Hydrocephalus Flashcards
what most often causes porencephaly?
intrauterine parvovirus infection
where is CSF produced?
choroid plexus in lateral and third ventricle
choroid plexus in fourth ventricle
micro capillaries of subarachnoid space
how often is the total CSF replaced?
3-5 times daily
does increased intracranial pressure slow down CSF production?
no
how is CSF flow achieved?
mainly pulsatile function of blood flow to brain and choroid plexus
ciliary function of ependymal cells may contribute
what is the most important for cSF absorption?
arachnoid villi
in what type of hydrocephalus is intracranial pressure increased?
obstructive
what happens in compensatory hydrocephalus?
brain tissue is replaced by CSF
normal intracranial pressure
what are the clinical signs of congenital hydrocephalus?
dome shaped head, open fontanelle
dullness, dementia, learning deficits
difficulty to train habits
bilateral ventro-lateral strabismus
head pressing
blindness
ataxia
seizures
how old are dogs when they are usually diagnosed with congenital hydrocephalus?
3 months-1 year
what can loss of brain tissue be due to in compensatory hydrocephalus?
global ischemia
stroke
encephalitis
degenerative brain condition
radiation therapy
what is normal intracranial pressure?
8-13 mmHg
what can you give to reduce CSF production?
mannitol
hypertonic saline
omeprazole
acetazolamide
prednisone
how can you permanently control intracranial pressure?
ventriculo-peritoneal shunt
what is hydrocephalus?
increased CSF volume in ventricular system
often increased ICP
what causes the neurological deficits in hydrocephalus?
CSF accumulation
damage to nervous tissue structures
what is ventriculomegalia?
enlarged ventricular systeem
no clinical signs, breed specific
what is seen in hydranencephaly?
near total absence of cerebral neocortex and basal ganglia
no rim brain tissues between CSF accumulation and dura mater
asymmetrical remaining brain tissues
what do intrauterine parvovirus infections cause?
hydranencephaly
porencephaly
what is porencephaly?
cavities communicating with ventricles or subarachnoid space
how is CSF produced?
ultra filtration
constant flow rate
how is CSF absorbed?
arachnoid villi
cribriform plate
cranial nerves
nerve roots of front and hind legs
in what type of hydrocephalus is brain herniation a concern?
obstructive
what are the possible pathophysiologies to congenital hydrocephalus?
stenosis of mesencephalic aqueduct
malformation lateral ventricles
abnormally formed arachnoid villi
abnormal intrauterine development, delayed growth and patency of mesencephalic aqueduct
what are the disadvantages of an intracranial shunt?
infection
hemorrhage
where is the catheter in ventriculo-peritoneal shunt?
intra-ventricular
what are the components of a ventriculo-peritoneal shunt?
intra-ventricular catheter
pressure valve
abdominal catheter
what are the three major groups hydrocephalus?
congenital
obstructive
compensatory
