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Biomedical subjects

E Sforza

Publications and source records attributed to E Sforza.

At least 55 records · Page 3Linked to original sources
PubMed1995

Dissociated 24-hour patterns of somatotropin and prolactin in fatal familial insomnia.

To assess the changes in the 24-hour profiles of serum somatotropin and prolactin levels during total disruption of the sleep/wake cycle sustained over several months, we studied 2 subjects affected by fatal familial insomnia, a rare disease characterized by selective thalamic degeneration that causes chronic sleep loss. Under standardized conditions and polysomnographic control, the patients underwent repeated 24-hour study sessions covering the entire clinical course of the disease. Hormones were assayed at 30-min intervals. Four healthy volunteers were used as controls. A sleep/wake cycle was always absent in fatal familial insomnia. Serum somatotropin and prolactin concentrations never exceeded the normal range of variation. The nocturnal elevation of somatotropin disappeared simultaneously with sleep loss, whereas a significant 24-hour component of variations in serum prolactin levels was present for months after total disruption of the sleep/wake cycle, with normally placed nocturnal acrophases. Complete obliteration of the 24-hour component was achieved for prolactin only in the advanced stages, through a progressive decrease in 24-hour amplitude of variation. Selective and progressive degeneration of the mediodorsal and anterior ventral nuclei of the thalamus causes an early obliteration of the 24-hour rhythm of somatotropin and a later disappearance of circadian prolactin rhythmicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Determinants of effective continuous positive airway pressure in obstructive sleep apnea. Role of respiratory effort.

We investigated whether cephalometric measurements, nocturnal indices of negative intrathoracic pressure, or the frequency of sleep-related breathing disorders were related to the level of effective continuous positive airway pressure (CPAP) in patients with obstructive sleep apnea (OSA). We examined 22 OSA patients who underwent two consecutive polysomnographic recordings, the first for diagnosis and the second for CPAP titration. Cephalometric measurements, spirometric data, and blood-gas analysis results were available for all subjects. In the diagnostic polysomnography, at least 30 apneas were analyzed during non-rapid-eye-movement (NREM) sleep and 10 apneas during rapid eye movement (REM) sleep for each patient. Swings in esophageal pressure (Pes) during the preapneic period and during the beginning and the end of obstructive apneas were calculated as the average of three consecutive breaths (or ineffective efforts). The difference in Pes from the minimal initial to the maximal final apneic respiratory effort (DPes) and the rate of increase in Pes (RPes = DPes/apnea duration) during apnea were computed. Within an apnea, the lowest Pes always occurred during the first three occluded breaths and the highest during the last three, with a more marked difference in NREM sleep. The level of effective CPAP was correlated with the length of the soft palate (r = 0.69, p = 0.000), RPes (r = 0.55, p = 0.008), and DPes (r = 0.49, p = 0.02). The correlations of effective CPAP level with body mass index and apnea + hypopnea index were not significant. A model including length of the uvula, DPes, and RPes accounted for 56 to 59% of the variability in effective CPAP.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1995

Determinants of the awakening rise in systemic blood pressure in obstructive sleep apnea syndrome.

To investigate the factors responsible for the morning rise in blood pressure (BP) in obstructive sleep apnea syndrome (OSAS) we examined a group of 253 consecutive snorers or OSAS patients. On the basis of their AHI the patients were classified in four groups. BP was measured on the evening before sleep onset and on the following morning after 15 min of rest by a finger arterial pressure device (Finapres). In 150 subjects BP was monitored during the night by a Finapres device. In the morning BP increased in the patient group with an average difference of 9.9 +/- 0.5 mmHg for systolic (SBP) and 9.9 +/- 0.4 mmHg for diastolic pressure (DBP). The increase was significant in snorers and OSAS patients without differences between groups. The morning rise in SBP was related to diurnal values of SBP, age and AHI whereas the time spent in apnea and the diurnal values of DBP significantly contributed to the DBP increase. In the subgroup of 150 patients in whom BP was analyzed during sleep, the awakening increase was related to the absolute BP value during sleep and to the BP changes from wakefulness to sleep. The magnitude of the BP changes from evening to morning was not dependent on the degree of BP variability during sleep. We conclude that the awakening increase in BP in patients with snoring or OSAS may be mediated by the setting of pressure response to apnea or to mechanical effort during sleep. Anthropometric variables and diurnal cardiovascular setting may play an additional role in modulating the final pressure response to upper airway obstruction.

