Neuro Flashcards
1
Q
Alzheimers pathophysiology
A
neurofibrillary triangles and amyloid plaque deposits in hippocampus and temporal cortex
reduced acetylcholine production
global progressive impairment of brain function and intellect
2
Q
Alzheimers genetics
A
risk factor- epsilon 4 of apolipoprotein E gene
early onset- APP, PSEN1, PSEN2
3
Q
normal pressure hydrocephalus
A
apathy, inattention
urinary incontinence
gait apraxia
reversible dementia
50-70y/o
4
Q
prion disease presentation
A
myoclonic jerks, seizures
cerebellar ataxia
starts < 50y
rapid onset and progression
5
Q
alzheimer’s management
A
cholinesterase inhibitors for mild-mod disease to improve behaviour and cognition- donepezil, rivastigmine, galantamine
NMDA antagonist memantine for mod-severe
avoid TCAs and anticholinergics
6
Q
types of amyloidosis
A
AL- most common, associated with myeloma
AA- assoc w/ inflammatory arthropathies and IBD
ATTR- auto dom
7
Q
amyloidosis treatment
A
AL- chemo melphalan then stem cell
AA- control underlying condition
8
Q
amyloidosis presentation
A
bruising, SOB, oedema, peripheral neuropathy, autonomic symptoms
AA- kidney, liver, spleen deposits. nephrotic syndrome or renal dysfunction
AL- SOB, weakness, proteinuria, nephrotic syndrome, renal dysfunction, cardiomyopathy, HF
9
Q
amyloidosis poor prognostic factors
A
heart involvement
requirement of dialysis
10
Q
amyloidosis investigation
A
serum immunofixation monoclonal protein
urine immunofixation
Ig free light chain assay raised kappa lambda
bone marrow clonal plasma cells
beta 2 microglobulin
congo red staining
11
Q
kernig sign
A
pain and resistance on passive knee extension with hips flexed
12
Q
brudzinski sign
A
hip flex on bending head forward
13
Q
meningitis predisposing factors
A
influenza A
asplenia
complement deficiencies
14
Q
meningitis most common organisms
A
children > 3 months:
neisseria meningitidis
strep pneumoniae
hib
neonates < 1 month:
strep agalactiae
ecoli
strep pneumoniae
listeria
15
Q
cushings reflex
A
bradycardia
hypertension
irregular respiration
assoc w/ cerebral herniation in meningitis
16
Q
LP results in bacterial meningitis
A
opening pressure > 180
WBC 10-10 000 mostly neutrophils
glucose < 0.4
protein > 0.45
17
Q
abx for meningitis
A
non blanching rash:
benpen ASAP (300/600/1200mg) (<1y/1-9y/>9y)
without non blanching rash:
ceftriaxone or benpen or cefotaxime or chloramphenicol
vanc if foreign travel
ciproflox for prophylaxis for contacts
18
Q
behcet’s presentation
A
recurrent oral ulcers
and at least two of:
genital ulcers
erythema nodosum, acne lesions
uveitis, hypopyon
positive pathergy test (papule/pustule after skin prick)
GI symptoms
DVT, thrombophlebitis
seizures, CN palsies, dizziness, memory problems
19
Q
behcets treatment
A
ulcers:
topical steroids
colchicine, oral steroids, azathioprine
TNF alpha inhibitors
eyes:
pred + azathio
pred + monoclonal ab
GI/CNS:
pred + monoclonal ab
major vasc:
pred + ciclosporin
20
Q
ischaemic stroke cerebral infarction pathophysiology
A
necrotic pathway w/ rapid cytoskeletal breakdown
apoptotic pathway
reduced cerebral blood flow results in death of brain tissue within 4-10 mins
21
Q
left vs right hemisphere stroke symptoms
A
left:
aphasia, R sensory and motor loss, R visual field defects, dysarthria, dyscalculia, dysgraphia
right:
L sensory and motor loss, left gaze disturbance, dysarthria, aphasia, spatial disorientation
22
Q
stroke management
A
thrombolysis with alteplase if presenting within 4.5 hours
aspirin 24h after thrombolysis
thrombectomy if presenting within 6h
load with aspirin if not thrombolysed
2 week follow up:
start clopi or aspirin + dipyrimidole
23
Q
haemorrhagic stroke BP targets
A
rapidly lower BP if within 6h onset and SBP 150-220
rapidly lower BP if beyond 6h onset but SBP > 220
target SBP 130-140
do not offer rapid BP lowering therapy for pt with structural cause, GCS < 6 or planning early neurosurgery
24
Q
when to admit TIA?
