoid haemorrhage/meningitis/ encephalitis
Always rule out meningitis!!
55
first and second step of meningitis investigation?
1 - CT head scan
2. lumbar puncture - L4/L5
look for: appearance, cell count, glucose levels, capsular antigen test
56
investigation if there are cerebral signs of a stroke?
```
1. CT/MRI
if not diagnosed from CT/ MRI then:
- metabolic screens
- lumbar puncture (looking for meningitis)
- EEG for epilepsy
```
57
locked in syndrome is total paralysis below the level of which nerve nuclei?
3rd - so paralysis from pons and below
58
how to look for locked in syndrome?
eye movement but NOT horizontally
59
at what score on the GCS do you need to intubate and vent?
GCS > or equal to 8
60
how to treat raised ICP?
- drug?
- head tilted at what angle?
- osmotic agent - mannitol - to stop brainstem herniation
- head angle at 30-45 deg. - to encourage venous return
- mantain PO2 to reduce PCO2
- reduce metabolism (to decrease temp), can also use barbituates
61
features of someone having a non-epileptic attack (pseudoseizure)?
- young
- F>M
- recent stress
- Hx of psychiatric issues
62
diagnosis of someone having a non-epileptic attack (pseudoseizure)?
- sinusoidal tremor, NOT jerking
- pelvic thrusting
- side to side head movements
- eyes closed, resisting opening
63
scale used to tell if stroke or not?
ROSIER scale
-2 -> 5 scale
>0 = stroke
-1 if loss of consciousness or seizure
+1 for weakness of face, arm or leg, or speech problems
64
glasgow coma scale - full?
```
EYES
4 - spontaneous
3 - to speech
2 - to pain
1 - no response
```
```
SPEECH
5 - orientated to time, place, person
4 - confused
3 - innapropriate words
2 - incomprehensible sounds
1 - none
```
```
MOTOR
6 - obeys commands
5 - moves to localised pain
4 - flexes to withdraw from pain
3 - abnormal flexion
2 - abnormal extension
1 - none
```
65
glasgow coma scale -
1. what three things are tested?
2. considered a coma if GCS is __ or less?
3. what is the normal score if healthy?
4. what is the lowest possible score?
1. eye opening, verbal response, motor response
2. 8
3. 15
4. 3
score:
eye opening - 2 or less
verbal response - 2 or less
motor response - 4 or less
66
define stroke
A SUDDEN onset of focal or global neuro symptoms caused by ISCHEMIA or HAEMorrhage, lasting more than 24H
67
A stroke where symptoms relieve within 24 hours is known as what?
Transient ischaemic stroke
- 10% stroke likelihood within 2 weeks following TIA
- treat with antihypertensives, antiplatetets, statins, endartectomy if carotid artery stenosis
68
what is the name for stroke caused by large arteries branching off small arteries?
lipohyalinosis - lacunar stroke
common in brainstem, basal ganglia and subcortical areas
69
what is the best type of drug for treating AF so that risk of ischaemic stroke is minimised
DOAC (direct oral anticoagulant) such as apixiban - less risk of bleeding than anticoag such as warfarin or an antiplatelet such as aspirin
risk of embolic stroke after AF is 5x
70
where is wernickes area and what does it control
speech, temporal lobe
71
A stroke in the anterior cerebral artery would cause weakness in the legs or arm/face?
legs> arms/face
72
A stroke in the middle cerebral artery would cause weakness in the legs or arm/face?
arm/face UMN > leg
73
Injuries to the pyramidal tract above the medulla generally cause weakness in arm/leg on opposite side as CN problem. This is known as what?
Contralateral hemiparesis
74
damage to the optic nerve causes lost vision in one eye, but damage beyon the __ causes vision loss in both eyes
optic chiasm
75
what is:
- PACS
- TACS
- POCS
- LACS
- PACS = partial anterior
- TACS = total anterior
- POCS = posterior
- LACS = lacunar
76
what would a LACS stroke not have using the oxford classification, that other strokes would (think table)
LACS would not have any cortical signs - so no hemianopia ( loss of one half of visual field) , dysphasia (LHS) , neglect (RHS)
- this is because LACS only affects the small perforating arteries, and therefore has no affect on higher function
77
what would POCS have using the oxford classication that no other stroke class does?
