Hydrocephalus is a condition in which there is cerebrospinal fluid accumulation (CSF) in the brain. This usually causes increased pressure inside the skull. Older people may experience headaches, double vision, poor balance, urinary incontinence, personality changes, or mental disorders. In infants there may be a rapid increase in head size. Other symptoms may include vomiting, drowsiness, seizures, and eyesight down the eyes.
Hydrocephalus may occur due to birth defects or acquired later in life. Associated birth defects include neural tube defects and those that cause aqueductal stenosis. Other causes include meningitis, brain tumors, traumatic brain injury, intraventricular hemorrhage, and subarachnoid hemorrhage. There are four types of hydrocephalus: communicating, not communicating, ex-vacuo, and normal pressure. Diagnosis is usually done by medical examination and imaging.
Hydrocephalus is usually treated by a surgical placement of the shunt system. A procedure called third ventriculostomy can be an option in some people. Complications of the shunt may include overdrainage, underdrainage, mechanical failure, infection, or obstruction. This may require replacement. Results vary; However, many people with shunts live a normal life. Without treatment, death can occur.
About one to two per 1,000 newborns have hydrocephalus. Rates in developing countries may be more. The normal pressure of hydrocephalus is thought to affect about 5 per 100,000 people with increased rates as they get older. Description of hydrocephalus by Hippocrates dates back more than 2000 years. The word "hydrocephalus" comes from the Greek hydro - , which means 'water', and kephalos , meaning 'head'.
Video Hydrocephalus
Signs and symptoms
Clinical presentation of hydrocephalus varies with chronicity. Acute dilation of the ventricular system is more likely to manifest by nonspecific signs and symptoms of increased intracranial pressure. In contrast, chronic dilatation (especially in the elderly population) may have a more dangerous onset, for example, with a Triad of Judges (Adams triad).
Symptoms of increased intracranial pressure may include headache, vomiting, nausea, papilledema, drowsiness or coma. Increased intracranial pressure can lead to uncal or tonsillar herniation, leading to life-threatening compression of the brain stem.
Three of the way instability, urinary incontinence and dementia are relatively typical manifestations of different entities of normal pressure of hydrocephalus (NPH). Focal neurologic deficits may also occur, such as abducens nerve palsy and vertical gaze palsy (Parinaud syndrome due to quadrigeminal plate compression, in which the nerve center coordinating conjugated vertical eye movements resides). The symptoms depend on the cause of the blockage, the age of a person, and how much brain tissue has been damaged by the swelling.
In infants with hydrocephalus, CSF accumulates in the central nervous system, causing the fontanelle (soft spot) to stand out and the head to be larger than expected. Early symptoms may also include:
- The eyes that look down;
- Irritability;
- Seizures;
- Stitches apart;
- Sleepiness;
- Vomiting.
Possible symptoms in older children may include:
- A short, squeaky, high-pitched cry;
- Changes in personality, memory, or ability to think or think;
- Change of face appearance and eye distance;
- Uncontrolled eye or eye movements;
- Difficulty eating;
- Excessive sleepiness;
- Headaches;
- Irritability, poor emotional control;
- Loss of bladder control (urinary incontinence);
- Loss of coordination and difficulty walking;
- Muscle flexibility (seizures);
- Slow growth (children 0-5 years);
- Slow or limited movement;
- Vomiting.
Because hydrocephalus can injure the brain, thoughts and behavior can be affected. Learning disabilities including short-term memory loss are common among those with hydrocephalus, which tend to score better on verbal IQ than on performance IQ, which is thought to reflect the distribution of nerve damage to the brain. However, the severity of hydrocephalus can vary greatly between individuals and some average or above average intelligences. A person with hydrocephalus may have coordination and visual problems, problems with coordination, or may be awkward. They may reach puberty earlier than the average child (see puberty prematurely). About one in four have epilepsy.
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Cause
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Congenital hydrocephalus is present in infants before birth, which means the fetus develops hydrocephalus in the uterus during fetal development. The most common cause of congenital hydrocephalus is aqueductal stenosis. Aqueductal stenosis occurs when a narrow section between the third and fourth ventricles in the brain is hampered or too narrow to allow the cerebral spinal fluid to flow enough. The fluid accumulates in the upper ventricle, causing hydrocephalus.
Other causes of congenital hydrocephalus include neural tube defects, arachnoid cysts, Dandy-Walker syndrome, and Arnold-Chiari malformation.
The skull bones join at the end of the third year of life. For a head enlargement to occur, hydrocephalus must occur before that. The causes are usually genetic but also obtainable and usually occur within the first few months of life, which includes 1) intraventricular matrix haemorrhage in premature infants, 2) infection, 3) Arnold-Chiari type II malformation, 4) waterway atresia and stenosis, and 5 ) Dandy-Walker Malformation.