A
more than one in a week
ongoing neuro symptoms
severe cardiac stenosis
suspected cardio embolic cause
bleeding disorder or on anticoag
no one at home in case of further symptoms
25
TIA management
300mg aspirin 2/52
stroke doctor within 24h
switch aspirin to clopi 75mg after 2/52
add statin 40mg
stroke clinic within 7 days if TIA happened over a week ago
26
decompressive hemicraniotomy criteria
within 48h ischaemic stroke
clinical deficits suggest MCA territory
reduced consciousness
infarct of at least 50% of MCA territory
infarct volume > 145cm
27
NIHSS scoring
1a level of consciousness (/3)
1b level of consciousness questions (/2)
1c commands (/2)
2 best gaze (/2)
3 visual defects (/3)
4 facial palsy (/3)
5a,b motor arm (/4)
6a,b motor leg (/4)
7 limb ataxia /2
8 sensory /2
9 aphasia
10 dysarthria
11 extinction and inattention
28
ABCD2 score stroke
total score /7
age > 60y
BP > 140/90
diabetes
uni weakness (2)
speech impairment
> 60 mins (2)
10-15 mins (1)
29
botulism toxins
7 neurotoxins
A, B, E cause disease in humans
metalloproteinase
cleaves SNARE proteins at NMJ
30
botulism presentation
symmetrical descending flaccid paralysis
absent deep tendon reflexes
urinary retention, constipation, postural hypotension, dry mouth
normal sensory nerve studies
reduced muscle action potentials
31
botulin antitoxin
human for infants
horse derived heptavalent antitoxin for adults
32
chronic vs episodic cluster headache
clusters > 1y or remission < 1 month
33
cluster prophylaxis
verapamil
topiramate, valproate, lithium second line
34
cerebral mets- most common source
lung
breast
bowel
melanoma
renal cell
35
glioblastoma multiforme
regional heterogeneity within single lesion
highly anaplastic glial cells
vascular proliferation and thrombosis
necrosis
greyish ill defined mass with areas of necrosis and haemorrhage
36
anaplastic astrocytoma
nuclear atypia, diffusely infiltrating astrocytes
no microvascular proliferation or necrosis
round rubbery lobulated mass
firmly attached to dura
white ill defined mass
calcification not uncommon
sometimes whorls and lobules or sheets of spindles
37
presentation of function pituitary tumours
GH excess- acromegaly
ACTH excess- cushings
PRL excess- galactorrhoea
TSH excess (rare)- hyperthyroidism
38
micro vs macroadenoma
micro < 10mm
macro > 10mm
39
commonly used MRI sequences for brain tumours
T1 weighted- CSF low signal (dark)
T2 weighted- CSF high signal (white)
FLAIR for periventricular lesions
STIR
40
stereotactic RTX indications
small target < 3cm
AVM lesions not amenable to clipping or coiling
vestibular schwannoma/acoustic neuroma
mets
41
curative resection is not possible for what types of primary brain tumour?
