Hydrocephalus Flashcards
Definition of Hydrocephalus
Hydrocephalus is a neurological condition characterized by the abnormal accumulation of cerebrospinal fluid (CSF) within the brain, leading to an enlargement of the ventricles. This accumulation of fluid can cause increased pressure on the brain, resulting in various neurological symptoms.
Pathomechanism of Hydrocephalus
Obstruction: The most common type of hydrocephalus, known as obstructive hydrocephalus, occurs when there is a blockage within the pathways that allow CSF to flow freely. This obstruction can occur at various sites, including the cerebral aqueduct, foramen of Monro, or the outlet foramina.
Impaired absorption: Some cases of hydrocephalus result from impaired absorption of CSF by the arachnoid granulations or other mechanisms responsible for CSF drainage.
Causes of Hydrocephalus
Hydrocephalus can be congenital (present at birth) or acquired. Congenital hydrocephalus can be caused by genetic factors or prenatal infections. Acquired hydrocephalus can develop due to various reasons, including:
Intracranial hemorrhage: Bleeding within the brain can obstruct CSF flow and lead to hydrocephalus.
Infections: Infections such as meningitis or encephalitis can cause inflammation and blockage of CSF pathways.
Tumors: Brain tumors or other masses can obstruct CSF circulation and result in hydrocephalus.
Trauma: Head injuries or trauma can cause bleeding or swelling, leading to hydrocephalus.
Intraventricular hemorrhage: Bleeding within the ventricles, often seen in premature infants, can cause hydrocephalus.
Symptoms of Hydrocephalus
The symptoms of hydrocephalus can vary depending on the age of onset, the rate of progression, and the underlying cause. In infants and young children, symptoms may include:
Rapid head growth
Bulging fontanelles (soft spots on the baby’s skull)
High-pitched cry
Poor feeding and vomiting
Irritability or restlessness
Seizures
Downward deviation of the eyes (sunsetting sign)
Developmental delays or regression
In older children and adults, symptoms may include:
Headaches
Nausea and vomiting
Blurred or double vision
Changes in balance and coordination
Cognitive impairment and memory problems
Urinary incontinence or frequent urination
Difficulty with concentration and attention
Personality changes or mood swings
Diagnosis of Hydrocephalus
The diagnosis of hydrocephalus involves a thorough medical evaluation, neurological examination, and diagnostic tests, including:
Imaging tests: Magnetic resonance imaging (MRI) or computed tomography (CT) scans can reveal the enlargement of ventricles and help identify the underlying cause.
Lumbar puncture: Analysis of CSF obtained through a lumbar puncture can provide information about the pressure, composition, and presence of infection or other abnormalities.
Differential diagnosis of Hydrocephalus
Differential diagnosis involves distinguishing hydrocephalus from other conditions with similar symptoms, such as:
Normal-pressure hydrocephalus (NPH): A condition characterized by enlarged ventricles, but without the typical signs of increased intracranial pressure.
Brain tumors: Tumors in the brain can cause similar symptoms to hydrocephalus.
Chiari malformation: A structural abnormality where the lower part of the brain extends into the spinal canal, leading to CSF flow obstruction.
Treatment of Hydrocephalus
The treatment of hydrocephalus aims to reduce CSF accumulation, relieve symptoms, and prevent complications. It may involve:
Shunt placement: The most common treatment for hydrocephalus involves surgically placing a shunt system to divert excess CSF from the brain to another body cavity (usually the peritoneal cavity or the right atrium of the heart).
Endoscopic third ventriculostomy (ETV): In select cases, a neurosurgeon may perform an ETV procedure to create an opening in the floor of the third ventricle, allowing CSF to flow directly to the basal cisterns.
Medical management: In some cases, medications may be prescribed to reduce CSF production or manage associated symptoms, such as seizures or headaches.
Complications of Hydrocephalus
Shunt malfunction or infection: Shunt systems can malfunction or become infected, requiring surgical intervention.
Developmental delays: If hydrocephalus is not promptly treated, it can lead to long-term cognitive and developmental impairments.
Vision problems: Increased pressure on the optic nerves can result in visual disturbances or even vision loss.
Learning difficulties: Hydrocephalus can interfere with cognitive functioning, leading to learning disabilities and academic challenges.
Epilepsy: Some individuals with hydrocephalus may develop epilepsy or seizures.
