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Flashcards in Neuro Deck (33)
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1

Define conciousness

Consciousness: Wakefulness and awareness
Assessment relies on physical responses at the bedside

2

Define minimally conscious state
Legal aspects?

-May move finger
-Continual (>4weeks) versus permanent (years)
-Could get better
Official solicitor protects people with minimal consciousness

3

Define persistent vegetative state

Some weeks/months after initial injury
Unawareness of self
Awake but not aware
May open eyes, can breathe and heart will pump
Will not respond to commands, loved ones
Permanent>6 months

4

Define coma

Not awake and not aware
Eyes are closed
No response to environment, voices or pain

5

Brainstem involvement in consciousness?

• Survival functions
• Contains ascending reticular activating system (RAS)
• Determines how awake people are, necessary for consciousness

6

Define locked in syndrome

Patient fully awake and alert but cannot move or speak
Can mimic loss of consciousness
Ocular muscle usually spared (communicate by blinking)
After basilar artery occlusion/pontine injury/ALS/MS

7

Name 2 confounders of the Glasgow Coma Scale

Spinal cord injury
Deafness

8

When are pupils small and reactive?

Opioid use

9

When are pupils small and unreactive?

Pontine haemorrhage

10

When are pupils unreactive

Atropine

11

When are pupils unreactive and dilated?

Brainstem herniation
Seizures

12

Definition of a stroke

Sudden onset loss of CNS functioning lasting >24 hrs due to a vascular cause
Cause of 1/10 deaths in UK

13

Causes of stroke

• 85% ischaemic
• 15% haemorrhagic

14

Causes of ischaemic stroke (12)

• Atherothrombosis: 50%, large vessel atheroma causing local narrowing and distal thromboembolism, usually aortic arch, carotid bifurcation, vertebral artery
• Small vessel disease: 20-25%, lipohyalinosis and fibrinoid degeneration of small intracranial vessels, hypertension. Causes small lacunar infarcts of internal capsule
• Cardioembolic: 20-25%, emboli secondary to arrhythmia (AF), valvular disease (replacements, vegetations), poor LV function, post MI. Usually left side of heart-> intracranial vessels unless septal defect, then from DVTs
• Arterial dissection (may present with neck pain and Horner’s syndrome)
• Hypotension-> watershed infarct after cardiac arrest
• Vasculitis
• Hypercoagulability: Antiphospholipid syndrome, malignancy
• Genetic disorders: mitochondrial, homocysteinuria, CT disorders, sickle cell
• Illicit drugs (cocaine)
• Secondary to CNS infection (syphilis, HIV)
• Trauma to neck vessels
• Secondary to venous sinus thrombosis

15

4 types of intracranial haemorrhage

• Intracerebral
• Subarachnoid
• Subdural
• Extradural

16

Causes of intracerebral haemorrhage

• Hypertension
• Amyloid angiopathy
• Trauma
• Bleeding disorders
• Illicit drugs (cocaine, amphetamines)
• Vascular malformations

17

Definition of SAH

Subarachnoid haemorrhage
Blood between arachnoid and pia mater
Most often occurs after trauma
If not trauma, usually a spontaneous haemorrhage due to a vascular anomaly

18

Symptoms of SAH

• Vary from delayed presentation of low-grade headache to coma or sudden death
• Headache (sudden, thunder clap, worst headache ever, occipital
• Nausea and vomiting
• Meningism (neck stiffness, photophobia)
• Seizure and transient loss of consciousness

19

Management of SAH

• Assess GCS and look for focal deficits
• Plain CT scan (93% sensitivity 24 hrs, 50% at 1 week)
• If –ve but high clinical suspicion-> LP 12 hrs after onset of symptoms (4 bottles for red cell count, glucose, spectrophotometry and cell counts again)
• CT angiogram/catheter angiography to find vascular anomaly

20

Treatment of SAH

• Resuscitation, airway protection if GCS<8
• Analgesia and anti-emetics
• IV hydration to maintain cerebral blood flow and avoid ischaemia
• NIMODIPINE 50mg 4hrly for 21 days from onset of symptoms
• BP control (hypertension-> rebleed, hypotension-> ischaemia)
• VTE prophylaxis
• Neuro obs
• Hydrocephalus treatment (shunt?, head up)
• Aneurysm? Embolisation via coiling or craniotomy and clipping

21

3 main complications of SAH

• Vasospasm (leads to delayed ischaemic neurological deifcits)
• Hydropcephalus (communicating/obstructive, may require LP or shunt)
• Hyponatraemia (cerebral salt wasting and SIADH, risk of seizures)

22

Factors associated with aneurysm rupture

• Previous rupture of same aneurysm (30% rebleed within 1 month)
• Previous rupture of a contemporaneous aneurysm
• Size
• Posterior circulation
• Smoking
• Evidence of growth/compression (IIIrd nerve palsy)

23

Describe subdural haemorrhage

• Collection of blood in the potential space between dura and arachnoid mater
• Seen in extremes of age, esp after trauma (eg falls in the elderly)
• May present with cerebral contusions and depressed GCS
• Due to stretching and tearing of the bridging veins as they cross to drain into a dural sinus when shearing force is applied
• Crescent shaped

24

Describe extradural haemorrhage

• Collection of blood between the inner surface of the skull and the outer layer of dura
• Commonly associated with trauma and associated skull fracture, seen in the young. On-going severe headache, gradually lose consciousness over next few hours.
• Usually the bleeding is associated with a torn middle meningeal artery
• Lens/lemon shaped
• Can cause midline shift/herniation

25

Describe clinical presentation of TACI and PACI

• TACI = total so all 3, PACI is partial to 2/3

• Contralateral hemiparesis (relative leg sparing) and/or hemisensory loss
• Contralateral homonymous hemianopia
• Dysphasia (if dominant hemisphere, receptive W if more posterior, expressive B if more anterior) or sensory neglect and apraxia (non-dominant hemisphere, gaze towards side of lesion)

26

Describe clinical presentation of POCI

Posterior circulation infarct
• Vertebrobasilar territory
• Ipsilateral cerebellar signs (cerebellum)
• Contralateral homonymous hemianopia (occipital lobe)
• Diplopia, quadrantparesis, cerebellar features, crossed sensory symptoms, Horner’s syndrome (brainstem)

27

LACI clinical presentation

Lacunar, internal capsule
Complete contralateral hemiparesis and/or hemisensory loss

28

Define amaurosis fugax

• Transient monocular blindness
• Transient retinal artery occlusion (from carotid)

29

Initial management of stroke

• Acute stroke unit
• Supportive measures (O2, IV fluid, glucose and electrolyte monitoring)
• CT within 1 hr
• Thrombolysis with IV rTPA if ischaemic (or clot retrieval!?)
• Aspirin if ischaemic, 300mg for 2 weeks then 75mg for life

30

How do you investigate cause of stroke

Carotid dopplers, ECG, echo, ESR