control term two (1) Flashcards
how many vertebrae are there?
7 cervical 12 thoracic 5 lumbar 5 sacral (fused) 1 coccygeal (made of 4 fused segments)
30 total
(33 if include different segments of coccyx)
how many spinal cord segments are there?
31 (one more than no. vertebrae
8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
what doe each spinal cord segment give rise to?
a PAIR of spinal nerves
how are the spinal nerves named?
cervical region: spinal nerve goes ABOVE vertebrae (ie C1 is above c1 vertebrae)
below cervical region: spinal nerve goes BELOW vertebrae (ie T1 is below T1 vertebrae)
what spinal nerve comes out above T1 vertebrae
C8
where are the 2 enlargements of the spinal cord?
cervical enlargement
lumbosacral enlargement
what is the most inferior tip of the spinal cord called? and at what vertebral level does it occur?
conus medullaris (medullary cone)
vertebrae L2
what is the structure that connects the end of the spinal cord to the coccyx?
filum terminale
extension of pia matter
what are the 2 differences between the meninges that surround the spinal cord and the ones that surround the brain?
surrounding spinal cord: only ONE layer of dura matter (brain has 2)
- spinal dura is a continuation of the meningeal layer (layer closest to brain/spinal cord)
spinal cord has denticulate ligaments (brain doesn’t)
what are denticulate ligaments?
little extensions of PIA matter which extend laterally, anchoring spinal cord to vertebral column
- prevent spinal cord rotating within vertebral column
- have about 21/22 of them down length of cord
how does the CSF from the brain enter the subarachnoid space surrounding the spinal cord?
by leaving the ventricular system via the lateral and median apetures
what are the 2 layers of dura matter that surround the brain? which is closest to the brain? where do they go when the brain –> spinal cord?
meningeal layer
- closest to brain
- surrounds spinal cord
periosteal layer
- closest to skull
- fold around onto superficial surface of skull
nb also have periosteal dura surrounding vertebrae
what is the potential space between the arachnoid matter and the dura matter?
subdural space
where is the epidural space?
outside (superficial to) the dura
aka extradural space
where is anaesthetic injected into for a spinal block?
subarachnoid space
what are the nerves which fill the vertebral column called inferior to the end of the spinal cord? at what levels of vertebrae do these arise?
cauda equine
“horses tail”
L2-S2
what is the area in the vertebral column called inferior to the spinal cord (from L2 down)?
what 3 things are found in this space?
lumbar cistern
- CSF
- Filum terminale
- cauda equina
what is a lumbar puncture? and where is it performed?
collection of CSF (via a needle) for testing
lumbar cisterne
so no risk of puncturing spinal cord
why does the spinal cord not terminate at the coccyx?
itdid, in the foetus, but then the foetal vertebral column grows faster than the spinal cord and so it looks like spinal cord has shrunk
describe the blood supply of the spinal cord
the 2 vertebral arteries each give off a branch anteriorly which combine to form ONE ANTERIOR SPINAL ARTERY, they both also give of a branch posteriorly, TWO POSTERIOR SPINAL ARTERIES
these arteries are supported by SEGMENTAL MEDULARY and RADICULAR arteries along length of cord
what 4 sections of white matter are in the spinal cord?
- dorsal white column
- lateral white column
- ventral white column
- ventral white commissure
what 4 sections of grey matter are in the spinal cord?
- dorsal grey horn
- lateral grey horn (only sometimes!!)
- ventral grey horn
- dorsal grey commissure
what type of fibres do dorsal + ventral roots tend to carry?
dorsal - sensory
ventral - motor
where do you get lateral grey horns? why here?