brainstem/cerebellar signs
78
what one out of the 3 cortical signs does TACS have to have
hemianopia (loss of visual field in one eye) plus one other out of dysphasia (LHS) or neglect
79
TACS is often due to a stroke in either of which two arteries?
middle cerebral or carotid
80
basilar artery occlusion (type of POCS) causes ischaemia in which area of the brain stem? any clinically identifiable features?
pons
- bilateral but can be asymetrical
- PROGRESSIVE DETERIORATION
81
neglect (one of the 3 cortical signs) in the oxford classification of strokes, is often known as what?
agnosia - cant process sensory information
82
test for stroke (newtons third law) involving pushing one leg down and moving one up is known as?
hoovers sign
83
what letter of the alphabet is associated with common stroke mimics?
S -
Seizures, snycope, sugar, sepsis + previous stroke, severe migraine
84
ischemic and haemorragic stroke, which one: MRI or CT?
MRI for infarct
| CT for heam - shows up blood and is faster
85
What are the criteria for admisinister tPA in ischeamic stroke?
- exclusion criteria too
- use within 4.5 hours of symptom onset
- symptoms need to be present for at least 60 mins
- consent as there is a disabling neurological affect
86
exclusion criteria when thinking about administering tPA in ischaemic stroke?
- if patient is on anything making haemorrhage more likely
- blood on CT
- recent surgery
- recent bleeding
- taking anticoag
- BP over 185 systolic or 110 diastolic
- sugar too high or low - might be a stroke mimic (think of the S's)
87
signs of UMN lesion v LMN lesions?
UMN: hyper
- stiffness
- strong reflex
- postitive baninski - foot extends
- can wrinkle all of forehead
LMN:
- muscle wastage
- lack of reflexes
- fasciltations
- can only wrinkle one side of forehead
88
polyneuropathy, myelopathy and cauda equina: UMN or LMN lesions?
polyneuropathy : LMN. peripheral nerve damage, often from diabetes or alcohol. no urinary incontinence
myelopathy: UMN, spinal cord compression, signs in all four limbs
cauda equina: UMN. herniated disk at lumbar spine
89
where to perform a lumbar puncture?
L3/4
90
the right middle cerebral artery supplies what functions?
left both strength and sensation
91
the left middle cerebral artery supplies what functions?
right body strength, sensation and LANGUAGE
92
the posterior cerebral artery supplies what functions?
The left cerebral artery supplies the right visual field
| right cerebral artery supplies the left visual field
93
most intracranial aneurysms arise from where in the circle of willis?
Branch points
94
cerebellum strokes are supplied by which arteries in the circle of willis?
Superior, anterior inferior and posterior inferior cerebellar arteries
95
what connects the two lateral ventricles to the third ventricle?
Foramina of Munro - also known as interventricular foramina
96
what connects the third ventricle to the 4th?
mesencephalic aqueduct (cebrebral aqueduct of sylvius)
97
the 4th ventricle empties into the subarachnoid space through the median and lateral apertures (foramina), what are their names? - clue - median foramina is a colour)
median aperture: foramen of magendie
| lateral aperture: foramen of luschka
98
what is hydrocephalus?
abnormal accumulation of CSF within ventricles of the brain
99
what is hydrocephalus?
an abnormal accumulation of CSF within the ventricles of the brain
100
types of hypdrocephalus?
Communicating: Defect in CSF reabsorption by the arachnoid granulations.
Obstructive: Block before the arachnoid granulations.
101
Most common cause of hydrocephalus
Aqueduct stenosis - usually seen in infancy
102
what is Dandywalker malformation in hydrocephalus?
atresia of foramina of luschka and magendie.
| signs: small cerebellum, large CSF space in posterior fossa.
103
What are the signs of hydrocephalus?
same signs as increase ICP: papillodema, upgaze, gait changes
104
treatment for hydrocephalus
communicative - lumbar puncture
| obstructive - External ventricular drain or endoscopic third ventriculostomy or ventriculo-peritoneal shunt
105
frontal lobe functions?
precentral gyrus - voluntary control of movement
speech
higher order functions - restraint, initiative, order (RIO)
106
frontal lobe examinations?
