Patients with subacute hemiplegia following stroke will be evaluated. Diaphragm morphology (diaphragm excursion, end-inspiratory and end-expiratory diaphragm thickness, and thickening fraction) will be assessed using ultrasonography. Respiratory muscle strength will be measured by maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP). No intervention will be applied. This is an observational study.

The MMSE, developed by Folstein et al. in 1975, is a widely used, valid, and reliable test for assessing cognitive impairment. The MMSE is a 30-point, multi-item scale that evaluates five domains: orientation (10 points), registration (3 points), attention and calculation (5 points), recall (3 points), and language (9 points). In 2002, Güngen et al. demonstrated that the Turkish version of the MMSE is valid and reliable.

Respiratory muscle strength will be measured using an electronic, portable intraoral pressure device (MicroRPM, Micro Medical; United Kingdom). All measurements will be performed in the seated position. The nasal airway will be occluded using a nose clip, and an appropriate mouthpiece will be used.

For MIP assessment, the patient will first perform a maximal expiration before placing the device in the mouth, followed by a maximal inspiratory effort (Müller maneuver) at maximum speed sustained for 1-3 seconds.

This maneuver will be repeated three times, and the highest value will be recorded in cmH₂O.

Respiratory muscle strength will be measured using an electronic, portable intraoral pressure device (MicroRPM, Micro Medical; United Kingdom). All measurements will be performed in the seated position. The nasal airway will be occluded using a nose clip, and an appropriate mouthpiece will be used.

For MEP assessment, the patient will first perform a maximal inspiration before placing the device in the mouth, followed by a maximal expiratory effort (Valsalva maneuver) at maximum speed sustained for 1-3 seconds.

This maneuver will be repeated three times, and the highest value will be recorded in cmH₂O.

Diaphragm excursion will be assessed using M-mode ultrasonography, and diaphragm thickness and contractility will be measured using B-mode ultrasonography.

Patients will be evaluated in the supine position. Diaphragm thickness will be measured at end-expiration from the 9th intercostal space along the anterior axillary line using a 7-MHz linear transducer. Diaphragm motion during normal and deep breathing will be assessed with a 3.5-MHz curved transducer from the right hemidiaphragm.

The difference between inspiratory and expiratory measurements will be analyzed, and diaphragm thickening fraction will be calculated.