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Biomedical subjects

M Nygaard

Publications and source records attributed to M Nygaard.

5 recordsLinked to original sources

Non-verbal learning disabilities in children with infantile hydrocephalus, aged 4-7 years: a population-based, controlled study.

The aim of this population-based, controlled study was to investigate non-verbal learning disabilities (NLD) in children with infantile hydrocephalus (IH). For this purpose, the results from subtests measuring either assets or deficits within Rourke's model of NLD were analyzed. Children with myelomeningocele (MMC), intracranial tumors, or IQ < 70 were excluded. Of the 52 IH children included in the study, 46 were shunt-treated, whereas 6 were not shunted. The 44 controls were matched according to age, gender, and geographic variables. The Neuropsychological Assessment of Children (NEPSY) was administered to 52 children (age 4-7) with IH; (F = 17, M = 35), and to 44 controls (F = 17, M = 27). The tests used were classified along each of the dimensions "assets" or "deficits", according to Rourke's model of the elements and the dynamics of the NLD syndrome. Differences between sum scores for the subtests classified as "assets", versus "deficits" were significantly higher in the IH group as compared with the controls (p < 0.005). These findings are compatible with a higher frequency of NLD in the IH group, in which neurological confounding factors have been excluded. In addition, the model of the elements and the dynamics of the NLD syndrome may be useful when analyzing neuropsychological test results obtained with traditional and comprehensive test batteries.

Case-Control Studies↗

Early periprosthetic femoral bone remodelling using different bearing material combinations in total hip arthroplasties: a prospective randomised study.

The present study was performed to test the hypothesis that different bearing materials have an impact on femoral bone remodelling within the first year after a total hip arthroplasty. A total of 225 patients with osteoarthrosis of the hip or avascular necrosis of the femoral head were included in this randomised prospective study. All patients had an identical hybrid total hip arthroplasty (cemented BiMetric stem and cementless RingLoc acetabular cup) except for the bearing materials: polyethylene-on-zirconia (n = 78), CoCr-on-CoCr (n = 71), or alumina-on-alumina (n = 76). Bone mineral density (BMD) was measured with Dual-energy X-ray absorptiometry (DEXA) in seven Gruen zones adjacent to the femoral implant. The DEXA scan was performed within one week after surgery and was repeated one year postoperatively. There was no significant difference in periprosthetic BMD change between the three groups. After twelve months the relative BMD decrease was highest in the proximal part of the femur, - 6.2% in the greater trochanter region and - 12.7% in the lesser trochanter region. In the distal zones the relative BMD decrease was -5.3, -4.2, -2.1, -2.3, and -5.6%, respectively. The use of different bearing materials had no significant impact on femoral bone remodelling adjacent to the cemented hip stem within one year after surgery.

Aged↗

On-line analysis of middle latency auditory evoked potentials (MLAEP) for monitoring depth of anaesthesia in laboratory rats.

In laboratory animals as well as in human beings a depth of anaesthesia, where the subject has no pain or recall of events from the surgery, should be provided. Haemodynamic parameters such as heart rate and blood pressure are not a guarantee for an optimal depth of anaesthesia, especially when using neuromuscular blocking agents (NMBA). A number of studies suggest that the Middle Latency Auditory Evoked Potentials (MLAEP) contain information about the state of consciousness in humans. The purpose of this study was to examine whether the AEP could serve as an indicator of depth of anaesthesia in rats. The AEP was elicited with a click stimulus and monitored in an 80 ms window synchronised to the stimulus. The AEP was extracted applying an Auto Regressive Model with Exogenous Input (ARX-model) from which a Depth of Anaesthesia Index (DAI) was calculated. DAI was normalised to 100 while awake and decreasing gradually to a level between 50 and 20 as the rat was anaesthetised. Nine rats were anaesthetised and included in the study. Four doses of Hypnorm vet. and Dormicum were given as a total, each with 5 minutes interval. Clinical signs of the level of anaesthesia were observed simultaneously with the AEP. The results showed that in four rats DAI decreased to a level below 30 while anaesthetised. In the remaining five rats the AEP was only decreased to a level below 45. The results indicated that a simple dosing regimen based on weight was unable to give the same depth of anaesthesia in individual rats. The decrease in the DAI correlated well with the loss of stimulus response. In conclusion, MLAEP could be used as an indicator of depth of anaesthesia in rats during Hypnorm vet. and Dormicum administration. However studies applying other anaesthetic drugs should be carried out, before a conclusion of the general utility of the method can be made.

Analysis of Variance↗