Neuro Flashcards
Unconsciousness / coma
- Consciousness – state of wakefulness and awareness of self and surroundings
- Coma – unarousable unresponsiveness
Vegetative state
- widespread cortex damage, brainstem function normal
Minimally conscious syndrome
- some sentient behaviour, eg maybe vague pain perception
Locked-in syndrome
- unresponsiveness due to massive brainstem damage, functioning cortex
Brain-stem death
Neurological damage to brainstem resulting in irreversible loss of consciousness and loss of spontaneous ventilation
Pre-conditions for brain-stem death testing
- GCS E1V1M1, mechanically ventilated with apnoea - deep coma
- Proof that patient condition is due to irreversible, structural brain damage
- 2 doctors of sufficient experience to perform testing - one consultant, the other fully qualified with full GMC registration for minimum 6yrs - neither to be member of transplant team (if considered)
- Exclude reversible causes
- No sedation
- Normal electrolytes
- Patient >2mo old
Testing for brain death
- Fixed pupils which do not respond to sharp changes in intensity of light
- No corneal reflex
- Absent oculo-vestibular reflexes - no eye movts in the caloric test - inject >50mls ice-cold water into each ear
- No response to supraorbital pressure
- No cough reflex to bronchial stimulation
- No gag reflex to pharyngeal stimulation
- No spontaneous ventilation effort with apnoea testing
Stroke
- CVA - sudden interruption in vascular supply of brain -> irreversible brain death
Stroke types
Ischaemic
- 85%, thrombo/embolus, also shock, vasculitis
- RFs - age, HTN, smoking, high cholesterol, DM, AF, cOCP, FHx, carotid artery stenosis
Haemorrhagic
- 15%, intracerebral/subarach
- RFs - age, HTN, AV malformation, anticoagulation
Stroke general Px
- Sudden onset, asymmetrical
- Limb weakness
- Facial weakness
- Dysphasia
- Swallowing difficulties
- Visual field defects (homonymous hemianopia)
- Sensory loss
- Ataxia, vertigo (posterior circulation infarct)
- FAST - face, arms, speech, time
Oxford Stroke Classification
Assess for:
- unilateral hemiparesis +/- hemisensory loss of face, arm, leg
- homonymous hemianopia
- higher cognitive dysfunction, eg dysphasia
TACS / PACS / LACS / POCS
Total anterior circulation infarct (TACS)
- ACA and MCA
- All 3 criteria above present
Partial anterior circulation infarct (PACS)
- Smaller arteries of anterior circulation
- 2 of above criteria present
Lacunar syndrome (LACS)
- Arteries around internal capsule, thalamus, basal ganglia
1 of following
- Unilateral weakness +/- sensory deficit of face, arm, leg
- Pure sensory stroke
- Ataxic hemiparesis
Posterior circulation syndrome (POCS)
- Vertebrobasilar arteries
1 of following
- Cerebellar / brainstem syndromes
- Loss of consciousness
- Isolated homonymous hemianopia
Brainstem infarct
- quadriplegia
- locked-in syndrome (basilar artery)
Lateral medullary syndrome (PICA) - Wallenberg
- Ipsilateral - ataxia, nystagmus, dysphagia, facial numbness, CN palsy (Horner’s)
- Contralateral - limb sensory loss
Weber syndrome - branches of PCA that supply midbrain
- Ipsilateral CN3 palsy
- Contralateral weakness of upper + lower limbs
Anterior inferior cerebellar artery (AICA) - lateral pontine syndrome
- Similar to Wallenberg’s (above), but
- Ipsilateral - facial paralysis and deafness
Retinal/ophthalmic artery
- amaurosis fugax
Stroke by areas
ACA
- Contralateral hemiparesis + sensory loss, lower limbs > upper limbs
MCA
- Contralateral hemiparesis + sensory loss, upper > lower
- Contralateral homonymous hemianopia
- Aphasia
PCA
- Contralateral homonymous hemianopia with macular sparing
- Visual agnosia – unable to recognise objects
Stroke Ix
- ROSIER tool
- NIHSS score
- non-contrast CT head - low density areas of ischaemia
- MRI head
- CT / MR angio
- BMs - exclude hypo
- carotid US/CT/MRI
- ECG - AF
Stroke Mx
Aspirin 300mg
- daily for 2wks
Thrombolysis - alteplase (tissue plasminogen activator)
- <4.5hrs onset of sx, unless CI’d
Thrombectomy
- <6hrs (with thrombolysis <4.5hrs) if confirmed occlusion of proximal anterior circulation
- if well 6-24hrs previously + confirmed occlusion of proximal anterior circulation + potential to salvage brain tissue
- (with thrombolysis <4.5hrs) if well 24hrs previously + confirmed occlusion of proximal posterior circulation + potential to salvage brain tissue
Secondary prevention
- clopidogrel
- aspirin + MR dipyridamole
- statin
Carotid endarterectomy
- if stenosis >70%
- consider angioplasty / stenting
Pt with AF
- warfarin / DOAC
- start immediately in TIA
- wait 2wks in acute stroke
Stroke mx of other issues
Fluids
- assess hydration
- oral hydration, IV saline (no dextrose)
Glycaemic control
- monitor BMs - aim for 4-11
- IV insulin / glucose infusions for diabetics
BP Mx
- use anti-HTN if hypertensive emergency
- IV labetalol, nicardipine….
Feeding
- screen for safe swallow
- NG feed
- nasal bridle tube / gastrostomy
- assess meds for NG feed
- nutritional support
Disability
- Barthel index to measure functional decline
TIA
- transient episode of neurological dysfunction caused by focal brain/spinal cord/retinal ischaemia, without acute infarction
- crescendo TIAs - 2+ TIAs in 1wk - high risk of stroke
TIA Px
- Typically resolve in 1hr
- Unilateral weakness / sensory loss
- Aphasia / dysarthria
- Ataxia, vertigo, loss of balance
- Visual problems, amaurosis fugax, diplopia, homonymous hemianopia
TIA Ix
- CT
- MRI, inc diffusion-weighted / blood-sensitive
- Carotid imaging - doppler, CT/MRI