Because the shunt systems are too expensive for most people in developing countries, such people often die without getting a shunt. Worse, the rate of revision in shunt systems adds to the cost of shunting many times. Looking at this point, a study compares shunt systems and highlights the role of low-cost shunt systems in most of the developing countries. It compares the Chhabra shunt system to shunt systems from developed countries.

Examples of possible complications include shunt malfunction, shunt failure, and shunt infection, along with infection of the shunt tract following surgery (the most common reason for shunt failure is infection of the shunt tract). Although a shunt generally works well, it may stop working if it disconnects, becomes blocked (clogged), infected, or it is outgrown. If this happens the cerebrospinal fluid will begin to accumulate again and a number of physical symptoms will develop (headaches, nausea, vomiting, photophobia/light sensitivity), some extremely serious, like seizures. The shunt failure rate is also relatively high (of the 40,000 surgeries performed annually to treat hydrocephalus, only 30% are a patient's first surgery) and it is not uncommon for patients to have multiple shunt revisions within their lifetime.

Another complication can occur when CSF drains more rapidly than it is produced by the choroid plexus, causing symptoms - listlessness, severe headaches, irritability, light sensitivity, auditory hyperesthesia (sound sensitivity), nausea, vomiting, dizziness, vertigo, migraines, seizures, a change in personality, weakness in the arms or legs, strabismus, and double vision - to appear when the patient is vertical. If the patient lies down, the symptoms usually vanish quickly. A CT scan may or may not show any change in ventricle size, particularly if the patient has a history of slit-like ventricles. Difficulty in diagnosing overdrainage can make treatment of this complication particularly frustrating for patients and their families. Resistance to traditional analgesic pharmacological therapy may also be a sign of shunt overdrainage "or" failure.

The diagnosis of cerebrospinal fluid buildup is complex and requires specialist expertise. Diagnosis of the particular complication usually depends on when the symptoms appear - that is, whether symptoms occur when the patient is upright or in a prone position, with the head at roughly the same level as the feet.

There is no standard treatment for hydranencephaly. Treatment is symptomatic and supportive. Hydrocephalus may be treated with surgical treatment of a shunt, which often grants a much better prognosis and greater quality of life.

The prognosis for children with hydranencephaly is generally quite poor. Death often occurs in the first year of life, but other children may live several years.

Medical text identifies that hydranencephalic children simply have only their brain stem function remaining, thus leaving formal treatment options as symptomatic and supportive. Severe hydrocephalus causing macrocephaly, a larger than average head circumference, can easily be managed by placement of a shunt and often displays a misdiagnosis of another lesser variation of cephalic condition due to the blanketing nature of hydrocephalus. Plagiocephaly, the asymmetrical distortion of the skull, is another typical associated condition that is easily managed through positioning and strengthening exercises to prevent torticollis, a constant spasm or extreme tightening of the neck muscles.

Colpocephaly is usually non-fatal. There has been relatively little research conducted to improve treatments for colpocephaly, and there is no known definitive treatment of colpocephaly yet. Specific treatment depends on associated symptoms and the degree of dysfunction. Anticonvulsant medications can be given to prevent seizure complications, and physical therapy is used to prevent contractures (shrinkage or shortening of muscles) in patients that have limited mobility. Patients can also undergo surgeries for stiff joints to improve motor function. The prognosis for individuals with colpocephaly depends on the severity of the associated conditions and the degree of abnormal brain development.

A rare case of colpocephaly is described in literature which is associated with macrocephaly instead of microcephaly. Increased intracranial pressure was also found in the condition. Similar symptoms (absence of corpus callosum and increased head circumference) were noted as in the case of colpocephaly that is associated with microcephaly. A bi-ventricular peritoneal shunt was performed, which greatly improved the symptoms of the condition. Ventriculo-peritoneal shunts are used to drain the fluid into the peritoneal cavity.

The general purpose of the following treatment methods is to divert the flow of CSF from the blocked aqueduct, which is causing the buildup of CSF, and allow the flow to continue. Another goal of these treatments is to reduce the stress within the ventricles. Studies have not shown that either of the following treatments results in a higher IQ of the patient, and there is not statistical difference in a patient's quality of life based on treatment method. The following treatment methods are not used for aqueductal stenosis caused by tumor compression; if the obstruction is a direct result of tumor compression, CSF flow may be normalized by the surgical removal of the tumor.

