Thursday, May 21, 2015

A 2 Month Old Baby Is Hospitalized With Hydrocephalus Since Birth

A 2 month old baby who was diagnosed as a case of hydrocephalus on a prenatal ultrasound is hospitalized since birth and is under the care of pediatricians and neurosurgeons. The baby has an enlarged head circumference above 95 percentile and has difficulty feeding and has had 3 episodes of seizures. There is no active infection and there is plan for surgically inserting a shunt system.
The picture of the patient is shown below;

The eyes show the sun-set sign characteristic of hydrocephalus in babies.

Case Discussion:
Hydrocephalus is derived for the Greek words: Hydro means water and cephalus means head. It is a condition that is characterized by excessive accumulation of fluid in the brain. Since in young babies the skull sutures ares till open, the excess fluid leads to rapid enlargement of the head.

Physiology:  Cerebrospinal fluid (CSF)is an essential component of the nervous system that circulates through a system of passageways known as ventricles in the brain and exists through a reservoir known as cistern. CSF provides nutrients to the brain and takes away the waste products. If there is a blockage at any of these passages the fluid starts to accumulate leading to hydrocephalus. Sometimes there is no blockage but there is excess production of fluid and inadequate absorption leading to accumulation.

1. Congenital Hydrocephalus: a baby may born with a congenital defect leading to hydrocephalus which is sometimes even diagnosed prenatally. The conditions include;

  • Aqueductal stenosis.
  • Spina bifida.
  • Arnold chiari malformations
  • Dandy Walker syndrome
  • Vein of Galen malformations.
  • Craniosynostosis.
2. Acquired Causes: Sometimes hydrocephalus occurs later in life and causes include:
  • Hemorrhage
  • Infection
  • Trauma
  • Tumor
  • Cysts
Types Of Hydrocephalus:
1. Communicating: when CSF can still flow among the ventricles.
2. Non-communicating: also called obstructive , occurs when the flow of CSF is blocked. 

Clinical Features: depend upon the patient's age and the underlying cause:
1. Small babies and children may present with;
  • poor feeding
  • irritability
  • vomiting
  • rapidly enlarging size of the head
  • seizures
  • delayed milestones
  • visual problems
2. Adults may have:
  • headaches
  • urinary incontinence
  • gait abnormalities
  • blurred vision or double vision.
  • dementia
Physical Examination:

Examination in infants may reveal the following findings:
  • Head enlargement (head circumference ≥98th percentile for age)
  • Dysjunction of sutures
  • Dilated scalp veins
  • Tense fontanelle
  • Setting-sun sign: Characteristic of increased intracranial pressure (ICP); downward deviation of ocular globes, retracted upper lids, visible white sclerae above iris
  • Increased limb tone (spasticity preferentially affects the lower limbs)
Children and adults may demonstrate the following findings on physical examination:
  • Papilledema
  • Failure of upward gaze: Due to pressure on the tectal plate through the suprapineal recess; the limitation of upward gaze is of supranuclear origin
  • Unsteady gait
  • Large head
  • Unilateral or bilateral sixth nerve palsy (secondary to increased ICP)
Children may also exhibit the Macewen sign, in which a "cracked pot" sound is noted on percussion of the head.
Patients with NPH may exhibit the following findings on examination:
  • Normal muscle strength; no sensory loss
  • Increased reflexes and Babinski response in one or both feet: Search for vascular risk factors (causing associated brain microangiopathy or vascular Parkinsonism), which are common in NPH patients
  • Variable difficulty in walking: May have mild imbalance to inability to walk or to stand; the classic gait impairment consists of short steps, wide base, externally rotated feet, and lack of festination (hastening of cadence with progressively shortening stride length, a hallmark of the gait impairment of Parkinson disease)
  • Frontal release signs (in late stages): Appearance of sucking and grasping reflexes
Diagnostic Testing
No specific blood tests are recommended in the workup for hydrocephalus. However, consider genetic testing and counseling when X-linked hydrocephalus is suspected, and evaluate the CSF in posthemorrhagic and postmeningitic hydrocephalus for protein concentration and to exclude residual infection.
Obtain electroencephalography in patients with seizures.
Imaging studies
The following imaging studies may be used to evaluate patients with suspected hydrocephalus:
  • Computed tomography (CT) scanning: To assess size of ventricles and other structures
  • Magnetic resonance imaging (MRI): To assess for Chiari malformation or cerebellar or periaqueductal tumors
  • Ultrasonography through anterior fontanelle in infants: To assess for subependymal and intraventricular hemorrhage; to follow infants for possible progressive hydrocephalus
  • Skull radiography: To detect erosion of sella turcica, or "beaten copper cranium" (or "beaten silver cranium")—the latter can also be seen in craniosynostosis; (after shunt insertion) to confirm correct positioning of installed hardware
  • MRI cine: To measure CSF stroke volume (SV) in the cerebral aqueduct; however, such measurements don’t appear to be useful in predicting response to shunting
  • Diffusion tensor imaging (DTI): To detect differences in fractional anisotropy and mean diffusivity of the brain parenchyma surrounding the ventricles; allows recognition of microstructural changes in periventricular white matter region that may be too subtle on conventional MRI 
  • Radionuclide cisternography (in NPH): To assess the prognosis with regard to possible shunting—however, due to its poor sensitivity in predicting shunt response when the ventricular to total intracranial activity (V/T) 
  • ratio is less than 32%, this test is no longer commonly used.
it is important to treat hydrocephalus as early as possible because it may lead to permanent damage to the brain resulting in mental and physical disabilities

Surgical treatment is the preferred therapeutic option in patients with hydrocephalus. Most patients eventually undergo shunt placements, such as the following:
  • Ventriculoperitoneal (VP) shunt (most common)
  • Ventriculoatrial (VA) shunt (or "vascular shunt")
  • Lumboperitoneal shunt: Only used for communicating hydrocephalus, CSF fistula, or pseudotumor cerebri)
  • Torkildsen shunt (rarely): Effective only in acquired obstructive hydrocephalus
  • Ventriculopleural shunt (second-line therapy): Used if other shunt types contraindicated
Rapid-onset hydrocephalus with Increased intracranial presuure is an emergency. The following procedures can be done, depending on each specific case:
  • Ventricular tap in infants
  • Open ventricular drainage in children and adults
  • Lumbar puncture (LP) in posthemorrhagic and postmeningitic hydrocephalus
  • VP or VA shunt
Repeat LPs can be performed for cases of hydrocephalus after intraventricular hemorrhage (which can resolve spontaneously). If reabsorption does not resume when the CSF protein content is less than 100 mg/dL, spontaneous resorption is unlikely to occur. LPs can be performed only in cases of communicating hydrocephalus.
Alternatives to shunting include the following:
  • Choroid plexectomy or choroid plexus coagulation
  • Opening of a stenosed aqueduct
  • Endoscopic fenestration of the floor of the third ventricle (however, contraindicated in communicating hydrocephalus)
Conservative management
Medical treatment is not effective in long-term treatment of chronic hydrocephalus; it is used as a temporizing measure to delay surgical intervention. Medical therapy may be tried in premature infants with posthemorrhagic hydrocephalus (in the absence of acute hydrocephalus). Normal CSF absorption may resume spontaneously during this interim period.
Medication as treatment for hydrocephalus is controversial and should be used only as a temporary measure for posthemorrhagic hydrocephalus in neonates. Such agents include carbonic anhydrase inhibitors (eg, acetazolamide) and loop diuretics (eg, furosemide).

No comments:

Post a Comment