The Ultrasonographic Evaluation of Abdominal Accessory Respiratory Muscle Thickness in Patients With Parkinson's Disease: Correlation With Disease Severity and Expiratory Respiratory Muscle Strength

Parkinson's disease is a neurodegenerative disorder characterized by both motor and non-motor symptoms. The involvement of respiratory muscles can lead to impairments in respiratory function in these patients. In this study is to evaluate the thickness of abdominal accessory respiratory muscles using ultrasonography in patients with Parkinson's disease. Additionally, the relationship between disease severity and expiratory respiratory muscle strength will be examined.

The study will include Parkinson's patients at different stages of the disease, with respiratory muscle thickness measured via ultrasonography. The collected data will then be compared with disease severity and expiratory muscle strength.

Study Overview

• Status: Recruiting
• Conditions: Parkinson Disease (PD); Maximum Inspiratory Pressure; Maximum Expiratory Pressure; Abdominal Accessory Respiratory Muscle Thickness

Detailed Description

Parkinson's disease is a neurodegenerative disorder characterized by both motor and non-motor symptoms. The involvement of respiratory muscles can lead to impairments in respiratory function in these patients.

This observational, cross sectional study will include Parkinson's patients at different stages of the disease, with respiratory muscle thickness measured via ultrasonography. The collected data will then be compared with disease severity and expiratory muscle strength. In this study is to evaluate the thickness of abdominal accessory respiratory muscles (rectus abdominis, transversus abdominis, and oblique muscles) using ultrasonography in patients with Parkinson's disease. Additionally, the relationship between disease severity and expiratory respiratory muscle strength will be examined. Respiratory muscle strength will be assessed using maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) measurements. Disease severity will be evaluated using standardized clinical scales.

These findings will underscore the importance of evaluating respiratory muscles in Parkinson's disease and may contribute to the development of rehabilitation programs targeting respiratory muscles in the later stages of the disease.

• Study Type: Observational
• Enrollment (Estimated): 36

Contacts and Locations

• Study Contact: Name: AYŞE NUR SARIKOÇ; Phone Number: +905412105141; Email: aysenuryigit885@gmail.com

Study Locations

• Turkey (Türkiye)
  • BAHÇELİEVLER
    • Istanbul, BAHÇELİEVLER, Turkey (Türkiye), 34180
      • Recruiting
      • İstanbul Fizik Tedavi Ve Rehabilitasyon Eğitim Ve Araştirma Hastanesi
      • Contact: İSTANBUL FİZİK TEDAVİ VE REHABİLİTASYON EAH İSTANBUL FİZİK TEDAVİ VE REHABİLİTASYON EAH; Phone Number: 0(212) 496 50 00; Email: istanbulfth2@saglik.gov.tr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

THE GROUP WITH PARKINSON'S DIAGNOSIS AND HOEHN YAHR STAGE 1-2-3

Description

Inclusion Criteria:

• Age > 18 years
• Parkinson's disease diagnosis with Modified Hoehn and Yahr stages 1-2-3
• Mini-Mental State Examination (MMSE) score > 23
• Body Mass Index (BMI) < 30

Exclusion Criteria:

• Active smokers
• Individuals with a diagnosis of active chest disease
• Those with hemodynamic instability
• Individuals with unstable vital signs
• Parkinson's patients who cannot be controlled with medical treatment
• Parkinson Plus syndromes

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Parkinson Disease (PD); Abdominal Accesory Respiratory Muscles (rectus abdominis, transversus abdominis, and oblique muscles) and MIP(maximum inspiratory pressure) MEP(maximum expiratory pressure) values of the group with Parkinson's diagnosis and Hoehn Yahr Stage 1-2-3 will be measured, a 6-Minute Walk Test will be performed and the results will be noted.
Control Group; Abdominal Accessory Respiratory Muscles (rectus abdominis, transversus abdominis, and oblique muscles) and MIP (maximum inspiratory muscles) MEP(maximum expiratory muscles) values of age and gender matched healthy values of age and gender matched healthy volunteers without any diagnosis of neuromuscular disease or chest diseases will be measured and the results will be noted.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximal Expiratory Pressure (MEP) Measurement	MEP assesses the strength of abdominal and accessory expiratory muscles. During the maneuver, the patient is asked to blow forcefully into the mouthpiece for at least 1.5 seconds, as if inflating a balloon. The pressure generated during rapid expiration is measured by sensors, and after 1.5-2.0 seconds the shutter opens, ending the test. If multiple tests are conducted, the patient rests for at least 1 minute between trials, and a maximum of 3-5 trials are performed. Differences greater than 10 cmH₂O between trials are not accepted. The highest measurement is reported together with the predicted value. The MicroRPM Respiratory Pressure Meter (MicroDirect, USA) will be used.	to be measured only once at the start day 1
Maximal Inspiratory Pressure (MIP) Measurement	MIP is used to assess the strength of inspiratory respiratory muscles. During the test, the patient is instructed to exhale down to residual volume. MIP is defined as the maximum negative pressure measured during a maximal inspiratory effort performed after reaching residual volume. Measurements will be taken using the MicroRPM Respiratory Pressure Meter (MicroDirect, USA).	to be measured only once at the start day 1
Ultrasonographic Assessment of Abdominal Accessory Respiratory Muscles	Ultrasound measurements of the rectus abdominis, external oblique, internal oblique, and transversus abdominis muscles will be performed. Measurements will be taken in the supine position with the patient lying on their back, eyes facing upward, arms resting symmetrically beside the trunk, and lower extremities in full knee extension with an intermalleolar distance of 10 cm. Muscle thickness will be recorded at the end of normal expiration and at the end of forced expiration.	to be measured only once at the start day 1

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Six Minute Walk Test (6MWT)	The 6MWT is performed in a corridor with a flat, firm surface that is at least 30 meters long and marked at 3-meter intervals. Turning points should be indicated with a colored object. Start and finish lines are designated. The patient is asked to walk the longest distance possible within 6 minutes. The distance walked is measured and recorded.	to be measured only once at the start day 1
Modified Hoehn and Yahr Staging	This scale, developed by Margaret Hoehn and Melvin Yahr in 1967, is used to determine the severity of Parkinson's disease. It evaluates patient functionality, symptom laterality, pattern of involvement, and balance. The scoring ranges from 1 to 5. The Modified Hoehn & Yahr staging system includes additional stages 1.5 and 2.5. As the stage progresses, symptoms become more widespread, balance impairment and functional limitation increase; in the later stages, the patient becomes dependent on assistance or care.	to be measured only once at the start day 1

Collaborators and Investigators

• Sponsor: Istanbul Physical Medicine Rehabilitation Training and Research Hospital

Study record dates

Study Major Dates

• Study Start (Actual): December 29, 2025
• Primary Completion (Estimated): February 28, 2026
• Study Completion (Estimated): April 20, 2026

Study Registration Dates

• First Submitted: December 8, 2025
• First Submitted That Met QC Criteria: December 22, 2025
• First Posted (Estimated): December 30, 2025

Study Record Updates

• Last Update Posted (Estimated): January 2, 2026
• Last Update Submitted That Met QC Criteria: December 29, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: ultrasound; respiratory; abdominal muscles; parkinson disease; respiratory muscles; MIP; abdominal muscles ultrasonography; expiratory muscle strenght; maximum expiratory pressure (MEP)
• Additional Relevant MeSH Terms: Synucleinopathies; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Neurodegenerative Diseases; Movement Disorders; Parkinsonian Disorders; Basal Ganglia Diseases; Parkinson Disease
• Other Study ID Numbers: 2025-28

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared due to institutional policies and privacy considerations.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No