An extracranial shunt is essentially a sturdy tube with a catheter on one end to drain the third ventricle. The shunt also has a valve which serves to maintain one-way flow of the CSF and regulates the flow rate. The end with the catheter is placed in the third ventricle to drain the excess CSF and the other end is placed in the peritoneal cavity or atrium of the heart (making it a ventriculoperitoneal or ventriculoatrial shunt, respectively). The excess CSF which is diverted to a cavity is then reabsorbed by the surrounding tissue where it is drained to.

The procedure to insert this device is a technically straightforward endoscopic surgery with a low mortality rate (essentially 0% mortality since the 1970s). If the shunt has an adjustable valve the current method of setting the valve pressure is to choose one setting, observe the patient to see if CSF flow improves and the symptoms lessen over time, and adjust the pressure setting as needed if improvement isn't seen. For example, if there is not enough CSF flow, another surgery is performed to lower the valve pressure so that less force needs to be applied to open the valve and thereby drain more CSF.

This treatment method has several possible problems with it (with a 50% failure rate in 2 years), and unfortunately shunt malfunctions and associated complications cause a death rate of 1.2% per year. Problems which can necessitate a secondary surgery to fix them include: mechanical failure, incorrect catheter size, inappropriate valve drainage pressure, and infection.

- Inappropriate valve pressure can lead to "overdraining" or "underdraining", both of which should be treated by adjusting the valve pressure. Overdraining occurs when the valve pressure is too low and CSF flows out of the third ventricle too quickly. The ventricle then collapses and blood vessles can be torn in the process. This in turn can lead to headache, hemorrhage, or slit ventricle syndrome. Underdraining occurs when the valve pressure is too high and CSF flows out too slowly. This results in symptoms of hydrocephalus as the CSF is still collecting rather than being absorbed or diverted.

- Risk of infection is due to the fact that a foreign object is being introduced into the body. Infection can have symptoms of fever and soreness of the neck and shoulders.

In utero exposure to cocaine and other street drugs can lead to hydranencephaly.

Stem cell therapy is considered a very promising treatment for patients with colpocephaly. Oligodendroglial cells can be used which will increase the production of myelin and alleviate symptoms of colpocephaly. Damage to the developing oligodendrocytes near the cerebral ventricles causes cerebral palsy as well as other demyelinating diseases such as multiple sclerosis and leukodystrophies. Demyelination reduces the speed of conduction in affected nerves resulting in disabilities in cognition, sensation, and motor. Therefore, by using oligodendrocyte stem cells the effects of cerebral palsy can be treated and other symptoms of colpocephaly can be alleviated.

Patients with dementia who are confined to a nursing home and may have undiagnosed NPH can possibly become independent again once treated. So far only one study was able to evaluate the prevalence of NPH, both diagnosed and undiagnosed, among residents of assisted-living facilities, showing a prevalence in 9 to 14% of the residents.

NPH may be relieved by surgically implanting a ventriculoperitoneal shunt to drain excess cerebrospinal fluid to the abdomen where it is absorbed. Once the shunt is in place, the ventricles usually diminish in size in 3 to 4 days, regardless of the duration of the hydrocephalus. Even though the ventricular swelling diminishes, only 21% of patients show a marked improvement in symptoms. The most likely patients to show improvement are those that show only gait disturbance, mild or no incontinence, and mild dementia. A more recent study (2004) found better outcomes, concluding that if patients with idiopathic normal pressure hydrocephalus are correctly identified, shunt insertion yielded beneficial outcomes in 86% of patients, in either gait disturbance (81%), improved continence (70%), or both. They also observed that measurements in the diagnostic clinical triad, the cortical sulci size, and periventricular lucencies were related to outcome. However, other factors such as age of the patient, symptom duration, dilation of ventricles, and the degree of presurgical dementia were unrelated to outcome.

In utero exposure to cocaine and other street drugs can lead to schizencephaly.

Low-pressure hydrocephalus (LPH) is a condition whereby ventricles are enlarged and the individual experiences severe dementia, inability to walk, and incontinence - despite very low intracranial pressure (ICP). Low pressure hydrocephalus appears to be a more acute form of normal pressure hydrocephalus. If not diagnosed in a timely fashion, the individual runs the risk of remaining in the low pressure hydrocephalic state or LPHS. Shunt revisions, even when they are set to drain at a low ICP, are not always effective. The pressure in the brain does not get high enough to allow the cerebrospinal fluid to drain in a shunt system, therefore the shunt is open, but malfunctioning in LPH. In cases of LPH, chronic infarcts can also develop along the corona radiata in response to the tension in the brain as the ventricles increase in size. Certain causes of LPH include trauma, tumor, bleeding, inflammation of the lining of the brain, whole brain radiation, as well as other brain pathology that affects the compliance of the brain parenchyma. One treatment for the LPHS is an external ventricular drain (EVD) set at negative pressures. According to Pang & Altschuler et al., a controlled, steady, negative pressure siphoning with EVD, carefully monitored with partial computer tomography scans is a safe and effective way of treating LPH. In their experience, this approach helps restore the brain mantle. They caution against dropping or raising the pressure of the EVD too quickly as it increases risk and also destabilizes the ventricles. Getting the ventricles smaller, is the initial step, stabilising them is the second step before placing a shunt – which is the final step in therapy. Any variation from this formula can lead to an ineffective, yet patent shunt system, despite a low-pressure setting. Care should be taken with EVD therapy, as mismanagement of the EVD can lead to long-term permanent complications and brain injury.

