Neurological Emergencies Flashcards
To Do: Status Epilepticus Subarachnoid Haemorrhage Meningitis Other... Done:
A patient presents to A and E with “the worst headache of ther life”. They have associated N and V.
What is the main differential diagnosis,
and what is the cause in 70% of these cases?
Subarachnoid haemorrhage
Berry auneurysms
A patient presents to A and E with “the worst headache of ther life”. They have associated N and V.
What is the main differential diagnosis,
and what is the cause in 15% of these cases?
Subarachnoid haemorrhage
AV malformations
A patient presents to A and E with “the worst headache of ther life”. They have associated N and V.
How might this condition have presented in a less fortunate patient?
Coma
Seizures
Sudden death
Why do some patients with a SAH get meningism?
Blood acts as an irritant -> chemical meningitis
A patient presents to A and E with “the worst headache of ther life”. They have associated N and V.
What signs might you elicit O/E?
Kernig's sign Signs of meningism Impaired consciousness Cranial nerve palsys Hemiplegia
With a SAH, how quickly can CNS deficits become permenant?
Within minutes
What is the overall mortality for a patient with an SAH?
35-50%
Is prognosis with an SAH better or worse with an aneurysm than an AVM?
Worst with aneurysm, better with AVM, best with no lesion detected.
Why is blood in the subarachnoid space bad?
It acts as an irritant causing vasospasm -> ischaemia -> secondary brain damage.
How common is rebleeding following a SAH?
Very - usually ocurs within 7 days.
How do we investigate suspected SAH?
CT ASAP if within the first 12 hours.
LP 12 hours after the event.
Check clotting screen.
How good are CT scans for picking up subarachnoid haemorrhages?
95% can be picked up if done within 24 hours, but CT shows fresh blood up best so ideally do ASAP for clearest diagnosis.
What does a subarachnoid haemorrhage look like on CT?
No characteristic shape - just an area of hyperdensity.
Why do we do an LP 12 hours after a SAH, and what can it tell us?
To look for RBCs and xanthochromia in the CSF.
We do it after 12 hours so the SAH blood has time to break down and form the xanthochromia, so SAH isn’t confused with RBCs from the trauma of LP procedure.
It tells us if there has been a SAH.
What do we send off the CSF for when we do an LP for ?SAH?
Xanthochromia
MC&S
Glucose
Protein
Might as well screen for infection while we are in there!
A pt presents to A&E with a thunderclap headache. SAH has been confirmed.
How should we manage this patient?
Initially with ABCDE.
Stabilise
Prevent rebleed
Treat vasospasm
Correct any biochemical abnormalities e.g. hyponatraemia
Refer for neurosurgical intervention.
Why is it important to manage cerebral vasospasm in a SAH pt?
It causes focal cerebral ischaemia -> death.
How do we try and prevent cerebral vasospasm post-SAH?
Hydration with normal saline -> hypervolaemia and haemodilution
Nimodipine 60mg 4 hourly
Re-examine regularly for changes in function.
What is nimodipine?
A calcium antagonist used to prevent vasospasm post-SAH.
What neurosurgical interventions are possible for SAH?
Clipping or endovascular coiling of aneurysm depending on pt, site and size of aneurysm, and comorbidities.
A pt comes in with a thunderclap headache, and SAH is diagnosed.
After initial management, the pt appears stable, but after admission for observation, he suddenly becomes drowsy and his GCS drops.
What should we do?
Get an urgent CT head as he might have a re-bleed or hydrocephalus.
A pt comes in with a thunderclap headache, and SAH is diagnosed.
After initial management, the pt appears stable, but after admission for observation, he suddenly becomes drowsy and his GCS drops.
Other than drowsiness/drop in GCS, what other indications are there for urgent CT post SAH?
Seizures
Focal neurological deficit (new)
Coma
Cognitive decline (acute)
Need to check for a re-bleed or hydrocephalus!!
What are the common complications associated with SAH?
Re-bleeding Hydrocephalus Cerebral ischaemia Hyponatraemia Headaches Hypopituitarism
Death
A pt is brought to A&E by their partner, because they were complaining of a headache when they woke up this morning, and since then they have become drowsy and aren’t responding appropriately or at all to stimulus.
What are we most worried about here, and what could cause this?
RICP
Head injury Intracranial tumour Intracranial bleed Infection (meningitis, encephalitis, abscess) Hydrocephalus Cerebral oedema
A pt is brought to A&E with a history of headache on waking then progressive cognitive decline. There was no history of trauma.
What signs might you see on assessment of this individual?
Reduced GCS (drowsy, irritable, lethargic) HR low but BP high (Cushing’s reflex) Pupil changes Reduced visual acuity May have papilloedema
How should a patient with suspected RICP be investigated?
ABCDE
Identify the cause:
- Focused hx and examination (e.g. may have purpuric rash, may have Hx of AF)
- Bloods and urine for infection/metabolic disturbance/clotting/toxicology
- CXR for ?infection source
- CT head
- LP if not contraindicated
What are the contraindications for lumbar puncture?
- Bleeding diathesis
- Infection at site of needle insertion
- Cardiorespiratory compromise
- RICP weirdly… unless treating known intracranial HTN. Get a CT first
How do we manage RICP?
Treat the cause, bring down ICP, and prevent secondary injury
What secondary injury can occur from RICP?
- Herniation syndromes
- Seizures
- Stroke
- Neurological damage
- Death
What respiratory manoeuvre can we use to help reduce RICP? How does it work?
Hyperventilation if intubated.
Reduces pCO2 which causes cerebral vasoconstriction -> lowers ICP.
What agents can we give short term to reduce ICP?
Osmotic agents e.g. mannitol - 20% solution 0.25-0.5g/kg IV over 10-20 minutes.
