Low abdominal contribution to breathing as daytime predictor of nocturnal desaturation in adolescents and young adults with Duchenne Muscular Dystrophy.

In the respiratory management of DMD patients it is still under debate what parameter should indicate the correct timing for institution of nocturnal non-invasive ventilation (NIV), in addition to forced vital capacity, which is generally considered as a prognostic marker of disease progression. The aim of this study was to determine if volume variations of rib cage and abdominal compartments measured by Opto-Electronic Plethysmography can be helpful to distinguish between those patients who are in the early stages of nocturnal oxygen desaturation development and those who do not yet. Pulmonary function, abdominal contribution to tidal volume and to inspiratory capacity (%Abd IC) and a set of breathing pattern indexes were assessed in 40 DMD patients older than 14 years and not yet under nocturnal NIV. ROC analysis revealed that among all the considered parameters, %Abd IC in supine position was the best discriminator between DeSat (at least 10% of the night time with SpO(2) < 95%) and NonDeSat patients, providing an area under the curve with 95%CI equal to 0.752. In conclusion, in adolescents and adults DMD patients who present either no sign or only mild nocturnal oxygen desaturation, a reduced abdominal contribution to inspiratory capacity is a marker of the onset of diaphragm weakness and should be considered to identify the correct timing for the institution of nocturnal NIV.

Respiratory pattern in an adult population of dystrophic patients.

We studied respiratory function and Chest Wall kinematics in a large population of adult patients affected by slow course muscular dystrophies such as Limb-Girdle Muscular Dystrophy (LGMD, n=38), Becker Muscular Dystrophy (BMD, n=20) and Facio-Scapulo Humeral Dystrophy (FSHD, n=30), through standard spirometry and through the Optoelectronic Plethysmography, to measure the thoraco-abdominal motion during Quiet Breathing and Slow Vital Capacity maneuvers. Within the restrictive pulmonary syndrome characterizing LGMD and FSHD, several different thoraco-abdominal patterns compared to those of healthy subjects were present in the more advanced stages of the disease. These differences were present in the seated position, during the execution of a maximal maneuver such as Slow Vital Capacity. A global respiratory (both inspiratory and expiratory) muscle involvement was more pronounced in the LGMD and FSHD than in the BMD patients, and a significant reduction of abdominal contribution in wheelchair bound patients was observed. In conclusion, OEP technique is able to reveal mild initial modifications in the respiratory muscles in FSHD and LGMD patients, which could be helpful for functional and new therapeutic strategy evaluation.

Design of a 3D surface scanner prototype suitable for MR.

The detection of body movements during MR examination could help in reducing motion artifacts or to get patient responses during functional magnetic resonance. It can be supported by a slit scanner, that combines a camera with a light stripe projector to obtain 3D coordinates of points forming the external surface of the body. In this work we propose a slit scanner prototype based on a miniaturized projector without moving parts. Just small sized hardware is required to analyze the video signal, operating in time domain instead of spatial domain. To accomplish this, the camera is placed with its pixel columns as more parallel as possible to the projected light stripes and the camera video signal is analyzed by a resistor transistor logic after analog processing.

Quantitative evaluation protocol for upper limb motor coordination analysis in patients with ataxia.

Objective and quantitative measurement is crucial in the definition of functional impairment and in the tracking of disease progress over time of patients affected by progressive pathologies, such as ataxia. A new experimental procedure for the quantitative description of upper limb movement and coordination analysis was developed by the integration of an optoelectronic system and dedicated electronic board with four visual and pressure stimuli. 20 passive retroreflective markers were placed on the subject's body and two types pointing tests were defined: in the first one, the subjects were asked to reach with the index finger five consecutive times each of the three targets ("repetitive test"), and in the second one, the subjects were asked to randomly reach the targets with the index finger ("random test"). The preliminary results showed that patients affected by ataxia took more time with a less smooth finger tip movement to perform the reaching tests when compared to healthy subjects. The velocity was lower and its profile was more irregular in ataxic subjects. The new developed experimental procedure seems to be very promising in the quantitative description of upper limb movements of pathological and healthy subjects and it seems to be able to distinguish the impairments due to different levels of ataxia.

Effects of gender and posture on thoraco-abdominal kinematics during quiet breathing in healthy adults.

To investigate the effects of posture and gender on thoraco-abdominal motion and breathing pattern, 34 healthy men and women were studied by Opto-Electronic Plethysmography during quiet breathing in five different postures from seated (with and without back support) to supine position. Chest wall kinematics and breathing pattern were significantly influenced by position and gender. The progressively increased inclination of the trunk determined a progressive reduction of rib cage displacement, tidal volume, and minute ventilation and a progressive increase of abdominal contribution to tidal volume. Female subjects were characterized by smaller dimensions of the rib cage compartment and during quiet breathing by lower tidal volume, minute ventilation and abdominal contribution to tidal volume than males. The effect of posture on abdominal kinematics was significant only in women. The presence of a back support in seated position determined differences in breathing pattern. In conclusion, posture and gender have a strong influence on breathing and on chest wall kinematics.

