Hydrocephalus Flashcards
What is hydrocephalus?
The accumulation of CSF in or around the ventricles, which usually results in ventricular expansion and pressure on other parts of the brain. Hydrocephalus is usually secondary to another condition and can be congential or acquired. It can happen idiopathically in adults or secondary to atrophy, strokes, or other conditions.
What can be seen with hydrocephalus?
Accumulation of CSF results in impairment of gait, atypical eye movements, headaches, vomiting, and cognitive difficulties.
Treatment is required to prevent additional injury to the brain and death.
What is normal pressure hydrocephalus?
Results from impaired reabsorption of CSF, leading to ventriculomegaly. May be associated with increased intracranial pressure that is sporadic and fluctuating.
In some cases, NPH has no obvious cause, but may be due to another injury, such as tumor, hemorrhage, or TBI.
Idiopathic NPH is not well understood.
What is the overall prevalence of NPH?
About .5%
Within whom is NPH diagnosed?
Most common in people over age 65.
How is NPH diagnosed?
Often diagnosed by radiological study in people presenting with headaches, urinary incontinence, gait abnormalities, and mental decline. Can be confused with PD and other forms of dementia. When it is not identified, it can be very incapacitating. Early identification is important as symptoms may be reversed with treatment (shunting to reduce accumulation of CSF or enlargement of ventricles).
Describe treatments for NPH
Most common treatment is implantation of a shunt that diverts the flow of CSF around the site of blockage. The most common shunt placement is in a right posterior ventricle with a valve that drains fluid into the peritoneal cavity (below intestines). However, any ventricle is a candidate for shunting, and it is not unusual to have bilateral shunts. Other treatments include endoscopic third ventriculostomy, in which the floor of the 3rd ventricle is perforated to drain CSF into an open CSF space. Shunts often fail and need to be revised - which may involve replacing the shunt, lengthening the tube, or other procedures. Shunts can also become blocked or infected. Shunts do alleviate pressure on the brain and can restore motor and mental functions.
What are expectations neuropsychologically for adults presenting with idiopathic NPH?
NP performance may be variable. Areas of poor performance often improve with shunting. Deficits are especially apparent on motor-based tasks, but extend to most areas assessed, including attention, processing speed, spatial skills, and executive functions.
Improvement after shunting is most likely to be seen in who?
Patients who have not shown severe gait difficulties or evidence of dementia or stroke.
What would be the expected neuropsych profile for congenital hydrocephalus?
IQ - lower PRI vs VCI. Poorer scores observed on tasks with a motor component.
Achievement - poor math. Ok reading and spelling.
Attn - impaired focused and sustained attn
PS - impaired, especially on paper and pencil timed tasks
Language - largely preserved
Visuospatial - complex visuoconstruction impaired
Memory - verbal and nonverbal learning and memory impaired
Exec fxn - impaired on most tests. may be secondary to attention and motor px
Sensorimotor - motor deficits
What are common types of congenital hydrocephalus?
Spina bifida
Aqueductal stenosis
Dandy Walker syndrome
prematurity intraventricular hemorrhage
What is internal hydrocephalus?
Usually refers to obstructive hydrocephalus involving the foramen of Monro or aqueductal stenosis. These are classic forms of congenital hydrocephalus that result in accumulation of CSF, increased intracranial pressure, ventricular expansion, and compression of the brain
What is external hydrocephalus?
Usually involves the subarachnoid spaces and is most often used to describe individuals with disorders of CSF absorption (e.g., meningitis), but is also used to describe other forms of hydrocephalus external to the ventricles that do not necessarily involve increased intracranial pressure.
What is communicating hydrocephalus?
Communicating hydrocephalus is not an obstructive process. It refers to abnormalities of CSF absorption. Can occur after injuries affecting the subarachnoid space around the ventricles that are involved in absorption of CSF. Intracranial pressure is not always increased in these examples of ventricular enlargement with accumulated CSF. An example is the development of enlarged ventricles in people with dementia and other conditions associated with brain tissue loss.
What is noncommunicating hydrocephalus?
Noncommunicating hydrocephalus is the obstructive form of hydrocephalus associated with congenital disorders, but can be associated with other disorders (e.g., cysts) that obstruct the outflow of CSF into the subarachnoid space.