In newborns and toddlers with hydrocephalus, the head circumference swelled rapidly and soon surpassed the 97th percentile. Because the skull bones have not been united strongly, prominently, the anterior and posterior fontanella may be present even when the patient is in an upright position.
Babies show fretfulness, lack of food, and frequent vomiting. When hydrocephalus develops, suspended animation occurs, and the baby shows a lack of interest around him. Then, the upper eyelid becomes pulled and the eyes are turned downwards ("sunset eyes") (due to the hydrocephalic pressure on the mesencephalic tegmentum and the paralysis of the upward view). The movement becomes weak and the arms become shaky. Papilledema is absent but there may be reduced vision. The head becomes so enlarged that the child can finally lie in bed.
About 80-90% of fetuses or newborns with spina bifida - often associated with meningocele or myelomeningocele - develop hydrocephalus.
Acquired
This condition is obtained as a result of CNS infection, meningitis, brain tumor, head trauma, toxoplasmosis, intracranial hemorrhage (subarachnoid or intraparenchymal) and usually painful.
Type
The cause of hydrocephalus is not known with certainty and may be multifactorial. This may be caused by a disruption of cerebrospinal fluid flow (CSF), reabsorption, or excessive CSF production.
- CSF flow obstruction blocks the cerebrospinal fluid-free pathway through ventricular and subarachnoid systems (eg, cerebrospinal duct stenosis or obstruction of the foramen interventricular) secondary to tumors, haemorrhages, infections or congenital malformations) and may result in increased system stress central nervous system.
- Hydrocephalus may also be caused by excess production of cerebrospinal fluid (relative obstruction) (eg, Choroid plexus papilloma, villous hypertrophy).
- Bilateral ureteral obstruction is a rare cause of hydrocephalus, but is reported.
Based on the underlying mechanism, hydrocephalus can be classified into communicating and non-communicating (obstructive). Both forms can be either congenital or acquired.
Communicate
Communicating hydrocephalus, also known as non-obstructive hydrocephalus, is caused by a cerebrospinal fluid reabsorption disorder in the absence of CSF flow obstruction between the ventricle and subarachnoid space. It has been suggested that this is due to a functional disorder of arachnoid granulation (also called arachnoid granulation or Pacchioni granulation), which lies along the superior sagittal sinus and is the site of reabsorption of the cerebrospinal fluid back into the venous system. Various neurological conditions may result in hydrocephalus communication, including subarachnoid/intraventricular hemorrhage, meningitis and absence of congiital villi arachnoid. Subarachnoid scarring and fibrosis after infection, inflammation, or hemorrhagic events can also prevent CSF resorption, leading to diffuse ventricle dilatation.
Non-communicating
Noncommunicative hydrocephalus, or obstructive hydrocephalus, is caused by CSF-flow obstruction.
- The Foramen of Monro obstruction can cause a single dilation or, if large enough (eg, in colloid cysts), both lateral ventricles. The water channel from Sylvius, usually narrow to begin with, may be blocked by a number of genetic or acquired lesions (eg, atresia, ependymitis, bleeding, tumors) and leads to dilatation of both the lateral ventricle and the third ventricle.
- The four ventricular obstruction will lead to dilatation of the waterways as well as the lateral and third ventricle (eg, Chiari malformation).
- The Luschka foramen and Magendie foramen may be blocked due to congenital malformations (eg Dandy-Walker malformations).
More
- The normal pressure of hydrocephalus (NPH) is a particular form of chronic hydrocephalus that is communicated, characterized by enlarged cerebral ventricles, with only intermittently elevated cerebrospinal fluid pressure. Characteristics of triassic symptoms are; dementia, apraxic action and urinary incontinence. The diagnosis of NPH can be established only with the help of continuous recording of intraventricular pressure (more than 24 hours or longer), as more often than indirect measurements produce a normal pressure value. Dynamic compliance studies can also help. Changes in adherence (elasticity) of the ventricular wall, as well as increased viscosity of cerebrospinal fluid, may play a role in pathogenesis. Hydrocephalus ex vacuo also refers to enlargement of the cerebral ventricles and subarachnoid space, and usually due to brain atrophy (as occurs in dementia), post-traumatic brain injury and even in some psychiatric disorders, such as schizophrenia. In contrast to hydrocephalus, this is the imposition of CSF space compensation in response to parenchymal loss of the brain - not a result of increased CSF pressure.