glioblastoma
anaplastic astrocytoma
42
indications for surgery for pituitary tymours
non functional w/ mass effect
cushings
acromegaly
acute visual deterioration
pituitary apoplexy
43
dementia w/ Lewy bodies
alpha synuclein aggregates in brainstem and cortex
neurotransmitter deficiencies, predominantly cholinergic and dopaminergic
fluctuating levels of arousal
REM sleep disorder
44
treating dementia w/ lewy bodies
cholinesterase inhibitors for cognitive symptoms
dopaminergics for parkinsonism
dopaminergics can worsen confusion and hallucinations
45
parkinsonism
bradykinesia and at least one of:
tremor/rigidity/gait disturbance
46
encephalitis most common causative organism in UK
HSV 1
47
causes of encephalitis (infectious)
HSV, VZV, enterovirus, adenovirus, parechovirus, HIV
TB, listeria, strep pneumoniae, neisseria meningitidis, syphilis
crypto neoformans, toxoplasma, rickettsiae, fungal
48
causes of antibody associated encephalitis
paraneoplastic
non paraneoplastic
hashimotos
49
CSF findings in CNS infections
normal:
opening pressure 10-20
0.45g protein
50-66% glucose
bacterial:
raised opening pressure
100-50000 cells (neutrophils)
1g protein
40% glucose (low)
viral:
normal opening pressure
5-1000 cells (lymphocytes)
0.5-1.0g protein
50-66% glucose (normal)
TB:
high or v high pressure
5-500 cells (lymphocytes)
1-5g protein
glucose 33% (v low)
fungal:
v high opening pressure
0-1000 cells (lymphocytes)
0.5-2g protein
30-50% glucose
50
encephalitis management
IV aciclovir
also IV ben pen to cover for meningitis
add broad spec abx if bacterial encephalitis is suspected
51
neuological manifestations of eosinophilic granulomatosis w/ polyangiitis (churg strauss)
peripheral neuropathy/mononeuritis multiplex
stroke
52
management of epilepsy in pregnancy
5mg folic acid preconception and first 3/12 pregnancy
fetal anomaly scan 19-20 weeks
if on phenytoin, give vit K from 36 weeks (to counteract coagulopathy)
increased clearance of antiepileptics in pregnancy
53
epilepsy predisposing factors
premature birth
head injury
complicated febrile seizures
genetic conditions
FHx
structural abnormalities incl stroke and trauma
infections (TB, malaria, HIV, zika)
metabolic e.g. uraemia
immune mediated (anti NMDA encephalitis, anti LG1 encephalitis)
dementia and neurodegenerative conditions
54
seizure pathophysiology
influx of extracellular calcium and depolarisation neural membrane
> Na channels open
> influx of Na
> repetitive action potential
> hyperpolarisation of GABA receptors/K channels (spike on EEG)
55
eliptogenesis
transformation of normal neuronal network into one that is chronically hyper excitable
56
focal impaired awareness seizure anatomy
medial temporal (mostly hippocampal) focus
57
focal impaired awareness seizure features
impaired or loss of consciousness
aura
automatism
post ictal confusion
58
DVLA and seizures
inform after first episode
stop for 6 months after first seizure with normal EEG
stop for 12 months if abnormal report
can drive if seizure free (and aura free) for one year or if nocturnal only for the past 3 years
for vocational group 1 or group 2 license, needs to be seizure free, not on antiepileptics and no continuing liability for 10 years
59
epilepsy referral to tertiary services
poor control w/ medication within 2y or 2 drugs
60
resolution of epilepsy is defined as?
