Raised Intracranial Pressure Flashcards
What is idiopathic intracranial hypertension (IIH)?
increased ICP in an alert and orientated patient (syndrome of reduced CSF absorption)
What are IIH RF?
- Female sex
- Obesity
- Endocrine conditions
What are the causes of general raised ICP?
- Primary or metastatic tumours
- Head injury
- Haemorrhage
- Infection: meningitis, encephalitis, brain abscess
- Hydrocephalus
- Cerebral oedema
- Statis epilepticus
- Idiopathic
What are the symptoms in IIH?
- Headaches
- Pulse-synchronus tinnitus
- Transient visual obscuration
- Visual loss
What are the signs of IIH?
- Papilloedmea
- Six nerve paraesis
- Disturbances in sensory visual function
What are raised ICP symptoms?
- Headache worse on coughing leaning forward
- Vomiting
- Altered GCS
- Low HR and high BP
- Pupil changes
- Decreased visual acuity
What are some DDx for IIH?
Intracranial structural anomalies
What criteria is used for IIH?
Dandy criteria
What investigations are used for IIH?
- Visual field testing (perimetry): enlarged blind spots and other visual field deficiets
- Dilated fundoscopy: Frizen grading of papilloedema
- Visual acuity: usually normal
- MRI of brain
- LP at L3/L4: high pressure
What may the MRI brain show in IIH?
- transverse sinus stenosis
- empty stella
What investigations do you do for raised ICP?
- UandE, FBC, LFTs, serum osmolarity, clotting, blood culture
- Consider tox screen
- CXR
- CT brain
- LP if safe
Why do you do a CXR in rasied ICP?
any source of infection that may indicate abscess
What is the management plan in raised ICP?
- ABC
- Correct hypotension
- Elevate head 30-40 degrees
- If intubated hyperventilate
- Osmotric agents can be useful
- Corticosteroid not effective in reducing ICP except for oedema surrounding tumours
- Other measures
- Restrict fluid
When may a patient need urgent neurosurgery for rasied ICP?
- from focal causes e.g. haematomas by craniotomy or burr hole
- ICP bolt placed to measure
What is the management for IIH?
1st line: management of factors that may increase ICP: weight loss
When may you use medication for IIH?
depends on symptoms
What are examples of treatment for the optic effect of rasied ICP?
- Optic nerve sheath fenestration or CSF shunting: progressive visual loss
- Optical prisms (for diplopia of 6th nerve palsy)
What medications may you prescribe for symptoms of raised ICP?
- Pharmacotherapy e.g. acetazolamide and/or furosemide
- Analgesia: for persistent headache
- Cerebral fluid shunting for headache
- NSAIDs: neck pain
- Transverse sinus stenting: persistent pulse synchronous tinnitus
What are possible complications for raised ICP?
- Brain herniation
2. Irreversible vision loss
What are different types of brain herniation?
- uncal herniation
- cerbral tonsil herniation
- subfalcian (cingulate) herniation
What is Cushing’s triad seen in ICP?
- Increased systolic BP
- Irregular breathing
- Bradycardia
What investigations is done in ICP?
- URGENT HEAD CT
2. NEVER DO LP – can cause brainstem herniation
When is ICP worse and why?
- Headache worse in morning
1. rise in ICP during the night as a consequence of recumbency
2. a rise in PCO2 during sleep caused by respiratory depression
3. probably a decrease in CSF absorption
Why do you get decreasing GCS with increased ICP?
consequence of caudal displacement of the diencephalon and midbrain
How do you manage idiopathic rasied ICP?
- Management of risk factors (e.g. weight loss)
- Analgesia (Naproxen, Amitrytpiline)
- Or treat underlying cause
How can you see papillodema on fundoscopy?
not shrap optic disc slightly blurred
