Hydrocephalus

Key points

The term "hydrocephalus" defines a serious disease characterized by the pathological accumulation of CSF in the sub-arachnoid space and in the cerebral ventricles.

Hydrocephalus: causes

The main cause of hydrocephalus lies in the exaggerated increase in intracranial pressure, which favors the accumulation of CSF in the brain. In turn, intracranial hypertension can be induced by: encephalocele, spina bifida, cerebral hematoma, encephalitis, meningitis , CNS malformations, brain tumor.

Hydrocephalus: symptoms

Hydrocephalus in newborns and children up to 2 years old → increased head circumference, epilepsy, convulsions, neck pain, loss of appetite, obesity, precocious puberty, mood changes, vomiting
Hydrocephalus in children (> 2 years) and in adults → mood alteration, cognitive / memory impairment, fever, lethargy, bowel / bladder incontinence, spasms, Parkinson-like symptoms, etc.

Hydrocephalus: diagnosis
The most suitable diagnostic strategies to ascertain a suspicion of hydrocephalus are: Neurological test for hydrocephalus, Imaging test (MRI, CT, brain ultrasound), Arteriography, Intracranial pressure detection.

Hydrocephalus: therapy

Treatment for hydrocephalus is exclusively surgical: surgical shunt, ventriculostomy, removal of cerebral portions that produce CSF.

Definition of hydrocephalus

Hydrocephalus is an exaggerated and pathological increase in the quantity of CSF in the sub-arachnoid space and / or in the cerebral ventricles, an expression of intracranial hypertension. Generally, hydrocephalus forms when the amount of cerebrospinal fluid produced far exceeds that which is reabsorbed; sometimes, the pathological accumulation of the CSF is the result of abnormal absorption.

Under physiological conditions, CSF flows into the cerebral ventricles, permeates the brain and spinal column. Hydrocephalus is formed when the pressure exerted by the cerebrospinal fluid increases exaggeratedly: in such circumstances, the patient runs the risk of suffering even serious brain damage. When the excess CSF pours into the meningeal space, the volume of the skull tends to increase.
Although it can affect anyone, hydrocephalus occurs more frequently in pediatric age (a primary pathological condition). It is estimated that the incidence of congenital hydrocephalus is 3 children per 1,000 healthy births.
In this informative article, we will try to simplify some complex concepts, focusing on triggers, main symptoms and complications related to hydrocephalus. For a better understanding of the disease, we will also investigate diagnostic techniques, available therapies and prevention.

Causes

Hydrocephalus is caused by alterations or defects in the CSF dynamics.
To better understand the causes involved in hydrocephalus, let's take a step back, briefly recalling the circulation of the liquor.
Cerebrospinal fluid is produced in the chorioid plexuses, permeates the CNS, circulates in the cavities of the skull base and in the spinal cord. This fluid rachido-spinal it is subsequently reabsorbed into the bloodstream through the arachnoid villi. The aforementioned mechanism allows a dynamic balance between production and reabsorption of the liquor: when this system is destabilized, the liquor accumulates, therefore it triggers a series of events that lead inexorably to hydrocephalus.

Alteration of CSF dynamics → accumulation of CSF in the brain → dilation of the cerebral ventricles → ↑ intracranial pressure → hydrocephalus

How can liquor accumulate?

CSF can accumulate under multiple circumstances:

Excessive production of CSF → "hydrocephalus due to overproduction of CSF" (typical variant of patients with chorioid plexus papilloma or diffuse villous hyperplasia)
Defect of CSF resorption mechanisms → "obstructive hydrocephalus"
Delay in the development of arachnoid function and blockage of the physiological circulation of the CSF → "external hydrocephalus", typical of premature babies and newborns genetically predisposed to a large head circumference

What are the triggers of hydrocephalus?

We have analyzed like hydrocephalus is formed; now we see because.
Hydrocephalus can be congenital / malformative or acquired, therefore it depends on underlying pathologies:

Encephalocele: consists of a "herniation of the meningeal and brain tissue, expression of a severe congenital brain malformation
Spina bifida: its most fearful complication is hydrocephalus
Intracerebral hematoma
Intraventricular haemorrhages: particularly common are postpartum ones (typical of premature babies)
Encephalitis: inflammation of the brain
Intrauterine infections (eg. Toxoplasmosis)
Meningitis: inflammation of the meninges with a predominantly infectious etiology (from meningococcus or pneumococcus)
Stenosis of the Silvio aqueduct (or mesencephalic aqueduct): narrowing of the longitudinal canal located in the midbrain
Arnold-Chiari syndrome: rare malformation of the posterior cranial fossa
Dandy-Walker syndrome: another rare structural abnormality of the CNS
Head trauma
Central nervous system tumors (brain or spinal cord cancer)

In some patients, the diagnosis of hydrocephalus is not justified by any obvious cause: in such circumstances, we speak of idiopathic hydrocephalus.

Risk factors

Some possible risk factors associated with hydrocephalus have been identified. The anomalies at the level of the Central Nervous System contribute to obstruct the flow of CSF: this could trigger an onset of hydrocephalus. Complications during childbirth can also alter the dynamics of CSF. therefore favor hydrocephalus.
Pregnant women should always undergo normal routine checks: the absence of prenatal tests or care prevents, in fact, any damage to the fetus, including hydrocephalus, to be detected.
The woman in childbirth should refrain from drinking alcohol during pregnancy: in fact, as some scientific studies show, children born to alcoholic women are more exposed to the risk of hydrocephalus.
The pregnant woman must pay particular attention to infections during pregnancy: it seems, in fact, that relatively simple diseases such as rubella, mumps or syphilis can, in some way, predispose the unborn child to the risk of hydrocephalus.