Corticosteroids can be used only for oedema surrounding intracranial tumour.
What kinds of herniation syndromes are possible as a result of RICP?
Uncal herniation
Cerebellar tonsil herniation
Subfalcian (cingulate) herniation
A pt is being managed for RICP when he suddenly develops ataxia and a VIth nerve palsy.
What is likely to have happened?
Cerebellar tonsil herniation due to increased pressure in the posterior fossa -> cerebellar tonsils to herniate through the foramen magnum.
A woman presents to A&E with neck stiffness, photophobia, and a headache.
What other symptoms might she have considering the most likely diagnosis?
Fever
Cranial nerve palsy symptoms e.g. diplopia, facial drooping
Altered level of consciousness
Non-blanching rash
A woman presents to A&E with a headache, neck stiffness, and photophobia.
How should she be managed?
ABCDE
Septic screen -> sepsis 6
Try and find the source of infection
How is meningism different from RICP?
Meningism is signs of irritation to the meninges, but not necessarily with RICP.
Meningism - photophobia, stiff neck, Kernig’s sign.
Signs of RICP - altered level of consciousness, altered respiratory pattern, HTN, bradycardia.
They can occur together however.
How can we manage a pt who is meningitic but has no signs of shock?
Still ABCDE
Take blood cultures
Start IV abx
Give 10mg IV dexamethasone
Airway support and fluid resus
LP can wait until they are stable, and if they have no signs of RICP.
How can we manage a patient who is meningitic and in shock?
Get ICU involved
Basically the same, but start sepsis pathway and may also need intubation.
What antibiotics should be given for bacterial meningitis?
Depends on local policy, but generally:
Ceftriaxone, with amoxicillin if over 60 yo
Because Leicester is weird like tis, what organism can cause meningitis herethat you might not see elsewhere?
TB yayay that makes this so much fun!
How should encephalitis be managed?
Supportively
Give specific antivirals e.g. aciclovir for HSV, other treatments for CMV and toxoplasmosis.
How does encephalitis present differently to meningitis?
Bizarre behaviour/confusion Decreased GCS or coma Focal neurological signs Seizure May have hx of recent travel or animal bite.
May be preceded by infectious prodrome.
Why is head trauma a neurological emergency?
It is a leading cause of death in adults under 45 years.
What is a factor in a significant number of head injuries?
Alcohol 🍻
What are the 2 types of head trauma?
Primary and secondary
What are the 2 types of primary head injury?
Focal and diffuse
What is status epilepticus?
Seizures lasting for 30 minutes or more, or multiple seizures with no complete regaining of consciousness in between.
What are the possible causes of status epilepticus?
Known epilepsy
Structural brain lesion (esp. if 1st seizure)
Eclampsia (any possibility of pregnancy?)
Infection
Metabolic/Toxins/Alcohol
How should ?status epilepticus be managed initially?
ABCDE
Including open/secure airway, O2, suction, metabolic screen, anticonvulsant levels.
IV bolus or lorazepam and repeat if required
How much lorazepam can be given to a pt in status, and how frequently?
4mg, repeat dose if no response after 10-20 minutes.
If lorazepam fails to get pt out of status, what other drugs can we give them?
IV Phenytoin 15-18 mg/kg at 50mg/min
If after 60-90 minutes no response to Phenytoin, escalate to general anaesthesia e.g. propofol
Who needs to be called if a pt has been treated for status epilepticus for more than 20 minutes?
An anaesthetist
Why might IV lorazepam be problematic for a pt in status epilepticus?
What can we do instead?
IV access may not be easy to establish in a seizing pt.
Can give buccal midazolam, or rectal diazepam instead
If you suspect alcohol withdrawal might be involved in status epilepticus, what can you give the pt?
Thiamine infusion
If we suspect metabolic disturbance causing status epilepticus, what can we di?
Treat the cause e.g. glucose for hypoglycaemia
If a pt who is in status epilepticus is already on phenytoin, what can we give instead?
IV Phenobarbital
Which neurological emergency are cancer pts at an increased risk of developing?
Spinal cord compression
Specifically metastatic SCC or secondary to direct tunour extension into vertebral column.
What % of cancer pts are affected by spinal cord compression?
Up to 5% of cancer pts
What are the features of spinal cord compression?
Back pain - earliest and most common symptom
Lower limb weakness
Sensory changes
Neurological changes depend on the level of the lesion
How should oncological spinal cord compression be managed?
Best rest
High dose oral steroids
May need radiotherapy or surgery
What is radicular pain?
Pain that radiates into the lower extremity along the course of a spinal nerve root.
What are the causes of spinal cord compression?
Degenerative disc lesion Degenerative vertebral lesions TB Epidural abscess Vertebral neoplasm Epidural haemorrhage Paget’s disease
How can you tell where spinal cord compression has occurred?
By assessing the functional losses from hx and examination -the highest level of symptoms is the lowest possible level of spinal cord compression.
If there is autonomic involvement in SCC, what does that suggest?
A worse prognosis as it is a late stage sign.
Will spinal cord compression cause upper or lower motor neurone signs?
Upper motor neurone signs.
Although at the level of the compression, reflexes will be absent as the LMN within the ventral horn is compressed.
How should suspected spinal cord compression be investigated?
Full hx and examination
MRI of whole spine within a day (within a week if potentialy metastatic)
Routine bloods may be helpful, including a Group and Save, and a clotting screen.
How should spinal cord compression be managed?
High dose corticosteroids with a PPI for gastric protection
Imaging -> neurosurgical opinion for decompression
A woman presents to A&E with acute onset lower back pain and urinary incontinence.
What is your immediate worry?
Cauda equina syndrome