Hydrocephalus: a hydrodynamic disorder of the cerebrospinal fluid

Hydrocephalus: a hydrodynamic disorder of the cerebrospinal fluid

Hydrocephalus is a neurological pathology that arises when there is an alteration in the production of cerebrospinal fluid (CSF), this implies a volume increase, this can be presented abundantly in the subarachnoid space or in the ventricles, disabling or altering its absorption and free flow.

The intracranial volume is formed by: cerebrospinal fluid or CSF, the blood volume and that of the cerebral parenchyma. In hydrocephalus the liquid begins to accumulate, so the head size can be larger than normal, gradually increasing the pressure of the cerebral parenchyma, from the intraventicular compartment to the extra-axial subarachnoid space, thereby increasing the size of the ventricles causing compression of the cisterns subarachnoid against the skull, which It produces neurological dysfunction.


  • 1 Functions of cerebrospinal fluid
  • 2 Prevalence of hydrocephalus
  • 3 Etiology of hydrocephalus
  • 4 Types of hydrocephalus
  • 5 Clinical manifestations of hydrocephalus
  • 6 Differences between children and adults: symptoms of hydrocephalus
  • 7 Hydrocephalus and locomotion
  • 8 Hydrocephalus: cabinet diagnosis
  • 9 Treating hydrocephalus
  • 10 Complications of hydrocephalus

Cerebrospinal fluid functions

This liquid crystalline is found in the subarachnoid space and spinal cord, The mechanical function of the cerebrospinal fluid is to protect the central nervous system (CNS), it also functions as transport of nutrients for neurons, neurotransmitters and hormones; for your hygiene uses antibodies and lymphocytes, collecting metabolic wastes and acting as drainage, compensating for this way the changes in the volume of the intracranial blood.

Under normal conditions, the cerebrospinal fluid (SCI) is absorbed into the bloodstream and circulates through the ventricles, going to closed cisterns or reservoirs on the brain base. The total volume of CSF in adults is 120 to 150 ml. Its production is mainly generated by ependymal or ependymocyte cells and choroidal plexus, normal production is 0.2 to 0.35 ml / min. The capacity of the lateral ventricles and the third ventricle in adults is 20 ml.

Prevalence of hydrocephalus

The global prevalence is estimated between one and 1.5% of the world's population, the incidence with Congenital hydrocephalus is 0.9 to 1.8 / 1000 live births, with Myelomeningocele associated hydrocephalus ranges from 1.3 to 2.9 / 1000 live births. They are currently conducting important research to improve the diagnosis, treatment and quality of life of the patient.

When the ventricles dilate abnormally, cranial pressure is generated that can be harmful to brain tissue. When it is progressive and not treated properly”.

The National Institute of Neurological Disorders and Stroke (NINDS), seeks to reduce neurological disorders and their effects, emphasize assessing children with hydrocephalus, taking into account their: cognitive development, behavioral adjustment and academic results.

The Hydrocephalus Clinical Research Network and collaborators have pediatric centers that study populations of patients with hydrocephalus to assess the potential of new treatments.

Etiology of hydrocephalus

Hydrocephalus can arise as a result of various alterations, here are some:

  1. Intraventricular hemorrhage
  2. Subarachnoid hemorrhage, which obstructs the passage of the ventricles to the cisterns and eliminates the cisterns themselves.
  3. Malabsorption
  4. There are certain tumors that can produce abundantly fluid.
  5. Aqueductal stenosis
  6. Developmental disorders related to defects in the neural tube such as: encephalocele and spina bifida.
  7. Infections.
  8. Meningitis.
  9. Traumatic injuries.

Congenital causesin pediatric age

Acquired Causesin pediatric age

Causes in adulthood
Agenesis of the foramen of Monro.

Arnold-Chiari malformation type 1 and 2.

Dandi-Walker malformation.

Broker-Adams syndrome, thumb adduction, mental retardation and aqueduct stenosis.

Congenital toxoplasmosis.

Increased venous pressure (achondroplasia, sinus thrombosis and craniostenosis).

As a result of infections: meningitisespecially bacterial and cysticercosis.

