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Biomedical subjects

J Zeitlhofer

Publications and source records attributed to J Zeitlhofer.

At least 55 records · Page 3Linked to original sources
PubMed1996

[Sleep apnea in myasthenia gravis].

19 middle-aged patients with myasthenia gravis (MG) and 10 age-matched controls underwent overnight polysomnography and neuropsychological testing, in order to assess the frequency, degree, type and risk factors of sleep apneas in MG and to show their influence on sleep profile and neuropsychological variables. We observed in 60% of the myasthenics, low grade central type of sleep apneas and hypopneas with resulting oxygen desaturations, occasionally occurring during REM-sleep without influence on sleep profile and vigilance but resulting in significant memory impairment. The only found risk factor for the development of sleep apneas was age.

Adult↗
PubMed1995

[Sleep apnea as a risk factor].

Sleep apnea and snoring are widely discussed as risk factors for internal and neurological diseases. The prevalence of snoring in an Austrian population survey is about 27.2% (males 36.5%, females 18.9%), and that of apnea (respectively irregularity and/or cessation of breathing) about 8.5% (31% of all snorers). Clinical symptoms like naps, daytime sleepiness, unquiet sleep, hypertonia, headache in the morning and psychological symptoms may be characteristics of sleep apnea. They should lead to further diagnosis and removal of this risk factor for ischemic heart disease and stroke.

Adolescent↗
PubMed1994

Insomnia in generalized anxiety disorder: polysomnographic, psychometric and clinical investigations before, during and after therapy with a long- versus a short-half-life benzodiazepine (quazepam versus triazolam).

Within a double-blind, comparative study on the effects of the long-half-life benzodiazepine (BDZ), quazepam, and the short-half-life BDZ, triazolam, on clinical symptomatology, sleep and anxiety of 45 patients with insomnia based on a mild to moderate generalized anxiety disorder (GAD) (ICD-9 code: 307.42-1, 300,0; ASDC-APSS-Code: A.2.a), we compared, in a first step at baseline, drug-free polysomnographic and psychometric data of 22 patients recorded in the laboratory (L-group) and 21 patients recorded by the Oxford Medilog 9000 system at home (H-group) with those of normal controls. Sleep efficiency, total sleep time, wake within total sleep period (middle insomnia) and wake before buzzer (late insomnia) were significantly deteriorated in both patient groups as compared with controls, while sleep induction time only differed significantly in home recordings. Regarding sleep architecture, stage (S)2 was reduced, S3 and S4 increased in the H-group only, while no intergroup differences were seen in S1, SREM and REM latency. Subjective sleep quality was reduced in both patient groups, but not awakening quality. Psychometric tests in the morning demonstrated for the noopsyche, only a significantly deteriorated psychomotor activity in both patient groups. In the thymopsyche, evening well-being and mood in the morning were reduced in both the L- and H-group, affectivity and morning well-being only in the H-group. The psychopharmacological part of the study was completed by 40 patients (there were 4 drop-outs in the triazolam, 1 in the quazepam group). They were treated after 1 week placebo with either 15-30 mg (median 15 mg) quazepam or 0.25-0.5 mg (median 0.25 mg) triazolam for 4 weeks, and thereafter for 2 weeks with placebo. Anxiety (rated by HAMA and SAS) improved significantly with both drugs and remained improved throughout 2 weeks post-drug placebo, with quazepam being slightly superior to triazolam. Polysomnography demonstrated a shortened sleep onset only after quazepam. Sleep efficiency improved after acute administration of both drugs, but the improvement was maintained by quazepam only (tolerance development with triazolam). Rebound insomnia was observed only in the 1st post-triazolam placebo night (significant intergroup difference based on confirmatory testing). S2 increased, S3 + S4 decreased under and after quazepam, which represents a normalization in home-recorded GAD patients. S1 decreased with both drugs, SREM only under quazepam. Subjective sleep quality behaved very similarly to objective sleep efficiency. Awakening quality improved after acute therapy with both drugs, somatic complaints only with quazepam.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1994

Automatic sleep-spindle detection procedure: aspects of reliability and validity.

The paper describes a reliable and valid method for the automatic detection of sleep spindles in whole night polygraphy. The recording of a multi-channel EEG during sleep polysomnography was performed in 10 healthy volunteers aged 20-35 years. This objective method should improve the time-consuming and subjective visual evaluation by increasing the accuracy and allowing the calculation of quantitative variables (i.e., frequency and amplitude), thereby facilitating scientific work with quantitative data. An important part of the method is the treatment of artifacts (i.e., muscle and spindle-like alpha activity). Compared to hardware solutions, our software method has the advantage of higher flexibility in regard to artifact identification and usual spindle definitions.

