Hydrocephalus is a clinical condition characterized by disturbance of cerebrospinal fluid regulation in the central nervous system. Cerebrospinal fluid regulation has three important steps - formation, flow and absorption.
Infants with hydrocephalus presents with complaints such as poor feeding, vomiting, reduced activity and irritability. Children and adults with hydrocephalus present with complaints such as slowing of higher brain functions, headaches in the morning, neck pain, vomiting specially in the morning, visual abnormality, drowsiness, difficulty in walking. In children there may be delayed growth and sexual maturation. Symptoms of normal pressure hydrocephalus (NPH) include gait disturbance, dementia, and inability to control urination .
Examination in infants may reveal head circumference ≥98th percentile for age, disjunction of sutures, dilated scalp veins, tense fontanelle, setting-sun sign, and lower limb spasticity.
Papilledema, failure of upward gaze, unsteady gait, large head, sixth nerve palsy and Macewen sign may be observed in examination of children and adults. Patients with NPH may exhibit increased reflexes and Babinski response in one or both feet. Variable difficulty in walking, sucking and grasping reflexes in adults may occur .
Size of ventricles and other structures could be assessed by computed tomography scanning (CT). Malformations or tumors are detected by magnetic resonance imaging (MRI). Ultrasonography through anterior fontanelle in infants may diagnose subependymal and intraventricular hemorrhage. Skull radiography detects erosion of sella turcica or beaten copper cranium seen in craniosynostosis to confirm position. MRI cine measures CSF stroke volume in the cerebral aqueduct. Diffusion tensor imaging (DTI) detects microstructural changes in periventricular white matter.
CSF examination is recommended in suspected case of hydrocephalus after hemorrhage and meningitis. Electroencephalography is recommended in patients with seizures. If X-linked hydrocephalus is suspected, genetic testing and counseling is recommended .
A surgical shunt placement is the preferred therapeutic option. Ventriculoperitoneal shunt is the most common procedure.
Ventriculoatrial shunt, lumboperitoneal shunt (used for communicating hydrocephalus, CSF fistula, or pseudotumor cerebri), Torkildsen shunt (in acquired obstructive hydrocephalus) and ventriculopleural shunt are other possible procedures .
Hydrocephalus of rapid-onset needs immediate attention which is managed by ventricular tap in infants, open ventricular drainage in children and adults, lumbar puncture (LP) in posthemorrhagic and postmeningitic hydrocephalus or ventriculoperitoneal or ventriculoatrial shunt.
Alternatives to shunting include choroid plexectomy, opening of a stenosed aqueduct and endoscopic fenestration of the floor of the third ventricle (contraindication is communicating hydrocephalus). Medical treatment with acetazolamide or furosemide may be advised in premature infants with non–acute posthemorrhagic hydrocephalus for delaying surgical intervention .
Hydrocephalus requires regular and long term follow-up. There could be complications after treatment such as, infection and choking or collapse of shunt causing rise in CSF pressure in which additional surgeries are considered. Children with hydrocephalus have developmental defects of motor function, mental retardation, defective vision, and risk for epilepsy. Patients with epilepsy have poor prognosis and are more likely to have an IQ lower than 90. About 60% of children with hydrocephalus attend the school and approximately 40% of children will lead normal lives .
Congenital hydrocephalus occurring in infants may be idiopathic, as a result of premature or obstructed delivery, a brain defect restricting the flow of cerebrospinal fluid, spina bifida, X-linked mutation, Dandy Walker malformation and arachnoid cysts the brain and spinal cord .
Acquired hydrocephalus occurs usually due to a blockage between the ventricles of the brain as a result of an injury or illnesses such as hemorrhage, meningitis, brain tumors, head injury, stroke in adults or children. In older people after brain injury, bleeding or infection, without any clear reason normal pressure hydrocephalus (NPH) may develop.
Approximately hydrocephalus accounts for 0.6 percent of all pediatric hospital admissions and three out of every thousand are born with hydrocephalus. The incidence of acquired hydrocephalus is not known. There is an equal incidence in both sexes with exceptions of X–linked disorders and normal pressure hydrocephalus. The disease shows two peaks one at infancy and other at adulthood on age curve. Adult cases account for 40% of total cases .
CSF is produced by the choroid plexus within brain ventricles at the rate of 0.20-0.35 ml/min and total volume in an adult is 120 ml. CSF flows from the lateral ventricle into the venous drainage through various foramina and ventricles in brain. The intracranial pressure increases if CSF is produced excessively or there is increased resistance to CSF flow, or there is increased venous sinus pressure.
First, temporal and frontal horns dilate asymmetrically resulting in elevation of the corpus callosum, followed by stretching of the septum pellucidum, thinning of the cerebral mantle, or enlargement of the third ventricle into the pituitary fossa which may result in pituitary dysfunction .
The mechanism of NPH is unclear and may be due to resistance to flow of resulting in intermittently elevation of CSF pressure, at night and ventricular enlargement is maintained despite normal pressure. This reflects increased force on the ventricular wall.
Hydrocephalus is not preventable. The risk could be minimized by regular antenatal check up and preventing premature labor. Posthemorrhagic and postmeningitic hydrocephalus could be prevented by avoiding head injuries and prompt treatment with antibiotics respectively.
Hydrocephalus is also termed as a hydrodynamic cerebrospinal fluid (CSF) disorder and is characterized by increase in volume of this fluid. If it progresses naturally without interventions, it leads to tonsillar herniation and compression of the brain stem which may cause respiratory arrest and death. This condition is diagnosed based on clinical findings, ophthalmic examination, CSF examination and CT scan of the head.
Such patients are treated with a shunt. Patients are reassessed for shunt revisions, complications and failure. In infants and children, hydrocephalus may cause poor development of cognitive function. It may cause loss of cognitive function in adults . Persistent visual loss if occurs may persist even after treatment.
Hydrocephalus is a clinical condition characterized by disturbance of cerebrospinal fluid regulation (CSF) in the central nervous system ie. production, flow and absorption.
Hydrocephalus may be inborn without any cause or secondary to complications of delivery such as delay or obstruction, genetic disorders, spinal and brain malformations.
In adults or children there is usually acquired hydrocephalus due to a blockage between the ventricles of the brain as a result of an injury or illnesses such as subarachnoid hemorrhage, venous thrombosis, meningitis, brain tumors, head injury or stroke.
Infants with hydrocephalus presents with complaints such as poor feeding, reduced activity, irritability, and vomiting. Children and adults presents with symptoms such as slowing of higher brain functions, headaches in the morning, neck pain, vomiting specially in the morning, blurred vision, double vision, difficulty in walking or drowsiness.
Hydrocephalus may be diagnosed on history and clinical examination along with investigations such as X-ray, CT, MRI, and USG. Other investigations such as CSF examination, electroencephalography, genetic screening may be advised if required based on the suspected cause.
A surgical shunt placement is the preferred therapeutic option. Hydrocephalus with rapid-onset is an emergency which is managed by ventricular tap or drainage in infants and children or adults respectively. Lumbar puncture (LP) is treatment procedure for posthemorrhagic and postmeningitic hydrocephalus. Choroid plexectomy and opening of a stenosed aqueduct are alternatives to shunting, endoscopic fenestration of the floor of the third ventricle. Medical treatment with acetazolamide or furosemide may be advised in premature infants with non–acute posthemorrhagic hydrocephalus for delaying surgical intervention.