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Biomedical subjects

M Fagerlund

Publications and source records attributed to M Fagerlund.

At least 37 records · Page 2Linked to original sources
PubMed1995

Cerebrospinal fluid shunt dynamics in patients with idiopathic adult hydrocephalus syndrome.

The objective was to assess CSF dynamics of different shunt constructions in patients with adult hydrocephalus syndrome and correlate these findings to clinical outcome, neuroradiology, and the specifications of the shunts provided by the manufacturer. Thirty four patients with idiopathic adult hydrocephalus (normal pressure hydrocephalus) syndrome were included in a prospective, consecutive case series. A differential pressure valve (Cordis Hakim standard system) was used in 28 patients and a variable resistance valve (Cordis Orbis-Sigma) in six. A constant pressure infusion method was used; CSF pressure and conductance were determined before surgery. Three months after shunt placement CSF pressure, the "pressure v flow" curve, and gravity induced flow were measured. There was no difference between mean preoperative and postoperative resting CSF pressures in patients with Hakim shunts. The opening pressures of the Hakim shunts were higher than the value proposed by the manufacturer. A pronounced gravity effect induced CSF flow and decrease of the CSF pressure. In functioning variable resistance valves, CSF dynamics normalised postoperatively. There was no gravity effect and the characteristics shaped "pressure v flow" curve was sometimes seen. Six patients (three differential pressure valves, three variable resistance valves) had non-functioning shunts. Four of these patients were improved after the operation but improvement was transient in three. In all patients, there was no relation between the width of the ventricles and clinical improvement or CSF pressure. In conclusion, the differential pressure valve system does not behave according to the specifications provided by the manufacturer. A decrease in CSF pressure in patients with this shunt was solely due to the effect of gravity. Eleven percent of the differential pressure valves and 50% of the variable resistance valves were non-functioning. In the functioning variable resistance valves, the antisiphon system seems to be effective.

Aged↗
PubMed1994

Describing the size of lumbar disc herniations using computed tomography. A comparison of different size index calculations and their relation to sciatica.

STUDY DESIGN: The study compared different methods to measure the absolute and relative size of lumbar disc herniations on computed tomography scans and their relation to sciatica. METHODS: Computed tomography (CT) examinations were done before and at 3 and 24 months after nonoperative treatment in 30 patients with lumbar disc herniations. The size of the herniation was described by different indexes and related to the degree of sciatica. One index was formed by the area of the herniation in relation to the spinal canal (A-index), whereas two indexes were formed by linear measurements of the herniation in relation to the spinal canal in either two (ST-index) or one direction (S-index). RESULTS: Each index was correlated significantly to the degree of sciatica. The area of the herniations decreased markedly over time. CONCLUSIONS: Linear measurements of the herniation in two perpendicular directions provide a practical and accurate way of describing the size of lumbar disc herniations.

Adult↗
PubMed1994

MRI and neurology in acute whiplash trauma. No correlation in prospective examination of 39 cases.

39 consecutive cases of whiplash injury of the neck were examined clinically and with MRI at a mean of 11 days after trauma. 26 of these showed changes on MRI with disc lesions in 25, 10 of which were classified as disc herniations, and a muscle lesion in 1 case. All had neck pain or headache. 29 cases had neurological deficits, mostly sensibility disturbances. 22 of the 26 cases with pathologic MRI findings had neurological signs, as had 7 of the 10 cases with disc herniation. The relationship between the MRI findings and the clinical symptoms and signs was poor.

Adolescent↗
PubMed1993

[Hypofractionation. A method for stereotaxic radiation of major brain lesions with linear accelerator].

Fifteen patients with brain tumours or arteriovenous malformations (AVMs) underwent hypofractionated stereotactic irradiation, 2-5 fractions being delivered using a linear accelerator and a non-invasive stereotactic frame. Results of the treatment of brain metastases were comparable with those reported for single fraction radiosurgery. With the AVMs, the rate of obliteration would seem to be slower than that after radiosurgery, perhaps because the irradiated volumes in our study were significantly larger than those treated with radiosurgery. An advantage of hypofractionated stereotactic irradiation is that larger brain lesions can be treated than is appropriate with radiosurgery.

Adult↗
PubMed1992

Piroxicam and indomethacin suppositories for painful coxarthrosis.

Six orthopaedic clinics in Sweden made a comparison of the effects and side effects of Piroxicam (20 mg) and Indomethacin (100 mg) suppositories in 261 patients with painful coxarthrosis on the waiting list for total hip replacement (THR). The study was designed as a single blind study over 4 weeks. Amount of pain and range of motion was registered before the trial and compared with findings after 4 weeks, including reported side effects. Both drugs gave satisfactory pain relief without any appreciable variation on weightbearing or at rest. On the other hand, the trial showed a significant difference (p = 0.0033, Student's-test) between the two drugs as regards the frequency of side effects from the lower gastrointestinal tract, where piroxicam had a lower rate compared with indomethacin. No serious complications occurred; 16 patients dropped out, 8 in each group.

