Control - Clinical Flashcards
what is consciousness vs wakefulness
c - awareness, alertness, appropriate responses (thinking feeling etc)
w - activity of reticular activating substance from the brainstem associated with connections between cells and areas of the cerebral cortex
what is coma and how it is measured
eyes not open, no command response, no voluntary movement
not secondary use to paralytic agents
measured using Glasgow coma scale (GCS) - come = lower than 8
what is locked in syndrome
aware awake and breathe
cannot move or speak
damage to ventral pons
can blink, feel pain, autonomic system still works
what is vegetative state vs persistent VS
no evidence of awareness of self or environment
no language
no voluntary moves or expression
PVS - after 30 days not response
50% chance improve
reflex autonomic and sponanteous behaviours yes but not awareness of self or environment
what causes a vegetative state
destruction of cortex and hemispheres but intact ascending reticular activating substance
what is minimal conscious state
severely altered consciousness
reproducible but inconsistent
how do you measure level of disorders of consciousness
SMART - sensory modality assessment and rehabilitation technique
what is brain stem death and how do you test for it
no breathe or conscious, destroy brainstem, no electrical activity
absent brain stem reflexes - persistent apnoea - requires 2 assessments on two occasions
what are the three types of anaesthesia
general - total loss
regional - region or part of body
local - topical, infiltration
what are the three A’s of anaesthesia
amnesia - unconsciousness
analgesia - pain relief
akinesia - paralysis
what is balanced anaesthesia and what is the triad of balanced anaethsisa
smaller doses of a combination of drugs - max benefit and final toxic
unconsciousness , analgesia, muscle relaxation
what does the process of anaesthesia involve
induction, maintenance and reversal of process
describe how you would induce loss of consciousness
and common agents
IV - modulate transmitters gated ion channels acting on PNS/cerebral cortex/ RAS, basal ganglia, cerebellum, motor pathways
thiopentone, ketamine, etomiidate, propofol
how do we maintain loss of consciousness in aneasthtsia
vapour - NO, soflurane, desflurane
uses minimum alveolar consciousness - minimum amount of vapour to prevent reaction to standard surgical stimuli in 50% subjects
what are the problems with being under general anaesthesia for too long
hangover effects, stored in fat cells and releases slowly
amnesia, hypnosis, vasodilation, organ perfusion and hepatotoxicity
what type of agents are used for analgesia in anaesthetic
opioids - short or long acting
fentanyl, morphine, paracetamol
how do you reverse muscle relaxation in anaesthesia
reversal with neostigmine and glycopyrrolate
what is the clinical diagnosis of stroke
sudden onset
focal neurological deficit
of presumed vascular origin
symps last more than 24 hours or leading to death
if symps last less than 24 hours classed as TIA
what are the two types of strokes and how common are they
ischemic (85%) and haemorrhage (15%)
what are the causes and risks of ischamic stroke
thrombosis of large extra cranial arteries
small arteries intracranially
embolism (in the heart or vital arteries)
(most common is large vessel atherosclerosis)
risks - hypertension, obesity, diet, cardiac, diabetes
what are the best treatments for secondary stroke prevention
aspirin, warfarin - anticoagulants and decrease risk of clotting
carotid endarterectomy
drugs to lower BP such as aspirin and clopidogrel
what does FAST mean in stroke
face
arms
speech
time
what is the pathophysiology of stroke
initial reduction in cerebral blood flow - alteration sin cellar chemistry caused by ischemia and cellular necrosis
what are the thresholds of cerebral ischamia
normal is 50 ml/100g/min which can be above 20 ml
10-20 is electrical malfunctions
7.5-10 - release K and water out intracellularly
0-7.5 - cell death
describe the ischeamic penumbra
zone of reversible ischaemia around core or irreversible infarction
overtime from 1 to 30 min the ischamia increase in the penumbra
after a couple jours the ischamia reaches the oligemia where blood flow is reduced but no damage
what is sentrievers used for
halt stroke in time
stent across occlusion to reperfuse the brain
what is the definition of TIA
neurological defect lasting less than 24 ours attributable to cerebral or retinal ischamiea - may or may not have brain damage
what are the causes of TIA
vascular risk factors - arterial disease - cardiac embolism
what types of diseases does TIA mimic
