- Elevated ICP symptoms: These are symptoms of shunt malfunction that include headache, lethargy, vomiting, and irritability. Signs include increasing head circumference and papilledema.
- Low ICP symptoms: Symptoms of low ICP include headache (worse with upright posture), usually progressing as the day goes on and improving with recumbency.
Variable patterns of presentation
- Intermittent shunt malfunction: Episodic high-pressure symptoms are the mainstay, sometimes associated with activity.
- Elevated ICP with functioning shunt: This has been termed cephalocranial disproportion. An example is seen in shunted children with craniofacial syndromes. Headaches, vomiting, and papilledema can lead to visual loss elevated ICP is left untreated.
- Elevated ICP with malfunctioning shunt (normal volume hydrocephalus): This has been termed normal volume hydrocephalus, or shunt pseudotumor. The patient may have morning headaches unrelieved by analgesics or visual changes similar to cephalocranial disproportion symptoms above.
- Low ICP: This has been attributed to shunt overdrainage. Low ICP symptoms progress during the day with the headache improved with recumbency. Rarely, cranial nerve 6 palsies can occur.
- Headache unrelated to shunt function: Not uncommonly there will be a family history of migraines, episodic headache, or headaches relieved by rest.
Time for evolution
- Variable: Onset can be either insidious or rapid, requiring urgent evaluation in the ER. A history of recurrent visits to the ER and multiple surgical interventions is common in this patient population.
Few nonsurgical interventions alleviate symptoms.
- Steroids: Steroids can help temporarily prior to surgical intervention.
- Hydration: IV fluids can reduce symptoms in the child with overdrainage or low ICP.
Preparation for definitive intervention, nonemergent
- Planned evaluation: The problem can be approached systematically. Generally this will include a course of ICP monitoring, so the patient will need to be prepared for surgery and a monitored bed space arranged.
Preparation for definitive intervention, emergent
- Symptomatic elevated ICP: Emergent surgery may be required for shunt revision or for the addition of a new shunt in the setting of raised ICP. Preparation would be the same as for any shunt revision (3).
- HOB, positioning, and activity: Admission to the ICU or a monitored unit is often warranted to monitor the child closely. The HOB is elevated to encourage venous return and lower the ICP.
- Vital signs: Close monitoring of vital signs to look for bradycardia, hypertension, or respiratory compromise is essential (Cushing’s triad).