Aged↗
PubMed1992

Straight leg raising test versus radiologic size, shape, and position of lumbar disc hernias.

In 30 patients with a computed tomography-verified lumbar disc herniation, the relation between the straight leg raising test and the size, shape, and position of the hernia was evaluated before, 3, and 24 months after inception of nonoperative treatment. Hernia size was expressed as an index relating it to the size of the spinal canal. The limitation of the straight leg raising test was not related to size or position of the hernia. Before treatment, straight leg raising was equally restricted in patients with sharply pointed or blunt hernias, but after 3 months straight leg raising was less limited in patients with sharply pointed hernias, whereas after 24 months straight leg raising was regularly normalized. Size index was lower for sharply pointed hernias at all three computed tomography scans. A decrease in hernia size over time, irrespective of shape, was not correlated to a concomitant improvement in straight leg raising. It must be presumed that additional factors, such as inflammatory reactions affecting the nerve roots, are of importance for the magnitude of straight leg raising.

Adult↗
PubMed1992

Ultra low field MR imaging of cervical spine involvement in rheumatoid arthritis.

In a study of 30 patients with longstanding rheumatoid arthritis the diagnostic usefulness of ultra low field MR equipment was analyzed in assessing lesions of the craniocervical junction. It was found that at 0.04 T all the examinations were diagnostic and that in combination with plain radiography the diagnostic information obtained was valuable in further planning of the treatment strategies. The neurologic findings were related to the degree and severity of atlantoaxial luxation, either horizontal or vertical, and to the periodontoid pannus formation. The correlation between the degree of cord compression shown with MR imaging and the clinical symptoms, especially long tract symptoms, was poor. The only correlating factor was the duration of the disease.

Adult↗
PubMed1991

Electroencephalographic and neuroradiological findings in adults with newly diagnosed unprovoked seizures.

Adult persons, 17 years old or older, with newly diagnosed (incident) epileptic seizures were prospectively identified in a community-based study. Electroencephalographic (EEG) recordings when awake and/or during sleep were performed in 103 persons (96.3%). Epileptiform activity was recorded during wakefulness in 18 of 101 persons (18%) and during sleep in another 11 persons (10.7%) of whom 10 had no epileptiform activity on wake EEGs. Pathological findings on EEGs recorded during sleep or when awake were more common in persons with partial seizures than in those with primary generalized tonic-clonic seizures. EEG recording during sleep significantly increased the proportion of pathological findings in partial seizures compared with other seizure types. 45 persons (42.1%) were neuroradiologically investigated by both computerized tomography (CT) and magnetic resonance imaging (MRI) using a low-field-strength imager (0.02 tesla). 2 persons with normal CT had pathological findings on MRI. 4 persons with normal MRI had pathological findings on CT.

Adolescent↗
PubMed1989

Knee extensor muscle function before and after reconstruction of anterior cruciate ligament tear.

Knee extensor performance, in 17 subjects with chronic anterior cruciate ligament (ACL) tear, was investigated preoperatively and on four different occasions postoperatively, using isokinetic measurements and electromyography of single maximum and repetitive manoeuvres. Preoperatively maximum mechanical output was comparatively low (injured leg), deteriorating further by 50% at fourteen weeks postoperatively. Endurance also falls markedly. Thereafter knee-extensor performance improved successively, mostly during intensive training (14-20 weeks postoperatively) irrespective of the training programme used. After one year, maximum performance was still unequal but the injured leg had achieved the "normal" preoperative noninjured value. Fatiguability/endurance level improved over preoperative values. Muscular work/integrated EMG was stable while EMG/t increased. Twenty weeks postoperatively quadriceps area was decreased to 69%, cf. noninjured control. The early postoperative loss of performance was evidently caused by loss of muscle mass. Neuromuscular relearning appears to be a sizable factor in later recovery. Isokinetic training does not offer any specific advantage in the early muscular rehabilitation after ACL reconstruction.

Adolescent↗
PubMed1988

Fatigue during dynamic muscle contractions in male sprinters and marathon runners: relationships between performance, electromyographic activity, muscle cross-sectional area and morphology.

