Can clinicians correctly predict intracranial pressure state based on clinical symptoms alone in shunted patients?

Background: Clinicians are well-versed in the classical symptoms of low vs. high intracranial pressure (ICP). However, symptoms may not be as predictable of ICP state in shunted patients with chronic symptoms. In this study, we assess whether clinicians can predict high vs. low ICP state in chronically symptomatic shunted patients without any diagnostic clues.

Methods: A detailed retrospective analysis was performed on 259 patients undergoing ICP monitoring. A total of 17 patients who had a ventriculoperitoneal shunt were identified, with a suspected chronic abnormal ICP state based only on clinical symptoms. Patients with investigations guiding towards a likely pressure state were excluded, e.g., imaging or ophthalmological findings suggestive of ICP state.

Results: Clinical suspicion of ICP state was incorrect in 16 out of 17 cases (P<0.05). The symptoms described by patients were suggestive of abnormal ICP states; however, 13 out of 17 cases demonstrated ICP within the normal range (-1.3 to 5.3 mmHg). Three patients with occipital headaches worse on standing, typical of low-pressure symptoms, were in fact shown to have ICP above 10.0 mmHg.

Conclusions: This study casts doubt on the utility of classic symptoms in diagnosing abnormal ICP state in chronically symptomatic shunted patients with equivocal adjuncts. Additionally, it highlights the importance of ICP monitoring for this patient group.