Search PubMed⌕ Search

Biomedical subjects

E Lugaresi

Publications and source records attributed to E Lugaresi.

At least 91 records · Page 5Linked to original sources
PubMed1995

Defective brain and muscle energy metabolism shown by in vivo 31P magnetic resonance spectroscopy in nonaffected carriers of 11778 mtDNA mutation.

In vivo phosphorus magnetic resonance spectroscopy (31P-MRS) showed defective brain and muscle energy metabolism in three affected siblings in a family with Leber's hereditary optic neuropathy (LHON) with the 11778 mtDNA mutation. We studied 14 nonaffected members of the same pedigree by 31P-MRS and molecular genetics. Nine of 14 individuals studied had the 11778 mtDNA mutation, with various degrees of heteroplasmy. A decreased brain energy reserve, as shown by low phosphocreatine content and phosphorylation potential and high [ADP], was present in eight of these nine subjects with the 11778 mutation. A low rate of postexercise phosphocreatine recovery in muscle was present in six of the nine mutated individuals. Normal MRS findings in the brain of one and the muscle of three carriers were accompanied by a low percentage of mutated mtDNA. All subjects without mutation had normal brain and muscle MRS. 31P-MRS disclosed defective bioenergetics in the brain or muscle or both of all asymptomatic carriers studied from our pedigree.

Adenosine Diphosphate↗
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

Tardive pain.

Explore the source record for details and available documents.

Aged↗
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

Functional alterations of the mitochondrially encoded ND4 subunit associated with Leber's hereditary optic neuropathy.

Leber's hereditary optic neuropathy (LHON) is a maternally inherited disease associated with point mutations in mitochondrial DNA. The most frequent of these mutations is the G-to-A substitution at nucleotide position 11,778 which changes an evolutionarily conserved arginine with a histidine at position 340 in subunit ND4 of NADH:ubiquinone reductase (respiratory complex I). We report that this amino acid substitution alters the affinity of complex I for the ubiquinone substrate and induces resistance towards its potent inhibitor rotenone in mitochondria of LHON patients. Such changes could reflect a substantial loss in the energy conserving function of NADH:ubiquinone reductase and thus explain the pathological effect of the ND4/11,778 mutation.

Amino Acid Sequence↗
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

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

31P-magnetic resonance spectroscopy in migraine without aura.

We investigated 22 patients with migraine without aura, all drug-free and in headache-free periods, by means of 31P-magnetic resonance spectroscopy (MRS) of brain and muscle. Brain 31P-MRS showed significantly low phosphocreatine, increased adenosine diphosphate, and decreased phosphorylation potential. There was a slow rate of phosphocreatine recovery after exercise in the muscle of 12 of 22 patients. Energy metabolism is abnormal in migraine without aura, as previously demonstrated in patients with migraine stroke and migraine with aura.

Adolescent↗
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

Transient global amnesia: neuropsychological findings after single and multiple attacks.

We examined by neuropsychological tests 41 patients who had presented attacks of transient global amnesia (TGA; 31 had single and 10 multiple episodes), comparing them with 41 matched normal controls. Patients with single attacks showed only two impaired memory tasks with respect to controls (immediate and long-term verbal memory), while patients with multiple attacks showed more impaired tasks in memory and visuoperceptual ability. These data confirm that TGA is a benign syndrome, but could leave a few subclinical memory deficits probably exacerbated by repeated attacks.

Aged↗
PubMed1993

[18F]FDG PET in fatal familial insomnia: the functional effects of thalamic lesions.

We used [18F]2-fluoro-2-deoxy-D-glucose ([18F]FDG) and positron emission tomography (PET) to study regional cerebral glucose utilization (rCMRglc) in four patients with fatal familial insomnia (FFI), a prion disease with a mutation at codon 178 of the prion protein gene. Two patients, presenting only with insomnia and dysautonomia, had a prominent and, in one case, selective thalamic hypometabolism. The remaining two cases presented a more complex clinical picture with multiple neurologic deficits, with both thalamic and widespread brain hypometabolism involving the majority of cortical structures, basal ganglia, and the cerebellum. This widespread pattern was present in the early stage of the disease and showed significant worsening as the disease progressed in one patient examined twice. The thalamic hypometabolism, consistently found with PET in FFI patients, is in agreement with the neuropathologic findings and is a hallmark of the disease.

Adult↗
PubMed1992

Endogenous benzodiazepine receptor ligands in idiopathic recurring stupor.

"Endozepines" are endogenous ligands for the benzodiazepine recognition sites on gamma-aminobutyric acid A receptors in the nervous system. Idiopathic recurring stupor (IRS) is a syndrome of spontaneous stupor or coma that is not associated with known metabolic, toxic, or structural abnormalities but can be reversed by flumazenil, a pure benzodiazepine antagonist. We measured endozepine-2 and endozepine-4 by high-performance liquid chromatography and radioreceptor assay in serum and cerebrospinal fluid from three patients with IRS. During episodes of stupor there was a large (up to 300-fold compared with control patients) increase of endozepine-4 content in cerebrospinal fluid and serum, but a return to normal concentrations between attacks. Endozepine-4 may contribute to, or be the cause of, IRS. The reasons for abnormal concentrations of endozepine in blood and brain are unknown.

Adult↗