Time-Synchronized MRI-Assessment of Respiratory Apparatus Subsystems-A Feasibility Study.

The thorax (TH), the thoracic diaphragm (TD), and the abdominal wall (AW) are three sub-systems of the respiratory apparatus whose displacement motion has been well studied with the use of magnetic resonance imaging (MRI). Another sub-system, which has however received less research attention with respect to breathing, is the pelvic floor (PF). In particular, there is no study that has investigated the displacement of all four sub-systems simultaneously. Addressing this issue, it was the purpose of this feasibility study to establish a data acquisition paradigm for time-synchronous quantitative analysis of dynamic MRI data from these four major contributors to respiration and phonation (TH, TD, AW, and PF). Three healthy females were asked to breathe in and out forcefully while being recorded in a 1.5-Tesla whole body MR-scanner. Spanning a sequence of 15.12 seconds, 40 MRI data frames were acquired. Each data frame contained two slices, simultaneously documenting the mid-sagittal (TH, TD, PF) and transversal (AW) planes. The displacement motion of the four anatomical structures of interest was documented using kymographic analysis, resulting in time-varying calibrated structure displacement data. After computing the fundamental frequency of the cyclical breathing motion, the phase offsets of the TH, PF, and AW with respect to the TD were computed. Data analysis revealed three fundamentally different displacement patterns. Total structure displacement was in the range of 0.94 cm (TH) to 4.27 cm (TD). Phase delays of up to 90∘ (i.e., a quarter of a breathing cycle) between different structures were found. Motion offsets in the range of -28.30∘ to 14.90∘ were computed for the PF with respect to the TD. The diversity of results in only three investigated participants suggests a variety of possible breathing strategies, warranting further research.

Breathing, (S)Training and the Pelvic Floor-A Basic Concept.

BACKGROUND: The current scientific literature is inconsistent regarding the potential beneficial or deleterious effects of high-intensity physical activities on the pelvic floor (PF) in women. So far, it has not been established with certainty whether disparate breathing mechanisms may exert short- or long-term influence on the PF function in this context, although based on the established physiological interrelationship of breathing with PF activation, this seems plausible. OBJECTIVE: To propose a basic concept of the influence of different breathing patterns on the PF during strenuous physical efforts. Methodical approaches: Review of the recent literature, basic knowledge of classical western medicine regarding the principles of muscle physiology and the biomechanics of breathing, additional schematic illustrations, and magnetic resonance imaging (MRI) data corroborate the proposed concept and exemplify the consequences of strenuous efforts on the PF in relation to respective breathing phases. CONCLUSION: The pelvic floor muscles (PFMs) physiologically act as expiratory muscles in synergy with the anterolateral abdominal muscles, contracting during expiration and relaxing during inspiration. Obviously, a strenuous physical effort requires an expiratory motor synergy with the PFM and abdominal muscles in a co-contracted status to train the PFM and protect the PF against high intra-abdominal pressure (IAP). Holding breath in an inspiratory pattern during exertion stresses the PF because the high IAP impinges on the relaxed, hence insufficiently protected, PFMs. It seems conceivable that such disadvantageous breathing, if performed regularly and repeatedly, may ultimately cause PF dysfunction. At any rate, future research needs to take into account the respective breathing cycles during measurements and interventions addressing PFM function.

Inappropriate pelvic floor muscle activation during forced exhalation and coughing in elderly female inpatients with urinary incontinence.

BACKGROUND: Reduced pelvic floor muscle (PFM) contraction strength is a common condition in elderly female patients with urinary incontinence (UI). However, little data exist to demonstrate the importance of appropriate PFM activation during exhaling and coughing. OBJECTIVES: To analyse breathing and coughing patterns in elderly female inpatients with UI, and to assess PFM activation patterns during exhalation and coughing. DESIGN: Retrospective chart data analysis. PATIENTS AND METHODS: Data from 177 elderly female inpatients with UI were analysed to determine voluntary PFM contraction strength, as well as PFM activation and displacement of the pelvic floor (PF) and abdominal wall during forced exhalation and coughing. Clinical data were obtained by means of inspection and digital palpation in the course of a routine clinical UI assessment. Data collected were correlated with age, body mass index and number of childbirths, and categorised by predominant UI symptoms, history of previous hysterectomy and history of PFM training. RESULTS: Independent of voluntary PFM contraction strength, nearly all patients (n=168) demonstrated bulging of the abdominal wall and PF during forced exhalation and coughing instead of contracting the PFMs and consequently lifting the PF, which would be in accordance with physiological breathing synergies. None of the nine women who reflexively contracted the PFM physiologically in accordance with an expiratory breathing pattern complained of symptoms of stress UI alone. CONCLUSION: A high percentage of elderly females with UI do not activate their PFMs appropriately during forced exhalation and coughing, possibly contributing to or exacerbating UI.

Proof of concept: differential effects of Valsalva and straining maneuvers on the pelvic floor.

OBJECTIVE: To prove a basic physiological principle in healthy women, demonstrating different movement patterns of diaphragm, pelvic floor, and muscular wall surrounding the abdominal cavity during a Valsalva maneuver as opposed to a straining maneuver, by means of real-time dynamic magnetic resonance imaging (MRI). STUDY DESIGN: The study was performed at Hochzirl Hospital, Austria and Department of Radiology, Medical University Innsbruck, Austria. Four healthy women underwent MRI measurements in a 1.5-T whole body MR-scanner. Coronal, sagittal, and axial slices were acquired simultaneously and a dynamic MRI sequence was used to assess cranio-caudal movements of the diaphragm and pelvic floor and of concomitant changes in anterolateral abdominal muscle thickness and abdominal diameter at the umbilical level. RESULTS: Both the Valsalva maneuver and the straining maneuver began with deep inspiration and downward movement of the diaphragm. During the exertion phase of both maneuvers, abdominal muscle thickness increased and abdominal diameter decreased. During the Valsalva maneuver, the pelvic floor moved cranially parallel to the diaphragm, whereas during the straining maneuver, the pelvic floor was markedly displaced caudally. CONCLUSION: The Valsalva maneuver reflects an expiratory pattern with diaphragm and pelvic floor elevation, whereas during straining the pelvic floor descends.

