Presenting symptoms correspond to those of acute hydrocephalus and include the following:
- Macrocephaly: 80% of cases present in infancy with a large or increasing head circumference.
- Elevated ICP: Symptoms associated with intracranial hypertension are frequent and include headaches, lethargy, nausea/vomiting, and papilledema.
- Seizures: Up to 15% of patients have a history of seizures.
- Impaired motor function: Ataxia, spasticity, and poor motor function are common.
- Cognitive impairment: Intellectual function is impaired in 50–75% of patients.
Patterns of evolution
- Macrocrania in infancy: The condition is usually evidenced in infancy with macrocephaly or significantly elevated ICP.
- Symptoms due to hydrocephalus later in life: The condition may become apparent later in life due to progressive hydrocephalus.
Time for evolution
- Variable: The time for evolution is variable.
- Stabilization: Many patients present with stabilized ICP, with compensated hydrocephalus. In these cases, no intervention may be indicated. However, elevated ICP may require intervention for control.
- Preparation for definitive intervention, nonemergent: Imaging studies should include MRI with and without contrast. An assessment of ICP should be made to determine the need and timing of intervention. This assessment can include ophthalmological examination. Routine preoperative laboratory tests and assessment are performed.
- Preparation for definitive intervention, emergent: Patients may be critically ill with elevated ICP. CSF drainage would be indicated, either at the bedside in an ICU or in the operating room. Appropriate interventions to allow CSF drainage should be planned.
- CSF drainage parameters: When an EVD is required, the CSF should be drained to a normal pressure (i.e., 5-10 mmHg), but not too aggressively to prevent upward herniation.