Мидың көлемі ұлғаюы және оның салдары

Abnormal increase in cerebrospinal fluid in the ventricles of the brain

the medical condition

The clinical presentation of hydrocephalus varies with chronicity. Acute dilatation of the ventricular system is more likely to manifest with the nonspecific signs and symptoms of increased intracranial pressure (ICP). By contrast, chronic dilatation (especially in the elderly population) may have a more insidious onset presenting, for instance, with Hakim's triad (Adams' triad). Symptoms of increased ICP may include headaches, vomiting, nausea, papilledema, sleepiness, or coma. With increased levels of CSF, there have been cases of hearing loss due to CSF creating pressure on the auditory pathways or disrupting the communication of inner ear fluid. Elevated ICP of different etiologies have been linked to sensorineural hearing loss (SNHL). Transient SNHL has been reported after the loss of CSF with shunt surgeries. Hearing loss is a rare but well known sequela of procedures resulting in CSF loss. Hakim's triad of gait instability, urinary incontinence, and dementia is a relatively typical manifestation of the distinct entity normal pressure hydrocephalus. Focal neurological deficits may also occur, such as abducens nerve palsy and vertical gaze palsy (Parinaud syndrome due to compression of the quadrigeminal plate, where the neural centers coordinating the conjugated vertical eye movement are located). The symptoms depend on the cause of the blockage, the person's age, and how much brain tissue has been damaged by the swelling. Because hydrocephalus can injure the brain, thought and behavior may be adversely affected. Learning disabilities, including short term memory loss, are common among those with hydrocephalus, who 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 differ considerably between individuals, and some are of average or above average intelligence. Someone with hydrocephalus may have coordination and visual problems, or clumsiness. They may reach puberty earlier than the average child (this is called precocious puberty). About one in four develops epilepsy.

Congenital hydrocephalus is present in the infant prior to birth, meaning the fetus developed hydrocephalus in utero during fetal development. The most common cause of congenital hydrocephalus is aqueductal stenosis, which occurs when the narrow passage between the third and fourth ventricles in the brain is blocked or too narrow to allow sufficient cerebral spinal fluid to drain. Fluid accumulates in the upper ventricles, causing hydrocephalus. Other causes of congenital hydrocephalus include neural tube defects, arachnoid cysts, Dandy–Walker syndrome, and Arnold–Chiari malformation. The cranial bones fuse by the end of the third year of life. For head enlargement to occur, hydrocephalus must occur before then. The causes are usually genetic, but can also be acquired and usually occur within the first few months of life, which include intraventricular matrix hemorrhages in premature infants, infections, type II Arnold Chiari malformation, aqueduct atresia and stenosis, and Dandy Walker malformation. Hydrocephalus can also occur with craniosynostosis, being a constant feature of kleeblattschadel and frequently seen in syndomic cases (mostly in Crouzon syndrome). Hydrocephalus has also been seen in cases of congenital syphilis. In newborns and toddlers with hydrocephalus, the head circumference is enlarged rapidly and soon surpasses the 97th percentile. Since the skull bones have not yet firmly joined, bulging, firm anterior and posterior fontanelles may be present even when the person is in an upright position. The infant exhibits fretfulness, poor feeding, and frequent vomiting. As the hydrocephalus progresses, torpor sets in, and infants show lack of interest in their surroundings. Later on, their upper eyelids become retracted and their eyes are turned downwards ("sunset eyes") (due to hydrocephalic pressure on the mesencephalic tegmentum and paralysis of upward gaze). Movements become weak and the arms may become tremulous. Papilledema is absent, but vision may be reduced. The head becomes so enlarged that they eventually may be bedridden. About 80–90% of fetuses or newborn infants with spina bifida—often associated with meningocele or myelomeningocele—develop hydrocephalus.

This condition is acquired as a consequence of CNS infections, meningitis, brain tumors, head trauma, toxoplasmosis, or intracranial hemorrhage (subarachnoid or intraparenchymal), and is usually painful.

The cause of hydrocephalus is not known with certainty and is probably multifactorial. It may be caused by impaired CSF flow, reabsorption, or excessive CSF production. Obstruction to CSF flow hinders its free passage through the ventricular system and subarachnoid space (e. g., stenosis of the cerebral aqueduct or obstruction of the interventricular foramina secondary to tumors, hemorrhages, infections or congenital malformations) and can cause increases in ICP. Hydrocephalus can also be caused by overproduction of CSF (relative obstruction) (e. g., choroid plexus papilloma, villous hypertrophy). Bilateral ureteric obstruction is a rare, but reported, cause of hydrocephalus. Hydrocephalus can be classified into communicating and noncommunicating (obstructive). Both forms can be either congenital or acquired.

