HYDROCEPHALUSNEIL BARRY11/0537/1159MEDICAL AND SURGICALCONDITIONS

Definition Hydrocephalus is an abnormal expansion of cavities

(ventricles) within the brain that is caused by the accumulation of cerebrospinal fluid. Hydrocephalus comes from two Greek words: hydros means water and cephalus means head.

There are two main varieties of hydrocephalus: congenital and acquired. An obstruction of the cerebral aqueduct (aqueductal stenosis) is the most frequent cause of congenital hydrocephalus. Acquired hydrocephalus may result from spina bifida, intraventricular hemorrhage, meningitis, head trauma, tumors, and cysts.

Definition of Adult Hydrocephalus Ventricular enlargement due to altered

CSF flow or resorption, with or without symptoms or neurologic impairment

Obstructive Hydrocephalus Impairment of CSF flow within the ventricular

system Communicating Hydrocephalus

Impairment of CSF flow or resorption outside the ventricular system

Impaired flow through the subarachnoid space Impaired resorption at the arachnoid

granulations

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Hydrocephalus is the result of an imbalance between the formation and

drainage of cerebrospinal fluid (CSF). Approximately 500 milliliters (about a pint) of CSF is formed

within the brain each day, by epidermal cells in structures collectively called the choroid plexus. These cells line chambers called ventricles that are located within the brain.

There are four ventricles in a human brain. Once formed, CSF usually circulates among all the ventricles before it is absorbed and returned to the circulatory system.

The normal adult volume of circulating CSF is 150 ml. The CSF turn-over rate is more than three times per day. Because production is independent of absorption, reduced absorption causes CSF to accumulate within the ventricles.

Obstructive Hydrocephalus:Aqueductal Stenosis

36-yo man with headaches,syncope, job impairment

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Communicating Hydrocephalus Idiopathic

In the elderly, normal pressure hydrocephalus

Chronic, insidious onset Symptomatic (secondary)

hydrocephalus Post-subarachnoid hemorrhage

(aneurysm), post-infectious, post-traumatic

Acute, subacute or chronic onset

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Normal Pressure Hydrocephalus NPH is a treatable form of dementia,

gait apraxia and urinary incontinence Treatment is surgical--shunt insertion Treatable nature of NPH distinguishes it

from the essentially untreatable nature of most dementias

Common diagnostic tests do not predict the outcome from shunt surgery very well

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NPH Diagnosis NPH clinically overlaps with many

conditions of the elderly Vascular dementia Degenerative dementias or disease Cervical stenosis/myelopathy Lumbar stenosis Peripheral neuropathy

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Aetiology Hydrocephalus has a variety of causes

including: congenital brain defects hemorrhage, either into the ventricles or

the subarachnoid space infection of the central nervous system

(syphilis, herpes, meningitis, encephalitis, or mumps)

tumor

Hydrocephalus that is congenital (present at birth) is thought to be caused by a complex interaction of genetic and environmental factors. Aqueductal stenosis, an obstruction of the cerebral aqueduct, is the most frequent cause of congenital hydrocephalus.

Signs and symptoms of elevated-pressure hydrocephalus include:

headache nausea and vomiting, especially in the

morning lethargy disturbances in walking (gait) double vision subtle difficulties in learning and memory delay in children achieving developmental

milestones

Irritability is the most common sign of hydrocephalus in infants. If this is not treated, it may lead to lethargy. Bulging of the fontanelles, or the soft spots between the skull bones, may also be an early sign. When hydrocephalus occurs in infants, fusion of the skull bones is prevented. This leads to abnormal expansion of the skull.

Symptoms of normal pressure hydrocephalus include dementia, gait abnormalities, and incontinence (involuntary urination or bowel movements).

TREATMENT The primary method of treatment for both

elevated and normal pressure hydrocephalus is surgical installation of a shunt. A shunt is a tube connecting the ventricles of the brain to an alternative drainage site, usually the abdominal cavity. A shunt contains a one-way valve to prevent reverse flow of fluid. In some cases of non-communicating hydrocephalus, a direct connection can be made between one of the ventricles and the subarachnoid space, allowing drainage without a shunt.

Spina Bifida

Spina Bifida

Spina bifida begins usually before the woman knows she is pregnant (day 21-28)

The tissues that form the neural tube do not close or stay completely closed.

An opening in the vertebrae that protect the spinal cord is formed.

Potential Causes

Homocysteine concentration in the bloodstream is increased Homocysteine is a byproduct of

Methionine It can be reused to recreate Methionine In acetaminophen poisoning, methionine

prevents the breakdown products of acetaminophen from damaging the liver.

Potential Causes Cont’d

A family with one child that has spina bifida are 8 times more likely to have another with the disease

Genetic factors (heredity)Environmental factors

Nutrition Substance exposure Decreased folic acid intake during

pregnancy

Types and of Spina Bifida

1. Occulta “hidden”this type is covered by a layer of skin and is not visible outside the body, however the vertebrae are malformed.

2. Meningocelethe spinal cord membrane bulges out of an opening that is caused by damaged or missing vertebrae and is usually seen as a cyst or bump covered by skin, the spinal cord develops normally

3. Myelomeningocelethe spinal cord, nerves and membrane sticks out from the opening in the spine, usually breaking the skin causing spinal fluid leakage. After surgery, paralysis is still present.

Spina Bifida Complications

Degrees of spine exposure at birth can cause: Paralysis Need for surgery Spine problems More mild problems that require the use of

crutches, wheelchair, or leg braces.Can also be accompanied by learning

problems, and difficulties with bowels and urination, as well as fluid on the brain

TreatmentMeningocele can be treated surgically

to restore normal spinal cord functionMyelomeningocele spina bifida is

operated on within 48 hours after birth to prevent severe bacterial infection. Surgeons place the spinal cord back in the canal and cover it with muscle and skin. Paralysis and bowel problems still persist after surgery.

Treatment Initial surgery may be carried out during the first days of

life, providing protection against injury and infection. Subsequent surgery is often necessary to protect against

excessive curvature of the spine, and in the presence of hydrocephaly, to place a mechanical shunt to decrease the pressure and amount of cerebrospinal fluid in the cavities of the brain.

Because of weakness or paralysis below the level of the spine abnormality, most children will require physical therapy, bracing, and other orthopedic assistance to enable them to walk. A variety of approaches including periodic bladder catheterization, surgical diversion of urine, and antibiotics are used to protect urinary function

Benefits• Decrease handicaps• Corrected brain

malformationsRisks• Infection• Blood loss• Premature delivery• Organ immaturity• Death

Fetal Surgery Treatment

References

http://kidshealth.org/kid/health_problems/birth_defect/spina_bifida_p2.html

http://www.medscape.com/viewarticle/525049 www.ninds.nih.gov/disorders/spina_bifida/spina_bifida.htm

www.sbhao.on.ca/SBinfo.asp http://www.fetal-surgery.com/ "Hydrocephalus." American Association of Neurological

Surgeons/Congress of Neurological Surgeons. http://www.neurosurgery.org/pubpages/patres/hydrobroch.html .⟨ ⟩

"Hydrocephalus." Institute for Neurology and Neurosurgery. Beth Israel Medical Center, New York, NY. http://nyneurosurgery.org/child/hydrocephalus/hydrocephalus.ht⟨

m .⟩ "Hydrocephalus." National Library of Medicine. MEDLINEplus.

http://www.nlm.nih.gov/medlineplus/hydrocephalus.html.