 GLOSSARY OF TERMS Adult Onset Normal Pressure Hydrocephalus A Work in Progress - Last Updated 8-13-06
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| ADULT ONSET HYDROCEPHALUS | Any
hydrocephalus
which
appears in adulthood from a variety of causes, including head injury,
stroke, meningitis, or unknown cause. |
| CATHETER |
Small silicone tube, the part of the shunt which allows the Cerebral Spinal Fluid to circulate. |
| CEREBROSPINAL FLUID |
Cerebrospinal Fluid is
a clear bodily fluid which provides a cushion between the skull and the
cerebral cortex. It also occupies the ventricular system of the
brain and the spinal cord. The body makes almost a pint of this
fluid daily. It is in constant production, circulation, and
absorption. The fluid provides nourishment, carries away any
debris (such as extra protein cells), and protects us from injury. |
| CEREBRAL VENTRICLES |
The chambers within the
brain
which contain Cerebral Spinal Fluid |
| CISTERNOGRAPHY | Isotopic cisternography involves injecting a radioactive isotope into the lower back through a spinal tap. This allows the absorption of CSF to be monitored over a period of time (up to 4 days of hospitilization) |
| CSF | See Cerebrospinal Fluid |
| COMMUNICATING
HYDROCEPHALUS |
Also described as
"non-obstructive", this type of hydrocephalus is caused by a lack of
absorption of the cerebral spinal fluid rather than a blockage. |
| CT SCAN |
Computed
Tomography
(CT) Scan of
the head uses an x-ray beam, which passes
through the head allowing a computer to make a picture of the brain in
slices. A
CT will show if the ventricles are enlarged or if there is an obvious
blockage. |
| DEMENTIA | Loss of mental
function. Caused
by head injury, disease (such as Alzheimers Disease or Hydrocephalus),
stroke, or medication. It can also be caused by a deficiency in
Vitamin B12 or other chemical imbalance. Sometimes cause is unknown.
May be exhibited by
mild confusion or profound mental disability. |
| ETV | Endoscopic Third Ventriculostomy (ETV)
is a surgical procedure which involves making a hole in the floor of
the
third ventricle to allow free flow of spinal fluid into the basal
cisterns for absorption. It is not commonly used to treat communicating
hydrocephalus, but it has been successful in some cases. |
| EXTERNAL VENTRICULAR
DRAIN (EVD) |
External Ventricular Drain (EVD) is device
somewhat similar to a shunt, functioning on the outside of the
body. A catheter is implanted into the brain to drain the excess
CSF (Cerebral Spinal Fluid). The flow is regulated by either
raising or lowering the bag (where the fluid is emptied into).
|
| FIXED SHUNT |
In a fixed shunt, the
valve is pre-set for high, medium, or low pressure. |
| HOSPITAL
PSYCHOSIS |
Hospital
Psychosis usually is a temporary period of anxiety, and even delusions
or hallucinations caused by the stressful environment of the
hospital. It is often difficult to diagnose, since medications,
anesthesia, and changes in the CSF pressure in the brain may cause
similar symptoms in some patients. For more about Hospital
Psychosis, visit this LINK.
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| HYDROCEPHALUS |
Hydrocephalus results
from the
accessive accumulation of cerebrospinal fluid in the brain. It
can be congenital or develop later in life from known or unknown causes. |
| ICP MONITOR |
Intracranial Pressure
Monitor. The placement of an Intracranial Pressure Monitor allows
for a period of continuous recording of intracranial pressure. It
allows the identification of episodic waves of high pressure that are
missed with isolated lumbar measurement. A catheter or small
fiber optic cable is inserted through the skull
into the brain. This procedure requires approximately 24 hours of
hospitalization. |
| IDIOPATHIC |
The dictionary says,
"arising spontaneously or from an obscure or unknown cause" |
| INCONTINENCE |
Inability to prevent
discharge
of urine or feces. Urinary urgency or incontinence is a common
symptom of Normal Pressure Hydrocephalus. |
| ISOTOPIC CISTERNOGRAPHY | Isotopic cisternography
involves injecting a radioactive isotope into the lower back through a
spinal tap. This allows the absorption of CSF to be monitored over a
period of time (up to 4 days of hospitilization) |
| LATERAL VENTRICLE | There are two Lateral
Ventricles, small chambers beneath
the surface of the brain that contain Cerebrospinal Fluid. Most of the
CSF is made by
the choroid plexus that lays on the floor of the lateral ventricles;
CSF must pass from the right and left lateral ventricles. These
are the ventricles affected by Normal Pressure Hydrocephalus. |
| LUMBAR PUNCTURE & LUMBAR DRAIN |
Lumbar puncture (spinal tap) can be used to measure CSF pressure and analyze the fluid. A LUMBAR DRAIN helps indicate whether a shunt, the common treatment for hydrocephalus, may be successful. Typically, it is conducted over a period of three or four days in the hospital while volume of Cerebrospinal Fluid removed is monitored. Even temporary improvement of symptoms is encouraging for the success of a shunt in treating the hydrocephalus. More on Lumbar Drain. |
|
LUMBO-PERITONEAL SHUNT (L-P) |
The CSF (Cerebrospinal
Fluid) is shunted from the lumbar sub-arachnoid spaces to the
peritoneal cavity.
