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Biomedical subjects

A Persson

Publications and source records attributed to A Persson.

At least 181 records · Page 10Linked to original sources
PubMed1971

Effect of L-dopa on speech in Parkinsonism. An EMG study of labial articulatory function.

The articulatory function of the labial musculature has been investigated electromyographically before and after treatment with l-dopa in patients with Parkinsonism who had dysarthria. Before medication the EMG traces generally showed a constant, abnormally increased, tonic activity, together with disturbed reciprocal innervation, which impaired the articulatory activity. After medication the tonic hyperactivity was reduced and the reciprocal innervation re-established. This normalization of the EMG articulatory pattern was paralleled by an improvement of the dysarthria.

Dihydroxyphenylalanine↗
PubMedDate not supplied

Valproate in the treatment of absence epilepsy in children: a study of dose-response relationships.

Seven children with absence epilepsy were treated with valproate (VPA). All but one child became free of absence seizures during VPA monotherapy. EEG was recorded for 24 h before start of VPA treatment and repeatedly during treatment. Correlation between plasma VPA concentration and reduction of the number of epileptic discharges was significant. Plasma concentration of 440-660 microM VPA was needed to achieve at least 50% reduction of seizure activity.

Adolescent↗
PubMedDate not supplied

Effect of a hydroxyl ion-releasing composite resin on plaque acidogenicity.

The aim of this in vivo study was to evaluate the neutralizing capacity, registered as change of plaque acidogenicity, on aged proximal restorations of an ion-releasing composite resin (IRCR), which releases hydroxyl, calcium, and fluoride ions at low pH. Twenty patients, with a mean age of 63 years (range 43-85), participated. All had one aged proximal IRCR restoration (mean age 15 months) and one nonrestored enamel surface to make an intraindividual comparison possible. The neutralizing effect of the IRCR was evaluated by measuring plaque pH, using the microtouch method, after a mouthrinse with 10% sucrose. The plaque pH measurements were repeated 1.5 years later on the IRCR (mean age 34 months), the enamel surfaces and a universal hybrid composite resin (CR). At both 15 and 34 months, the plaque on the IRCR surfaces showed the least acidogenic potential for the whole 60-min time interval. The largest differences between the IRCR, CR and enamel were found during the first 15 min. At 15 months, the total areas under the plaque pH curve (AUC(5.7) and AUC(6.2)) differed significantly between the IRCR and enamel surfaces for the time periods 0-5 min and 5-15 min. At 34 months, significant differences were found between IRCR and CR at the 0- to 5-min time period. It can be concluded that IRCR restorations countered the plaque pH fall and maintained it at levels where less enamel and dentin demineralization can occur.

Acrylic Resins↗
PubMedDate not supplied

Clinical diagnosis of frontal lobe dementia and Alzheimer's disease: relation to cerebral perfusion, brain atrophy and electroencephalography.

The regional cerebral blood flow, brain atrophy, white matter changes and neurophysiologic changes were evaluated in 28 patients with a clinical diagnosis of probable Alzheimer's disease (AD) and in 8 patients with a clinical diagnosis of frontal lobe dementia (FLD) using single photon emission computed tomography, magnetic resonance imaging and electroencephalography (EEG). We found that FLD patients had more severe frontal blood flow reduction and less severe parietal blood flow reduction compared to AD patients. Among patients with mild dementia the EEG changes were less severe in the FLD group. No significant differences were found in white matter changes or in regional atrophy.

Aged↗
PubMedDate not supplied

The cricothyroid muscle after cricothyroidotomy. A porcine experimental study.

Cricothyroidotomy in elective use or emergency situations has been discussed by several authors during recent years. The main complication reported has been subglottic stenosis. We have used this method for several years and among our patients there has been no case of stenosis. The major complication in our material has been voice dysfunction. Some of the patients had a change in voice quality consistent with dysfunction in the cricothyroid muscles (diminished voice range and a lowered pitch). The aim of this study was to investigate whether cricothyroidotomy and insertion of a tracheostomy tube caused physiological or morphological changes in the cricothyroid muscle, by direct injury or secondary to a peripheral nerve lesion. In the six animals that were cricothyroidotomized during 7-9 days and examined after 9-15 weeks, we found neither changes in the EMG nor in the muscle morphology indicating injury to the muscle or its peripheral nerve supply.

Animals↗
PubMedDate not supplied

Evaluation of laryngeal muscle function by quantitative analysis of the EMG interference pattern.

A computerized method for quantitative analysis of the EMG interference pattern was tested in the cricothyroid and thyroarytenoid muscles with the purpose of evaluating its usefulness for clinical purposes. In a normal male subject the mean amplitude and the number of turns/s were extracted from the EMG signal of sustained chest register phonations, with systematic variation of vocal pitch and intensity. In the cricothyroid, as well as the thyroarytenoid muscle, there was a considerable increase in mean amplitude and turns/s with both increased pitch and increased intensity. Pitch variation was the most effective way to induce changes in turns and amplitude levels in both muscles. In contrast to results from studies of larger muscles, the increase in both amplitude and turns was proportional to muscle force also at the highest loads.

Electromyography↗