T1-L2
S2-S4
the lateral grey horn is full of AUTONOMIC cell bodies so you get them where there is a lot of autonomic viscera (ie in thorax and pelvis)
what are the 3 types of nerve in a mixed spinal nerve? and where are their cell bodies? and where do they synapse?
somatic and visceral sensory
- cell bodies: dorsal root ganglion
- synapse: dorsal grey horn
somatic motor
- cell bodies and synapse: ventral grey horn
visceral motor
- cell bodies and synapse: lateral grey horn
as each mixed spinal nerve leaves the vertebral canal it takes with it the meningeal layers, what structure do these meningeal layers go on to form?
epineurium
“Epineurium, ie on top of neurons”
a protective outer sheath of connective tissue
what specific part of the spinal cord enlarges are the cervical and lumbosacral enlargements?
ventral grey horms
- as lots of motor fibres to limbs needed
does white matter increase or decrease as cord descends?
white matter INCREASES as cord descends
what are the 2 dorsal white matter columns on each side of the midline called? and what happens to them as you go down the spinal cord?
gracile fascicle (medially) - starts small but grows until it takes up the entire dorsal white matter column INFERIOR TO T6
cuneate fascicle (laterally) - starts large but shrinks as you go down, disappears at level of T6 vertebrae
what are the 4 main fibre tracts in the spinal cord? and which are ipsilateral and which are contralateral?
dorsal column (ipsilateral)
lateral corticospinal tract (ipsilateral)
ventral corticospinal tract(contralateral)
spinothalamic tract (contralateral)
“tracts on DORSal part of cord are IPSIlateral, ones on ventral side are contralateral - remember DORSI = IPSI”
what’s the difference between a stroke and a TIA?
symptoms last MORE than 24hours = stroke
symptoms last LESS than 24 hours = TIA
how can you differentiate between a ischaemic and haemmorhagic stroke on a CT scan?
infarction = dark (area of low density oedema)
bleed = white (area of high density ‘fresh’ blood)
nb after a while post-stroke a bleed will go darker and look like a infarct. Also you may see small strip of white in infarct (which is the actual clot)
during a stroke, what is the penumbra?
an area of brain tissue (outside the core, where there is irreversible cell damage) where electrical function is impaired, due to low/no perfusion, but the cells have not yet died and may restore function if repurfusion occurs
what compensatory processes occur when there is an infarct in the brain?
smaller (high resistance) vessels dilate to allow for greater perfusion
when these can dilate no more: body increases oxygen extraction from blood
only when these 2 methods have been exhausted will patients get stroke symptoms
suggest some immediate treatments which can be given to patients who’ve suffered an ischaemic stroke
- aspirin (and/or clopidogrel)
- BP lowering
- statins
- thrombolytic drugs (but see guidlines as lots of exclusions)
- warfarin (only if caused by AF)
consider surgery (removing clot by open surgery or using a stent), depending on location of clot
what is carotid endarterectomy`
surgery to unblock a carotid artery
what does aphasia mean?
inability (or impaired ability) to understand or produce speech
what does aphagia mean?
inability (or refusal) to swallow
describe the process of clot removal, using stents
go through artery in leg to affected arterty
place stent across occlusion: leave in position for 10 mins
repurfuse brain
‘relax’ and plan stratergy
most clots will lyse naturally or improves efficacy of IV tPA (IV thrombolytics)
withdraw stent (carefully to avoid bit breaking off and embolysing) with smaller clot ‘core’
are TIAs normally ischaemic or haemorhagic?
almost always ischaemic
name 5 conditions which may be mistaken for a TIA
- seizures
- syncope
- hypoglycaemia
- migraine
- acute confusional states (eg delerium)
what is todd’s paresis?
todd’s paresis is a focal weakness in a part of the body after a seizure (normally epileptic). This weakness typically affects appendages and is localized to either the left or right side of the body. It usually subsides completely within 48 hours. Todd’s paresis may also affect speech, eye position (gaze), or vision.
what signs/symptoms are typically seen in patients with clots in their anterior circulation (ie internal carotid arteries)?
- dysphasia/receptive aphasia
- amarausis fugax
= temporary painful loss of vision in one, or both, eyes
(patients describe like a shutter going down over eyes)
what are the two types of dysphasia? damage to which brain areas causes which? what is the difference between them?
expressive aphasia - broca’s area (trouble finding words to say!)
