PubMed Health⌕ Search

Biomedical subjects

V Brezinova

Publications and source records attributed to V Brezinova.

At least 19 recordsLinked to original sources
PubMed1991

Stapedius reflex decay test in diagnosis of myasthenia gravis (MG).

Stapedius reflex decay test (SRDT) was attempted in 30 patients with suspected myasthenia gravis (MG). In 43% of the sample measurement of the decay was not possible because of an audiologic abnormality, reflex threshold too high for safe testing or absence of the reflex with no obvious cause. A control group of 24 normal subjects showed a large variance and thus only a decay, after 5 minutes of stimulation, greater than 50% of the original value was considered abnormal. Out of 17 patients in whom SR decay was successfully measured, 7 (41%) had an abnormal value. Sensitivity of the test was found at 80%, specificity at 75%, when the clinical diagnosis of MG, upheld in follow-up, was taken as a criterion. The percentage of concordant abnormal findings was 50% for repetitive electrical stimulation of a peripheral nerve, 60% for positive effect of anticholinesterase drugs, 100% for presence of ACh receptor antibodies.

Acoustic Impedance Tests↗
PubMed1990

Common peroneal nerve dysfunction after high tibial osteotomy.

We assessed 16 patients before and after high tibial osteotomy by electrophysiological recordings, creatine phosphokinase levels, radiographs and intracompartmental pressure monitoring. We found mild electrophysiological abnormalities pre-operatively in 12 of the 16 patients, but postoperatively these had deteriorated in 11 of the 14 patients studied. Creatine phosphokinase levels, compartment pressure and radiological deformity were not predictive of the development of postoperative common peroneal nerve palsy. Patients who also had a proximal fibular osteotomy had greater electrical abnormalities postoperatively and two of them developed common peroneal palsies. Proximal fibular osteotomy appears to be a causative factor in the development of common peroneal nerve palsy; more work is needed on the blood supply of the nerve.

Adult↗
PubMed1983

Transient hypoxemia during sleep in chronic obstructive pulmonary disease is not a sleep apnea syndrome.

We measured ear oxygen saturation (SaO2), chest wall movement, and oronasal air flow, and took electroencephalographic tracings during nocturnal sleep in 20 healthy subjects and 20 similarly aged patients with chronic obstructive pulmonary disease (COPD), none of whom was obese. Thirteen of the patients with COPD were persistently hypoxemic and hypercapnic when awake ("blue and bloated", Type B); the remaining 7 maintained relatively normal arterial gas tensions when awake despite equally severe airways obstruction ("pink and puffing", Type A). Hypoxemic episodes (HE) (SaO2 falls of greater than 10%) occurred during sleep in all the blue bloaters but in only 3 of 7 pink puffers and 3 of 20 normal subjects. However, the maximal change in arterial oxygen tension (PaO2) (calculated from SaO2 values assuming normal pH) was similar in all 3 groups, averaging 24 mmHg. Furthermore, the cumulative duration of apnea and hypopnea was the same in each group. Only one patient COPD had more than 2 apneas per night, and obstructive apnea was seen only in the healthy subjects. Sleep apnea syndromes thus appear to be rare in nonobese patients with COPD. Of the 40 HE in patients with COPD, 29 occurred during periods of hypoventilation. In 10 blue bloaters whose arterial blood was sampled during sleep, the measured fall in PaO2 during the HE (mean, 11.2 mmHg) was greater than the rise in PaCO2 (mean, 4.2 mmHg). Although these changes in arterial gas tensions could be produced by an increase in ventilation-perfusion imbalance during the HE, it is suggested that unsteady-state gas exchange during transient hypoventilation could provide an alternative explanation.

Adult↗
PubMed1982

Irregular breathing and hypoxaemia during sleep in chronic stable asthma.

Breathing patterns, ear oxygen saturation (SaO2), and EEG sleep-stage throughout an undisturbed night's sleep were compared in ten adult stable asthmatics and ten age-matched healthy subjects. The two groups slept equally long (5.0-7.2, mean 6.2 h), but the asthmatics slept less well; they had more periods of wakefulness and drowsiness and irregular breathing than did the healthy subjects. They also had greater and more frequent falls in SaO2. Most hypoxaemic episodes occurred in the rapid-eye movement phase of sleep and were associated with hypopnoea or apnoea, but no patient had a classical sleep-apnoea syndrome. The severity of nocturnal hypoxaemia was related to the level of SaO2 when the subjects were awake, but did not correlate with the fall in forced expiratory volume recorded in eight out of ten asthmatics after sleep.