Blood Pressure↗
PubMed1995

Daytime sleepiness and nasal continuous positive airway pressure therapy in obstructive sleep apnea syndrome patients: effects of chronic treatment and 1-night therapy withdrawal.

A multiple sleep latency test (MSLT) was performed in 30 patients with obstructive sleep apnea syndrome (OSAS) at the time of diagnosis and after 1 year of home therapy with nasal continuous positive airway pressure (nCPAP). The MSLT was administered after two consecutive polysomnographic studies, one with (CPAP) and one without nCPAP (NCPAP) at baseline and at follow-up. After a year of therapy, the MSLT significantly rose from 3.1 +/- 0.3 to 9.8 +/- 1.0 minutes (p = 0.001). The increase in mean sleep latency was significantly correlated with the decrease in the number of arousals during the night (r = -0.48, p = 0.009). On the basis of MSLT value at follow-up, patients were split into two subgroups: the normalized group, in which 15 patients had an MSLT > or = 10 minutes, and the unnormalized group, consisting of 15 patients with an MSLT < 10 minutes. Normalized patients differed for a higher apnea+hypopnea index (AHI) time at baseline, a greater improvement in nocturnal hypoxemia and a greater nCPAP use at follow-up. After 1 night of therapy withdrawal, MSLT fell dramatically to 5.3 +/- 0.6 minutes, even though the subjects said they did not feel sleepy. The changes in MSLT after the night of treatment suspension were not correlated with changes in body mass index (BMI), AHI or nocturnal hypoxemia, whereas they were correlated negatively with changes in AHI time (r = -0.53, p = 0.003) and with the decrease in the number of arousals (r = -0.47, p = 0.009).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Cardiovascular autonomic dysfunction in normotensive awake subjects with obstructive sleep apnoea syndrome.

Cardiovascular autonomic function in normotensive awake patients with obstructive sleep apnoea syndrome was studied in 21 normotensive (mean age 48 +/- 14 years), drug-free men with obstructive sleep apnoea syndrome. Cardiovascular reflex tests with continuous blood pressure monitoring and biochemical indices were performed the morning after a standard polygraphic sleep recording. A group of 20 age-matched (mean age 49 +/- 19 years) normal subjects was used as controls. The obstructive sleep apnoea syndrome patients showed higher heart rate and noradrenaline plasma levels (p < 0.05) at rest and a higher blood pressure response to head-up tilt (p < 0.01), suggesting sympathetic overactivity. Respiratory arrhythmia, baroreflex sensitivity index and Valsalva ratio were significantly lower in the obstructive sleep apnoea syndrome group (p < 0.01) whereas the decrease in heart rate induced by the cold face test was significantly higher (p < 0.05) showing a blunting of reflexes dependent on baroreceptor or pulmonary afferents with normal or increased cardiac vagal efferent activity. These abnormalities in autonomic regulation may predispose obstructive sleep apnoea syndrome patients to cardiovascular complications like hypertension and cardiac arrhythmias.

Adult↗
PubMed1994

Neurofibromatosis associated with central alveolar hypoventilation syndrome during sleep.

We describe polygraphic respiratory alterations during sleep in a child with neurofibromatosis. The patient, a four-year-old boy, had a medical history of neurofibromatosis and recurrent acute respiratory failure responsive to mechanical ventilation. All-night polysomnography showed severe nocturnal hypoventilation with marked hypercapnia (TcPaCO2 70 mmHg) and hypoxemia (SaO2 less than 40%). Nocturnal hypoxemia and hypercapnia and depressed response to the hyperoxic hypercapnic test confirmed the diagnosis of central hypoventilation syndrome. Cerebral magnetic resonance imaging disclosed lucent areas in the globus pallidus, mesencephalus and left upper pons. Therapy with nocturnal nasal positive bilevel ventilation reversed nocturnal hypoxemia and hypercapnia. This study suggests that patients with neurofibromatosis should be investigated for concomitant severe hypoventilation, particularly when clinical symptoms suggest brain stem lesions.

Acute Disease↗
PubMed1994

Diurnal blood pressure variation and hormonal correlates in fatal familial insomnia.

