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Cognition, Movement and Senses > Neurosurgery - ICP, EDH, SDH, Contusions and Diffuse Axonal Injury, Tumours, Ischemia, Intracerebral Hematoma, Aneurysmal Bleeds, AVM, Cavernomas, Cauda Equina > Flashcards

Neurosurgery - ICP, EDH, SDH, Contusions and Diffuse Axonal Injury, Tumours, Ischemia, Intracerebral Hematoma, Aneurysmal Bleeds, AVM, Cavernomas, Cauda Equina Flashcards

1
Q

Describe the Monro-Kellie doctrine

  • what happens in a normal brain
  • what happens when there are problems
A

In a healthy brain, CSF volume, blood volume and brain volume exist in equilibrium => maintenance of a normal ICP (5-15)

Autoregulatory mechanisms

  • altered blood/CSF drainage
  • increased CO2 => VD
  • chronic increased HTN => curve shifts

If compensatory mechanisms overwhelmed => decompensated state where ICP rapidly increases => herniation
-small increases in volume => BIG increase in pressure

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2
Q

Indications for measuring ICP

When to be cautious with measuring ICP

A

Indications

  • Traumatic brain injury
  • Hydrocephalus
  • IIH
  • Conditions that are at high risk of developing hydrocephalus (SOL, SAH)

Caution in

  • coagulopathies, AC use
  • scalp infection, brain abscess

Single reading - lumbar puncture needle connected to a manometer

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3
Q

Herniation syndrome

  • 4 main types of herniation
  • presentation
A

Subfalcine - midline shift

  • hydrocephalus => headache
  • ACA compression => contralateral leg weakness

Central - temporal lobes down into tentorial notch => midbrain

  • fixed pupils
  • coma, bilateral decorticate => decerebrate posturing

Uncal - uncus of temporal down into tentorial notch => midbrain

  • ipsilateral CN3 palsy
  • PCA compression => contralateral hemiparesis, visual field loss
  • impaired consciousness, abnormal breathing, fixed pupils

Tonsillar - cerebellar tonsils => brainstem

  • obstructed CSF flow => acute hydrocephalus => headache
  • reduced consciousness, vomiting
  • dysconjugate eye movements
  • resp, cardiac arrest
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4
Q

Neurocritical assessment

  • GCS
  • scoring and management
A

E4

  • spontaneous
  • voice
  • pain
  • nothing

V5

  • oriented, appropriate
  • confused
  • incoherent words
  • incomprehensible sounds
  • nothing

M6

  • follows commands
  • localises to pain
  • withdraws from pain
  • decorticate posturing - loss of cortical communication
  • decerebrate posturing - loss of cerebrate communication
  • nothing

U8 - lost ability to protect airway

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5
Q

Brainstem death

-how to rule out mimics

A

Ruling out other causes

  • patient’s condition is due to irreversible brain death of known cause
  • sedative drugs worn off
  • hypothermia
  • correct circulatory (BP, PO2, PCO2), electrolyte, endocrine disturbances (hypothyroidism, adrenalism)

All brainstem reflexes absent

  • eye reflex (2,3) => no accommodation
  • corneal reflex (5,7) => no blinking
  • oculovestibular reflex (3,6,8) => no eye mv following ice cold water in each ear
  • vestibular reflex (3,6,8) => eyes don’t move according to head position
  • pain stimulus of supraorbital ridge (5,7) => no grimacing
  • gag reflex (9,10) => no gag, palate elevation due to pharyngeal stimulation
  • cough reflex (10) => no cough after bronchial catheter insertion

Apnea despite PaCO2 6.5kPa+
-confirm PaCO2 with ABG

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6
Q

Assessing ICP

A 
CT head - in acute
Good for 
-mass effect
-bleeding
-swelling

MRI - good for tissue assessment
T1 - CSF dark
T2 - CSF bright

US

  • neonates with open fontanelles
  • dopplers for blood flow assessment
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7
Q

Hydrocephalus

  • pathophysiology
  • types and causes
  • management of NPH
A

Increased CSF => ventricular dilation
-Most causes are idiopathic

Obstructive - blockage of CSF drainage
-tumour, cyst
-congenital
Communicating - reduced CSF uptake by arachnoid villi
-infective meningitis
-SAH
-congenital
-NPH

NPH - ventricular dilation in absence of ICP
-triad of ataxia, urinary incont, dementia
Management => surgical insertion of CSF shunt

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8
Q 
Hydrocephalus presentation
-generally
-specific to neonates due to open fontanelle
Investigations
Management
A

Generally

  • N+V, headache worse in the morning, agitation
  • progresses to altered GCS, blurred vision, ataxia, incontinence, papillodema

Neonates

  • rapid increase in head circumference, dilated scalp veins
  • bulging fontanelles
  • sunset eyes

Initial - CT head

  • enlarged ventricles - pattern can determine cause
  • loss of sulcal gyral pattern

Initial reduction in ICP - insert ext ventricular drain
Definitive - manage underlying cause
-ventriculoperitoneal shunt insertion

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9
Q

EDH

  • pathophysiology
  • presentation in addition to ICP symptoms
  • investigations
  • management
A

Dura most tightly attached at sutures - blood accummulates between sutures
-laceration of dural artery/venous sinus

LOC => Lucid period => slow deterioration

CT head - Lemon

Initial management

  • A-E
  • reverse AC
  • prophylactic ABx if open fracture, AED
  • reduce ICP - mannitol, barbiturates

Definitive - depends on patient and clinical features
-decompressive craniotomy

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10
Q

SDH

  • pathophysiology
  • presentation in addition to ICP
  • investigations
  • management
A

Laceration of bridging veins

  • in elderly, alcoholic, can be from trivial trauma
  • gradual onset of ICP symptoms

