hydrocephalus / ventricular system Flashcards
Hydrocephalus - types
- Communicating (nonobstructive)
- Noncommunicating (obstructive)
- Hydrocephalus mimics
- normal pressure hydrocephalus (a particular form of communicating hydrocephalus)
Hydrocephalus mimics –>
Ex vacuo ventriculomegaly –> appearance of increased CSF on imaging, due to decreased brain tissue (neuronal atrophy)
(TRIAD IS NOT SEEN)
Ex vacuo ventriculomegaly –>
appearance of increased CSF on imaging, due to decreased brain tissue (neuronal atrophy)
Ex vacuo ventriculomegaly is the appearance of increased CSF on imaging, due to
decreased brain tissue (neuronal atrophy)
causes of Ex vacuo ventriculomegaly
- Alzheimer disease
- advanced HIV
- Pick disease
- Huntington disease
Ex vacuo ventriculomegaly - ICP?
normal
Noncommunicating hydrocephalus is caused by
structural blockage of CSF circulation WITHIN ventricular system
Noncommunicating hydrocephalus is caused by structural blockage of CSF circulation with ventricular system - examples?
- stenosis of aqueduct of Sylvius
2. colloid cyst blocking foramen of Monro
Communicating (nonobstructive) hydrocephalus - types
- communicating hydrocephalus
2. normal pressure hydrocephalus
communicating hydrocephalus - mechanism
- decreased CSF absorption by arachnoid granulations
2. increased CSF production.
communicating hydrocephalus - clinical findings
- increased ICP
- papilledema
- herniation
communicating hydrocephalus - example of a cause
arachnoid scaring post-miningitis
Normal pressure hydrocephalus - affects the
elderly
causes of Normal pressure hydrocephalus
idiopathic
Normal pressure hydrocephalus - CSF pressure?
elevated only episodically
Normal pressure hydrocephalus do not result in
increased subarachnoid space volume
Normal pressure hydrocephalus causes (and mechanism)
expansion of ventricles distorts the fibers of the corona radiata –> triad of 1. urinary incontinence 2. ataxia
3. cognitive dysfunction (sometimes reversible)
(Does not results in increased subarachnoid space volume)
normal pressure hydrocephalus - symptoms
triad of 1. urinary incontinence 2. ataxia
3. cognitive dysfunction (sometimes reversible)