Management of shunt dysfunction using noninvasive intracranial pressure waveform monitoring: illustrative case

J Neurosurg Case Lessons. 2024 Mar 4;7(10):CASE23437. doi: 10.3171/CASE23437. Print 2024 Mar 4.

Abstract

Background: Normal pressure hydrocephalus (NPH) treatment consists of using valves for drainage, as it is for hydrocephalus in general. Despite this, complications can occur, putting the patient at risk, and neurological monitoring is crucial.

Observations: A 61-year-old male, who had been diagnosed with NPH 3 years prior and was being treated with a ventriculoperitoneal shunt with a programmable valve, presented to the emergency department because of a traumatic brain injury due to a fall from standing height. No previous complications were reported. He had an altered intracranial pressure (ICP) waveform in the emergency room when monitored with the brain4care device, with a P2/P1 ratio of 1.6. Imaging helped to confirm shunt dysfunction. Revision surgery normalized the ratio to 1.0, and the patient was discharged. Upon return after 14 days, an outpatient analysis revealed a ratio of 0.6, indicating improvement.

Lessons: In selected cases of NPH, noninvasive ICP waveform morphology analysis can be effective as a diagnostic aid, as well as in the pre- and postsurgical follow-up, given the possibility of comparing the values of ICP preoperatively and immediately postoperatively and the outpatient P2/P1 ratio, helping to manage these patients.

Keywords: intracranial pressure; neuroprotection; normal pressure hydrocephalus; ventriculoperitoneal shunt.