CT head - Banana
-loss of grey white differentiation
-midline shift
If acute on chronic - bright and dark blood in similar area

Initial management

  • A-E
  • reverse AC
  • prophylactic AED
  • reduce ICP - mannitol, barbiturates

Definitive - depends on patient and clinical presentation
-craniotomy

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11
Q

Contusions and diffuse axonal injury

  • pathophysiology
  • presentation
  • investigations
  • management
A

Rapid brain shifts within skull => axon sheared, microbleeds

LOC
Headache, N+V
Drowsiness, fatigue
Sleeping difficulty
Ataxia

CT head - very difficult to see due to small areas of injury
-can blossom in days post trauma

Initial - monitor and control ICP
Definitive - no surgery available
-rehabilitation if injury mild

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12
Q

Tumours

  • most common types in adults and children
  • presentation
  • investigations and diagnosis
  • management
A

Adults - gliomas (v aggressive), meningiomas (often benign), mets (breast, lung)

Paeds - most common solid tumour
-medulloblastoma, craniopharyngioma, astrocytomas, brainstem glioma

SOL => signs based on area affected

  • benign - more likely to present with headaches
  • malignant - more likely to present with seizures

CT diagnosis
-Staging MRI of neuraxis and CT CAP

Management is individual

  • manage life threatening conditions first - ICP
  • dexmeth - reduce swelling due to increased vascular burden of tumour
  • afterwards, manage tumour
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13
Q

Ischemia

  • pathophysiology
  • presentation
  • investigations
  • management
A

Insufficient blood flow to meet demand => hypoxia, brain death

Sudden loss, stroke

CT head, angio - locate point of ischemia

Management depends on cause of bleed
-if used, decompressive craniotomy most effective within 48hrs

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14
Q

Aneurysmal bleeds

  • most common cause
  • risk factors
  • investigations
  • management
  • prognosis
A

Most often cause SAH
Sudden severe headache

Risk factors

  • trauma
  • smoking
  • HTN
  • FHx
  • ADPKD
  • connective tissue disorders

CT angio

Management

  • stop bleed - endovascular coiling, neurosurgical clipping
  • reduce risk of rebleeding - nimodipine, lower HTN

Poor prognosis - degraded blood after initial bleed => vasospasm

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15
Q

AVM

  • pathophysiology
  • presentation
  • investigations
  • management
A

Congenital malformations

  • arteries draining directly into veins with no caps in between => high pressure bleeds
  • HIGH SUSPICION IN NEONATE A&E HIGH BP PRESENTATION
  • ICP presentation
  • purple birthmark, warmer skin, pulse around AVM

CT head, angio

Resection - can be risky
-consider size, pattern of venous drainage and site

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16
Q

Cavernomas

  • pathophysiology
  • presentation
  • investigations
  • management
A

Abnormal clusters of raspberry-like vessels
-generally asymptomatic

Symptomatic if bleeding
-stroke-like with increasd ICP symptoms

CT head, angio, MRI

  • popcorn like on MRI
  • multiple - genetic?

Neurosurgery involvement to remove cavernoma if
-mass effect
-intractable seizures
Always consider patient characteristics and clinical picture

17
Q

Spine - cauda equina

  • presentation
  • investigations
  • management
A

Low back pain
Bilateral sciatica, weakness
Urinary incontinence
Saddle anaesthesia

Urinary incontinence => immediate MRI
-TIME CRITICAL

Surgical decompression

18
Q

How to measure
-single reading
-continuous monitoring
Normal and increased ICP readings

A

Continuous monitoring

  • GOLD STANDARD - external ventricular drain
  • subarachnoid/epidural bolt

ICP monitoring - look at waveforms

Normal ICP waveform - P1>P2>P3

  • P1 - arterial pulsation
  • P2 -intracranial compliance
  • P3 - aortic valve closure

High ICP
-P2 highest

19
Q

Presentation of increased cranial pressure

A

Headache
Vomiting
Altered consciousness
Neuro deficits
Seizures
=> Cushings Triad = v poor prognosis
-ischemic brain => increased SNS => increased BP
-increased BP detected by baroceptors => increased PNS => bradycardia
-brainstem dysfunction => abnormal breathing

20
Q

Management of increased ICP

A

INITAL - REDUCE ICP FIRST

  • 30 bed elevation
  • hyperventilation => VC effect of low CO2
  • reduce fevers - reduce brain metabolic activity
  • manage seizures
  • analgesia, sedation
  • extraventricular drain/acetazolamide to reduce CSF production
  • mannitol - osmotic diuresis
  • barbiturate coma

DEFINITIVE - ADDRESS CAUSE

21
Q

GCS assessment in young children

A 
Eye and motor assessment is the same as adults
Voice
5-coos, babbles
4-cries but consolable
3-persistently irritable
2-grunts to pain/restless
1-no response
22
Q

Chiari malformations

  • what is it
  • presentation
A

Lower part of the brain pushes down into the spinal canal => obstruct outflow of CSF

STRAIN INDUCED HEADACHE => THINK CHIARI
Can cause CSF collection within spinal cord => syringomyelia
-posterior column most commonly affected

Brain MRI

If not symptomatic/progressing => watch and wait
Surgical management
-drain syrinx or restore normal CSF flow

23
Q

Autonomic dysfunction

  • pathophysiology
  • most common cause
  • presentation
  • management
A

Parasympathetic nervous system functions found in the cranial nerves
If damaged in TBI => sympathetic dominance
-increased HR, BP, ICP, temperature
-decreased CPP

Symptomatic treatment to decrease ICP (sedatives, analgesia, paralytics) => worsen symptooms

Cognition, Movement and Senses (80 decks)

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