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Biomedical subjects

E Sforza

Publications and source records attributed to E Sforza.

At least 37 records · Page 2Linked to original sources
PubMed1998

[Hypersomnia. Investigational strategy for evaluating hypersomnia].

CLINIC AND HISTORY: Expression of hypersomnia can take on several forms: long period of nocturnal sleep, excessive diurnal somnolence or both. History taking is essential. Useful tools include standardized questionnaires and a diary of sleeping habits. Not only do they provide evidence of the hypersomnia, but also information on possible eccentric origin(s). A pathological hypothesis can then be put forward: sleep apnea syndrome, narcolepsy, idiopathic hypersomnia, or periodic movements during sleep. POLYGRAPHY: Different recording protocols have been designed to determine sleep patterns, often depending on the clinical setting. The goal is to obtain an objective confirmation of hypersomnia and demonstrate a cause. The type of recording (hour and duration of the recording, parameters monitored) depends on the information desired. Because captors themselves sometimes perturb sleep, polygraphic explorations must be adapted to each individual situation.

Diagnosis, Differential↗
PubMed1998

[Starling resister and stability of sleep ventilation].

The upper airway can be described as a collapsible segment (the pharynx) interposed between two rigid bony (the cavum) or cartilaginous (the trachea) segments. Due to this structure, the pharynx behaves as a collapsible tube, in which airflow does not depend on the downstream pressure, but is limited to a maximum value which depends only on the upstream pressure and on the pressure surrounding the collapsible segment; this behavior, known as a Starling resistor can be modeled by the waterfall effect. Thus, the upper airways can be in three different conditions: an occluded condition, in which no flow is possible, a patent condition, in which flow depends on the difference between upstream and downstream pressures (according to Poiseuille's law), and a situation in which flow is limited. The behavior of the upper airway is largely dependent on its anatomic structure, but functional factors play a critical role. Among these sleep state is both a determinant of the collapsibility of the pharynx, and determined by the simulation of upper airway mechanoreceptors whose activity depends on the activity of respiratory muscles. Thus the interplay of three factors: ventilatory drive, upper airway collapsibility, and arousal threshold can predict most of the situations of stable and unstable ventilatory behavior during sleep. The level of the arousal threshold governs the stability of the ventilatory pattern, as it determines whether a combination of slow, respiratory effort, and blood gases can be maintained or is interrupted by an arousal.

Airway Resistance↗
PubMed1998

Time course of pulmonary artery pressure during sleep in sleep apnoea syndrome: role of recurrent apnoeas.

Recent results in animals have suggested that repetition of hypoxaemic stimuli may result in a progressive increase in pulmonary arterial pressure (Ppa). The purpose of the present study was to investigate the effects of recurrent obstructive apnoeas on Ppa. We have, therefore, examined the nocturnal trend of Ppa in seven obstructive sleep apnoea syndrome (OSAS) patients and in five snorers. Mean Ppa was measured before, at the start, at the end and after the selected apnoeas. The analysis was performed for each 1 h period for at least 7 h throughout the night on at least 10 randomly selected apnoeas per hour. In snorers, 100 randomly chosen values were measured during every hour of the night. In the morning after the nocturnal study, the Ppa responses to acute hypoxia and hypercapnia were measured. No Ppa changes throughout the 7 h were found during sleep in snorers [Ppa slope:-0.002+/-0.10 mmHg x h(-1)]. In OSAS patients a small but significant increase in Ppa throughout the night was noted, affecting the values before [Ppa slope: 0.7+/-0.16 mmHg x h(-1)], at the start of apnoea [Ppa slope: 0.530.1 mmHg x h(-1)] as well as at the end [Ppa slope: 0.44+/-0.08 mmHg x h(-1)] and in the postapnoeic period [Ppa slope: 0.55+/-0.1 mmHg x h(-1)]. When we limited the analysis to nonrapid eye movement (NREM) sleep, a trend in progressive Ppa was also present, irrespective of changes in apnoea duration and apnoea desaturation. The Ppa rise during the night was not affected by diurnal Ppa pulmonary vascular response to hypoxia and hypercapnia or indices of sleep apnoea severity. We conclude that in obstructive sleep apnoea, pulmonary artery pressure progressively increases during the night, reflecting the cumulative effects of apnoeas and nocturnal hypoxaemia.