Iatrogenies: hypervitaminosis: A and D.


Space-occupying lesions (20% of childhood hydrocephalus), the most common tumors are: medulloblastoma Y astrocytomas.

Vascular malformations

Head injury.

Previous posterior fossa surgery.

Stenosis of the aqueduct of Silvio.

Bacterial meningitis.

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Types of hydrocephalus

For its causes:

  1. Congenital: It occurs at birth as a result of a genetic predisposition and due to environmental factors, fetal ventriculomegaly can be applied, a very sensitive ultrasound sign for alterations of the fetal central nervous system, the assessment is performed in the fetal period or during childhood , is frequently associated with the macrocephaly. The most frequent etiology is due to the obstruction of the Silvio aqueduct, the Dandy-Walker malformation and the Arnold-Chiari malformation.
  2. Acquired: After birth, it can manifest itself at any stage of development, even in adulthood, its origin may be due to infections, head injuries, tumors, hemorrhages or strokes, among others.

For the existing "communication":

  1. Caller: It manifests when the subarachnoid space and ventricles are "communicated", hence its name. Its most common cause is a defect in absorption or insufficient venous drainage and the least frequent is the overproduction of cerebrospinal fluid.
  2. Obstructive: also known as "non-communicating", in this modality, the flow of cerebrospinal fluid is hindered, through one or more of the narrow pathways that connect the ventricles or at their exits to the subarachnoid space. The most common etiology is space-occupying lesions that alter the ventricular anatomy..

By cranial pressure:

Normative or "normal tension": In this condition there is intermittent pressure (ICP) intermittently, it usually manifests itself in people over 60 with increased ventricles, cerebrospinal fluid pressure is normal and manifests absence of papilledema, but presence of Hakkim-Adams triad contemplating: dementia, gait apraxia and incontinence. The basal cerebrospinal fluid (CSF) pressure is at the high limit of normal. Other manifestations may be loss of working memory, spontaneity and proactive thinking tends to diminish.

When manifesting among older adults, its character includes symptoms related to other conditions that commonly appear among this age group, such as functional movement disorders, may present: tics or shaking, occasional cramping or spasms, contractures, or functional dystonia and psychogenic tremor that can be disabling.

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Other criteria:

  1. External benign: There may be spontaneous remission in less than a year, it is typical of childhood, it consists of a defect in the absorption of CSF, there is an increase in intracranial pressure (ICP) and subarachnoid spaces.
  2. With stenosis of the aqueduct of Silvio (HSAS): it is encoded in the genetic predisposition, it is a phenotype component of the clinical spectrum of L1 syndrome or "CRASH syndrome", a congenital developmental disorder linked to X, causes a severe intellectual deficit, when it manifests severely it usually has a poor prognosis.
  3. Ex vacuo: Focal destructive lesions and cerebral atrophy lead to an abnormal increase in CSF within the central nervous system (CNS), brain damage caused by a traumatic injury may occur due to a stroke or stroke, which can end in the wasting or atrophy of brain tissue. Some theorists do not consider them as hydrocephalus because they are not the result of a hydrodynamic disorder.

For the duration, it can be:

  1. Sharp: it happens in a period of days, it can clearly be seen the temporary horns with a size greater than 2 mm., exudation or transependymal resorption manifested as hypodensity in computed tomography (CT) or by hypersensal in magnetic resonance sequences ( RM). The frontal and third ventricle horns have bulging, the hard body in sagittal sections it shows bulging and thinning, the ratio of the distance between the temporary antlers in relation to the biparietal diameter is greater than 30% or 0.3.
  2. Subacute: It lasts for weeks.
  3. Chronicle: With a lifetime that can go for a few months, it can be maintained for years. In computed tomography (CT) and magnetic resonance imaging (MRI), the temporal horns can be seen with less prominence than in acute hydrocephalus, erosion of the Turkish chair, atrophy of the corpus callosum as well as macrocephaly.

