Hydrocephalus Flashcards
Describe the pathway of CSF through the brain
- Produced in choroid plexus
- Lateral ventricle
- Third ventricle
- Cerebral aqueduct
- Fourth ventricle
- Subarachnoid space
- Arachnoid granuations drains into dural venous sinus
What effect does ICP have on the rate of production of CSF?
CSF production rate is constant and not influenced by ICP
What drives the CSF resorption rate?
The difference between ICP and venous sinus pressure
If ICP is much higher than venous pressure, the resorption rate will be high
helps drain fluid to lower high ICP
What are the classical signs of ICP?
Headache Nausea and vomiting Neurological signs Neck stiffness Papilloedema
Definition and clinical signs of tonsilar herniation.
Herniation of cerebral tonsils through foramen magnum causing brainstem compression.
Bradycardia, hypertension, irregular breathing
Definition and clinical signs of subfalcine/cingulate herniation.
Herniation of cingulate gyrus under falx cerebri.
Compresses anterior cerebral artery causing leg sensorimotor symptoms
Definition and clinical signs of tentorial/uncal herniation.
Herniation of medial temporal lobe over tentorium cerebelli
Compresses oculomotor nerve causing exotropia, pupillary dilation and ptosis
Name of herniation of brain through fracture site.
Transcalvarial herniation
Name of herniation of medial temporal lobe over tentorium cerebelli.
Uncul/tentorial herniation
Name of herniation of cingulate gyrus under falx cerebri.
Subfalcine/cingulate herniation
Name of herniation of cerbellar tonsils through foramen magnum
Tonsilar herniation/Chiari malformation
Presentation of congenital hydrocephalus.
Bulging fontanelle
Large head diameter
Sunsetting (eyes pushed down)
Failure to thrive
Treatment of congenital hydrocephalus.
Shunt
What is the commonest cause of congenital hydrocephalus?
Aqueductal stenosis
Is congenital hydrocephalus communicating or communicating?
Non-communciating
Name 3 causes of acquired non-communicating hydrocephalus.
Brain tumour
Infection
Haemorrhage
What are the two broad underlying processes which can cause communicating hydrocephalus?
Which of these two is commoner?
Overproduction (choroid plexus tumour)
Decreased absorption (meningitis, haemorrhage)
Decreased absorption is far commoner as choroid plexus tumours are rare
Classic symptoms in normal pressure hydrocephalus?
Gait disturbance
Dementia
Incontinence
How do you diagnose normal pressure hydrocephalus
MRI (dilated ventricles)
Tap test, drain some CSF and test gait and memory after draining (should improve)
How do you treat normal pressure hydrocephalus?
Shunt
Patient has increased ICP without dilatation of the ventricles.
What would you expect this patient to be like?
Young obese female
idiopathic intracranial hypertension
What is idiopathic intracranial hypertension?
Increased ICP without dilatation of the ventricles
How do you manage idiopathic intracranial hypertension?
Weight loss (first line)
Acetazolamide (second line)
Shunt (third line)
Subtemporal decompression (last line)
Patient presents with headache worse on standing up and galactorrhea.
Diagnosis?
What is this condition?
spontaneous intracranial hypotension
CSF leak in spinal cord secondary to connective tissue disease or trauma
Patient present with involuntary movements and hyperhidrosis
Diagnosis?
What is this condition?
Syringomyelia
Rare CSF filled cyst from dilated central canal
What are syringomyelia associated with?
Trauma
Chiara malformation
Name given to dilated ventricles caused by cortical atrophy?
Hydrocephalus ex vacuo