Adult↗
PubMed1998

Simplified diagnostic procedure for obstructive sleep apnoea syndrome: lower subsequent compliance with CPAP.

The aim of this study was to investigate whether a simplified diagnostic procedure based on ambulatory monitoring with MESAM IV altered subsequent compliance with continuous positive airway pressure (CPAP) in obstructive sleep apnoea (OSA) patients. During a period of 16 months, 60 patients with symptoms evocative of OSA and positive MESAM recording were prescribed CPAP after titration with standard polysomnography. Compliance was followed during 2 yrs based on built-in time counters and was compared with the compliance in two comparison groups: an equal number of equally severely affected patients diagnosed with standard polysomnography during the 18 months (8 months before and 8 months after) preceding and following the study period and a group of 48 patients with an estimated similar apnoea/hypopnoea index but less typical clinical and/or MESAM features, diagnosed as having OSA based on polysomnography during the study period. The three groups were not different by age, body mass index, or sleepiness score. Patients diagnosed with the ambulatory procedure had higher drop-out rates (21.7% versus 10% and 6.25%; p<0.05) and lower rates of use of their CPAP (43+/-0.3 h x night(-1)) than any of the control groups (53+/-0.2 and 5.6+/-0.2 h x night(-1), p<0.05). In conclusion, there is a risk that ambulatory diagnostic procedures alter the relationship of patients to their disease and/or the medical staff so that subsequent compliance with treatment may be decreased. The greatest care concerning compliance should be taken before an ambulatory-based diagnostic procedure is implemented.

Ambulatory Care↗
PubMed1998

Nocturnal evolution of respiratory effort in obstructive sleep apnoea syndrome: influence on arousal threshold.

It has been recently described that the overnight increase in maximal end-apnoeic oesophageal pressure (P(oes,max)), considered as an index of the arousal threshold to occlusion, mostly contributes to apnoea lengthening during the night. However, the rise in apnoea duration could also be caused by changes in hypoxaemia, chemosensitivity and upper airway resistance. To better define the relative contributions of each of these factors, we examined the recordings of nine patients. Before apnoea, the mean pulmonary resistance at peak inspiratory flow (RPIF) was computed. During apnoea, all swings in oesophageal pressure (P(oes)) were measured to define the P(oes,max), the increase from the minimum to the maximum (deltaP(oes)), the rate of increase in P(oes) (RP(oes)) and the P(oes) at the first occluded breath (P(oes,1)). A gradual and significant increase in apnoea duration (p=0.02), P(oes,max) (p=0.02) and deltaP(oes) (p=0.006) was present across the night without any changes in oxygen saturation, RPIF, and P(oes,1). The slope of increase in P(oes,max), apnoea duration and deltaP(oes) was correlated with the apnoea/hypopnoea index. We conclude that in obstructive sleep apnoea, the nocturnal rise in apnoea duration is attributable more to an increase in the arousal threshold related to apnoea recurrence than to changes in chemosensitivity and upper airway resistance.

Airway Resistance↗
PubMed1997

REM sleep behavior disorder: clinical and physiopathological findings.

Abnormalities of REM sleep i.e. absence of atonia and abnormal motor control which are described in patients with REM sleep behavior disorder, have induced clinical and physiopathological interest. Initial hypothesis of a simple dysfunction of REM sleep generators has not been confirmed. The prevalence in older subjects and in patients with parkinsonian syndromes suggest that the appearance of the parasomnia is related to alteration in the neurons of pontine area i.e. nucleus peduncolopontine, in which there is an integration of sleep-wake mechanisms and locomotor systems. Controversy surrounds the specificity of absence of atonia in the diagnosis of the parasomnia. Since this polygraphic finding may be present in subjects without any sleep complaint and in patients with initial neurological impairment, diagnosis of the sleep disorders might be allowed only when the polygraphic characteristic of persistent tonus and complex motor behavior are recorded.

