Hydrocephalus and raised ICP

Question 1

What are the two types of hydrocephalus?

Answer 1

communicating and non communicating

Question 2

Describe non communicating hydrocephalus?

Answer 2

obstruction to the flow of CSF occurs within the ventricular sytem - before the CSF flows out into the ventricuar space

Question 3

Describe communicating hydrocephalus?

Answer 3

obstruction to the flow of CSF is outside of the ventricular system, the dilation of the ventricles is constant throughout - eg in subarachnoid space or arachnoid granulations

Question 4

At what age do the cranial sutures close?

Answer 4

2/3 years

Question 5

What happens if there is hydrocephalus before 2/3 years?

Answer 5

cranial enlargement

Question 6

What happens if there is hydrocephalus after 2/3 years?

Answer 6

get expansion of the ventricles and increased cranial pressure

Question 7

What is hydrocephalus ex vacuo?

Answer 7

dilation of the ventricular system and a compensatory increase in CSF volume secondary to loss of brain parenchyma

Question 8

What is the equation that links MAP, ICP and CPP?

Answer 8

MAP - ICP = CPP

Question 9

What does a CPP <30 mean?

Answer 9

comatosed

Question 10

What is a normal MAP?

Answer 10

90

Question 11

What is a normal ICP?

Answer 11

10 (can be negative while lying down)

Question 12

What is a normal CPP?

Answer 12

80

Question 13

What is cushings triad?

Answer 13

decreased resp rate
increased CPP
MAP >100

Question 14

What is the Monroe-Kellie Doctorine?

Answer 14

three components in the skull - brain tissue, CSF, intracranial circulating blood

Question 15

What is pressure autoregulation of blood pressure?

Answer 15

arterioles dilate or constrict in response to changes in BP or ICP

Question 16

What is metabolic autoregulation of blood pressure?

Answer 16

arterioles dilate in response to chemicals - lactic acid or CO2

Question 17

What can cause problems with CSF flow?

Answer 17

obstruction of flow - masses and chiari malformations
increased production - choroid plexus papilloma (produces CSF)
decreased absorption - communicating hydrocephalus - due to SAH, meningitis or malignany meningeal disease

Question 18

What are the early signs of CSF flow issues?

Answer 18

drowsy 
headache
pupillary dysfunction
nausea and vomiting
blurring
visual field defects
decreased level of conciousness

Question 19

What are the later signs of CSF flow issues?

Answer 19

coma
fixed dilated pupils
hemiplegia
cushings triad
increased urinary output

Question 20

What is the treatment for raised ICP?

Answer 20

maintain midline and neutral postition of the head
loosen tube ties, collars, jewellery - prevent gagging/coughing
head of the bed at 30-45 degrees
maintain normocarbia - hyperventilating the patient
maintain fluid and electrolytes

Question 21

What medical treatment can be given for raised ICP?

Answer 21

diuretics - mannitol, hypertonic saline, furosemide urea
antiepileptics - prevent energy expenditure
surgical decompression

Question 22

What causes communicating hydrocephalus?

Answer 22

meningitis
post trauma
post SAH

Question 23

What causes non communicating hydrocephalus?

Answer 23

tumours
cysts
aqueductal stenosis - enlarged frontal horns

Question 24

What causes sunsetting eyes?

Answer 24

midbrain compression

Question 25

How do you treat hydrocephalus?

Answer 25

VP shunt

Question 26

What is the presentation of normal pressure hydrocephalus?

Answer 26

idiopathic disease of the elderly

Hakims triad - abnormal gait, urinary incontinence, dementia

Question 27

How is normal pressure hydrocephalus investigated?

Answer 27

CT and lumbar drain

test their gait, do a lumbar drain test, then test gait again and it should have improved

Question 28

What is the risk factors of idiopathic intracranial hypertension?

Answer 28

young
women
fat

Question 29

What is the presentation of idiopathic intracranial hypertension?

Answer 29

debilitating headaches
double vision
blurry vision
tinnitus
radicular pain
papilloedema

Question 30

What are the possible causes of idiopathic intracranial hypertension?

Answer 30

CSF imbalance
hormones - oestrogen
venous pressure
transverse/sigmoid sinus stenosis

Question 31

What is the first line treatment of idiopathic intracranial hypertension?

Answer 31

Acetazolamide/Topiramide - carbonic anhydrase inhibitor

AND WEIGHT LOSS

Question 32

What else can be done for idiopathic intracranial hypertension?

Answer 32

CSF inversion - LP or VP shunt

intraventional radiology - intracranial venous shunt/stenting

Question 33

What investigations are done for idiopathic intracranial hypertension?

Answer 33

LP
CT/MRI head
fundoscopy and opthamology review