Abdominal volume contribution to tidal volume as an early indicator of respiratory impairment in Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is characterised by progressive loss of muscular strength that leads to an increasingly restrictive pulmonary syndrome. However, it is still not clear whether this determines alterations in the breathing pattern. We studied: 66 DMD patients at different stages of the disease (mean+/- sem age 12.6+/-0.6 yrs, range 5-22 yrs of age), subdivided into four groups according to age; and 21 age-matched healthy male controls. Spirometry, lung volumes and nocturnal oxygen saturation were measured in all DMD patients. Ventilatory pattern and chest wall volume variations were assessed by optoelectronic plethysmography during spontaneous breathing both in seated and supine positions. Whilst in a seated position, no significant differences were found between patients and controls or between different age groups. In the supine position, the average contribution of abdominal volume change (DeltaV(AB)) to tidal volume progressively decreased with age (p<0.001). The patients who showed nocturnal hypoxaemia showed significantly lower Delta V(AB). In conclusion, chest wall motion during spontaneous breathing in awake conditions and in supine position is an important indicator of the degree of respiratory muscle impairment in DMD. DeltaV(AB) is not only an important marker of the progression of the disease but is also an early indicator of nocturnal hypoxaemia.

Balance in patients with anorexia and bulimia nervosa.

AIM: Neuro-muscular adaptations to the loss or increase in body weight may induce postural alterations. The aim of this study was to investigate the effect of body weight alterations on postural stability in patients with anorexia nervosa and bulimia. METHODS: The study enrolled 15 women affected by anorexia nervosa (AN), (mean body mass index [BMI] 15.8+/-1.8 kg/m(2)), 15 women affected by bulimia nervosa (BN), (mean BMI 20.1+/-2.9 kg/m(2)) and 11 healthy matched women (HC), (mean BMI 20.1+/-1 kg/m(2)). Two quiet standing conditions with eyes open (EO) and closed (EC) were analysed with an optoelectronic system (Vicon 460, Viconpeak, Oxford, UK) with passive markers to estimate the centre of mass (CoM) position. RESULTS: BN patients were more unstable than HC, showing statistically significant differences in antero-posterior CoM excursions and path length. AN patients showed non significant differences from HC. Only HC showed differences between EO and EC conditions, with significantly greater excursions in medio-lateral direction in EC condition (P<0.013) as well as an increased sway area (P<0.022). CONCLUSIONS: In BN, musculoskeletal factors seem to play a major role in the diminished postural control, which appear to be linked to body weight fluctuations rather than to BMI absolute values. No clear-cut postural instability was demonstrated in patients with AN as compared to HC. Visual input appears not to affect balance in patients with eating disorders. Possible further causes of postural instability in BN and implications for rehabilitation treatment are discussed.

Use of the normalcy index for the evaluation of gait pathology.

The normalcy index (NI) has been proposed as a method for quantifying the amount of deviation in a subject's gait, compared to the gait of the average unimpaired person. The NI was computed for a sample of 144 children affected by cerebral palsy, five idiopathic toe-walkers and 12 able-bodied subjects. It was sensitive enough to distinguish unimpaired subjects from idiopathic toe-walkers and to distinguish between the plegic and uninvolved limbs of hemiplegic patients. The NI was robust enough to categorize pathology, ranging from mild disorders to quadriplegia. The NI was found to be clinically applicable, reliable and easy to use, making it a valuable element in the quantitative evaluation of gait pathology.

Biomechanical analysis of sit-to-stand movement in normal and obese subjects.

OBJECTIVE: Main purpose of this study was to develop a biomechanical model for the analysis of sit-to-stand movement in normal and obese subjects. DESIGN: A biomechanical model describing sit-to-stand was developed using kinetic and kinematic experimental data. Trunk flexion, feet movement, knee and hip joint torques were assumed as sensible indexes to discriminate between normal and obese subjects. BACKGROUND: Sit-to-stand is a functional task that may become difficult for certain patients. The analysis of its execution provides useful biomechanical information on the motor ability of selected subjects. METHODS: Sit-to-stand was recorded using an optoelectronic system and a force platform in 40 obese patients and 10 normal subjects. A biomechanical model was developed using inverse dynamics equations. RESULTS: Kinematic and kinetic indexes evidenced differences in motion strategy between normal and obese subjects. Obese subjects rise from the chair limiting trunk flexion (mean value: 73.1 degrees ) and moving their feet backwards from initial position (mean deviation: 50 mm). Normal subjects, instead, show a higher trunk flexion (mean value: 49.2 degrees, a lower angular value between trunk and the horizontal means increased flexion) and fixed feet position (mean deviation: 5 mm). As for kinetics, obese patients show knee joint torque higher than hip torque (maximum knee torque: 0.75 Nm/kg; maximum hip torque: 0.59 Nm/kg), while normal subjects show opposite behaviour (maximum knee torque: 0.38 Nm/kg; maximum hip torque: 0.98 Nm/kg). RELEVANCE: We found differences in motion strategy between normal and obese subjects performing sit-to-stand movement, which may be used to plan and evaluate rehabilitative treatments.

[Case of cardiac amyloidosis associated with IgG-K multiple myeloma in the framework of restrictive myocardiopathy]. / Caso di amiloidosi cardiaca, in mieloma multiplo IgG-K secernente, con quadro di miocardiopatia restrittiva.

Primary amyloidosis, due to amassing of fragments of light chains of IgG, often causes cardiac involvement. We describe a 65-year-old woman with multiple myeloma efficaciously treated with chemotherapy. Amyloidosis had been supported by myelic biopsy. The patient came to our observation because of right heart failure, hypotension and syncope: she was treated with a dopamine i.v. and was in cachectic status. She had a moderate pericardial effusion. ECG showed reduction of QRS amplitude, I degree atrioventricular block, posterior fascicular and right bundle branch block. Right cardiac catheterization showed a restrictive situation. After 1 week exitus occurred by asystole. In this case, there were other involvements by amyloidosis, besides the cardia one: that of autonomic nervous system and, probably, surrenal.