Journal Article↗
PubMed1997

Epidemiological, clinical and therapeutic evaluation of the Italian cholera epidemic in 1994.

In the period between 18 October and 4 December 1994, 12 indigenous cases of cholera were registered in the southern Italian region of Puglia, 10 of them were diagnosed in our Departments of Infectious Diseases. All patients were infected by consumption of raw fish or mussels. The patients had an elevated mean age and most were affected with systemic pathologies. The clinical course was mild and rarely complicated, although frequently the characteristic riziform diarrhoea was absent. In all patients V. cholerae serotype Ogawa biotype El Tor, was isolated; one patient was co-infected by Salmonella typhi. All strains showed resistance to cotrimoxazole and tetracycline. Nine of ten patients were treated with oral ciprofloxacin at 1 g/day for 10 days resulting in disappearance of the symptoms within a median of 36 hours and negative fecal cultures within a median of 24 hours. Our data suggest that Italy is at high risk of infection imported from nearby nations. The resistance to commonly used antibiotics for treatment of cholera and the good response to ciprofloxacin suggest including fluoroquinolones among the drugs of first choice geographical areas involved in the circulation of resistant strains of V. cholerae O1.

Adult↗
PubMed1997

Five-year effects of nasal continuous positive airway pressure in obstructive sleep apnoea syndrome.

There have been very few studies assessing the long-term physiological effects of nasal continuous positive airway pressure (CPAP) for the obstructive sleep apnoea syndrome. We therefore investigated prospectively the evolution of lung function, arterial blood gases and pulmonary haemodynamics in patients with this syndrome treated with CPAP. Sixty five patients were included. The mean duration of home treatment with nasal CPAP was 64+/-6 months. Most of the patients (77%) were smokers at the baseline assessment. We observed a small, but significant, decrease in forced expiratory volume in one second (FEV1) from 80+/-21% at baseline (t0) to 76+/-21% of the predicted value at the follow-up evaluation (t5) (p<0.01). Arterial oxygen tension (P[a,O2]) for the group as a whole remained stable (9.4+/-1.5 kPa (71+/-11 mmHg) versus 9.4+/-1.2 kPa (71+/-9 mmHg)). However, P(a,O2) increased in the subgroup of patients with hypoxaemia at t0 (n=23), from 7.8+/-0.7 kPa (59+/-5 mmHg) to 8.9+/-1.2 kPa (67+/-9 mmHg). Arterial carbon dioxide tension (P[a,CO2]) for the group as a whole increased slightly, but significantly, from 5.2+/-0.7 kPa (39+/-5 mmHg) to 5.4+/-0.5 kPa (41+/-4 mmHg) (p<0.05). Mean pulmonary artery pressure (Ppa) at rest did not change (16+/-5 mmHg versus 17+/-5 mmHg; NS) nor did exercising Ppa. In the 11 patients with pulmonary hypertension at t0, Ppa was 24+/-5 mmHg at t0 versus 20+/-7 mmHg at t5 (NS). We conclude that the significant decrease of forced expiratory volume in one second after 5 yr follow-up was related to a high percentage of smokers and exsmokers in the study population. Daytime arterial oxygen tension and pulmonary artery pressure remained stable in an unselected series of 65 obstructive sleep apnoea syndrome patients treated for 5 yrs with nasal continuous positive airway pressure, unlike arterial carbon dioxide tension, which increased by a small, but significant, amount.

Female↗
PubMed1997

Respiratory effort during obstructive sleep apnea: role of age and sleep state.

