Hydrocephalus and shunt emergencies: Case

This girl has an obstructed ventriculoperitoneal shunt with preterminal features of brainstem herniation. The early-morning headache that wakes her, the projectile vomiting, and the increasing drowsiness are the classic triad of raised intracranial pressure, and the shunt pump that does not refill points to a proximal obstruction. The bradycardia, the hypertension, and the irregular respirations are the Cushing triad, which means the brainstem is being squeezed now. Her glucose is normal, so hypoglycaemia is excluded, and the priority is to bridge her to theatre at once. ^[1]

Clinical findings and assessment

The key findings are the five-day history of progressive raised-pressure symptoms, the shunt pump that does not refill, and the preterminal Cushing triad. The pattern is unmistakable for a shunt malfunction with impending herniation, and the working diagnosis is an obstructed shunt, most likely at the proximal catheter. The bradycardia of 44 and the hypertension of 150 over 95 are not incidental; they are the autonomic response to the rising intracranial pressure, and they signal that the brainstem is under threat. ^[3]

The differential of a shunted child with vomiting and drowsiness includes gastroenteritis, a viral illness, and migraine, and all three are common. The rule is that vomiting in a shunted child is gastroenteritis only after the shunt series is clear and the ventricles are stable, and this girl's Cushing triad puts her beyond that reassurance. Overdrainage and the slit ventricle syndrome present with a positional headache and small ventricles, which is the opposite of her enlarging-pressure picture, and shunt infection presents with fever and track inflammation, which she does not have. The obstructed shunt is the diagnosis. ^[10]