Rapidly progressive brain atrophy in ventilated patients: a retrospective descriptive study

Area of Science:

• Neurology
• Critical Care Medicine
• Radiology

Background:

• The link between mechanical ventilation and brain volume changes remains unclear.
• Intensive Care Unit-Acquired Weakness (ICU-AW) is a significant concern for ventilated patients.
• Understanding brain volume changes may offer insights into ICU-AW development.

Purpose of the Study:

• To assess brain volume changes in patients requiring mechanical ventilation.
• To identify associations between brain volume reduction and the development of ICU-AW.
• To compare muscle strength outcomes between patients with and without significant brain volume loss.

Main Methods:

• Retrospective analysis of 84 mechanically ventilated ICU patients with at least two head CT scans.
• Automated segmentation used to quantify brain volume changes from baseline.
• Patients categorized into 'brain atrophy' (>0% reduction) and 'preserved brain volume' (≤0% reduction) groups.
• Medical Research Council (MRC) scores at discharge used to assess ICU-AW.

Main Results:

• 71 patients (84.5%) were classified in the brain atrophy group, showing a median volume reduction of 3.3% over 30 days.
• The brain atrophy group had significantly lower median MRC scores (36) compared to the preserved brain volume group (48).
• A significant association was found between brain volume reduction and lower muscle strength at discharge.

Conclusions:

• Rapidly progressive brain atrophy is common in ICU patients on mechanical ventilation.
• Brain atrophy is significantly associated with the development of ICU-AW.
• These findings highlight a potential mechanism linking ventilation to long-term neurological deficits.