TRAUMA AND CSF Flashcards
What is the most important score in the GCS?
motor response
Where is CSF produced?
choroid plexus in ventricles
CSF flow
lateral ventricles –> via foramen of munro –> third ventricle –> via aquedcut of sylvius –> fourth ventricle –> foramina of magendie and luschka –> subarachoid space –> arachnoid granulations –> venous blood
Symptoms of cerebral herniation
- Extensor response
- Cushing’s triad (hypertension, bradycardia and irregular breathing)
- Unreactive pupil (uncal herniation)
Name the 3 types of herniation
Uncal, tonsilar, subfalcarine
Which part of the brain herniates in uncal herniation?
medial temporal lobe through the tentorium
How does an uncal herniation present?
- pupillary dilatation due to involvement of ipsilateral oculomotor nerve
- contralaterl hemiparesis
Which part of the brain herniated in a subfalcine herniation?
the cingulate gyrus
How does a subfalcine herniation present?
weakness in lower extremities
What part of the brain herniates in a tonsilar herniation?
cerebellar tonsils are displaced into the forman magnum
Give 2 causes of a tonsilar herniation
- Posterior fossa lesion
- Arnold-Chiari malformation
How does a tonsilar herniation present?
medullary compression and ischaemia characterized by neck stinfness, abnormal neck posture, respiration anomaly (Cheyne-Stokes breathing; periods of tachypnea and tachycardia followed by periods of bradycardia and bradypnea) and coma.
Following a car accident a patient presents with unilateral pupil mydriasis that does not constrict to light. Which type of herniation is this?
uncal herniation would present with pupillary dilatation due to compression of the ipsilateral oculomotor nerve
Normal ICP
5-15 mmHg
3 intracranial components
brain tissue, CSF and blood
PC: a progressive shuffling gait and urinary incontinence. His wife is claiming that he has been forgetting his keys and taking his medication. What is the most likely diagnosis?
Normal pressure hydrocephalus
Baby with big head, failure to thrive. On exam she has sunsetting eyes. Whats the most likely cause?
Non-communicating hydrocephalus due to aqueduct stenosis
How does an extradural haematoma present?
- young adult with closed head trauma
- brief loss of consciousness then lucid interval then deterioration
- headache, vomiting, contralateral hemiparesis and ipsilatral pupillary dilatation
Investigation of extradural haematoma
CT shows lens-shaped haematoma that pushes away the dura
Between which layers is an extradural haematoma?
skull and dura
Between which layers is a subdural haematoma?
dura and arachnoid
Between which layers is a subarachnoid ?
arachnoid and pia
How does an acute subdural haematoma present?
- very severe head trauma
- immediate symptoms
- severely decreased consciousness
How long after trauma does a chronic subdural haematoma display symptoms?
3-7 weeks
What is the driving factor for chronic subdural haematoma?
brain atrophy which stretched the bridging veins allowing them to rupture with minor trauma
Investigate subdural haematoma
CT shows crescent that cannot cross falx cerebri or tentorium
ACUTE: hyperdense crescent
CHRONIC: hypodense cresent, slow growing
How does normal pressure hydrocephalus present?
- shuffling gait 2. dementia 3. urinary incontinence
Treatment of normal pressure hydrocephalus
ventriculo-peritoneal shunt
What is communicating hydrocephalus?
due to CSF absorption (impaired arachnoid granulations)
What is non-communicating hydrocephalus?
obstruction of CSF flow
- small fourth ventricle in comparison to others
Causes of non-communicating hydrocephalus
- tumours compressing the ventricles
- a colloid cyst obstructing the third ventricle can be seen
- stenosis of the aqueduct.
Symptoms of congenital hydrocephalus
- Failure to thrive.
- Dilated scalp veins.
- Increased head circumference.
- Impaired upgaze due to compression on the tectal plate.
- ‘Setting sun’ appearance: downward deviation of the globe on lid retraction.
- Raised ICP and diplopia (due to sixth nerve palsy).
- Vomiting.
- Macewen sign: ‘cracked pot’ sound on head percussion.
Signs and symptoms of acquired hydrocephalus
- Headaches: more prominent in the mornings.
- Vomiting.
- Diplopia.
- Impaired upgaze due to compression on the tectal plate.
- Raised ICP.
- Papillodema
- Drowsiness.
- Incontinence.
- Gait abnormalities.
Investigate hydrocephalus
MRI
Manage hydrocephalus
VP shunt or endoscopic third ventriculostomy (ETV) if non-communicating
What are Chiari malformations?
- congenital or aquired
- malformation of hindbrain
- impaired CSF circulation through foramen magnum
Which chiari malformation is more severe?
Chiari II (Arnold-Chiari)
What is Chiari I ?
- most common
- caudal displacement of cerebellar tonsils below foramen magnum
- +/- syringomyelia
What is syringomyelia?
an expanding cystic cavity or syrinx forming in the spinal cord that can cause damage to the central spinal cord
signs and symptoms of Chiari I
- headache (esp with cough and neck extension)
- downbeat nystagmus
- central cord symptoms if syringomyelia
- ataxic gait
What is Arnold-Chiari?
Cerebellum and medulla are caudally displaced below the foramen magnum
and herniation of fourth ventricle
What condition is Arnold-Chiari associated with?
spinabifida
What age group does Arnold-Chiari affect?
symptomatic during infancy or childhood
Syptoms of Arnold-Chiari
- severe brainstem dysfunction causing dysphagia, apnoea, stridor and nystagmus
- weakness that can progress to quadriplegia
Treatment of chiari malformation
Suboccipital craniectomy and upper cervical laminectomy to decompress the malformation at the foramen magnum are usually required with cord drainage.
Clinical featurs of idiopathic intracranial hypertension
- headache (worse in morning, relieved by standing)
- bilateral papilloedema
- N+V
- sixth nerve palsy
What size are the ventricles in idiopathic itracranial hypertension?
normal or reduced
Treatment of idiopathic intracranial hypertension
weight loss and diuretics
lumbo-peritoneal shunt (surgical)