- reading/writing/comprehension relatively intact
receptive aphasia - wernicke’s area (get words out but is all gobblydeygoop, they don’t realise they don’t make sense!)
- reading/writing/comprehension impaired
what signs/symptoms are typically seen in patients with clots in their posterior circulation (ie vertebral arteries)?
ataxia (poor coordination)
diplopia (double vision)
vertigo
bilateral symptoms
what signs/symptoms can be seen in patients with clots in either their anterior or posterior circulation?
- visual field disturbances
- hemiparesis
- hemisensory loss
what is hemianopia?
blindness over half field of vision
nb NOT blind in one eye!!
what is the ABCD2 score used to assess? and what does it stand for?
assess someone’s likelihood of getting a stroke after having a TIA (NOT used for diagnosis of stroke or TIA)
A = age B = BP C = clinical features D = duration symptoms D = diabetes
on a CT scan, what is a wedged shape area of hypodensity on the right lateral side of the brain indicative of?
an infarct in the right middle cerebral artery
“remember the MCA does NOT supply the ‘middle’ (medial aspects) of the cerebrum, the ACA does that”
what is dysarthria?
Dysarthria often is characterized by slurred or slow speech that can be difficult to understand
due to weakness + incoordination of oropharyngeal muscles
- NOT aphasia!!
where is wernickes area?
posterior section of the superior temporal gyrus
“on the V shaped junction where the temporal lobe is separated from rest of brain by the lateral fissure”
nb this is in the LEFT hemisphere for 95% of right handed people, but only 60% of left-handed people (so in 40% of lefties, it’s on right)
where is broca’s area?
infero-lateral frontal lobe
nb on LEFT side for majority of right handed people but can be on right side for left handed people
blood pressure rises acutely after a stroke (may settle within a few days), however antihypertensive treatment is NOT recommended, unless… (4)
- intracerebral haemorrhage with systolic BP>200
- hypertensive encephalopathy/neuropathycardiomyopathy
- aortic dissection
- eclampsia/preeclampsia (in pregnancy)
what should goals for rehabilitation be?
SMART
Specific Measurable Achievable Relevant Time-limited
when should stroke rehabilitation begin?
in hospital, basically ASAP!
what type of pneumonia do stroke patients normally get? why?
right basal pneumonia
because they aspirate on food (due to lack/poor swallowing ability)
due to layout/angle of bronci, aspiration food norm goes to right lower lobe
(nb NG tube is not completely protective against aspiration and families occasionally feed patients against advice!)
how do you assess the swallowing ability of a patient?
- position patient correctly
- ensure they are alert
1) give single teaspoon of water
2) give 2 further teaspoons of water
3) give 50ml of water
do they do any of these things: - drooling from mouth? - coughing or choking? - wet voice or cough? if YES, don't progress to next stage, keep NIL BY MOUTH + refer to speech and language therapist
nb if still unsafe after 6 weeks: consider gastrostomy tube
what are the risk factors for pressure ulcers? 6
- immobility
- malnutrition
- diabetes
- smoking
- terminal illness
- sensory impairment (as less able to feel pain of growing sore)
what 3 factors result in pressure sores developing?
- sustained pressure (often over bony priominence)
- friction (+ shear forces when moving patient)
- moisture (dt incontinence, sweating)
what’s the difference between shoulder subluxation and dislocation?
dislocation is when the head of the humerus comes fully out of the glenoid fossa, subluxation is when it shifts out of it’s proper position (normally due to damage/weakness of rotator cuff muscles) but is still in the glenoid fossa
why are stroke patients susceptible to shoulder subluxation? 2
how is it treated?
- weakness of rotator cuff muscles on stroke side
- neglect of affected limb (in right-sided stroke only)
management: optimise positioning, support shoulder
what are other possible causes of shoulder pain in stroke patients (apart from shoulder subluxation)? 3
how do you rule these out?