Clinical manifestations of hydrocephalus

They vary in each individual due to particular differences, some clinical manifestations are due to the increase in tone in extremities and environmental factors, it is essential to take into account the age, since the ability to tolerate the pressure arising from the increase and to store CSF in children is different. The skull and brain of infants has greater plasticity, in children the most frequent etiologies are infectious.

In the small ones, the cranial sutures (fissures that connect the bones of the skull) can expand, making it possible to contain the increase in fluid because your skull has not closed. During this stage, a typical manifestation is the increase in head size.

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Differences between children and adults: symptoms of hydrocephalus

Hydrocephalus leads to changes in biopsychosocial development, cognitive problems are common, such as perceptual disturbances, difficulties in learning and verbal skills. In adults and children this is some symptomatology that can manifest:

  • Headache.
  • Sleep and sleepiness
  • Lethargy.
  • Fall asleep
  • Effects on evolution in development.
  • The process of: thinking, attention, memory, language and learning is affected.
  • Personality changes
  • Irritability.
  • Blurry vision.
  • Double vision.
  • Limitation to see up.
  • Balance problems
  • Alterations in hearing.
  • Strabismus with deviation of the eyes down.
  • Nausea and / vomiting
  • Gait disorders, when walking.
  • Difficulty controlling the bladder or urinary incontinence and in some cases faecal ...
  • Endocrine imbalance (hormonal problems).
  • Seizures

Baby with hydrocephalus and the Pizarro Scale

When it occurs at birth it may be due to congenital malformations. In them the diagnosis is feasible that manifests as: irritability, excessive sleepiness, vomiting, seizures and / or due to sign of the setting sun, What is it an eye deviation down, more typical of the condition due to symptoms associated with other causes.

It is common as they grow older to present delayed speech development and poor coordination. When the baby has the "mollera" very mired it can be by dehydration. Other symptoms are:

  • Abnormal enlargement of the head, there is an increase in the head circumference (≥98 to the age percentile).
  • Tense or bulky fontanelle
  • Cranial suture disjunction.
  • Bright and bulky scalp, the veins of it, you can see so dilated.
  • Sign of the setting sun: It is characteristic of the increase in intracranial pressure (ICP), it consists in deviation of the downward movement of the eyeballs, upper eyelids retracted, white sclera visible above the iris. and increased tone of the limbs, said spasticity affects lower limbs.

It is necessary to take care of newborns, children and older adults, as well as people with different abilities, prevent and avoid significant falls, trauma and infections that can diminish their quality of life in an important way.

Pizarro scale

It is used to compare the normal growth of the cranial perimeter, which must occur in the newborn up to 12 months:



cm / month





Frequent symptomatology of hydrocephalus during childhood

  • Spasticity of the lower extremities that causes inability or difficulty walking.
  • Macrocephaly, this condition may occur despite the closure of the cranial sutures.
  • Papiledema due to increased intracranial pressure (ICP).
  • Paralysis of the VI cranial nerve corresponding to the external ocular motor nerve affects the ability to move the eye outwards.
  • Vertical gaze paralysis, it is of supranuclear origin, it happens due to the pressure of the tectal saucer through the suprapineal recess, other symptoms of the dorsal midbrain syndrome can be manifested, such as dissociation in the response to light, retraction and retraction nystagmus Eyelid (Collier sign).
  • McEwen sign or "cascade pot sound" when percussing the head, based on the comparative study of the loudness of the different cranial regions.
  • Neck Pain.
  • Headache, mainly when waking up in the morning.
  • Decreased mental capacity, cognitive impairment may occur.
  • Delayed growth and early sexual maturation.
  • Epileptic seizures may manifest.

Common symptoms of hydrocephalus in adulthood

  • Walking unstable, due to truncal or limb ataxia.
  • Accommodation failure, vertical gaze paralysis.
  • When it manifested from childhood, hydrocephalus can occur macrocephaly.
  • Papiledema
  • Uni and bilateral paralysis of the VI cranial nerve.
  • Urinary incontinence and in some cases when it is persistent, it can also be fecal, which warns significant destruction of the frontal lobe and the progression of the condition.