Mechanism
Hydrocephalus is usually due to a blockage of cerebrospinal fluid flow (CSF) in the ventricle or in the subarachnoid space in the brain. In a person without hydrocephalus, CSF continues to circulate through the brain, ventricle and spinal cord and is continuously channeled into the circulatory system. Alternatively, this condition may be due to the overproduction of CSF, from congenital malformations blocking normal drainage of fluid, or from complications of head or infection injury.
Brain compression by accumulated fluid can eventually lead to neurological symptoms such as convulsions, intellectual disabilities and epileptic seizures. These signs occur more quickly in adults, whose skulls can no longer be extended to accommodate the increased volume of fluid in them. Fetuses, infants, and young children with hydrocephalus usually have abnormally large heads, excluding the face, because fluid pressure causes the individual skull bones - which have not yet fused - to bulge out at their time points. Another medical sign, in infants, is a typical fixed picture with white eyes on the iris, as if the baby is trying to check its own lower eyelid.
High intracranial pressure can cause brain compression, which causes brain damage and other complications. The conditions among affected individuals vary greatly.
If the fourth ventricle foramina or cerebral ducts are blocked, cerebrospinal fluid (CSF) may accumulate in the ventricles. This condition is called internal hydrocephalus and results in an increase in CSF pressure. The production of CSF continues, even when parts that normally allow it to get out of the brain are blocked. As a result, fluid builds up inside the brain, causing pressure that dilates the ventricles and suppresses the neural tissues. Nerve tissue compression usually results in irreparable brain damage. If the skull bone does not fully harden when hydrocephalus occurs, the pressure can also greatly enlarge the head. Cerebral waterways may be blocked at birth or may become blocked at a later date because of tumors that grow in the brainstem.
Treatment
Hydrocephalus can be successfully treated by placing a drainage tube (shunt) between the ventricles of the brain and the abdominal cavity. There is some risk of infection being inserted into the brain through these shunts, however, and the shunt should be replaced as the person grows. Subarachnoid hemorrhage can block the return of CSF to the circulation.
It must be distinguished from external hydrocephalus. This is a condition commonly seen in infants and involves an enlarged fluid space or subarachnoid space around the outside of the brain. This is generally a benign condition that resolves spontaneously at the age of 2 years. (Greenberg, Handbook of Neurosurgery, 5th Edition, p. 174). Good imaging studies and medical history can help distinguish external hydrocephalus from subdural hemorrhage or a collection of chronic extra-axial fluid accompanied by vomiting, headache and seizures.
Hydrocephalus treatment is surgical, creating a way for excess fluid to dry. In the short term, external ventricular duct (EVD), also known as extraventricular drain or ventriculostomy, provides relief. In the long run, some patients will require different types of cerebral shunt. This involves placing a ventricular catheter (a silicone tube) into the cerebral ventricle to pass through the flow of obstruction/arachnoid granulation malfunction and drain the excess fluid into another body cavity, from which it can be reabsorbed. Most shunts drain fluid into the peritoneal shunt, but alternate sites include the right atrium (ventriculo-atrial shunt), the ventriculo-pleural shunt, and the gallbladder. The shunt system can also be placed in the spinal lumbar space and has CSF directed into the peritoneal cavity (Lumbar-peritoneal shunt). The alternative treatment for obstructive hydrocephalus in selected patients is the third ventriculostomy endoscopy (ETV), where surgery is made on the third ventricular floor allowing CSF to flow directly into the basal cistern, resulting in any obstruction shortcuts, such as aqueductal stenosis. It may or may not be appropriate based on individual anatomy. For infants, ETV is sometimes combined with choroid plexus cauterization, which reduces the amount of cerebrospinal fluid produced by the brain. The technique, known as ETV/CPC was pioneered in Uganda by neurosurgeon Ben Warf and is now used in several US hospitals.
Shunt Complication
Examples of possible complications include shunt malfunction, shunt failure, and shunt infection, along with shunt infection after surgery (the most common reason for shunt failure is shunt channel infection). Although the shunt generally works well, it may stop working if it is disconnected, becomes blocked (clogged), infected, or too large. If this happens, the cerebrospinal fluid will begin to accumulate again and a number of physical symptoms will develop (headache, nausea, vomiting, photophobia/light sensitivity), some very serious, such as seizures. The rate of shunt failure is also relatively high (from 40,000 surgeries performed annually to treat hydrocephalus, only 30% is the patient's first surgery) and it is not uncommon for patients to have multiple shunt revisions in their lifetime.
