# LONGITUDINAL ASSESSMENT OF LOWER LIMB MUSCLE QUANTITY AND QUALITY IN ACUTE STROKE PATIENTS

## TL;DR

This study shows that muscle quality in stroke patients declines quickly in the first 10 days, especially in the affected limb, and is linked to muscle quantity loss.

## Contribution

The study identifies early deterioration of muscle quality in acute stroke patients and links it to muscle quantity reduction.

## Key findings

- Muscle thickness decreased in both paretic and non-paretic limbs within 10 days.
- Echo intensity increased only in the paretic limb, indicating muscle quality deterioration.
- Changes in echo intensity were closely correlated with changes in muscle thickness in the paretic limb.

## Abstract

This longitudinal study evaluated acute-phase stroke patients, examining changes in skeletal muscle quantity and quality. The research aimed to determine when muscle quality deteriorates, its relationship with muscle quantity, and contributing factors.

Prospective observational study.

Forty stroke patients.

Muscle quantity was assessed as the thickness of the anterior and lateral mid-thigh, while muscle quality was assessed by echo intensity of the rectus femoris and vastus lateralis. Measurements on paretic and non-paretic limbs were taken on the first day after stroke onset and on the 10th day.

Muscle thickness of all regions of paretic and non-paretic limbs significantly decreased at 10 days, whereas echo intensity significantly increased only in the paretic limb. A significant negative correlation between changes in muscle thickness and echo intensity was observed in the paretic limb only. Multiple regression analysis revealed that the only variable that explains the changes in echo intensity was the changes in muscle thickness of the paretic limb.

Muscle quality begins to deteriorate as early as the acute phase of stroke. To prevent this deterioration, it is important to encourage skeletal muscle activity during the acute phase of immobilization and to minimise the reduction in muscle quantity.

This study aimed to determine the onset of skeletal muscle quality deterioration after stroke and to identify factors contributing to this change. Forty stroke patients were assessed for 10 days to evaluate change in muscle thickness, i.e., muscle quantity, and echo intensity, i.e., muscle quality, using ultrasound. Echo intensity is an index of skeletal muscle quality, with higher values indicating increased intramuscular fat and connective tissue. We found that the muscle thickness of both the paretic and non-paretic limbs decreased after 10 days, but the echo intensity increased only in the paretic limb. Importantly, patients who experienced greater decreases in muscle quantity also exhibited more pronounced deterioration in muscle quality, and the extent of change in echo intensity was closely correlated with the change in muscle thickness. These findings suggest that muscle quality deteriorates rapidly following stroke, and that preventing muscle quantity loss may be key to preserving muscle quality.