- wernickes area by giving three commands
- brocas by testing fluency
- look for decorticate posture and altered behaviour
- UMN pyramidal signs - weakness, hyper, up going
- plantar reflex
- pronator drift
- speech
107
parietal lobe functions
body image representation - primary somatosensory area in postcentral gyrus - think of the formative q when guy didnt recognise himself or his surroundings
visuospatial coordination
numeracy
language
108
parietal lobe examination
tests of the non dominant side -
- hemineglect - lack of awareness of self
- constructional apraxia - cant copy drawing
109
temporal lobe functions
- processing auditory input (heschl gyrus)
- long term memory
- emotion (amygdala)
- visual fields ( myers loop)
110
pneumonic for testing cerebellum problem. (hint - guy in our year)
DANISH P
```
Disdiachokinesia - cant rapidly move muscles eg finger tapping
Ataxia
N
I
S
H
P
```
111
pneumonic for testing cerebellum problem. (hint - guy in our year
DANISH P
Disdiachokinesia - cant rapidly move muscles eg finger tapping
Ataxia - cant coordinate basic muscle movements
Nystagmus
Intention tremor - rhythmic muscle movements during voluntary movement
Slurred speech
Hypotonia
Past pointing
vertigo too
112
gerstmanns syndrome makes you think of a problem in which lobe?
Parietal
gerstmanns syndrome: acalculia, agraphia, right left confusion, finger agnosia
cant do math,s cant draw, forgetting himself
113
ataxia and poor coordination - which part of the brain is the problem?
CEREBELLUM
remember danish P
```
Dydiakochinesa
Ataxia
Nystagmus
Intention tremor
Slurred speech
Hypotonia
Past pointing
Vertigo
```
114
what are the long tract signs seen in myelopathy?
think of LMN signs
clonus, increased tone, proprioception impairment, hoffman sign, upgoing plantar (positive babinski test)
115
what are myelopathy and radiculopathy
MYELOPATHY
spinal cord problems
UMN long tract signs
bilateral
RADICULOPATHY
```
nerve root problem
slipped disk
unilateral
LMN signs
can be localised to specific dermatome
pain in dermatome and weakness in corresponding myotome
```
116
what are the dermatomes for the toe, knee and achiles?
Knee - L3/4
achiles - S1
Big toe - L5
117
symptoms of cauda equina?
```
Bilateral leg pain
numbness around stomach
pins and needles senstion
bladder disturbance
LMN signs
```
118
if there are UMN signs but only problems with the lower limbs not upper, which level of the spinal cord is the problem likely to be in?
Thoracic level, if pain was in upper and lower limbs and there were UMN signs = cervical
119
full GCS scale?
```
EYES
4 - spontaneous
3 - open to speech
2 - open to pain
1 - NR
```
```
SPEECH
5 - orientated to person, place
4 - confused
3 - innapropriate words
2 - incomprehensible sounds
1 - nr
```
```
MOTOR
6 - obeys commands
5 - localised to pain
4 - flexion in response to pain
3 - abnormal flexion
2 - abnormal extension
1 - none
```
120
how much CSF is there in the brain at any one time (in ml)?
how much CSF is produced per day (in cc) ?
150ml
production: 400-450 cc/day
121
what is the blood volume in the brain?
| what is the paranchyme volume in the brain?
blood volume: 150 ml
paranchyme volume: 1400ml
total volume in the brain: 1700 ml
122
Monroe kelly doctrine
CPP = MAP - ICP
123
cerebral blood flow
14% of cardiac output
50ml / 100g / min
or 700ml / min
more in grey matter
124
how much water is in CSF
Normal ICP 5 to 15 cm of water
125
Sustained increase beyond __ of water in the CSF indicates pathological problem
20cm
126
Mean arterial pressure – (MAP) is the ___ pressure plus ___ of the pulse pressure (difference between the systolic and diastolic)
MAP = Diastolic pressure + 1/3rd of pulse pressure
127
What age of patients is cerebral ischaemia common in?
Younger
raised ICP = decreased CPP
128
what things are low density on a CT and what colour do they show up as
Low density = CSF, air, chronic old blood - shows up black
| High density = bone, acte new blood - shows up white
129
Extradural haemorrhage vs subdural -
| what are the differences
EDH
- unlikely in extremes of age
- peels dura off skull
- lense or egg shaped
- from direct impact
- find fracture in squamous temporal bone or middle meningeal artery
- P will have lucid interval and then deterioration
SDH
- common in elderly
- crescent shaped
- not from direct impact, from tearing of bridging veins
