6: Hydrocephalus Flashcards Preview

Neurology Week 3 2018/19 > 6: Hydrocephalus > Flashcards

Flashcards in 6: Hydrocephalus Deck (33)
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1

What is the normal CSF pressure in the subarachnoid space?

10 mmHg

2

Anyone with a CSF pressure greater than ___ mmHg should be suspected of having hydrocephalus.

15 mmHg

3

How much circulating CSF does a typical adult have at any one time?

How much CSF do you produce per day?

1600ml circulating at any one time

500ml produced per day

4

CSF production (increases / decreases) as you get older.

decreases

5

What happens if you remove too much CSF during a lumbar puncture?

Tonsilar herniation

Cushing's response - hypertension, bradycardia, irregular breathing

 

6

What causes increased CSF pressure?

Blockage of ventricles

Overproduction of CSF

Impaired CSF absorption

7

Which drug decreases CSF production?

Acetazolamide

8

Which structures absorb CSF from the cranial cavity?

Arachnoid granulations

9

ICP affects CSF (production / absorption).

 

CSF absorption only, inverse relationship

10

What are the functions of CSF?

Maintenance of homeostasis e.g nutrition, ions

Keeps the brain buoyant - reduces pressure exerted on skull

11

What is a Chiari malformation?

What disease does it cause?

Congenital OR acquired tonsilar herniation of cerebellum and brainstem through the foramen magnum and into the spinal canal

Syringomyelia

12

What is syringomyelia?

Which malformation can cause it?

Abnormal fluid-filled cavity/ies within the spinal cord

Chiari malformation

13

How can syringomyelia cause hydrocephalus?

Impaired CSF flow from spinal cord to brain due to compression of central canal by syrinxes

CSF builds up and ICP increases

14

What is the physical presentation of hydrocephalus in children?

Abnormally large head

Thin, shiny scalp with visible veins

Bulging fontanelles

Sunset eyes

 

15

What eye sign can be seen in children with hydrocephalus?

"Sunset" eyes

Downward gaze with area of sclera visible between upper eyelid and iris

16

Which structure in the brain is compressed to cause a sunset gaze?

Tectal plate

17

What are the neuro symptoms of paediatric hydrocephalus?

Sensory and motor problems

Behavioural changes - sleeping, feeding, irritability

Vomiting

18

Why can hydrocephalus cause visual loss?

Increased CSF volume

=> Increased ICP

=> Pressure on meninges surrounding CN II

=> Papilloedema

=> Visual loss

19

Acquired hydrocephalus tends to be a ___ disease.

resolving

20

Which acute brain disease causes acquired hydrocephalus?

Why?

Subarachnoid haemorrhage

Arachnoid granulations are blocked with blood and can't absorb CSF properly

21

Which tube can be fitted to drain CSF from the ventricles of a patient with hydrocephalus?

Ventriculoperitoneal shunt

Valves only open if ICP is too high, avoiding excessive draining of CSF 

22

Why are shunts avoided in hydrocephalus involving tumours?

Tumour may be disseminated into peritoneal cavity

23

What is craniosynostosis?

Inappropriate fusion of cranial bones caused by rapid head size changes

24

What are the signs and symptoms of a blocked shunt in patients with hydrocephalus?

N&V

Headache

Blurred vision

"Sunsetting" - lack of upgaze

pretty much the same as hydrocephalus

25

What is the gold standard investigation for hydrocephalus?

CT scan

26

What is a more long-term option compared to a shunt for treating patients with some types of hydrocephalus?

Endoscopic third ventriculostomy

drilling a hole in the floor of the 3rd ventricle to let CSF drain

27

What is a disease presenting as a triad of ataxia, memory decline and incontinence?

Normal pressure hydrocephalus 

28

What is normal pressure hydrocephalus?

What does it present as?

What is the investigation?

Enlarged cerebral ventricles with normal CSF pressure

Ataxia, memory decline and incontinence

Head scan - CT/MRI

29

How is normal pressure hydrocephalus treated?

Shunt

30

Which group of patients typically develop idiopathic intracranial hypertension?

Obese women