Communicating hydrocephalus, also known as nonobstructive hydrocephalus, is caused by impaired CSF reabsorption in the absence of any obstruction of CSF flow between the ventricles and subarachnoid space. This may be due to functional impairment of the arachnoidal granulations (also called arachnoid granulations or Pacchioni's granulations), which are located along the superior sagittal sinus, and is the site of CSF reabsorption back into the venous system. Various neurologic conditions may result in communicating hydrocephalus, including subarachnoid/intraventricular hemorrhage, meningitis, and congenital absence of arachnoid villi. Scarring and fibrosis of the subarachnoid space following infectious, inflammatory, or hemorrhagic events can also prevent reabsorption of CSF, causing diffuse ventricular dilatation.

Noncommunicating hydrocephalus, or obstructive hydrocephalus, is caused by an obstruction to the flow of CSF. Foramen of Monro obstruction may lead to dilation of one, or if large enough (e. g., in colloid cyst), both lateral ventricles. The aqueduct of Sylvius, normally narrow, may be obstructed by a number of genetic or acquired lesions (e. g., atresia, ependymitis, hemorrhage, or tumor) and lead to dilation of both lateral ventricles, as well as the third ventricle. Fourth ventricle obstruction leads to dilatation of the aqueduct, as well as the lateral and third ventricles (e. g., Chiari malformation). The foramina of Luschka and foramen of Magendie may be obstructed due to congenital malformation (e. g., Dandy–Walker malformation).

Normal pressure hydrocephalus (NPH) is a particular form of chronic communicating hydrocephalus, characterized by enlarged cerebral ventricles, with only intermittently elevated cerebrospinal fluid pressure. Characteristic triad of symptoms are; dementia, apraxic gait and urinary incontinence. The diagnosis of NPH can be established only with the help of continuous intraventricular pressure recordings (over 24 hours or even longer), since more often than not instant measurements yield normal pressure values. Dynamic compliance studies may be also helpful. Altered compliance (elasticity) of the ventricular walls, as well as increased viscosity of the cerebrospinal fluid, may play a role in the pathogenesis. Hydrocephalus ex vacuo also refers to an enlargement of cerebral ventricles and subarachnoid spaces, and is usually due to brain atrophy (as it occurs in dementias), post traumatic brain injuries, and even in some psychiatric disorders, such as schizophrenia. As opposed to hydrocephalus, this is a compensatory enlargement of the CSF spaces in response to brain parenchyma loss; it is not the result of increased CSF pressure.]] Hydrocephalus is usually due to blockage of CSF outflow in the ventricles or in the subarachnoid space over the brain. In a person without hydrocephalus, CSF continuously circulates through the brain, its ventricles and the spinal cord and is continuously drained away into the circulatory system. Alternatively, the condition may result from an overproduction of the CSF, from a congenital malformation blocking normal drainage of the fluid, or from complications of head injuries or infections. Compression of the brain by the accumulating fluid eventually may cause neurological symptoms such as convulsions, intellectual disability, and epileptic seizures. These signs occur sooner in adults, whose skulls are no longer able to expand to accommodate the increasing fluid volume within. Fetuses, infants, and young children with hydrocephalus typically have an abnormally large head, excluding the face, because the pressure of the fluid causes the individual skull bones—which have yet to fuse—to bulge outward at their juncture points. Another medical sign, in infants, is a characteristic fixed downward gaze with whites of the eyes showing above the iris, as though the infant were trying to examine its own lower eyelids. The elevated ICP may cause compression of the brain, leading to brain damage and other complications. A complication often overlooked is the possibility of hearing loss due to ICP. The mechanism of ICP on hearing loss is presumed that the transmission of CSF pressure to and from the Perilymphatic space through a patent cochlear aqueduct. The cochlear aqueduct connects the Perilymphatic space of the inner ear with the subarachnoid space of the posterior cranial fossa. A loss of CSF pressure can induce Perilymphatic loss or endolymphatic hydrops resembling the clinical presentation of Ménière's disease associated hearing loss in the low frequencies.