Fatal familial insomnia is a prion disease in which a selective thalamic degeneration leads to total sleep deprivation, hypertension, dysautonomia, adrenal overactivity, and impaired motor functions. With patients under continuous recumbency and polysomnographic control, we assessed the changes in the 24-hour patterns of blood pressure, heart rate, plasma catecholamines, corticotropin, and serum cortisol in three patients at different stages of the disease. Six healthy volunteers were used as control subjects. A dominant 24-hour component was detected at rhythm analysis of all variables, both in patients and control subjects. In the patients, the amplitudes gradually decreased as the disease progressed, leading to the obliteration of any significant dirunal variation only in the preterminal stage. A shift in phase corresponded to the loss of the nocturnal fall in blood pressure in an early stage of the disease, when nocturnal bradycardia was still preserved. Plasma cortisol was high and became increasingly elevated, whereas corticotropin remained within normal levels; abnormal nocturnal peaks appeared in their circadian patterns. The disrupted patterns of cortisol and blood pressure preceded the development of hypertension and severe dysautonomia, which in turn were paralleled by increasing catecholamine and heart rate levels. Our data demonstrate that in patients with fatal familial insomnia the changes detectable in the rhythmic component of diurnal blood pressure variability result in a pattern of secondary hypertension. Disturbances in thalamic, pituitary-adrenal, and autonomic functions seem to be involved in mediating these changes.

Adrenocorticotropic Hormone↗
PubMed1994

Natural evolution of sleep apnoea syndrome: a five year longitudinal study.

We wanted to investigate the natural evolution of Obstructive Sleep Apnoea Syndrome (OSAS). We therefore followed 58 patients who refused any treatment at the time of diagnosis. Of the eligible patients 32 subjects enrolled in instrumental follow-up. The effects on daytime somnolence, daytime lung function and nocturnal respiratory disturbances were retrospectively evaluated by repeating Multiple Sleep Latency Test (MSLT), spirometry and polysomnography after a follow-up period of at least 5 years (5.7 +/- 0.2 SEM yrs). In the patient group as a whole the mean Apnoea+Hypopnoea Index (AHI), the mean low arterial oxygen saturation (Sao2) and the mean Body Mass Index (BMI) did not change over time. The only significant differences were the increase in mean duration of apnoeas (21.0 vs 23.5 s) and hypopneas (13.5 vs 16.3 s) and the decrease in AHI < 80% (13.3 vs 7.9). No correlations were found between the changes in AHI or mean low Sao2 and age, BMI, AHI, mean low Sao2, pulmonary function tests or arterial blood gases at baseline. No significant changes were observed in systemic blood pressure, pulmonary function tests, blood gases analysis or MSLT. "Improved" (n = 6) and "worsened" (n = 7) groups were defined by a reduction or increase in AHI over 35% of baseline value. At baseline the "worsened" group tended to have lower AHI and higher mean low Sao2 compared with the "improved" group. In the "worsened" group the BMI rose significantly from 26.0 to 29.2, AHI rose significantly from 14.1 to 51.3 and mean low Sao2 decreased from 92 to 90 (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Body Mass Index↗
PubMed1994

Progressive disruption of the circadian rhythm of melatonin in fatal familial insomnia.

Fatal familial insomnia (FFI) is a disease characterized by loss of sleep activity due to selective thalamic degeneration. To assess the secretory pattern of melatonin (MT) in FFI, we studied two cases of overt disease under standardized conditions and polysomnographic control. Each patient underwent repeated 24-h study sessions, and MT was assayed at 30-min intervals. Six healthy volunteers were used as controls. Slow wave sleep was never recorded, whereas occasional episodes of enacted dreaming accompanied by rapid ocular movements and complex muscular activities were documented, with no detectable rhythm. Plasma MT concentrations gradually decreased as the disease progressed. A significant circadian rhythm was detected in the earlier recordings, with decreasing amplitudes with disease progression. Complete rhythm obliteration was achieved in the most advanced stage. Normally placed nocturnal acrophases were detected in the earlier stages, but then a shift toward the daytime hours was observed. Thalamic lesions of FFI appear to determine a progressive disruption of the sleep/wake cycle accompanied by decreased circulating levels of MT, with progressive alterations in the circadian rhythm of this hormone. On the other hand, decreased secretion of MT may contribute to the sleep disturbances of FFI.

Adult↗
PubMed1994

Idiopathic recurring stupor.