OBJECTIVE: To evaluate the patients' individual characteristics predictive of the degree of respiratory effort developed during obstructive sleep apneas (OSAs). DESIGN: Prospective consecutive sample, collection of clinical and polysomnographic data. SETTING: University teaching hospital. PATIENTS: One hundred sixteen consecutive OSA patients with clinical symptoms of OSA and more than 20 apneas per hour of sleep. MEASUREMENTS: Anthropomorphic data, daytime blood gas values, and polysomnographic data. From esophageal pressure measurements during sleep, three indexes of respiratory effort during OSAs were derived: the maximal end-apneic esophageal pressure swing (PesMax), the increase in esophageal pressure swing (deltaPes) during the apnea, and its ratio to apnea duration (RPes). RESULTS: The indexes of respiratory effort were significantly lower in rapid eye movement (REM) than in non-REM sleep (PesMax: 50.9+/-2.5 vs 39.6+/-1.9 cm H2O, p<0.001; deltaPes: 30.9+/-1.7 vs 23.4+/-1.4 cm H2O, p<0.001; RPes: 1.05+/-0.05 vs 0.53+/-0.03 cm H2O/s, p<0.001); therefore, a separate analysis was conducted in non-REM and in REM sleep. Indexes were also significantly lower in subgroups of older as compared to younger patients (PesMax: 55.6+/-3.5 vs 40.0+/-2.2 cm H2O, p<0.001; deltaPes: 34.2+/-2.3 vs 24.1+/-1.6 cm H2O, p=0.001; RPes: 1.21+/-0.08 vs 0.8+/-0.05 cm H2O/s, p<0.001). The three indexes were closely correlated with each other and only PesMax correlation data are reported. In non-REM sleep, age was the most important single independent correlate of PesMax (r=-0.37, p=0.000). In REM sleep, the apnea-related hypoxemia, apnea duration, and age were the main contributors to the variance of PesMax. CONCLUSIONS: Respiratory effort in response to upper airway occlusion in OSA patients is lower in REM than in non-REM sleep and decreases with increasing age.

Adult↗
PubMed1996

[Propensity for sleep and diurnal somnolence in the course of sleep apnea syndrome].

Daytime sleepiness is one of the major symptoms of obstructive sleep apnea. However, its definition raises problems, since it may be based on either subjective feeling (evaluated by means of questionnaires or analog visual scales), physiological drive or need (inferred by a sleep latency) or on the concept of sleep propensity defined as the probability of falling asleep (measured by the occurrence of sleep in various circumstances of daily life). Data from the literature suggest that sleep fragmentation and hypoxemia, both related to sleep apneas, cause daytime sleepiness. Our own data show that sleep propensity in a group of 44 patients with obstructive sleep apnea was correlated with the increase in esophageal pressure swings during obstructive apneas. This result suggests that the increased respiratory effort against occluded upper airways also contributes to daytime sleepiness in patients with obstructive sleep apnea.

Circadian Rhythm↗
PubMed1996

Long-term compliance with CPAP therapy in obstructive sleep apnea patients and in snorers.

A prospective study aimed at objectively evaluating compliance with nasal continuous positive airway pressure (CPAP) treatment was conducted in 728 obstructive sleep apnea [OSA; apnea/hypopnea index (AHI) > 15 events/hour] patients and 98 nonapneic snorers (AHI < or = 15 events/hour). Five-hundred seventy-five OSA patients and 33 nonapneic snorers underwent CPAP therapy and were followed-up for an average of 1,176 +/- 38 days (27 to 4,203 days). Compliance to treatment was measured by the mean rate of use of the CPAP device obtained from a built-in time counter. Acceptance of treatment was measured using Kaplan-Meier's model. The acceptance of CPAP was greater than 90% at 3 years and greater than 85% at 7 years in OSA patients. It was greater than 60% at 3 years in nonapneic snorers. The mean rate of CPAP use was 5.7 +/- 1.8 hours/day in OSA patients and 5.6 +/- 1.4 hours/day in snorers who were still on CPAP on October 1, 1995. It was correlated positively with age, body mass index, and AHI, and it was correlated negatively with daytime partial pressure of oxygen (PaO2), forced expiratory volume in 1 second (FEV1), and vital capacity in the group of OSA patients. This study shows that CPAP therapy is reasonably accepted by OSA patients as well as by nonapneic snorers. Both within and between groups, objective disease severity (as measured by the respiratory event index and daytime and nighttime hypoxemia), rather than patients' symptoms or complaints, seemed to play a role in the quality of compliance to treatment.

