What are the presentation and imaging findings in an 8-year-old child with hydrocephalus?

Hydrocephalus Presentation and Imaging in an 8-Year-Old Child

In an 8-year-old child with hydrocephalus, expect headache (worse when upright), nausea/vomiting, altered mental status, visual disturbances including diplopia, and gait abnormalities; MRI head with and without contrast is the imaging modality of choice, with CT head without contrast as an acceptable alternative when MRI is unavailable. 1, 2

Clinical Presentation

Primary Symptoms of Increased Intracranial Pressure

At 8 years of age, the cranial sutures are fused, so the child presents with signs of elevated intracranial pressure rather than macrocephaly seen in infants 3, 4:

• Headache: Characteristically worse when upright or with activity, may be relieved by lying down 1
• Nausea and vomiting: Particularly common in acute presentations, often worse in the morning 1
• Altered mental status: Ranging from mild confusion to lethargy and obtundation 1
• Visual disturbances: Including diplopia (double vision), blurred vision, and visual field defects 1
• Gait abnormalities: Ranging from subtle changes to frank instability 1

Ophthalmologic Findings

• Papilledema: Due to increased intracranial pressure, visible on fundoscopic examination 1
• Cranial nerve palsies: Particularly affecting eye movements, including Parinaud's syndrome (upward gaze palsy) with acute obstructive hydrocephalus 1

Warning Signs Requiring Urgent Evaluation

These indicate critical elevation of intracranial pressure and require immediate intervention 1:

• Sudden severe headache (may indicate acute hydrocephalus or hemorrhage)
• Rapid deterioration in mental status from lethargy to obtundation
• New onset seizures
• Bradycardia with hypertension (Cushing's triad)

Clinical Pitfall

Symptoms may be subtle in school-age children, with a discrepancy between prominent subjective symptoms and subtle clinical signs on examination 1. Do not dismiss vague complaints of headache or behavioral changes without proper imaging evaluation.

Imaging Approach

First-Line Imaging: MRI Head

MRI of the head with and without IV contrast is the most useful imaging modality for evaluating hydrocephalus in an 8-year-old child 2:

• Superior soft tissue contrast resolution compared to CT, allowing better visualization of intracranial structures 2
• Detects space-occupying lesions (tumors, cysts) that may be causing obstructive hydrocephalus 2
• Evaluates for aqueductal stenosis, the most common cause of congenital hydrocephalus 3
• Assesses periventricular changes suggesting prior infection or other pathology 5
• Avoids radiation exposure, which is particularly important in children 2

IV contrast administration helps characterize any intracranial space-occupying lesion detected 2.

Alternative Imaging: CT Head

CT head without IV contrast is an acceptable alternative when MRI is unavailable or contraindicated 2:

• Useful for rapid evaluation of hydrocephalus and space-occupying lesions causing raised intracranial pressure 2
• Faster acquisition time, useful in unstable or uncooperative patients
• However, provides inferior soft tissue detail compared to MRI 2

There is no role for contrast-enhanced CT in the initial evaluation of suspected hydrocephalus 2.

Specialized Imaging Considerations

MR venography (MRV) or CT venography (CTV) should be considered if there is concern for cerebral venous sinus thrombosis as a cause of secondary hydrocephalus, particularly in children with risk factors for thrombosis 2.

Imaging Findings in Hydrocephalus

Key findings to assess on imaging 2:

• Ventricular enlargement: Dilation of lateral, third, and/or fourth ventricles
• Periventricular edema: Transependymal CSF flow (better seen on MRI)
• Effacement of sulci: Loss of normal cortical sulcal pattern
• Level of obstruction: Identify whether communicating or non-communicating hydrocephalus

Important caveat: Ventricle size alone is not necessarily a predictor of clinical outcome or treatment effectiveness 2. Clinical symptoms combined with imaging findings guide management decisions, not ventricle size in isolation.

Follow-Up Imaging

Ventricle size change should not be used as the sole measurement of effective treatment 2. Clinical improvement (resolution of symptoms, improved neurological function) is more important than radiographic reduction in ventricle size when assessing treatment response.