Adult↗
PubMed1994

[Epidemiology of sleep disorders in Austria].

UNLABELLED: Epidemiologic data on sleep disturbances in Austria were collected for the first time in March/April 1993 in a representative inquiry ( SAMPLE: n = 1000, 471 males, 529 females). 26% of the subjects reported sleep disturbances which were mostly chronic (21% had suffered from sleep disturbance for more than one year). The incidence of sleep disturbances increased with age, namely 13% in 14-30 year-old subjects, 22% in 31-50 year-old ones and 41% in subjects over 50. 7% suffered from disturbances in sleep initiation, i.e., they had a sleep latency of over 30 minutes. 19% of them had difficulties in getting to sleep at least once a week. Disturbances in maintaining sleep were reported by 28% of subjects, 56% of them needing longer than one hour to get back to sleep. 30% suffered from daytime sleepiness, 43% of the subjects were impaired by their sleep disturbances in some way, but only 34% had consulted their doctor.

Adolescent↗
PubMed1993

Changes of serum lipid patterns during long-term anticonvulsive treatment.

Serum lipids were determined in 97 patients (56 men, 41 women; ages 42 +/- 15 years) undergoing long-term anticonvulsive treatment (longer than 6 months). The total group showed increased total cholesterol, decreased high-density lipoprotein HDL cholesterol, an increased ratio of total to HDL cholesterol, and decreased apolipoprotein A1 and B values compared to population means. Considering males and females separately, all differences were significant (P < 0.01) in men, whereas in women only the differences in HDL cholesterol, ratio of total to HDL cholesterol, and apolipoproteins A1 and B reached the level of statistical significance. Considering the different anticonvulsant groups, cholesterol was significantly increased only in phenytoin-treated males; HDL cholesterol was significantly lowered and the ratio of total to HDL cholesterol significantly increased in all groups. Apolipoprotein A1 levels were significantly decreased in phenytoin-treated females and valproate-treated patients of both sexes. Apolipoprotein B levels were significantly decreased in all groups except carbamazepine-treated males. Especially in men treated with anticonvulsants these lipid levels may be considered a risk factor for atherosclerosis.

Adolescent↗
PubMed1993

Topographic mapping of EEG during sleep.

Topographic aspects of all night sleep EEG were investigated in 10 healthy volunteers (age 20-35 years). EEG brain maps showed an increase of delta power from stage 1 to 4, a decrease of alpha power most pronounced parieto-occipitally and a slowing of the dominant alpha frequency. Differences of EEG power in different sleep stages (as compared to wakefulness) are displayed topographically. Analysis of the course of stage 2 showed an increase of delta power and a decrease of theta power in the first sections of the night, and an increase of beta power later in the night.

Adult↗
PubMed1993

Occurrence of Andermann syndrome out of French Canada--agenesis of the corpus callosum with neuronopathy.

We report on two siblings, a boy and a girl, with agenesis of corpus callosum and neuronopathy. The children show diffuse hypotonia, delayed motor and mental development. Neurophysiological examinations revealed reduction of the motor nerve conduction velocity, absence of sensory nerve action potentials, abnormal somatosensory and visual evoked potentials. Nerve biopsies showed reduced density of myelinated and unmyelinated fibres in both children. We also found signs of hypomyelination and suggest this is secondary to degeneration of peripheral sensory and motor neurons. Our findings are consistent with the diagnosis of Andermann syndrome. This is the first report of the occurrence of Andermann syndrome out of French Canada.

Agenesis of Corpus Callosum↗
PubMed1993

Central nervous system function after cardiopulmonary bypass.

In a prospective study, an elderly group of patients (n = 63, 47 male, 16 female, age 40-65 years) was examined before and after open-heart surgery under cardiopulmonary bypass: postoperatively, 19 patients (30%) showed no clinical neuropsychiatric symptoms, whereas in 35 patients (56%) mild or transient neurological signs and in nine (14%) severe neurological complications were found. The postoperative EEG changes were characterized by a slight delta-theta increase, an alpha decrease and a significant slowing of the dominant frequency from 9.7 to 9.3 Hz. In brainstem auditory evoked potentials no changes were found, and in somatosensory evoked potentials (median nerve) the latency of the early cortical component, N20, increased. Cardiovascular reflexes showed increased changes, similar to those found in autonomic neuropathies. In the neuropsychological test battery, the Visual retention test (Benton) and the Rorschach test showed slight postoperative improvement, whereas other psychometric variables (flicker fusion frequency, reaction time) did not change. Despite an improved operative technique some minor clinical and neurophysiological disturbances of the central nervous system remain. However, specific pre- or peri-operative risk factors for these postoperative disturbances or complications could not be identified.