Body Mass Index↗
PubMed1996

Automatic Oxford-Medilog 9200 sleep staging scoring: comparison with visual analysis.

We report the results of a comparison study between automatic sleep staging using the ambulatory Oxford-Medilog 9200 system and visual analysis in a group of 30 subjects. Sleep analysis was performed during the second nighttime period of each 48-h polygraphic monitoring. The automatic analysis determined a significant underestimation of total sleep time and stage 2 non-rapid eye movement (NREM) sleep and an overestimation of stage 1. No significant differences were found between the two analyses regarding slow-wave sleep and REM sleep. The differences between automatic and visual analysis of stage 2 were correlated positively with the amplitude and duration of K-complexes and negatively with the amplitude and frequency of spindles. Differences in electroencephalographic characteristics of these sleep figures were correlated negatively with age. Our results showed that (a) the Oxford-Medilog 9200 sleep staging system did not improve the scoring of stages 1 and 2 NREM sleep and (b) the degree of differences between visual and automatic analysis are related to the amplitude and frequency of sleep figures, i.e., spindles and K-complexes, used in the scoring of stage 2.

Adolescent↗
PubMed1996

Role of chemosensitivity in intrathoracic pressure changes during obstructive sleep apnea.

We tested the hypothesis that the awake ventilatory response to hypoxia and hypercapnia may contribute to the variability of respiratory effort developed in response to upper airway obstruction in obstructive sleep apnea syndrome. The polygraphic recordings of 38 patients diagnosed as having obstructive sleep apnea on the basis of an apnea+hypopnea index greater than 10 were examined. All subjects received hypoxic and hypercapnic ventilatory tests the day before the nocturnal polysomnography. Thirty apneas during non-rapid eye movement (NREM) sleep and at least 10 apneas during rapid eye movement sleep were analyzed. For each considered apnea, we measured esophageal pressure (Pes) swings during the first three breaths preceding apnea and during the first three and last three occluded efforts occurring during the apnea. We considered as indices of respiratory effort the overall increase from the minimum to the maximum Pes (delta Pes), the rate of increase of Pes during apnea (RPes), and the maximal respiratory effort at the end of apnea (Pes max fin). In NREM sleep, all three indices of respiratory effort were correlated positively with the awake ventilatory response to hypoxia or hypercapnia and with the apnea index. No correlation was found between the indices of respiratory effort and body mass index, age, pulmonary function tests, awake blood gases, apnea duration, and apnea desaturation. In rapid eye movement sleep, none of the considered variables predicted the degree of respiratory effort. In conclusion, our results suggest that the degree of ventilatory response to upper airway occlusion in obstructive sleep apnea may be influenced by the sensitivity of central neural drive to chemical stimuli.

Adult↗
PubMed1996

Respiratory effort. A factor contributing to sleep propensity in patients with obstructive sleep apnea.

To test the hypothesis that respiratory effort during obstructive apneas contributes, together with hypoxemia and sleep fragmentation, to excessive daytime sleepiness, we investigated the relationship between daytime sleepiness and polysomnographic variables in 44 patients with obstructive sleep apnea (OSA). In all patients, daytime sleep propensity was assessed by an 11-item standardized self-questionnaire yielding a sleepiness score and by a modified sleep latency test yielding a mean sleep latency. Respiratory effort during apneas was evaluated by measuring esophageal pressure swings using an esophageal balloon. Within each apneic cycle, we measured the esophageal pressure swings during the first three and the last three occluded efforts during the apnea to define the overall increase, its ratio to apnea duration, and the maximal effort developed during obstruction. In the group of patients as a whole, the sleepiness score was negatively correlated with the mean sleep latency (r=-0.38, p=0.01). The sleepiness score was correlated with the indexes of respiratory effort during apneas (ie, the overall increase, its ratio to apnea duration, and the maximal end-apneic swing in esophageal pressure) and with the apnea+hypopnea index. The mean sleep latency was correlated with all indexes of nocturnal hypoxemia (ie, the mean lowest oxyhemoglobin saturation [SaO2] and the index of apnea associated with a fall in SaO2 below 90% and 80%). We conclude that the degree of respiratory effort during obstructive apneas contributes to self-rated sleep propensity in patients with OSA.