seizure free for 10 years
no antiepileptic drugs for at least 5y
61
tonic clonic treatment
sodium valproate
carbamazepine
lamotrigine
62
focal seizure treatment
carbamazepine
lamotrigine
63
absence seizure treatment
ethosuxamide
64
management of status epilepticus
pre hospital: 10-20mg PR diazepam or PO midaz and repeat every 15 mins
0-10 mins: IV loraz 0.1mg/kg and repeat once after 10-20 mins
0-160 mins: phenytoin infusion 15-18mg/kg or phosphenytoin infusion or phenobarbital bolus
refractory: GA (propofol/midaz/thiopental) continued for 12-24h after last seizure, then taper
65
management of status in children
5 min: PO 0.5mg/kg midaz or 0.1mg/kg loraz
15 min: 0.1 mg/kg loraz
25 min: phenytoin 20mg/kg infusion or phenobarbital if on regular phenytoin
45 min: RSI thiopental 4mg/kg
66
postural tremor
occurs when limb is raised against gravity
essential tremor
anxiety
alcohol
wilsons disease
67
essential tremor management
propranolol or primidone
deep brain stimulation, radiofrequency thalamotomy
68
friedreich's ataxia
auto rec
GAA repeat expansion of frataxin
most common cause of death is congestive HF and arrhthymias
life expectancy 40-50y
symptoms begin 5-20y
affected areas:
spinocerebellar tracts and dorsal columns in spinal cord
pyramidal tracts in cerebellum and medulla
69
friedreich's ataxia presentation
typically more slowly progressive than other dementias
progressive ataxia
absence of deep tendon reflexes
spasticity
peripheral sensory neuropathy
dysarthria, dysphagia
muscle weakness, progressive kyphoscoliosis
pes cavus, hammer toes
HOCM, fibrosis, CCF, arrhythmias
DM, optic atrophy, hearing loss
70
frontotemporal dementia pathophysiology
1/2: tau (Pick's bodies)
1/2: TDP 43 transactive response DNA binding protein 43
genes: C9orf72, MAPT, GRN
associated w/ progressive supranuclear palsy PSP, corticobasal degeneration CBD, familial MND
71
types/syndromes of frontotemporal dementia
behavioural variant
primary progressive aphasia
semantic
72
semantic dementia
syndrome of frontotemporal dementia
loss of vocabulary and loss of recognition of familiar faces or objects
fluency of speech maintained
73
histoplasmosis risk factor
caving (bat dropping)
74
guillain barre
most have preceding URTI or UTI
campylobacter is most common organism
ascending paralysis
flaccid tone, hypo/areflexia
raised protein in CSF
delayed conduction velocities
> IVIG and plasma exchange
most make full recovery
20% have long term weakness/paraesthesia/fatigue
75
headache urgent referral criteria
new/sudden/severe/unexpected
progressive/persistent
fever
neck pain/stiffness
photophobia
papilloedema
atypical or new onset aura and on COCP
visual disturbance or vomiting unless clearly migraine
contacts with similar symptoms
head trauma within last 3/12
worse on standing or lying down
pregnancy
malignancy history
HIV or immunosuppression
76
Holmes Adie syndrome
holmes adie pupil and absent deep tendon reflexes
absent/slow response to light but normal accommodation
80% unilateral
77
holmes adie syndrome pathophysiology
mostly idiopathic, assoc w/ syphilis, tumours, trauma, post op
damage to ciliary ganglion > interrupted parasympathetic supply to ciliary body and iris
damage to dorsal root ganglion > loss of deep tendon reflexes
78
Ross syndrome
variant of holmes adie
holmes adie pupil, loss of tendon reflexes and hypohidrosis
79
horner syndrome
ptosis + miosis + anhidrosis
interruption of sympathetic pupillomotor fibres
80
causes of horner syndrome
central: anhidrosis of face, arm and trunk
- syringomyelia, MS, encephalitis, brain tumours, lateral medullary syndrome
preganglionic: anhidrosis of face
- cervical rib, thyroid cancer or removal, bronchogenic pancoast tumour, trauma, thoracic aortic aneurysm
post ganglionic: no anhidrosis
- cluster headache, carotid artery dissection or aneurysm, carvenous sinus thrombosis, middle ear infection
81
pupilloconstrictor and pupillodilator pathway
constrictor:
Edinger Westphal nucleus in midbrain > orbit on CNIII
dilator:
1st order from posterior hypothalamus through brainstem to ciliospinal centre of Budge C8-T2
2nd order preganglionic neurones from cord to paravertebral sympathetic chain to superior cervical ganglion
3rd order postganglionic fibres traverse with internal carotid into skull to orbit
82
ptosis is caused by paralysis of...