siezures syncope hypoglycaemia migraine acute confusion states
what are the signs of TIA
dysphasia
transit blindness in one eye
ataxia, diplopia, vertigo
what is the scoring system for TIA
ABCD2
age blood pressure clinical features
duration of symptoms
diabetes
what is the treatment of TIA
polypill - statin, aspirin, folic acid
carotid endarectomy
targeting unstable plaque
occluded carotid artery
what are the three layers of the skin
epidermis (top) - stratified squamous, produces keratin - no blood vessels
dermis - fibrous and adipose - blood vessels nerve supply and sensory receptors
subcutis - boots - large blood vessels and supporting fat
ho would you describe the epithelium of the epidermis
keratinised stratified squamous epithelium
what are the 5 layers of thick skin
basal layer - stratum basale prickle cell layer - stratum spinosum granular layer - stratum granulosum stratum lucidum (only in skin of sole) keratin layer (stratum corneum)
what is the stratum lucidum
several layers of flattened dead cells
how do keratinocytes change as they move to the top of the skin
get more mature as they move up and lose nucleus and become flatter
what are three types of cells found in the epidermis
keratinocytes
melanocytes
langerhans cells
what is the function of langerhans cell is n the epidermis
APC’s of the skin
migrate to dermis then lymphatics
irregularly lobulated nuclei
what are the “extras” of the skin and what is their role
sebaceous gland - secrete sebum into hair follicle and surface of skin
hair follicle
eccrine glands - thermoregulation - sweat production
apocrine glands
erector pilli muscle - smooth muscle - contract when cold for thermoregulation
what are the skin differences between the scalp and the foot
foot = no hair, glabourous, dermis thicker, epidermis thicker,
scalp - lots of hair, thin epidermis, no basket weaved keratin
what are the 4 skin receptors
meissners corpuscles - fast adapting discriminatory touch and vibration
merkel - slow adapting discrimantory touch and pressure
pacinian - encapsulated boddie sin deep skin - fast adapting rapid vibration (deepest)
ruffini ending
which layers of skin do you find the sensory receptors merkel cells and meissners corpuscle
merkel cells - intra epidermal receptors of the basal layer
meissners corpuscle - superficial dermis
what are the three degrees of burn
1st - no damage to dermis, superficial burn affecting epidermis
no sensory receptors in epidermis so feel pain
2nd - damage to dermis and epidermis - pain
3rd - full thickness burn - damage to epidermis dermis and subcutaneous tissue - does not hurt as all receptors burnt away
what are the kinds of sensations we feel from the outside vs internal
outside - touch
inside - temperature and pain
what are the 4 main classes of somatosensory receptors
tactile (innocuous) sensations - low threshold mechanoreceptors - merkel, ruffini, meissner, pacinian
proprioception - muscle spindle and joint golgi tendon
thermal sensations - thermorecerptors localised to decree zones
nociceptive - mechanical, thermal and polymodal nociceptors
what are the specific locations of the sensory receptors of the skin
meissners and merkel beneath dermis Meissners between dermal papillae
merkel aligned with pupillage
pacinian located in subcutaneous tissue
ruffians located deep in there dermis
what is the morphology of the 4 skin receptors
meissners - looping axonal terminals that intertwine supporting cells
merkels - dome structure atop axon terminals
pacinain corpuscle - sensory axon surrounded ny fluid (onion)
ruffini - nerve terminals intertwined with collagen fibrils
noicceptors - free nerve endings penetrate epithelial cells
what is the adaption vs receptive field size of the 4 skins receptors
fast adapting - mesissners and pacinian
slow adapting - ruffini / merkels
small receptive field - messiness and merkels
large receptive field ruffians and pacianin
which sensory receptors are used in braille
merkel afferents
describe the 2 point discrimination in different areas of sensitivity
sensitivity is correlated with density of the sensory innervation
areas of high sensitivity - fingertips and face can distinguish between two points very small apart
areas of low - toros and limbs - can’t discriminate two stimuli close
which family of receptors are responsible for thermal
TRP family
what is capsaicin and what receptors does it affect
chemical in the vanilloids cause burning sensation in mouth
act on thermal VR1 receptors also activated by heat
what are the two receptors involved in proprioception
the scull spindle - sensory feedback from muscle fibres on body poison and movement