Adult↗
PubMed1996

Respiratory effort during sleep apneas after interruption of long-term CPAP treatment in patients with obstructive sleep apnea.

Apneas generally reappear in patients with obstructive sleep apnea (OSA) when treatment with continuous positive airway pressure (CPAP) is interrupted. However, a single-night treatment interruption may be associated with a lesser severity of sleep apneas than before treatment. We hypothesized that this decrease in severity of sleep apneas reflects changes in the respiratory response to upper airway obstruction. Therefore, we compared indexes of respiratory effort during sleep in 25 patients with OSA before and after 1 year of CPAP treatment. Respiratory effort was assessed by means of an esophageal balloon. After 1 year of CPAP treatment, there was a decrease in the maximal end-apneic esophageal pressure swings (Pes) (from 56.7 +/- 5.4 to 30.3 +/- 2.6 cm H2O; p = 0.000; mean +/- SEM), in the overall increase in Pes during an apnea (35.2 +/- 3.6 vs 16.5 +/- 1.5 cm H2O; p = 0.000), as well as the rate of increase in Pes (1.1 +/- 0.1 vs 0.6 +/- 0.1 cm H2O/s; p = 0.000). Although body mass index (BMI) did not change significantly, the individual changes in BMI significantly correlated with the changes in respiratory effort after 1 year of CPAP treatment. Apnea duration and apnea-related oxygen desaturation also decreased significantly. We conclude that long-term CPAP treatment induces changes in respiratory control that persist at least on the first night of treatment interruption.

Esophagus↗
PubMed1995

Sleep-wake cycle abnormalities in fatal familial insomnia. Evidence of the role of the thalamus in sleep regulation.

Alterations in sleep organization were longitudinally studied in 6 new cases of fatal familial insomnia (FFI) by 24 h polygraphic recording. All patients showed an early reduction in sleep spindles and K complexes, and a drastic reduction in total sleep time and disruption of the cyclic sleep organization. Complete abolition of NREM sleep and persistence of only brief residual periods of REM sleep without atonia were features characteristic of the 3 patients with a short (less than 1 year) clinical course, and lacking in the 3 cases with a longer (more than 2 years) disease course. In the latter, sudden transitions from waking to NREM or REM sleep occurred, sometimes recurring periodically. Our findings confirm that impairment of sleep-wake regulation is a consistent distinctive feature of FFI.

Adult↗
PubMed1995

Prolactin secretion during sleep in obstructive sleep apnoea patients.

Plasma prolactin (PRL) concentration exhibits a sleep-dependent pattern, with highest levels during sleep and lowest levels during the waking period. The syndrome of obstructive sleep apnoea (OSA) is associated with severe hypoxaemia and chronic sleep fragmentation, both of which could affect the sleep-entrained PRL rhythm. Treatment with nasal continuous positive airway pressure (CPAP) immediately restores a normal sleep structure by successful abolition of the apnoeas. In the present study, seven OSA patients underwent two night studies, once when no treatment was given and once during the first night of CPAP treatment. Sleep was recorded polygraphically in all experiments. Plasma PRL was measured at 10 min intervals and secretory rates were calculated by a deconvolution procedure. CPAP treatment greatly reduced hypoxaemia and improved sleep quality. The secretory pulse amplitude and the total amount of PRL secreted during the night remained constant regardless of whether patients were treated or not. The only difference found was a lower pulse frequency in untreated OSA patients as compared to treated patients, which may be attributed either to hypoxaemia or to sleep disturbance or to the combined action of both. Treatment may be considered to normalize PRL release by restoring pulse frequency to values similar to those observed for normal subjects.

Journal Article↗