Longitudinal changes in anthropometrics and impact on self-reported physical function after traumatic brain injury

Area of Science:

• Critical Care Medicine
• Neurology
• Rehabilitation Medicine

Background:

• Traumatic brain injury (TBI) patients in intensive care units (ICUs) are susceptible to significant muscle wasting.
• Quantifying this muscle loss and its impact on recovery is crucial for patient management.

Purpose of the Study:

• To longitudinally track anthropometric changes in TBI patients.
• To compare non-invasive methods with dual-energy x-ray absorptiometry (DXA) for muscle mass assessment.
• To evaluate the relationship between anthropometric data and self-reported physical function.

Main Methods:

• Prospective observational study of moderate-to-severe TBI patients.
• Weekly measurements of quadriceps muscle layer thickness (QMLT) via ultrasound, alongside bodyweight and subjective global assessment (SGA).
• DXA for total body composition within 7 days of ICU discharge; functional outcomes assessed at 3 months using SF-36 and GOS-E.

Main Results:

• Significant weight loss and increased malnutrition prevalence observed during hospitalization.
• Quadriceps muscle layer thickness (QMLT) decreased in the ICU but stabilized post-discharge.
• Ultrasound-derived QMLT strongly correlated with DXA-measured lean mass (ρ = 0.74) and predicted improved physical function (SF-36 and GOS-E scores).

Conclusions:

• Muscle thickness is lost in the ICU following TBI, with stabilization occurring after ICU discharge.
• Ultrasound-measured QMLT shows promise as a surrogate for lean mass and a predictor of functional recovery.
• Further research is warranted to validate QMLT as a tool for assessing muscle mass and functional outcomes in trauma and critical illness.