golgi tendon - regulate muscle tension or force of contraction and prevent muscle eoverlaod
describe the 4 groups of sensory axons from the skin
Aa - largest diameter - proprioceptors of the skin - low threshold mechanoreceptors - rapid conducting
Ab - mechanoreceptors
Ad - pain / temperature - slow conducting
C - temperature, pain, itch
what is the relationship between axon diameter and speed of conduction
larger the diameter than quicker the conduction
which virus affects dermatomes
herpes zoster - chicken pox - primary sensory neurons - inflammation and blistering of skin of affected dorsal root
what is the main role of the two ascending spinal pathways
dorsal column - innocuous sensitivity (not harmful)
spinothalamaic - noxious and thermal sensitivity
where is crossing of the ascending spinal tracts
doral column crosses midline in medulla
spinothalamic crosses midline in the spinal cord
what is the difference in axon fibres in the ascending pathways
dorsal column = Aa/b/d
spinothalamic = Ad/c
what is agnosia
inability to recognise objects despite normal sensory functioning
where is the sensory integration area
posterior parietal cortex
what is astereoagnosia
inability to identify objects on basis of touch alone
damage to posterior parietal cortex
what is neglect syndrome
parietal cortical lesion - part of visual world in ignored
most common to the right hemisphere
describe the schematic representation of somatosensory processing
mechanorerptors - spinal cord - dorsal column in medulla - ventrobasal complex in thalamus - posterior parietal and post central gyrus - limbic system/motor system/ association pathways
what is brown sequared syndrome
hemicord lesion - inflammation of the spinal cord = myelitis
what is wallenburgs syndrome
stroke by occlusion of posterior inferior cerebellar artery
what are the red flags of a headache
cognitive effects, seizes, fever, visual disturbance, vomiting and weight loss
what is raised intracranial pressure due to
mass effect brain swelling increased venous pressure hydrocephalus increased CSF
what are the symptoms of raised intracranial pressure
headache - worse when lying, vomiting, seizures, papilloedema
what is the acute treatment for increased intracranial pressure
broad spectrum IV antibiotics such as cefotaxmie
steroids (dexamethasone)
what is temporal arteritis and treatment
inflammation of temporal arteries
transient loss of vision and tenet temporal artery
high dose steroids - prednisolone
how does a migraine occur
unilateral headache
cortical spreading depression caused by sleeping deprivation, hunger stress and oestrogen - releases chemically active irritants
what medications are used for migraine
naproxen
triptans
paracetamol
what are trigeminal autonomic cephalgia
activation of trigeminal - parasympathetic systems
causes short lasting headaches with unilateral pain
what are the types of headaches associated with trigeminal autonomic cephalgia
cluster headache
paroxysmal hemicranial
SUNCT
what is the management of trigeminal autonomic cephalgia
pain relief - sumatriptan and high flow oxygen
prevention - prednisolone, verapamil
what is a tension headache and its management
constricting high band
relaxation and massage
acupunture
what arse the causes of new daily persistent headache
raised ICP
Low ICP
chronic meningitic
post head injury
what is the definition of chronic daily headache and the causes
headache lasting more than 4 hours more than 15 days a most
de novo via new daily persistent headache
previous episodic headache
what are the categories of epilepsy
generalised or focal
what is the difference between generalised or focal epilepsy
g - whole brain affected with tonic clonic seizure
f - begin in certain part of the brain
what are some causes of symptomatic epilepsy
birth injury, infection, trauma, cavernoma
what disease shows grey matter around the ventricles and is a congenital malformation
perivenricualr nodular dysplasia
what is a cavernoma
blood vessel abnormality - raspberry look, risk of bleeding and seizure
what are the differential diagnosis of seizure
syncope
psychiatric illness
hypoglycaemia
cataplexy or sudden raised ICP
when taking history of epilepsy who do you need to question
witness of the event mainly
what is the difference between vasovagal and cardiac syncope
v - cause = illness or injury, rapid recovery prodrome of warmth light headedness and visual impairment - treat by recognise prodrome and lie down or raise legs
c - older people, vascular risk factors - pacemaker treatment
what is the cause of dissociative seizures
psychiatric cause - brain reacts by shutting down