superior tarsal muscle
83
testing for Horners syndrome
cocaine eye drops > lack of dilatation
apraclonidine hydrochloride beta adrenergic receptor agonist eye drops > affected eye more dilated
hydroxyamphetamine test to differentiate between 1st/2nd/3rd order (dilation occurs in 1st and 2nd order)
84
huntingtons genetics
CAG repeat expansion chromo 4
85
pharmacalogical management of chorea for huntingtons
anti dopaminergics e.g. tetrabenazine
86
medications associated w/ IIH
lithium
cimetidine
tetracycline
tamoxifen
vit A
nitrofurantoin
87
IIH diagnostic criteria
neuro exam normal except cranial nerves (may have 6th nerve palsy horizontal diplopia)
papilloedema
normal neuroimaging CT/MRI
normal CSF composition
opening pressure > 25
87
conditions associated w/ IIH
thyroid, cushings
IDA
chronic renal conditions
lyme
88
management of IIH
weight reduction
acetazolamide
topiramate
steroids for acute severe headache and papilloedema
series of LPs
ventriculoperitoneal shunt for recurrent disease
optic nerve sheath fenestration
89
lambert eaton myaesthenic syndrome
presynaptic autoantibodies to P/Q calcium channels
treat with 3,4 diaminopyridine and/or pyridostigmine, steroids, plasma exchange, IVIG
assoc w/ small cell lung, ovarian, breast, lymphoproliferative ca, T1DM, thyroid disorders
90
migraine prophylaxis
propranolol 80-160mg
topiramate 50-100mg
amitriptyline
botulinum or CGRP agent if refractory to 2 or more prophylactic drugs
91
managing mitochondrial disorders
coenzyme Q
amino acids and vitamins
physical exercise
92
lebers hereditary optic neuropathy
mito disorder
defective complex 1 NADH coQ oxidoreductase
> optic nerve degeneration
93
kearns sayre
mito disorder
degeneration of retinal pigments
> ophthalmoplegia, painful eyes, cardiac conduction defects
defects in ragged red fibres
94
MELAS syndrome
mitochondrial encephalopathy lactic acidosis stroke syndrome
energy deficiency, angiopathy, nitric oxide deficiency
95
MERF
myoclonic epilepsy w/ ragged red fibres
mito disorder
96
maternally inherited deafness and diabetes MIDD
mito disorder
3242 tRNA mutation
defective insulin secretion and cochlear hearing loss age 30-40y
97
pearson syndrome
mito disorder
DNA deletions
sideroblastic anaemia, pancreatic dysfunction
98
leigh syndrome
mito disorder
bilateral symmetric necrotising lesions
spongy changes and microcysts in basal ganlia, thalamus, brainstem, cord
99
mitochondrial neurogastrointestinal encephalopathy MNGIE
pseudo obstruction
TYMP mutation
100
causes of mononeuritis multiplex
diabetes
B12 deficiency
sarcoidosis
vasculitis
RA, SLE
HNPP
lyme, leprosy
101
MND features
asymmetrical UMN and LMN
muscle weakness, wasting , fasciculation brisk reflexes, spasticity
ALS- bulbar, arm and leg UMN and LMN signs. upper limb > lower limb.
PBP- facial weakness, dysphagia, progressive dysarthria, upper and lower limb weakness, emotional lability
PMA- LMN only, poor prognosis
PLS- progressive spastic weakness arms and legs, spastic dysarthria, sensation intact. aggressive course
102
causes of MND
infections (polio, tetanus, lyme)
lead
paraneoplastic
plasma cell dyscrasia
metabolic conditions
hyperlipidaemia
genetic
103
MND treatment
positive pressure ventilation
riluzole (bone marrow suppression and deranged LFTs)
104
Kennedy disease
X linked spinobulbar muscular atrophy
CAG expansion
LMN
progressive weakness and wasting, no spasticity
slight sensory neuropathy
assoc w/ gynaecomastia and reduced fertility
105
MS risk factors
HLA DRB1
EBV
vit D deficiency
smoking
relapses- stress, post partum, infection
106
MS 4 key areas of demyelination
periventricular
cortical/juxtacortical
infratentorial
spinal cord
107
Kurtzke Disability Status Score
used to monitor MS disease status
0- no signs/symptoms
10- death
108
primary and secondary progressive MS treatment
primary- ocrelizumab
secondary- siponimod
109