In some cases, the defect is linked to mutations of the EMX2, SIX3, and Collagen, type IV, alpha 1 genes. Because having a sibling with schizencephaly has been statistically shown to increase risk of the disorder, it is possible that there is a heritable genetic component to the disease.

While there is no current cure, the treatments for Chiari malformation are surgery and management of symptoms, based on the occurrence of clinical symptoms rather than the radiological findings. The presence of a syrinx is known to give specific signs and symptoms that vary from dysesthetic sensations to algothermal dissociation to spasticity and paresis. These are important indications that decompressive surgery is needed for patients with Chiari Malformation Type II. Type II patients have severe brain stem damage and rapidly diminishing neurological response.

Decompressive surgery involves removing the lamina of the first and sometimes the second or third cervical vertebrae and part of the occipital bone of the skull to relieve pressure. The flow of spinal fluid may be augmented by a shunt. Since this surgery usually involves the opening of the dura mater and the expansion of the space beneath, a dural graft is usually applied to cover the expanded posterior fossa.

A small number of neurological surgeons believe that detethering the spinal cord as an alternate approach relieves the compression of the brain against the skull opening (foramen magnum), obviating the need for decompression surgery and associated trauma. However, this approach is significantly less documented in the medical literature, with reports on only a handful of patients. It should be noted that the alternative spinal surgery is also not without risk.

Complications of decompression surgery can arise. They include bleeding, damage to structures in the brain and spinal canal, meningitis, CSF fistulas, occipito-cervical instability and pseudomeningeocele. Rare post-operative complications include hydrocephalus and brain stem compression by retroflexion of odontoid. Also, an extended CVD created by a wide opening and big duroplasty can cause a cerebellar "slump". This complication needs to be corrected by cranioplasty.

In certain cases, irreducible compression of the brainstem occurs from in front (anteriorly or ventral) resulting in a smaller posterior fossa and associated Chiari malformation. In these cases, an anterior decompression is required. The most commonly used approach is to operate through the mouth (transoral) to remove the bone compressing the brainstem, typically the odontoid. This results in decompressing the brainstem and therefore gives more room for the cerebellum, thus decompressing the Chiari malformation. Arnold Menzes, MD, is the neurosurgeon who pioneered this approach in the 1970s at the University of Iowa. Between 1984 and 2008 (the MR imaging era), 298 patients with irreducible ventral compression of the brainstem and Chiari type 1 malformation underwent a transoral approach for ventral cervicomedullary decompression at the University of Iowa. The results have been excellent resulting in improved brainstem function and resolution of the Chiari malformation in the majority of patients.

There are two types of normal pressure hydrocephalus: idiopathic and secondary. The secondary type of NPH can be due to a subarachnoid hemorrhage, head trauma, tumor, infection in the central nervous system, or a complication of cranial surgery.

The surgical treatment involves the resection of the extracranial venous package and ligation of the emissary communicating vein. In some cases of SP, surgical excision is performed for cosmetic reasons. The endovascular technique has been described by transvenous approach combined with direct puncture and the recently endovascular embolization with Onyx.

There is neither a single cause of spina bifida nor any known way to prevent it entirely. However, dietary supplementation with folic acid has been shown to be helpful in reducing the incidence of spina bifida. Sources of folic acid include whole grains, fortified breakfast cereals, dried beans, leaf vegetables and fruits.

Folate fortification of enriched grain products has been mandatory in the United States since 1998. The U.S. Food and Drug Administration, Public Health Agency of Canada and UK recommended amount of folic acid for women of childbearing age and women planning to become pregnant is at least 0.4 mg/day of folic acid from at least three months before conception, and continued for the first 12 weeks of pregnancy.

Women who have already had a baby with spina bifida or other type of neural tube defect, or are taking anticonvulsant medication, should take a higher dose of 4–5 mg/day.