who is affected most by dissociative seizures and what is the treatment
young females
psychological support
what is used to treat patient after first generalised tonic-clonic convulsion
anti-epileptic drugs (AED)
what is the treatment after first seizure
none
what are some counselling topics when you have epilepsy
management prevention occupational issues bathing driving leisure
what is the most common generalised type of epilepsy and what is it caused by
juvenile myoclonic epilepsy caused by sleep deprivation and stress
give an example of effective AED’s in juvenile myoclonic epilepsy
levetiracetam
what are the difference in side effects of lamotrigine vs topiramate/zonisamide
l - mood stabiliser
T/Z - makes moods worse
15 year old boy has vacant attacks over 3 months with memory loss and auditory hauulicinations - what is the likely cause
medial temporal lobe epilepsy
what is the most common focal epilepsy
medial temporal lobe epilepsy
which AED;s are used for medial temporal lobe epilepsy
lamotrigine and carbamazepine
what is the MRI difference in medial temporal lobe epilepsy vs frontal lobe epilepsy
temporal - high signal and atrophy in left hippocampus
frontal - small area high signal in frontal lobe
what symptoms are frontal lobe epilepsy associated with
tonic-clonic movements and psychiatric presentation
what is lennox gas taut syndrome and its treatment
1-7 y/o
nocturnal, atonic, myoclonic
slow wave ecg
t - sodium valproate, ketogenic diet (hunger = seizure control), vagus nerve stimulator
what are the top 3 neurological conditions
headache stroke epilepsy
what is the definition of epilepsy
abnormally excessive and hypersynchronous activity of neurones located predominantly in the cerebral cortex
what is secondary generalised seizures
partial seizure that later spreads to involve majority of 2 cerebral cortexes
what is status epilepticus
brain is in constant state of seizure - long lasting seizures
what are the two types of partial seizure
simple - when consciousness not impaired
complex - impairment of awareness and responsiveness
describe the montreal procedure
local anaesthetic during surgery - removal brain tissue after cortical stimulation
what is the neuronal mechanism of generalised seizures
thalamocortical circuitry attack and synchronised firing of neurones brain wide - bilateral symmetry
what is the main diagnostic tool in epilepsy
EEG
electroencephalogram
what are causes of seizures
hypoxia, infection, trauma, tumour, congenital abnormalities
what is the type of inheritance pattern of epilepsy
polygenic (not mendelian inheritance)
what are the usual tumours of the CNS in males vs females
male s- glioma
f - meningioma
what is the histological criteria for malignancy in brain tumours
mitotic activity
necrosis - secrete TNF to kill cells
vascular proliferation
what are microscopical features of astrocytic tumours
fine fibrillary and microcystic background
inc cellular density
pleomorphism
what is the difference between diffuse astrocytoma 2 and anapaestic astrocytoma 3
2 - fibrillary, low cellular density, mild atypia, no mitotic activity
3 - mitosis, moderate cellular density + pleomorphism
what are the 3 features of glioblastoma 4
high cellular density and mots is
necrosis and vascular proliferation
what are the features of pilocytic astrocytoma 1
children in cerebellum
pliocyetes
rosenthal fibres
what disease would you see round uniform nucelar cytoplasm and fried egg apparence with calcification of astrocytes
oligodendroglioma
what are three types of glioma
astrocytoma
oligodendroglioma
ependyoma
what are the features of ependyoma
well define tumour of ventricles
pseudo-rosettes
what would be present in a meningioma and who is affected more
women
whorls and psammoma bodies
what is PNET 4 (medulloblastoma) and who does it affect
children - high cellular density
rosette formation
what are three types of nerve sheath tumours
spindle cell tumour
shwannoma 1
neurofibroma 1
what are the presentation, signs and symptoms of intracranial tumours
raised ICP
epilepsy
headaches (morning)
blurred vision
give three examples of intracranial tumour markers
aFP, Bhcg, PSA
what are some investigations into intracranial tumours
fMRI
MRS
cerebral angiography
what are 4 surgical options for intracrhail tumours
stereotactic
neuro-navigation
endoscopic
free hand
which CNS tumour is the hardest to treat
high grade glioma - glioblastoma
which hemisphere is most dominant in language
left hemisphere
where would the lesion likely be in someone who is withdrawn, apethtic and bad tempered vs numbness down one side of body
frontal lobe - personality changes
parietal - sensory loss, dyspraxia