Idiopathic recurring stupor (IRS) is a disease of unknown pathogenesis presenting with recurrent stuporous states. We describe three IRS patients in whom there were no metabolic, toxic, or structural brain dysfunctions. Ictal EEGs were characterized by fast (14- to 16-Hz), unreactive background activity. Flumazenil, a benzodiazepine receptor antagonist, promptly resolved the clinical and EEG picture. In all patients, ictal plasma determination showed a marked increase in benzodiazepine-like activity identified as endozepine-4. IRS may be due to an unexplained excess of endozepine-4.

Adult↗
PubMed1994

Do autonomic cardiovascular reflexes predict the nocturnal rise in blood pressure in obstructive sleep apnea syndrome?

To investigate the relationship between nocturnal changes in blood pressure (BP) and diurnal cardiovascular reflexes we examined a group of 19 male normotensive obstructive sleep apnea syndrome (OSAS) patients. All patients underwent a full polysomnographic examination including BP monitoring by a finger arterial pressure device (Finapres) and a battery of cardiovascular reflex tests; plasma catecholamine levels at rest were also measured. During sleep, BP increased with an average difference of 15.4 +/- 7.5 mmHg for systolic and 8.3 +/- 4.6 mmHg for diastolic pressure. Compared with control subjects, OSAS patients had lower values of Valsalva ratio (VR) (1.75 +/- 0.4 vs 1.34 +/- 0.2, p = 0.0004), E/I ratio (1.35 +/- 0.2 vs 1.13 +/- 0.9, p = 0.0004) and baroreflex sensitivity index (BRSI) (5.4 +/- 2.1 vs 2.7 +/- 1.9 mms/mmg, p = 0.0006) and a higher systolic (p = 0.02) and diastolic (p = 0.002) pressure response to tilting-up test. Noradrenaline plasma levels were also significantly higher (345 +/- 125 vs 224 +/- 92 pg/ml, p = 0.001). No significant correlations were found between the nocturnal rise in BP and the pressure responses during sympathetic manoeuvres or rest levels of noradrenaline. The nocturnal changes in systolic blood pressure during the night were negatively dependent on the diurnal BRSI (r = -0.91, p = 0.0007) and VR (r = -0.70, p = 0.006). We conclude that the high levels of noradrenaline at rest and the altered sympathetic cardiovascular reflexes alone do not account for the nocturnal variation in blood pressure in OSAS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Paroxysmal periodic motor attacks during sleep: clinical and polygraphic features.

Three patients complained of paroxysmal motor attacks during sleep. Videopolygraphic recordings showed that motor activity could be divided into events of increasing behavioural complexity. Simpler motor events often represented the initial fragment of more complex attacks. Clinical features suggested the attacks represented frontal lobe epileptic seizures. The attacks recurred during NREM sleep with a periodic repetition every 20-60 sec. This periodicity could be related to the analogous physiological oscillation during light sleep and the periodicity of K complexes, exerting a facilitating influence upon epileptic mechanisms.

Adult↗
PubMed1993

Nocturnal pollakiuria is a symptom of obstructive sleep apnea.

An increased urine excretion has been reported in obstructive sleep apnea (OSA) patients, but it is not clear whether it results in an increased number of nocturnal micturitions. The present study was aimed at investigating the frequency of nocturnal micturitions in OSA patients using a standardized questionnaire prospectively given to 102 OSA patients and 86 healthy male subjects. The frequency of nocturnal micturitions was significantly greater in the OSA patients than in the healthy subjects (more than 70% of the OSA patients with an apnea+hypopnea index > 50 reported nocturnal micturitions more than twice a week versus less than 25% of the healthy subjects, p < 0.0001). The number of nocturnal micturitions was also greater in the OSA patients than in the healthy subjects. There was an effect of age on the frequency of nocturnal micturitions; however, when age-matched subsamples were considered, there was still a significant difference between OSA patients and healthy subjects. In a subgroup of 25 OSA patients reevaluated after at least 1 year of home treatment with nasal continuous positive airway pressure the reported frequency of nocturnal micturitions had significantly decreased (p < 0.001). These results suggest that investigations aimed at establishing a diagnosis of OSA should be part of the work-up of patients complaining of nocturnal pollakiuria.

Adult↗
PubMed1992

Idiopathic recurring stupor: a case with possible involvement of the gamma-aminobutyric acid (GABA)ergic system.