MS drugs safe in pregnancy
interferon
glatiramer acetate
natalizumab
glucocorticoids or plasma exchange for acute episodes during pregnancy
110
muscular dystrophy genetics
auto rec- some limb girdle
auto dom- myotonic dystrophy, fascioscapulohumeral, oculopharyngeal, some limb girdle
X linked- duchenne, becker, emery dreifuss
111
emery dreifuss MD
uncommon x linked muscular dystrophy
presents in teenage years
contractures and cardiomyopathy
death from first degree AV block
112
muscular dystrophy pathophysiology
Duchenne and Becker- dystrophin gene mutation (Xp21) > leakage of creatine phosphokinase CPK
other types- mutation of dystrophin associated glycoprotein complexed
113
muscular dystrophy medication
steroids, creatine
ataluren for DMD above 5y who can still walk
ACEi, beta blockers
114
myaesthenia gravis pathophysiology
90% cases nicotinic acetylcholine receptor
10% cases muscle specific tyrosine kinase MuSK
75% associated w/ thymus abnormalities
HLA B8, HLA DR3
HLA DR1 (ocular)
115
myaesthenia gravid presentation
ophthalmoplegia (ptosis, diplopia, weakness of eyelid closure)
muscle weakness (esp shoulder)
myaesthenic snarl
dysarthria, dysphagia, dysphonia (fatiguable)
breathing difficulty
116
most common CNS infections in advanced HIV
toxoplasmosis
cryptococcal meningitis, TB meningitis
PML (JC virus)
CMV encephalitis
neurosyphilis
CMV retinitis
117
features of cryptococcal and TB meningitis
cryptococcal- subacute over 1-2 weeks, often also disorientation and confusion
TB- subacute over several weeks, also constitutional symptoms
118
secondary causes of normal pressure hydrocephalus
intraventricular or subarach haemorrhage
meningitis
Paget
achondroplasia
119
features of normal pressure hydrocephalus
gait disturbance
urinary frequency/urgency/incontinence
cognitive impairment
UMN in lower extremities
120
predictors of improvement after shunting for normal pressure hydrocephalus
good- gait disorder as most prominent symptom, shorter duration of symptoms, clinical response from CSF removal
unfavourable- dementia early appearance, no gait disorder or appearing after dementia, alcoholism, marked white matter disease on MRI
121
features of parkinsons plus syndromes
reduced response to Ldopa
dysarthria
autonomic dysfunction
supranuclear gaze palsy
122
parkinsons plus syndromes
multiple system dystrophy
dementia w/ lewy bodies
progressive supranuclear palsy
corticobasal degeneration
123
medications causing parkinsonism
antipsychotics
metoclopramide
prochlorperazine
tetrabenazine
sodium valproate
lithium
124
adverse effects of ergot derived dopamine agonists e.g. cabergoline, pergolide
cardiac fibrosis
125
parkinsons drug treatment
- Ldopa + decarboxylase inhibitor
- dopamine agonist (pramipexole, ropinirole, rotigotine)
adjuvants:
- MAOBi
- COMTi- for people who have developed dyskinesia or motor fluctuations
- amantadine (dyskinesia)
- SC apomorphine- advanced disease
126
features of corticobasal degeneration
starts on one side of body then becomes bilateral
parkinsons symptoms + behavioural and cognitive changes
127
phenytoin toxicity
ataxia, nystagmus, dysarthria, confusion, impaired coordination, seizures, hypoglycaemia
hypotension, bradycardia, asystole
can > DRESS, TEN, SJS
no antidote
128
drugs causing polyneuropathies
isoniazid- subacute
pyridoxine- sensory
chemo- may start after stopping CTx
lead- may be acute, motor
129
CJD histopathology findings
vacuolar degeneration
130
CJD investigations
EEG: periodic sharp wave complexes in sporadic CJD
LP: high levels of proteins 14-3-3 and S100B
MRI: hyperintense signal change in basal ganglia and cortex
tissue diagnosis: gold standard but high morbidity and mortality
EEG and LP less sensitive in variant CJD (mad cow)
131
SAH ECG changes
QT prolongation
Q waves
dysrhthymias
ST elevation
132
SAH management
0.9% NaCl to prevent hyponatraemia