Adult↗
PubMed1982

Night sleep of patients with chronic ventilatory failure and age matched controls: number and duration of the EEG episodes of intervening wakefulness and drowsiness.

Characteristics of the episodes of wakefulness and drowsiness (stage 0 + 1) intervening in a night of electrophysiologically monitored sleep were compared in a homogeneous group of 13 patients (mean age 57 years) with severe hypoxic chronic bronchitis and emphysema (blue and bloated variety) and 8 age matched control subjects. The total amounts of stage 0 + 1 accumulated over one night (preceded by one night of adaptation) were high in both groups (28% in the patients, 22% in the control subjects). A significant difference was found in the number of brief arousals (episodes of stage 0 + 1 lasting for less than 1 min), which averaged 10/h of sleep in the patients, and 6/h of sleep in the control subjects (p less than 0.05, two tailed). The numbers of longer episodes of stage 0 + 1 were not significantly different and varied independently from the numbers of brief arousals in the individuals. Only a small proportion (8 %) of brief arousals was linked to episodes of hypopnea or apnea in the bronchitic patients. Large numbers of brief arousals/h of non rapid eye movement sleep inthe bronchitic patients correlated significantly with small percentages of stage 3 + 4 sleep (p less than 0.05), and were associated with smell numbers of hypoxemic episodes occurring predominantly in rapid eye movement sleep. The findings indicate a more fractionated sleep in the patients with chronic hypoxic bronchitis, and suggest that the brief arousals represent a limiting factor rather than a result of the nocturnal hypoxemic episodes occurring in these patients.

Arousal↗
PubMed1982

Sleep apnoea in acute bronchiolitis.

Three- to 4-hour polygraphic sleep studies were carried out in 16 infants aged between 1 and 6 months during and after recovery from acute bronchiolitis. During bronchiolitis 35% of total sleep time was active sleep compared with 31% after recovery. Respiration rate was increased during bronchiolitis and was higher in active sleep and quiet sleep irrespective of the stage of the illness. Apnoeic pauses were invariably shorter than 15 seconds, the mean duration for active sleep and quiet sleep being similar during infection and after recovery. Apnoeic episodes were central in type and generally initiated by a sign or body movements. Preapnoea heart rate was significantly higher than during or after apnoea. Apnoea index (the percentage of time the baby spends apnoeic), apnoea attack rate (the number of episodes of apnoea per unit time), and apnoea percentage (the distribution of episodes of apnoea while in a given sleep state) were increased significantly in quiet sleep during the index illness. Transcutaneous oxygen tension was significantly reduced during the course of infection, but comparable values were obtained in active sleep and quiet sleep during initial and recovery periods. These results show that the main changes in respiration pattern during the course of acute bronchiolitis occur in quiet sleep.

Acute Disease↗
PubMed1979

Transient hypoxaemia during sleep in chronic bronchitis and emphysema.

Arterial oxygenation, breathing pattern, and electroencephalogram were studied during sleep in patients with chronic bronchitis and emphysema and in healthy subjects. All of the 10 "blue and bloated" patients had episodes of transient hypoxaemia lasting 1--100 min, when their oxygen saturation fell by more than 10%, whereas such desaturation did not occur in 2 "pink and puffing" patients or in 4 healthy subjects. Hypoxaemic episodes usually occurred during the rapid-eye-movement stage of sleep. It is suggested that these hypoxaemic episodes result from a combination of hypoventilation and impaired ventilation/perfusion relationships and that these episodes may contribute to the development of the pulmonary hypertension and secondary polycythaemia which characterises "blue and bloated" patients.

Adult↗
PubMed1971

Drugs of dependence though not of abuse: fenfluramine and imipramine.

Measures of subjective feeling used by five patients indicated that depression of mood occurred about four days after fenfluramine withdrawal. An experiment in which another 11 patients took fenfluramine 80 mg for 28 days confirmed the depression, maximal on the fourth withdrawal day. It also indicated that in the first week of administration there was some mood elevation, but with feelings of impaired ability to concentrate. The drug reduced appetite and weight. A comparison is drawn with imipramine, which was found to induce initial and withdrawal changes of subjective experience (of dreaming) in six volunteers. It is suggested that certain mood-influencing drugs may not be drugs of abuse because of some unpleasant initial effects, though they can be drugs of dependence.

Adult↗