A patient had recurrent spontaneous episodes of stupor or coma in the absence of toxic, metabolic, or structural brain damage. Ictal electroencephalography showed fast 14 Hz background activity; sleep studies excluded narcolepsy. Flumazenil (Anexate), a benzodiazepine antagonist, promptly resolved the episodes and normalized the electroencephalogram. Radioreceptor binding studies showed the presence of a ligand to the central benzodiazepine receptor in plasma and cerebrospinal fluid during the episodes, suggesting a gamma-aminobutyric acid (GABA)ergic system involvement in the origin of the attacks.

Benzodiazepines↗
PubMed1992

Isolated failure of noradrenergic transmission in a case with orthostatic hypotension and hyperactivity of gastro-colic reflex.

We describe a 37-year-old man with a long-standing history of impotence and urgency of defaecation. The latter invariably followed the ingestion of food. Studies of cardiovascular autonomic function disclosed asymptomatic orthostatic hypotension due to isolated sympathetic noradrenergic failure with intact cardiac vagal control. There were no other neurological abnormalities. Levels of plasma noradrenaline and urinary vanillylmandelic acid were very low but plasma dopamine and urinary homovanillic acid were normal. A low level of dopamine-beta-hydroxylase activity was detected in plasma. The patient's parents were first cousins. The parents, the brother and the sister were investigated and clinical and biochemical studies showed no abnormalities. We conclude that this is a further observation of orthostatic hypotension due to isolated adrenergic failure with clinical and biochemical features different from cases previously described.

Adult↗
PubMed1992

Daytime sleepiness after long-term continuous positive airway pressure (CPAP) treatment in obstructive sleep apnea syndrome.

A modified maintenance of wakefulness test was performed in 58 patients with obstructive sleep apnea (OSA) syndrome before treatment and after long-term (554 +/- 28 days) home therapy with nasal continuous positive airway pressure (CPAP). Before treatment the patients had a shorter mean sleep latency than controls (16 +/- 1 vs. 27 +/- 1 min, mean +/- SEM, P less than 0.001). After treatment, the mean sleep latency increased to 20 +/- 1 min (P less than 0.002 as compared to baseline), but was still shorter than in controls (P less than 0.001). The incomplete normalization of the mean latency contrasted with the patients' claim that they no longer felt sleepy. The improvement in daytime alertness was significantly correlated with the reduction in sleep fragmentation after CPAP treatment and with the baseline mean sleep latency. These results support the hypothesis that sleep disruption related to respiratory events plays a role in the pathogenesis of daytime sleepiness.

Electrocardiography↗
PubMed1992

Haemodynamic effects of short-term nasal continuous positive airway pressure therapy in sleep apnoea syndrome: monitoring by a finger arterial pressure device.

We have evaluated the effects of short-term nasal continuous positive airway pressure (nCPAP) therapy on systemic blood pressure and heart rate in patients with obstructive sleep apnoea syndrome. Twenty five consecutive patients were examined during baseline conditions (No-CPAP) and during one night of nCPAP treatment (CPAP). The mean value and the variation coefficient of cardiovascular variables, examined by a finger arterial pressure device (Finapres), were determined in wakefulness and sleep. Without nCPAP an increase in blood pressure from wakefulness to sleep was observed in all patients from 138 +/- 3 mmHg to 146 +/- 3 and 155 +/- 4 mmHg, and from 80 +/- 1 mmHg to 82 +/- 2 and 84 +/- 2 mmHg, respectively, for systolic and diastolic values in non rapid eye movement (NREM) and rapid eye movement (REM) sleep. Conversely, heart rate decreased from 75 +/- 2 beats.min-1 to 70 +/- 2 and 69 +/- 2 beats.min-1. In addition, variability of heart rate and blood pressure was greatly increased compared with the awake state. Short-term nCPAP therapy significantly reduced systolic pressure from 144 +/- 3 mmHg to 137 +/- 3 and 143 +/- 4 mmHg during NREM and REM sleep, respectively, associated with a decrease in heart rate (from 69 +/- 2 to 65 +/- 2 beat.min-1). In total sleep and in all sleep stages a significantly reduced variability (p less than 0.001) was found. No changes were observed for diastolic pressure during CPAP night compared with baseline conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure Monitors↗