Hydrocephalus treatment is surgical, creating a way for the excess fluid to drain away. In the short term, an external ventricular drain (EVD), also known as an extraventricular drain or ventriculostomy, provides relief. In the long term, some people will need any of various types of cerebral shunt. It involves the placement of a ventricular catheter (a tube made of silastic) into the cerebral ventricles to bypass the flow obstruction/malfunctioning arachnoidal granulations and drain the excess fluid into other body cavities, from where it can be resorbed. Most shunts drain the fluid into the peritoneal cavity (ventriculoperitoneal shunt), but alternative sites include the right atrium (ventriculoatrial shunt), pleural cavity (ventriculopleural shunt), and gallbladder. A shunt system can also be placed in the lumbar space of the spine and have the CSF redirected to the peritoneal cavity (lumbar peritoneal shunt). An alternative treatment for obstructive hydrocephalus in selected people is the endoscopic third ventriculostomy (ETV), whereby a surgically created opening in the floor of the third ventricle allows the CSF to flow directly to the basal cisterns, thereby shortcutting any obstruction, as in aqueductal stenosis. This 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 Benjamin Warf and is now in use in several U. S. hospitals. Hydrocephalus can be successfully treated by placing a drainage tube (shunt) between the brain ventricles and abdominal cavity. Some risk exists of infection being introduced into the brain through these shunts, as they must be replaced as the person grows.

External hydrocephalus is a condition generally seen in infants which involves enlarged fluid spaces or subarachnoid spaces around the outside of the brain. This condition is generally benign, and resolves spontaneously by two years of age and therefore usually does not require insertion of a shunt. Imaging studies and a good medical history can help to differentiate external hydrocephalus from subdural hemorrhages or symptomatic chronic extra axial fluid collections which are accompanied by vomiting, headaches, and seizures.

The hydrocephalus disease burden are concentrated in the developing world while North America has the least number of cases. A systematic review in 2019 estimated that there are 180,000 childhood hydrocephalus cases from the African continent per year, followed by 90,000 cases from Southeast Asia and the Western Pacific. Latin America also has a high prevalence of hydrocephalus. However, data on hydrocephalus disease burden in adults are lacking.

In the pre historic area, there were various paintings or artifacts depicting children or adults with macrocephaly (large head) or clinical findings of hydrocephalus. However, due to lack of writing, it was unknown how the people thought of the disorder at that time and the ways to treat the disease. References to hydrocephalic skulls can be found in ancient Egyptian medical literature from 2,500 BC to 500 AD. He described it in his chapter on neurosurgical disease, describing infantile hydrocephalus as being caused by mechanical compression. He wrote:

The word hydrocephalus is from the Greek text=ὕδωρ meaning 'water' and text=κεφαλή meaning 'head'.

September was designated National Hydrocephalus Awareness Month in July 2009 by the U. S. Congress in The resolution campaign is due in part to the advocacy work of the Pediatric Hydrocephalus Foundation. Prior to July 2009, no awareness month for this condition had been designated. Many hydrocephalus organizations, such as the One Small Voice Foundation, promote awareness and fundraising activities.

One case of hydrocephalus was a man whose brain shrank to a thin sheet of tissue, due to a 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 age 44, he went to a hospital due to mild weakness in his left leg. When doctors learned of the man's medical history, they performed a CT and MRI scan, and were astonished to see "massive enlargement" of the lateral ventricles in the skull. Dr. Lionel Feuillet of Hôpital de la Timone in Marseille said, "The images were most unusual the brain was virtually absent." Intelligence tests showed the person had an IQ of 75, considered "Borderline intellectual functioning", just above what would be officially classified as intellectually disabled. The person was a married father of two children, and worked as a civil servant, leading an at least superficially normal life, despite having enlarged ventricles with a decreased volume of brain tissue. "What I find amazing to this day is how the brain can deal with something which you think should not be compatible with life", commented Dr. Max Muenke, a pediatric brain defect specialist at the National Human Genome Research Institute. "If something happens very slowly over quite some time, maybe over decades, the different parts of the brain take up functions that would normally be done by the part that is pushed to the side."

Ice hockey player Colby Cave had acute obstructive hydrocephalus due to a colloid cyst. Author Sherman Alexie, born with the condition, wrote about it in his semi autobiographical junior fiction novel The Absolutely True Diary of a Part Time Indian. Prince William, Duke of Gloucester (1689–1700), probably contracted meningitis at birth, which resulted in this condition. Emperor Ferdinand I of Austria (1793–1875) became emperor in 1835 despite various health issues including hydrocephalus and epilepsy. In the American folklore of the states of Ohio, Michigan, and Connecticut, an urban legend exists about the melon heads, the inbred descendants of families of people born with hydrocephaly. Masato Kudo, a professional soccer player, died of hydrocephalus on October 21, 2022.