Other complications can occur when CSF flows faster than those produced by the choroid plexus, causing symptoms - lethargy, severe headaches, irritability, light sensitivity, hearing hyperesthesia (nausea), nausea, vomiting, dizziness, vertigo, migraine, seizures, changes personality, weakness in the arms or legs, strabismus, and double vision - appear when the patient is vertical. If the patient is lying down, symptoms usually disappear quickly. CT scans may or may not show changes in ventricular size, especially if the patient has a ventricular history such as a gap. The difficulty in diagnosing overdrainage can make the treatment of these complications extremely frustrating for patients and their families. Resistance to traditional analgesic pharmacology therapy can also be a sign of failure overdrainage or failure.
The diagnosis of cerebrospinal fluid buildup is complex and requires specialist expertise. The diagnosis of a particular complication usually depends on when the symptoms appear - that is, whether the symptoms appear when the patient is upright or in a prone position, with the head at about the same level as the legs.
Developing country
Since shunt systems are too expensive for most people in developing countries, such people often die without getting a shunt. Worse, the revised level in the shunt system adds to the cost of shunting many times. Seeing this, a study compares the shunt system and highlights the role of cheap shunt systems in most developing countries. It compares the Chhabra shunt system to the shunt system of the developed countries.
History
Reference to the hydrocephalus skull can be found in the ancient Egyptian medical literature from 2500 BC to 500 AD. Hydrocephalus is described more clearly by the ancient Greek physician Hippocrates in the 4th century BC, while a more accurate description was then given by the Roman physician Galen in the 2nd century.
The first clinical description of the surgical procedure for hydrocephalus appears in Al-Tasrif (1000 AD) by the Arab surgeon, Abulcasis, which clearly describes the evacuation of superficial intracranial fluid in children with hydrocephalus. He described it in a chapter on neurosurgery, describing infantile hydrocephalus caused by mechanical compression. He writes:
Newborn skulls are often full of fluid, either because the guards have overcompensated them or for other unknown reasons. The volume of the skull then increases daily, so the skull bone fails to close. In this case, we must open the center of the skull in three places, make the liquid flow out, then close the wound and tighten the skull with a bandage.
In 1881, several years after the study of landmark Retzius and Key, Carl Wernicke pioneered a sterile ventricular stitch and an external drainage of cerebrospinal fluid for the treatment of hydrocephalus. This remained a tough condition until the 20th century, when shunts and other neurosurgical treatment modalities were developed.
This is a lesser known medical condition; relatively little research has been done to improve treatment, and there is still no cure. In developing countries, this condition is often not handled at birth. Before birth, the condition is difficult to diagnose, and there is limited access to medical care. However, when the bloated head protrudes, children are taken at great expense for care. At that time, brain tissue has not developed and neurosurgery is rare and difficult. Children are more often living with undeveloped brain tissue and consequential intellectual disabilities.
Society and culture
Awareness campaign
September was designated the National Hydrocephalus Awareness Month in July 2009 by the US Congress at HR373. The Resolution Campaign was partly due to Advocacy work from Pediatric Hydrocephalus Foundation, Inc. Prior to July 2009, there was no month of Awareness for this condition. Many hydrocephalus organizations in the United States use a variety of ribbon designs as part of their awareness and fundraising activities.
Exceptional case
One extraordinary case of hydrocephalus is a man whose brain shrinks onto a thin sheet of tissue, due to the buildup of cerebrospinal fluid in his skull. As a child, the man had a shunt, but it was removed when he was 14. In July 2007, at the age of 44, he went to the hospital because of a mild weakness on his left leg. When doctors know the medical history of the man, they do a tomography (CT) scan and magnetic resonance imaging (MRI), and are surprised to see the "enlargement" of the lateral ventricle in the skull. Dr Lionel Feuillet from HÃÆ'Â'pital de la Timone in Marseille said, "The pictures are the most unusual... the brain is almost nonexistent." The intelligence test shows the patient has an IQ of 75, below the average value of 100. This would be considered "limiting intellectual function", just above what is officially regarded as a mental challenge.
Patients are fathers who marry two children, and work as civil servants, leading the most superficial normal life, even though the ventricles are enlarged with decreased brain tissue volume. "What I find incredible for today is how the brain can handle something you think should not be compatible with life", comments Dr Max Muenke, a pediatric brain disabled specialist at the National Human Genome Research Institute. "If something happens very slowly for some time, maybe for decades, different parts of the brain take on the function that is usually done by the part being pushed aside."
Important case
- Author Sherman Alexie, born with this condition, wrote about him in the semi-autobiographical junior fiction novel The Real-Time Part-of-India Diary. .
- Prince William, Duke of Gloucester (1689-1700) is likely to develop meningitis at birth which results in this condition.
References
External links
- Hydrocephalus in Curlie (based on DMOZ)
- Guidelines for pediatric hydrocephalus
Source of the article : Wikipedia
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