3L or more per day to keep intravascular compartment filled
inotropes or vasopressors to prevent vasospasm and ischaemia
antihypertensives to keep SBP < 180
surgery- clipping, coiling, clot evacuation
LP or ventricular drainage of hydrocephalus
133
SAH most common cause
trauma then aneurysm
134
ct within 1h head inury
GCS <13
GCS < 15 at 2h
suspected open/depressed skull #
signs of basal skull #
focal neuro deficit
post trauma seizure
> 1 vomit
children:
LOC > 5 mins
drowsiness
3 or more vomits
dangerous mechanism
amnesia > 5 mins
children < 1y w/ bruising, swelling or lacerations > 5cm on head
CT within 8 hours if no risk factors but on anticoagulants
135
subdural haematoma on imagine
acute and chronic will be seen on non contrast CT
subacute need MRI or CT with contrast
136
early vs late syphilis
early:
< 2y post infection
primary, secondary, early latent
late:
> 2y post infection
late latent (confirmed infection in absence of current clinical features), tertiary
137
syphilis treatment
early:
- procaine penicillin 750mg IM OD for 10 days
- ben penicillin 2.4mg IM for 1-2 doses 1 week apart
- PO azithromycin if pen allergic or doxy 14/7
late:
- ben pen IM 3 doses week apart
- amox PO + probenecid 500mg QDS 28 days
- doxy if pen allergic
138
causes of trigeminal neuralgia
90% caused by vascular compression of trigeminal n
MS
AV malformations
tumours
skill base abnormalities
139
coma anatomy
interruption of ascending reticular activating system in midbrain and pons projecting to thalamus and cortex
causes:
- damage to reticular activating system at level of midbrain
- destruction to large surface of both cerebral hemispheres
- suppression of reticulocerebral functions by drugs/toxins/metabolic disturbances
140
brainstem reflexes and localising lesions
pupils normal- above thalamus and below pons
pupils pinpoint- opioid or pontine lesion
fixed midpoint pupils- midbrain
dilated pupils- CN3 or midbrain, sympathomimetics
141
ocular movements and localising causes of coma
roving eye/conjugate lateral nystagmus- intact brainstem. metabolic or bilateral hemisphere damage
skew deviaion- posterior fossa
oculocephalic dolls eye reflex- cerebral hemisphere
corneal reflex- eyelids will close if pons is intact. upward movement and eyelid closure if pons and midbrain are intact
142
breathing patterns and localising coma
cheyne stoke- most common
deep breathing- acidosis
yawning or hiccups- brainstem
regular shallow- OD
143
brain death
brainstem reflexes, motor responses, resp drive are absent
irreversible widespread brain lesion of known cause with satisfactory oxygenation, temp, no hypercapnia or sedation
144
causes of central and peripheral visual field loss
central:
ARMD, macular holes
optic neuropathy
lebers optic atrophy
retinal a occlusion
peripheral:
glaucoma
retinal detachment
retinitis pigmentosa
chorioretinitis
branch of retinal a occlusion
145
optic chiasm lesions
before chiasm:
ipsilateral defect
central, asymmetrical, unilateral
e.g. optic neuritis, optic atrophy, glaucoma, trauma
can also cause small defect in upper temporal field of other eye
at chiasm:
bitemporal hemianopia
pituitary tumour worse in upper field
craniopharyngioma worse in lower field
after chiasm:
homonymous defect
main optic radiation > complete homo hemi w/ macular sparing (e.g. stroke, MCA)
temporal radiation > upper quad homo hemi
parietal radiation > inferior quad homo hemi
anterior visual cortex- contra homo hemi w/ macula sparing (e.g. posterior cerebral a)
macular cortex > homo macular defect
146
wernickes pathophysiology
petechial haemorrhages in mammillary bodies
147
Wilsons disease
auto rec
ATP7B mutation
high levels of free copper (impaired binding and impaired excretion into bile)
reduced caeruloplasmin, increased urine copper
> fibrosis
children present more with liver disease
adults present more with neuro and eye signs
148
