# Occurrence Rates of Delirium in Brain Tumor Patients: A Systematic Review and Meta-Analysis

## TL;DR

This study finds that 17% of brain tumor patients experience delirium, with higher rates in those with secondary tumors and frontal or temporal lobe tumors.

## Contribution

The study provides the first comprehensive meta-analysis on delirium occurrence rates in brain tumor patients.

## Key findings

- 17% of brain tumor patients experience delirium, with 31% in secondary tumor patients.
- Delirium is more common in frontal and temporal lobe tumors compared to occipital lobe tumors.
- Patients with delirium had hospital stays 4.62 days longer than those without.

## Abstract

Delirium is a sudden state of confusion that can occur in hospitalized patients, leading to longer hospital stays, worse outcomes, and reduced quality of life. While delirium has been well studied in patients with other brain conditions like stroke and dementia, little is known about how often it occurs in patients with brain tumors. Brain tumor patients face unique challenges because their tumors can quickly change brain pressure and disrupt normal brain function, potentially making them more likely to develop confusion. This study examined research from the past 25 years to determine how often delirium occurs in hospitalized brain tumor patients. We found that 17% of all brain tumor patients experience delirium. Notably, the rates were higher in patients with secondary brain tumors (31%) compared to those with primary brain tumors. Among the primary tumors, high-grade glioma patients experienced delirium at a rate of 21%, while low-grade glioma patients had a rate of 10%. Patients with tumors in the front and side areas of the brain were more likely to develop delirium, and those who did develop delirium stayed in the hospital nearly 5 days longer. These findings help doctors better understand which brain tumor patients are at the highest risk for confusion and can guide efforts to prevent and treat delirium in this vulnerable population.

Background: The occurrence (incidence or prevalence) of delirium in brain tumors is unknown, yet delirium is associated with increased morbidity and mortality and worse quality of life. We conducted a systematic review and meta-analysis to determine the occurrence of delirium in hospitalized patients with brain tumors. Methods: PubMed, Scopus, and Web of Science were systematically searched for papers from 1 January 1999 to 12 July 2024, including references from texts. Cross-sectional, prospective, and other cohort study designs were included, and individual case reports, case series, editorials, and reviews were excluded. The included papers were scored using a validated sensitivity analysis tool and tested for quality and bias using funnel plots and Egger’s test. We used random effects models for the summary estimates. We performed subgroup analyses by tumor type, tumor location, delirium subtype, and length of stay. Results: Of the 452 studies screened, 27 were included, representing 35,958 patients. The overall occurrence of delirium was 0.17 (95% CI [0.11–0.24]). Delirium occurrence in patients with low-grade gliomas, high-grade gliomas, and brain metastases was 0.10 [0.06–0.16], 0.21 [0.10–0.40], and 0.31 [0.16–0.50], respectively. Compared to the occipital lobe, there was a higher occurrence of delirium for tumors in the frontal (RR 3.08 [1.35–8.22]) and temporal lobes (RR 2.88 [1.22–7.93]). The patients were more likely to have hypoactive (RR 1.61 [1.30; 1.98]) than hyperactive delirium. Delirium was associated with 4.62 additional hospitalized days compared to those without delirium (CI [3.23–6.01]). Discussion: We confirmed high occurrence rates of delirium in patients hospitalized with brain tumors. Patients with brain metastases had a higher occurrence of delirium compared to patients with gliomas, and delirium occurrence rates were higher in patients with frontotemporal tumors. Delirium occurrence rates in the literature are very heterogeneous and point toward a need for tailored assessments in patients with brain tumors.