ICP & Hydrocephalus Flashcards
What level is ICP at rest in adults?
7-15mmHg
What is the order in which fluid leaves the skull to compensate for raised ICP?
1) Venous blood
2) CSF
3) Arterial blood
Where is CSF made?
Choroid plexus of the Lat ventricles
What level of Cerebral Perfusion Pressure (CPP) is normal?
80-90
What level of CPP is life threating and not compatible with life?
Life threatening: 30
Not compatible with life >3min: 20
What is cerebral blood flow?
CPP/Cerebral vasc resistance
What does CO2 do to blood vessels?
CO2 is a potent dilator
What is communicating hydrocephalus?
Impaired CSF absorption
What are early signs of raised ICP?
Headache
Pupillary dysfunction +/- papilloedema
Changes in vision
Nausea and vomiting
↓ level of consciousness
What are late signs of raised ICP?
Coma
Fixed, dilated pupils
Hemiplegia
Bradycardia → Cushing’s triad
Hyperthermia
↑ urinary output
How is raised ICP managed non-medically?
Maintain head in midline to facilitate blood flow
Loosen tube ties, collars etc
HoB 30-45° elevation
Avoid gagging, coughing etc
Decrease environmental stimuli
Treat hyperthermia
Maintain fluid balance and normal electrolytes
Maintain normocarbia
How is raised ICP managed medically/surgically?
Diuretics (mannitol, hypertonic saline, furosemide)
Barbiturate coma (last choice before surgery)
Antiepileptics
Surgical decompression
What is chiari malformation?
When the cerebellar tonsils protrude below the area they are supposed to
What do patients with chiari malformation tend to present with?
Cough headache
Sleep apnoea
Syrinx (CSF flowing through central canal)
Can lumbar puncture be done in obstructive hydrocephalus?
No
How does communicating hydrocephalus present on CT?
Enlarged lateral, 3rd,& 4th ventricles
How does obstructive hydrocephalus present on CT?
Enlarged frontal horns
Rounded 3rd ventricle
Small/normal 4th ventricle
Who does normal pressure hydrocephalus present in?
Elderly
What triad does normal pressure hydrocephalus present with?
Hakim’s Triad:
- Abnormal gait
- Urinary incontinence
- Dementia
How is normal pressure hydrocephalus treated?
VP-shunt
Who most often present with idiopathic intracranial hypertension?
Woman of child-bearing age
Overweight
Signs and symptoms of idiopathic intracranial hypertension?
Headache
Double vision
Visual blurring
tinnitus
radicular pain
Papilloedema → 25% severe/permanent visual loss
How is idiopathic intracranial hypertension treated?
- Weight loss, bariatric surgery
- Diuretics
- CSF diversion
- Interventional radiology
