Raised intracranial pressure Flashcards
What is normal ICP
7-15mmHg in supine adults
What is cerebral perfusion pressure
net pressure gradient causing cerebral blood flow to the brain
MAP -ICP
What are some causes of ICP
space-occupying lesions
cerebral oedema
increased BP in CNS
hydrocephalus
How may someone that has raised ICP present
Headache - nocturnal or upon waking
worse on coughing/straining
Nausea and vomiting
Visual problems -
ptosis
cranial nerve 3 and 6 palsies
papilloedema
enlarged blind spots and constricted fields
Cushings triad
What is cushings triad
Widening PP
Bradycardia
irregular breathing
What is hydrocephalus
increase in circulating volume of CSF within cerebral ventricles beyonde normal limits
What is first line investigation
CR/MRI
normal CT does not necessarily exclude raised ICP
What are the 4 types of hydrocephalus
communicating - impaired absorption of CSF
non-communicating - obstructive
Normal pressure hydrocephalus -
dilated cerebral ventricles
triad of urinary incontinence, dementia , gait disturbances
Hydrocephalus ex vacuo
- compensatory dilation of ventricles and spaces in response to brain atrophy
What are other investigations
Invasive ICP monitoring
- catheter placed in lateral ventricles
-can take CSF samples and drain small amounts
- cut off >20mmHg determines need for further treatment
What is management for raised ICP
treat underlying cause
head elevation
IV MANNITOL -osmotic diuretic
controlled hyperventilation
- reduce CO2 means vasoconstriction fo cerebral arteries, reduced ICP
Removal of CSF
drain from intraventricular monitor
repeated LP
Ventriculoperitoneal shunt for hydrocephalus