Certain mutations in the gene "VANGL1" have been linked with spina bifida in some families with a history of the condition.

Surgeons at Vanderbilt University, led by Joseph Bruner, attempted to close spina bifida in 4 human fetuses using a skin graft from the mother using a laparoscope. Four cases were performed before stopping the procedure - two of the four fetuses died.

- 1998 – N. Scott Adzick and team at The Children's Hospital of Philadelphia performed open fetal surgery for spina bifida in an early gestation fetus (22-week gestation fetus) with a successful outcome. Open fetal surgery for myelomeningocele involves surgically opening the pregnant mother's abdomen and uterus to operate on the fetus. The exposed fetal spinal cord is covered in layers with surrounding fetal tissue at mid-gestation (19–25 weeks) to protect it from further damage caused by prolonged exposure to amniotic fluid. Between 1998 and 2003, Dr. Adzick, and his colleagues in the Center for Fetal Diagnosis and Treatment at The Children's Hospital Of Philadelphia, performed prenatal spina bifida repair in 58 mothers and observed significant benefit in the babies.

Fetal surgery after 25 weeks has not shown benefit in subsequent studies.

The prevalence of congenital Chiari I malformation, defined as tonsilar herniations of 3 to 5 mm or greater, was previously believed to be in the range of one per 1000 births, but is likely much higher. Women are three times more likely than men to have a congenital Chiari malformation. Type II malformations are more prevalent in people of Celtic descent. A study using upright MRI found cerebellar tonsillar ectopia in 23% of adults with headache from motor-vehicle-accident head trauma. Upright MRI was more than twice as sensitive as standard MRI, likely because gravity affects cerebellar position.

Cases of congenital Chiari malformation may be explained by evolutionary and genetic factors. Typically, an infant's brain weighs around 400g at birth and triples to 1100-1400g by age 11. At the same time the cranium triples in volume from 500 cm to 1500 cm to accommodate the growing brain. During human evolution, the skull underwent numerous changes to accommodate the growing brain. The evolutionary changes included increased size and shape of the skull, decreased basal angle and basicranial length. These modifications resulted in significant reduction of the size of the posterior fossa in modern humans. In normal adults, the posterior fossa comprises 27% of the total intracranial space, while in adults with Chiari Type I, it is only 21%. If a modern brain is paired with a less modern skull, the posterior fossa may be too small, so that the only place where the cerebellum can expand is the foramen magnum, leading to development of Chiari Type I. H. neanderthalensis had platycephalic (flattened) skull. Some cases of Chiari are associated with platybasia (flattening of the skull base).

Treatment for individuals with Dandy–Walker Syndrome generally consists of treating the associated problems, if needed.

A special tube (shunt) to reduce intracranial pressure may be placed inside the skull to control swelling. Endoscopic third ventriculostomy is also an option.

Treatment may also consist of various therapies such as occupational therapy, physiotherapy, speech therapy or specialized education. Services of a teacher of students with blindness/visual impairment may be helpful if the eyes are affected.

Head circumference measurements should be obtained regularly and monitored carefully to detect hydrocephalus. Neurosurgical procedures to relieve hydrocephalus are important. A ventriculoperitoneal shunt may be required in some infants. A pediatric cardiologist should be consulted to manage high-output failure, if present. Often patients need to be intubated. In most cases, the fistulous arteries feeding into the Vein of Galen must be blocked, thereby reducing the blood flow into the vein. Open surgery has a high morbidity and mortality. Recent advances over the past few decades have made endovascular embolization the preferred method of treatment. These treatments are preferred because they offer little threat to the surrounding brain tissue. However, there have been several reported cases of arteriovenous malformations recurring. The young age of many patients, the complex vascular anatomy, and the sensitive location of the Vein of Galen offer considerable challenges to surgeons. Another treatment option is Radiotherapy. Radiotherapy, also called radiosurgery, involves the use of focused beams to damage the blood vessel. Radiotherapy is often not pursued as a treatment because the effects of the procedure can take months or years and there is risk of damaging adjacent brain tissue.

The precise causes of syringomyelia are still unknown although blockage to the flow of cerebrospinal fluid has been known to be an important factor since the 1970s. Scientists in the UK and America continue to explore the mechanisms that lead to the formation of syrinxes in the spinal cord. It has been demonstrated a block to the free flow of cerebrospinal fluid is a contributory factor in the pathogenesis of the disease. Duke University in America and Warwick University are conducting research to explore genetic features of syringomyelia.

Surgical techniques are also being refined by the neurosurgical research community. Successful procedures expand the area around the cerebellum and spinal cord, thus improving the flow of cerebrospinal fluid thereby reducing the syrinx.

