Raised Intracranial Pressure Flashcards
Conditions
What is meningitis?
Inflammation of the meninges, most commonly viral
What are the clinical features of meningitis?
Photophobia
Nuchal rigidity
Brudzinski’s sign (bending head forward causes hip flexion)
Kernig’s sign (pain on extending knee during hip flexion)
What investigations can be done in suspected meningitis?
CT Lumbar puncture FBC, CRP, PGLU, COAG, EUC, Blood culture Chest x-ray to rule out pneumonia STIX to rule out UTI
How is meningitis managed?
In suspected meningitis give benzylpenicillin 1.2mg IM/IV immediately
ABC, protect airway, high flow O2, fluids
Antibiotics: cefotaxime (+ampicillin in over 55s)
Aciclovir if viral encephalitis is suspected
How would normal pressure hydrocephalus present?
Wet
Wobbly
Wacky
What would be found on CT/MRI in a patient with normal pressure hydrocephalus?
Communicating hydrocephalus
How are symptoms relieved in normal pressure hydrocephalus?
Symptoms improve with removal of CSF, gait first then incontinence and finally memory improvements
Describe the production, flow and reabsorption of CSF
Choroid plexus in the lateral ventricles, through foramen of Monro into 3rd ventricle, through aqueduct into 4th, out through Luschka and Magendie, around brain and spinal cord, reabsorbed by arachnoid villi in venous sinuses by pressure gradient
What usually results in communicating hydrocephalus (CoH)?
A problem with CSF resorption. Production>resorption
How does CoH usually present in young children?
Before sutures fuse, presents with disproportional increase in head circumference
How does CoH usually present in adults?
With symptoms of raised intracranial pressure
What are common symptoms of raised intracranial pressure?
Headache Nausea/vomiting Papilledema Gait disturbance 6th cranial nerve palsy Up gaze difficulty
What are possible causes of CoH?
Infection
Subarachnoid haemorrhage
Postoperative
Head trauma
What causes a non-communicating hydrocephalus (NCH)?
Any physical obstruction to normal flow of CSF
Give some example causes of a non communicating hydrocephalus ?
Aqueductal stenosis Tumour, masses, cancers Cysts Infection Haemorrhage Congenital
What is the earliest finding in hydrocephalus on a radiological scan?
Dilation of the temporal horns of the lateral ventricles. (They should be almost invisible in a normal brain scan)
What is the Evans ratio?
The ratio between the anterior horn width vs the width of the calvarium at the level of the foramen of Munro
How are cases of hydrocephalus treated?
Surgically
What is used as an emergency treatment for acute hydrocephalus?
External ventricular drain (EVD). A catheter through the scalp and skull into the lateral ventricle
What shunts can be used in hydrocephalus?
Ventriculo-peritoneal
Lumbar-peritoneal
Ventriculo-atrial
Why might a lumbar-peritoneal shunt be avoided?
Can cause overdrainage
Why might a ventriculo-atrial shunt be considered?
If a ventriculo-peritoneal shunt fails
What two methods can be used in NCH?
Removing the blockage
Third ventriculostomy
What is done in a third ventriculostomy?
Surgically open a hole in the floor of the thrid ventricle to allow CSF to flow straight into the interpeduncular cistern and pre-pontine space, bypassing the aqueduct