Hydrocephalus and locomotion

Thelocomotion It is a complex process that requires coordinationWhen there are alterations in the neural pathways, as is the case with hydrocephalus, this can contribute to their generation walking difficulties, the patient with functional weakness commonly drags a leg when walking, also promotes cautious gait and avoidant behaviors that can even be maladaptive and unfeasible because of the "fear of falling, especially when in their clinical history they had significant falls." It is essential to prevent falls in older adults, since they carry a high risk due to the complications that can occur, when they cause severe trauma.

Hydrocephalus: cabinet diagnosis

Diagnostic images help to establish very precise diagnoses, so that atypical manifestations can be easily appreciated, this is valid for the fetus, neonates, children and adults of all ages, they are a valuable tool to determine the cause for which there are excess CSF

It is proper to perform a complete neurological evaluation, practice pressure monitoring techniques, cranial computed tomography (CT), magnetic resonance imaging (MRI), scintigraphy for diagnosis of CSF circulation abnormalities, cisternography, in which a puncture is performed spinal cord in the lumbar area to apply a component called radioisotope, the images show when the cerebrospinal fluid leaks out of the brain or spine. In neonates, it can be done through transfontanelar ultrasound.

Treating hydrocephalus

The medical treatment pharmacological It is carried out waiting for normal resorption of cerebrospinal fluid (CSF) to delay surgical intervention. It acts on two mechanisms: decreasing the secretion of the CSF with acetazolamide, which is a carbonic anhydrase enzyme inhibitor and furosemide a loop diuretic, in this way it seeks to increase resorption.We continue to investigate options with better results in biomedical treatment.

It is common for the treatment to involve surgical procedures to derive the fluid, creating an “alternate path” for the exit of excess cerebrospinal fluid, it can be through a bypass system which has: catheter, a flexible silstic tube or shunt and a valve, which sustains the flow in only one direction and regulates the amount of cerebrospinal fluid flow.

One side of the catheter goes in the Central Nervous System (CNS), close to the spinal cord, passes through the neck and down, usually to the abdominal or "peritoneal" cavity, can also be "redirected" to other body regions for absorption, this is done through a surgical procedure.

Some examples of others derivation types Cerebrospinal fluid are:

  1. Ventriculostomyendoscopic third ventricle (VET): This procedure is performed with a neuroendoscope, which has a small fiber optic camera, which allows you to identify and see surgical areas that are difficult to access and very small, in order to make an opening at the base of the third ventricle to establish the correct flow and reabsorption of the CSF. It is done when the cause is a distal obstruction in the third ventricle (diencephalon cavity).
  2. Ventriculoperitoneal (VP): the most common, we also find the vascular derivation, lumboperitoneal, occasionally the Torkildsen derivation, effective for acquired obstructive hydrocephalus.
  3. Ventriculopleural, used in case other types of referral are contraindicated.
  4. Lumbar punctures (PL): they are used when there are "communicating" hydrocephalus or after intraventricular hemorrhage, they can be performed "lumbar punctures (PL) repeat”, When the level of proteins in the CSF is not restored, it is unlikely that the condition will be resolved in this way.

After an intervention of any kind, it must be carried proper medical follow-up To avoid possible complications of a shunt system, monitor and protect against infections.

When fluid drainage is excessive, it can cause the ventricles to collapse, giving way to breaking blood vessels, the shunt can cause cerebrospinal fluid to drain faster. Currently there are minimally invasive surgeries, without leaving foreign objects inside the body.

Complications of hydrocephalus

Patients with hydrocephalus may manifest cognitive problems and other conditions, compromising their optimal development, as they are not treated in a timely and adequate manner, there may be major difficulties, such as irreversible brain damage

For patients with hydrocephalus or cerebrospinal fluid hydrodynamic disorder Pharmacological treatment is necessary, they benefit from psycho-pedagogical interventions and rehabilitation, the continuous support of a multidisciplinary team must be led by a neurologist and other specialists, timely intervention and adherence to protocols suggested by health professionals, can predict a better prognosis for the patient.

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Bibliographic references

  • Castro Castro, J., Villafernández, J.M. et al. (2012). Basic neurosurgery for emergencies. Spain: Editorial Bubok, S. L.
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