- tear of rotator cuff muscles
- capsulitis
- tendonitis
exclude by ultrasound scan
what musculoskeletal problems may be unmasked or exacerbated when someone has a stroke? 3
why is this?
- chronic back pain
- osteoarthritis
- RA
because patients may compensate for weakness on affected side by increased use of unaffected side, putting excess pressure on bones/joints
what are the negative (1) and positive (2) phenomena which can be part of post stroke pain?
why does this occur?
negative:
- decreased sensation (numbness)
positive:
- paraesthesia, burning, shooting pains
- dysaesthesia: altered perception (eg soft touch felts as prickly pain)
because of damage to contralateral primary sensory cortex (during the stroke) leads to sensory disturbances
post-stroke pain doesn’t normally respond to normal analgesics (paracetamol, NSAIDs, opiates), what drugs may be used instead? 3
pregabalin or gabapentin (anti-epileptic agents)
amitriptyline (type of antidepressant)
give 3 examples of medical problems which can cause incontinence when a patient is also disabled by a stroke
diabetes mellitus (polyuria)
UTIs
prostatic hypertrophy
what % of people who have had a stroke experience depression?
50%
name 5 reasons why patients may develop depression after a stroke?
- changing relationship with partner/family
- medical condition (concern for future)
- COMMUNICATION (unable to express self)
- worry about financial problems (how pay for care)
- adjustment to disability (+ being dependent on others)
what 2 things is rehabilitation a balance between?
- restoration of function
- adaption to disability
what are the 2 things that the brain naturally does in the first few days post stroke which aid recovery?
- resolution of oedema
- repurfusion of ischaemic penumbra
what part of the visual field does the left cerebral hemisphere process?
RIGHT HALF of visual field
nb NOT all info from right EYE
what is neglect?
a stroke in which area of the brain leads to neglect?
problem of ATTENTION: failure to attend to/monitor LEFT side
may be visual and/or somatosensory
(NOT explainable by visual field defect or loss of sensation - may be confused with visual field defect!)
caused by stroke in RIGHT PARIETAL LOBE
what is agnosia?
o Modality-specific inability to access sematic knowledge of an object (or other stimulus)
- (ie inability to process sensory info)
Can apply to any sensory modality
Not attributable to sensory impairment alone
Eg visual agnosia
= Unable to recognise common object by sight alone. May be able to do so when allowed to use other modalities, eg touch
what is it called when someone is unable to recognise specific human faces?
prosopoAGNOSIA
a type of visual agnosia
after a stroke, what are the 4 symptoms which would mean someone would be absolutely barred from driving (unless they resolve)?
- seizure within past year
- visual neglect
- visual field defect
- cognitive impairment
nb absolute 1 month driving ban post stroke
whose responsibility is it to report to the DVLA if a person cannot drive for medical reasons?
the patients
but if they refuse to, dr may breach confidentiality and inform DVLA without patient’s consent
what is dyspraxia?
what anatomical lesions may cause this?
loss of ability to conceptialise, plan + execute complex sequence of motor actions
(not explainable by weakness or lack of comprehension of the task)
caused by loss of cortical pathways for initiating + performing skilled actions
anatomical lesions may include:
- left inferior parietal lobe
- supplementary motor area
describe a spastic hemiparetic gait
stiff legged
- spasticity of ankle plantar flexors and knee flexors
short, slow steps
unsteady, risk of falls
- ankle weak, unable to dorsiflex: even on uneven surfaces
- loss of ‘righting reflexes’
how do you manage a spastic hemiparetic gait? 4
splints to correct foot drop
physiotherapy
manage spasticity
walking aides
what is the management of spasticity more generally?
physiotherapy + splinting of joint to maintain range of movement
drugs:
- botulinum toxin injections (local)
- baclofen (systemic)
what differences can you see between T1 and T2 MRI scans?
T1
- fluid = dark
- fat = white
(therefore white matter (high in myelin fat) is white + grey matter is grey)
T2
- fluid = white
- fat = dark
(white matter = grey, grey matter = white)