|
| MRI |
Magnetic Resonance Imaging is non-invasive, using radio signals and a powerful magnet to show the anatomical structures of the brain. It can reveal if the ventricles are enlarged and evaluate the CSF flow. |
| NON-COMMUNICATING
HYDROCEPHALUS |
Non-Communicating
Hydrocephalus
is caused by a blockage of the flow of CSF (Cerebral Spinal Fluid). It
may have a number of causes, including congenital birth defect, brain
tumor, brain injury. |
| NORMAL PRESSURE HYDROCEPHALUS | Normal Pressure Hydrocephalus is a "communicating" or "non-obstructive" type of hydrocephalus. The distinguishing feature is the lack of absorption rather than the excess formation of fluid causing increased pressure. Except for occasional spikes in pressure, the pressure is "normal". The condition may have a number of causes, or the cause may never be known. It typically is diagnosed in patients over 55. |
| NPH | Normal Pressure Hydrocephalus |
| OBSTRUCTIVE
HYDROCEPHALUS |
See Non-Communicatng
Hydrocephalus. |
| OVER-DRAINAGE | Over-Drainage
is a condition in which too much
CSF is withdrawn from the cerebral ventricles. Usually symptoms are
noticed after being upright for awhile, and they can include headache
or migrane in the morning within an hour of getting up, dizziness,
nausea and vomiting. Over draining can result in 'slit
ventricle syndrome. Also called SYPHONING. |
| PERITONEUM | The thin lining of
body
cavities; CSF can be absorbed easily through the peritoneum lining the
abdominal cavity. |
| PROGRAMMABLE SHUNT |
A shunt which offers valve adjustment without surgery using a programming device. |
| SHUNT | In simple terms, the shunt is a mechanical
system that drains
cerebrospinal fluid from the brain to another cavity in the body.
The basic components of a shunt are
a silicone tube implanted in the ventricles of the brain, and the valve
may be fixed (set to low, medium or high) or programmable
(adjustable). The
tube leads to a valve which regulates Cerebrospinal Fluid pressure, and
adjusts to allow fluid to be released to a second tube. Typcially
this tube
is routed under the skin to release the fluid into the Peritoneal
Cavity (lower abdomen) or
the right atrium of the heart where it is absorbed by the
body. See also: VENTRICULO-ATRIAL
SHUNT (V-A), VENTRICULO-PERITONEAL
SHUNT (V-P), LUMBO-PERITONEAL SHUNT
(L-P) More about Shunts (with diagrams) |
| SHUNT SERIES |
A series of X-Rays
which follow the continuum of the shunt, from the valve through the
entire system. It is usually used in conjunction with the CT scan
to identify any problems. |
| SHYMA |
Syndrome
of
Hydrocephalus in
Young and Middle-aged Adults as described by Dr. Michael
Williams. See Hydrocephalus
Association web site. |
| SLIT VENTRICLE SYNDROME |
The ventricles become slit-like in
reaction to over-draining by the shunt. This often happens in
children who have been shunt dependent for several years. It may
cause headaches but may be asymptomatic. http://virtualtrials.com/shunts.cfm |
| THIRD VENTRICLE | The Third Ventricle is
the thin chamber deep in the
brain that contains CSF and connects the lateral ventricles to the
cerebral aqueduct; CSF must flow through the third ventricle in order
to exit the brain. |
| THIRD
VENTRICULOSCOPY |
The
surgical process of making a small hole in the floor of the third
ventricle so that CSF can escape into the subarachnoid space. This
procedure is used most often with pediatric cases of obstructive
(non-communicating) hydrocephalus. Normal Pressure Hydrocephalus
is a communicating hydrocephalus. Sources: Wayne State University |
| UNDER DRAINING (UNDER DRAINAGE) |
Under draining occurs when not enough
Cerebral Spinal Fluid (CSF) is taken. Symptoms usually come about
when the patient is either laying down or reclining the body at an
angle. Patient usually wakes up with a headache and it disappears
after he/she has been upright for 45 minutes to an hour (average). |
| VA SHUNT |
See Ventriculo-Atrial
Shunt |
| VENTRICLES |
There are 4 chambers in the brain,
called Ventricles, which produce the cerebral spinal fluid. The
lateral (2) ventricles - one is located on the left and right side of
the brain's hemispheres, the third is located in the middle, and the
4th is low and located at the back of the skull.The chambers within the
brain
which contain Cerebrospinal Fluid. Images of the Ventricles
of the brain. |
| VENTRICULO-ATRIAL
SHUNT (VA SHUNT) |
Shunt which drains the
CSF (Cerebrospinal Fluid) into the right atrium of the heart to be
absorbed into the blood stream. |
| VENTRICULO-PERITONEAL
SHUNT (VP SHUNT) |
Shunt
which drains the CSF (Cerebrospinal Fluid) into the abdominal cavity to
be absorbed by the peritoneum lining. This is the type of shunt most
often used to treat Normal Pressure Hydrocephalus. |
| VGB SHUNT Ventriculo-Gallbladder Shunt |
Shunt which drains the CSF into the
gallbladder. |
| VP SHUNT |
See
Ventriculo-Peritoneal
Shunt |
|
Thanks so much to Debbi Fields,
Director of the National Hydrocephalus Foundation, for her help with
these definitions, and her assistance and expert advice to this
group.
Other Sources: http://www.sophysa.com/patient/hydrocephalus/hydrocephalus8.htm http://www.neurosurgerytoday.org/what/patient_e/adult.asp http://www.hydroassoc.org/ http://www.hydrocephalus.org/facts/ http://www.nhfonline.org/treatment.php http://www.aafp.org/afp/20040915/1071.html |
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