Adult↗
PubMed1993

Occurrence of epileptiform activity in the routine EEG of epileptic patients.

In a retrospective study, the occurrence of epileptiform activity (EA) in routine EEG records of epileptic patients was investigated. Data were obtained from 1078 EEGs of 373 patients (199 men and 174 women; aged 17-87 (mean 34.2 +/-14.7)). The percentage of 38% of patients with EA in a single EEG could be increased to 77% by repeated records. After the 5th record however, the gain in new information decreased remarkably. No differences between seizure types could be detected. There was a relationship between EA and nonspecific EEG abnormalities. High EA rates were found for short time intervals since last seizure, young patients, long durations of the seizure disorder and for high seizure frequencies.

Adolescent↗
PubMed1993

[Sleep disorders in neurology: hyposomnia].

Sleep disturbances are an important health problem; about 20-33% of the population suffer from hyposomnias (lack of sleep). Hyposomnias often accompany neurological disorders (head traumas, chronic cephalea, pain, cerebrovascular and neuromuscular disorders, M. Parkinson, and dementia). Slow wave sleep decreases, arousals increase, and sleep is fragmented; these types of hyposomnias are treated by treatment of the basic neurological disease. Some sleep disturbances (e.g. sleep apneas) are a risk factor for cerebrovascular disorders.

Brain↗
PubMed1991

Human somatosensory cortical finger representation as studied by combined neuromagnetic and neuroelectric measurements.

We studied somatotopy of human hand somatosensory cortex using evoked responses recorded on magnetoencephalogram (MEG) and scalp-electroencephalogram (EEG) in conjunction with dipole modeling. We found a somatotopic arrangement of cortical digit representations with a sensory sequence from lateral inferior to medial superior in the anatomical order thumb, index finger, middle finger, ring finger, and little finger. MEG alone was able to reproduce this sensory sequence more accurately than scalp-EEG alone. However, the combined information provided by both techniques improved localization accuracy even further. As MEG and scalp-EEG are complementary and confirmatory techniques, this combined approach was useful to get more complete information on the functional organization of human hand somatosensory cortex.

Brain Mapping↗
PubMed1991

[Neurologic and psychiatric complications after heart surgery].

In 63 patients undergoing heart operations with extracorporeal circulation (47 males, 16 females, mean age 54 years; coronary artery bypass in 38 cases, valvular surgery in the rest) postoperative neurological and psychiatric complications were evaluated. 18 patients (29%) had no complications, whereas 35 patients (56%) showed minor or transient neurological symptoms, and 9 patients (14%) exhibited severe symptoms. Nine of the patients had slight psychiatric disturbances (affective disturbances, disorientation). No correlation was found between risk factors (age, nicotine abuse, hypertension, hypercholesteremia, neurologic and cardiac history), intraoperative parameters (duration of extracorporeal bypass, aortic clamp time, deviation of mean arterial pressure), postoperative parameters (internal complications) and the complication rate. Therefore no predisposing factors could be identified.

Adult↗
PubMed1991

[The significance of laboratory findings in long-term antiepileptic therapy].

A retrospective study of 316 patients (173 men, 143 women; mean age 39 [17-87] years) who had taken antiepileptics (phenytoin, phenobarbital, carbamazepine, valproic acid) for at least six months, was carried out to assess the biochemical and haematological changes in relation to the drug used, the therapeutic programme and the drug serum levels. The most frequent change was isolated elevation of gamma-GT (9-89% of cases depending on the drug), followed by elevation of alkaline phosphatase (16-44%). Increases in the transaminases GOT (4-13%) and GPT (4-19%) were infrequent and minor. Changes in the blood picture were very infrequent and never more than minimal. Correlation between all these changes and serum drug levels was poor (r less than 0.15). Correlations between drug serum level and dose were found in the case of phenobarbital (r = 0.6) and valproic acid (r = 0.5). There was hence no evidence of any clear connection between the biochemical findings and the serum concentrations of antiepileptic drugs or their-dosage. The results indicate that undue importance has previously been attached to routine checks of biochemical parameters; abnormal biochemical findings by themselves are not usually enough to necessitate changes in treatment. Determination of biochemical and haematological parameters is necessary only if there are clinical grounds for it such as suspicion of side effects, the occurrence of epileptic attacks despite therapy, or change from one drug to another.

Adolescent↗