It is also important to understand the role of birth defects in the development of hindbrain malformations that can lead to syringomyelia as syringomyelia is a feature of intrauterine life and is also associated with spina bifida. Learning when these defects occur during the development of the fetus can help us understand this and similar disorders, and may lead to preventive treatment that can stop the formation of some birth abnormalities. Dietary supplements of folic acid prior to pregnancy have been found to reduce the number of cases of spina bifida and are also implicated in prevention of cleft palate and some cardiac defects.

Diagnostic technology is another area for continued research. MRI has enabled scientists to see conditions in the spine, including syringomyelia before symptoms appear. A new technology, known as dynamic MRI, allows investigators to view spinal fluid flow within the syrinx. CT scans allow physicians to see abnormalities in the brain, and other diagnostic tests have also improved greatly with the availability of new, non-toxic, contrast dyes.

Surgery is not always an option when the anatomy of the malformation creates too much of a risk. Recent improvements in endovascular procedures have made many cases, which were not surgically accessible, treatable. Endovascular treatments involve delivering drugs, balloons, or coils to the site of the malformation through blood vessels via catheters. These treatments work by limiting blood flow through the vein. There is, however, still risk of complications from endovascular treatments. The wall of the vein can be damaged during the procedure and, in some cases, the emboli can become dislodged and travel through the vascular system. Two-dimensional echocardiography with color-flow imaging and pulsed Doppler ultrasound was used to evaluate one fetus and five neonates with a Vein of Galen malformation. Color-flow imaging and pulsed Doppler ultrasonography provided anatomical and pathophysiological information regarding cardiac hemodynamics and intracranial blood flow; with the patient's clinical status, these methods provided a reliable, noninvasive means to evaluate the effectiveness of therapy and the need for further treatment in neonates with Vein of Galen malformations. When none of these procedures are viable, shunting can be used to ameliorate the pressure inside the varix. Seizures usually are managed with antiepileptic medications.

Cerebellar stroke syndrome is a condition in which the circulation to the cerebellum is impaired due to a lesion of the superior cerebellar artery, anterior inferior cerebellar artery or the posterior inferior cerebellar artery.

Cardinal signs include vertigo, headache, vomiting, and ataxia.

Cerebellar strokes account for only 2-3% of the 600 000 strokes that occur each year in the United States. They are far less common than strokes which occur in the cerebral hemispheres. In recent years mortality rates have decreased due to advancements in health care which include earlier diagnosis through MRI and CT scanning. Advancements have also been made which allow earlier management for common complications of cerebellar stroke such as brainstem compression and hydrocephalus.

Research is still needed in the area of cerebellar stroke management; however, it has been proposed that several factors may lead to poor outcomes in individuals who suffer from cerebellar stroke. These factors include:

1. Declining levels of consciousness

2. New signs of brainstem involvement

3. Progressing Hydrocephalus

4. Stroke to the midline of the cerebellum (a.k.a. the vermis)

Surgery is not always recommended for syringomyelia patients. For many patients, the main treatment is analgesia. Physicians specializing in pain management can develop a medication and treatment plan to ameliorate pain. Medications to combat any neuropathic pain symptoms such as shooting and stabbing pains (e.g. gabapentin or pregabalin) would be first-line choices. Opiates are usually prescribed for pain for management of this condition. Facet injections are not indicated for treatment of syringomyelia.

Drugs have no curative value as a treatment for syringomyelia. Radiation is used rarely and is of little benefit except in the presence of a tumor. In these cases, it can halt the extension of a cavity and may help to alleviate pain.

In the absence of symptoms, syringomyelia is usually not treated. In addition, a physician may recommend not treating the condition in patients of advanced age or in cases where there is no progression of symptoms. Whether treated or not, many patients will be told to avoid activities that involve straining.

Since the natural history of syringomyelia is poorly understood, a conservative approach may be recommended. When surgery is not yet advised, patients should be carefully monitored. Periodic MRI's and physical evaluations should be scheduled at the recommendation of a qualified physician.

Most arachnoid cysts are asymptomatic, and do not require treatment. Where complications are present, leaving arachnoid cysts untreated, may cause permanent severe neurological damage due to the progressive expansion of the cyst(s) or hemorrhage (bleeding). However, with treatment most individuals with symptomatic arachnoid cysts do well.

More specific prognoses are listed below:

- Patients with impaired preoperative cognition had postoperative improvement after surgical decompression of the cyst.

- Surgery can resolve psychiatric manifestations in selected cases.