Diaphragm Morphology and Respiratory Muscle Strength in Subacute Hemiplegic Patients

The Relationship Between Diaphragm Morphology and Respiratory Muscle Strength in Subacute Hemiplegic Patients: A Cross-Sectional Study

The aim of this study is to determine the relationship between diaphragm morphology (diaphragm excursion, end-inspiratory and end-expiratory diaphragm thickness, and thickening fraction) and respiratory muscle strength (maximum inspiratory pressure - MIP and maximum expiratory pressure - MEP) in patients with subacute hemiplegia.

Stroke is a neurological condition that causes multidimensional impairments in motor, sensory, and pulmonary functions and is associated with a high long-term disability burden. After stroke, weakness particularly develops in the diaphragm and intercostal muscles; this results in reduced chest wall movements, ventilatory restriction, and decreased lung volumes. The diaphragm, the primary inspiratory muscle, being positioned higher on the paretic side and exhibiting reduced movement leads to decreased respiratory capacity and impaired cough effectiveness.

Diaphragm ultrasonography is a method that allows noninvasive, reliable, and reproducible evaluation of diaphragm thickness, excursion, and functional changes. The relationship between ultrasound parameters and respiratory muscle strength is of clinical importance in determining the degree of respiratory muscle weakness and setting rehabilitation goals.

Although it is known that post-stroke MIP and MEP values are significantly reduced compared to healthy individuals, the relationship between diaphragm morphology and respiratory muscle strength has been investigated to a limited extent, particularly in the subacute period. Demonstrating this relationship will make an important contribution to planning individualized respiratory rehabilitation in the early period.

Inclusion Criteria:

• Adults aged 18-80 years
• Clinical diagnosis of hemiplegia
• Subacute phase (1-6 months post-onset)
• Ability to tolerate diaphragm ultrasonography and MIP/MEP measurements
• MMSE score ≥ 24
• Adequate level of consciousness and ability to cooperate

Exclusion Criteria:

• Respiratory comorbidities such as COPD, asthma, or interstitial lung disease
• Diaphragmatic paralysis or severe chest wall deformity
• Acute cardiopulmonary conditions preventing respiratory function testing
• Severe cognitive impairment that may affect measurements
• Inability to perform ultrasound assessment due to prior gastric or abdominal surgery