High prevalence of pelvic floor muscle dysfunction in hospitalized elderly women with urinary incontinence.

INTRODUCTION AND HYPOTHESIS: The purpose of this study was to determine pelvic floor muscle (PFM) function in hospitalized elderly women with urinary incontinence (UI). METHODS: A cross-sectional study was performed using data of 704 patients, routinely collected by means of a clinical UI assessment. RESULTS: Only 25.5% of the patients were able to perform normal PFM contractions (Oxford grading scale score ≥3); 74.5% were unable to contract their PFM or showed weak PFM activity without circular contraction or elevation of the vagina. Vulvovaginal mucosal dystrophy was noted in 84% of the patients. A significant positive correlation of PFM function was found to cognitive status (MMSE score), mobility (Tinetti performance score), and history of previous PFM training; a negative correlation of PFM function was found to patients' age and vulvovaginal mucosal dystrophy, and no significant correlation to body mass index, parity, or history of hysterectomy. CONCLUSIONS: Targeted clinical UI assessment including digital vaginal palpation should be performed in all incontinent elderly women in order to detect PFM dysfunction and to optimize therapeutic measures.

Effects of multidimensional pelvic floor muscle training in healthy young women.

PURPOSE: Cross-sectional and interventional study to assess pelvic floor muscle (PFM) function in healthy young nulliparous women and to determine the effects of a 3-month PFM training program with emphasis on co-contraction of PFM and anterolateral abdominal muscles and on correctly performed coughing patterns. METHODS: PFM function was assessed by digital vaginal palpation in 40 volunteers and graded according to the 6-point Oxford grading scale. The PFM training program was comprised theoretical instruction, as well as verbal feedback during hands-on instruction and repeated training sessions focussing on strengthening PFM and anterolateral abdominal muscle co-contraction during forced expiration and coughing. RESULTS: At baseline, 30 women (75%) were able to perform normal PFM contractions at rest (Oxford scale score ≥ 3); only 4 of them (10%) presented additional involuntary PFM contractions before and during coughing. The remaining 10 women (25%) were unable to perform voluntary or involuntary PFM contractions. Mean Oxford scale score in the whole group was 3.3 ± 1.7. After completing the PFM training program, 29 women (72.5%) performed cough-related PFM contractions and group mean Oxford scale score increased significantly to 4.2 ± 1.0. CONCLUSIONS: The study shows that PFM dysfunction may be detected even in healthy young women. Multidimensional training, however, may significantly improve PFM function.

Phase-locked parallel movement of diaphragm and pelvic floor during breathing and coughing-a dynamic MRI investigation in healthy females.

INTRODUCTION AND HYPOTHESIS: the aim of this pilot study was to demonstrate physiological movements of the muscular walls surrounding the abdominal cavity during breathing and coughing in healthy nulliparous women by means of real-time dynamic magnetic resonance imaging (MRI). METHODS: eight volunteers underwent MRI measurements in a 1.5-T whole body MR-scanner. Coronal and sagittal slices were acquired simultaneously to assess respiratory-related cranio-caudal movement of diaphragm and pelvic floor (PF) and concomitant changes in horizontal abdominal diameter. RESULTS: respective mean amplitudes of cranio-caudal movement of the right and left diaphragmatic cupolae were 15 ± 6 and 9 ± 7 mm during quiet breathing; 32 ± 15 and 28 ± 16 mm during forceful breathing; and 32 ± 13 and 28 ± 7 mm during coughing. Both diaphragm and PF moved caudally during inspiration and cranially during expiration. Abdominal diameter decreased in all eight women consistently during the expiration phase of breathing, and in five women during coughing. CONCLUSIONS: in healthy women, real-time dynamic MRI demonstrates parallel cranio-caudal movement of the diaphragm and the PF during breathing and coughing and synchronous changes in abdominal wall diameter.

Breathing with the pelvic floor? Correlation of pelvic floor muscle function and expiratory flows in healthy young nulliparous women.

INTRODUCTION AND HYPOTHESIS: The aim of this cross-sectional study was to determine correlations between pelvic floor muscle (PFM) function and expiratory function in healthy young nulliparous women. METHODS: In 40 volunteers, PFM function was assessed by vaginal palpation. Forced expiration patterns were evaluated visually and by palpation of the suprapubic insertion region of the anterolateral abdominal muscles. Forced vital capacity (FVC) and forced expiratory flows (FEF) were determined by spirometry. RESULTS: Incremental positive correlation was found between voluntary PFM contraction strength and forced expiratory flow at 25%, 50% and 75% (FEF(25%), FEF(50%), FEF(75%)) of the FVC, respectively. Positive correlation was also found between PFM contraction strength and forced expired volume in 1 s (FEV(1)). No correlation was found between PFM contraction strength and FVC or peak expiratory flow (PEF). CONCLUSIONS: Despite some limitations of this study, the observed correlation between PFM contraction strength and forced expiratory flows may serve as theoretical background for a potential role of coordinated abdominal and PFM training in diseases with expiratory flow limitations.