Editor in Chief
- Progressive obtundation and herniation: Increasing ICP due to sudden obstruction of the CSF pathways can be followed within hours by acute dilatation of the system proximal to the block. A rapid and progressive rise in ICP results if the cranial sutures are closed. Death usually occurs rapidly unless treatment is instituted promptly.
- Causes: The most common causes of acute hydrocephalus include spontaneous intracranial (intraventricular) hemorrhage, posterior fossa tumor, acute exudative meningitis, head trauma, and sudden obstruction of ventricular shunts (12).
- Slow or no growth in ventricles: Chronic hydrocephalus may be associated with many compensatory adjustments, which occur if the ventricular obstruction is incomplete, that slow or arrest the pathological process. Some of these compensatory changes include expansion of the skull if the cranial sutures are open, contraction of the cerebral vascular volume, and generalized enlargement of the ventricular system in conjunction with brain atrophy.
- Normal ICP: Arrested hydrocephalus may be defined as a state of chronic hydrocephalus in which the CSF pressure has returned to normal. The rate of CSF absorption is equal to the rate of CSF formation in compensated, or “arrested,” hydrocephalus, and the size of the ventricles remains stable or decreases. New neurologic signs do not appear, and there is evidence of continuing psychomotor development with increasing age.
- Cause: Spontaneous arrest of hydrocephalus occurs most likely when the CSF obstruction is incomplete and when the block is distal (subarachnoid space) rather than proximal (intraventricular).
The symptoms that develop are usually related to raised ICP:
- Excessive irritability: Infants generally show poor feeding, excessive crying, and are inconsolable.
- Lethargy: Infants have decreased interaction, energy, and wakefulness.
Symptoms tend to be more common in the mornings, when ICP is higher because of the natural increase in blood volume that results from the normal decrease in ventilation. This causes retention of CO2 and leads to vasodilation. The flow of CSF also decreases overnight due to the child being recumbent.
- Nausea or vomiting
- Double vision from abducens nerve palsy: This can be unilateral or bilateral.
- Rare visual deficits: Rare visual deficits such as transient visual obscurations or related severe papilledema may occur.
Patterns of evolution
- Variable: Symptoms and signs evolve at a variable pace due to the degree of dependency of the patient on the treatment for his or her hydrocephalus and the degree of the treatment’s failure.
- Linear or fluctuating: The evolution can be linear in nature, or the signs of the failure may fluctuate in their intensity.
Time for evolution
- Acute hydrocephalus: Symptoms can develop within hours as ICP rises due to acute dilatation of the ventricular system proximal to the block. Death usually occurs rapidly unless treatment is instituted promptly.
- Chronic hydrocephalus: Slow evolution or arrested pathological signs of injury to the CNS may occur owing to compensatory mechanisms that dissipate any pressure due to the hydrocephalus.
- Arrested hydrocephalus: No evolution in symptoms occurs due to the fact that the CSF pressure has returned to normal and the pressure gradient between the cerebral ventricles and brain parenchyma has been dissipated.
Evaluation at Presentation
- See EVALUATION
If the patient is critically ill (i.e., severely obtunded, especially if bradycardia is present), immediate attention will include:
- Establishment of airway and ventilation
- Maintenance of hemodynamic stability
- Emergent insertion of an external ventricular drain
Preparation for definitive intervention, nonemergent
- Standard preoperative lab evaluation: Order preoperative blood work, including CBC and coagulation profile.
- Appropriate imaging: Obtain adequate preoperative imaging to assess detailed anatomy, including the possible need for an MRI.
Preparation for definitive intervention, emergent
- Stabilize patient for OR: Establish airway and ventilation. Maintain hemodynamic stability.
- Obtain needed assessment for surgery: Obtain urgent preoperative blood work, including CBC and coagulation profile.
- Routine: Routine admission orders are needed to prepare child for surgery.