Knee extensor fatigue and endurance during repeated maximum isokinetic manoeuvres were studied in five sprinters and five marathon runners, all males. Fatigue and endurance were expressed in terms of output (contractional work, CW) and input (integrated electromyograms, iEMG), and was related to muscle fibre composition of m. vastus lateralis and to cross-sectional area (CSA) of m. quadriceps. The initially performed contractional work was positively related to the calculated absolute type II fibre area of m. vastus lateralis, but not to the cross-sectional area of m. quadriceps. During the first 25 contractions, sprinters fatigued, with a slope of decline in contractional work that was correlated to the absolute type II fibre area, also after correction of performed work for CSA of m. quadriceps. As the electromyographic activity decreased less than the contractional work, a drastic fall in the CW/iEMG ratio was found in the sprinter group. Three out of five sprinters could perform less than 50 knee extensions, due to subjective discomfort in tested thighs. In contrast, all marathon runners could, after a minor similar decline in electromyographic activity and contractional work during the first part of the experiment, maintain a steady-state endurance level of CW and iEMG throughout the test (200 knee extensions). In conclusion, fatigue during isokinetic maximal knee extensions is closely related to the muscle structure of m. vastus lateralis.

Adult↗
PubMed1987

Sprinters and marathon runners. Does isokinetic knee extensor performance reflect muscle size and structure?

In order to evaluate relationships between structure and concentric function of the quadriceps muscle, isokinetic maximum knee extensor output at different velocities of angular motion (30-180 degrees s-1), integrated electromyographic activity (iEMG), cross-sectional area (CSA) of m. quadriceps and fibre composition of m. vastus lateralis were analysed in five sprinters and five marathon runners (all males). Both output and input parameters, concerning peak torque (PT), instantaneous power (IP), contractional work (CW) and the summed iEMG were closely correlated to the m. quadriceps CSA, as well as to the calculated absolute type II (A + B), IIA and IIB fibre areas of m. vastus lateralis. When PT, IP, CW and the summed iEMG were corrected for CSA, such relationships were found only at 180 degrees s-1 and only for type IIA fibre area. The electromyographic findings indicate that m. vastus lateralis was representative for the total mechanical output. The calculated mean power output (CW s-1) and output/input balance (CW/iEMG) describe similar relationships with the velocity of angular motion and were not related to the CSA or to the absolute area of any fibre type. The calculated optimal CW per second and CW/iEMG occur for sprinters at about 450 degrees s-1 and for marathon runners at about 270 degrees s-1, that is, velocities well above the capacity of the isokinetic dynamometer. Our observations indicate that the peak torque or instantaneous power, during single maximum knee extensions, at least at 180 degrees s-1, express characteristics of the muscle structure.

Adult↗
PubMed1986

Medullary compression in rheumatoid atlanto-axial subluxation evaluated by computerized tomography.

CT examination of rheumatoid dislocation in the C1-C2 region was performed in 20 patients with advanced disease. The patients were classified in three grades according to the degree of medullary compression caused by the odontoid process in the extended position of the neck. Five patients showed no dural or medullary compression (grade 1), nine dural compression (grade 2), and six medullary compression (grade 3). CT grading was found to correlate best with long tract symptoms. These were present in 4/6 grade 3 and 0/5 grade 1 patients, while 3/9 grade 2 patients had long tract symptoms. Tissue attenuation values over the anterior atlanto-axial joint indicated interposing firm connective tissue in patients showing no reduction of the subluxation on extension of the neck.

Adult↗
PubMed1985

An adapter for computed tomography-guided stereotaxis.

A new, versatile adapter for computed tomography-guided stereotaxis is presented. The instrument consists of a light aluminum frame, which by means of a nasion support and two ear plugs is fixed to the patient's head. Reproducibility of repeated fixations is very high. The adapter is fitted to most stereotactic frames and can be used in all adult patients. Comparison between computed tomography- and ventriculography-guided determinations of thalamic targets showed a mean difference of 0.6 and 0.7 mm for the x and y coordinates, respectively. The z coordinates seldom showed any measurable difference. We now perform all types of stereotactic neurosurgery (tumor biopsy, implantation of depth electrodes, thalamotomy, dentatotomy, cingulotomy, etc.) with computed tomography guidance only. The short-term results in a small number of patients have been at least as good as after conventional ventriculography-guided surgery. In addition to open stereotactic surgery, the adapter is also suitable for external stereotactic irradiation of intracranial targets with a linear accelerator.

Brain↗
PubMed1983

Correlations between echo-encephalographic and computer tomographic measures of third and lateral ventricle size in children and adults.

Accuracy of echo-encephalography (EVG) was assessed by comparison with computer-tomography (CT) in a material of 49 children aged 2 weeks to 15.5 years and 158 adults aged 17 to 83 years. Third ventricle width could be measured on EVG in all the patients, and the correlations with CT values were excellent both in children and adults (r = 0.89 and r = 0.94, respectively). Lateral ventricle echoes could be recorded in 43 children (87.7%) and in 95 adults (60.1%). There were very good correlations between lateral ventricle size estimated as LVI (lateral ventricle index on EVG) and BI (body index on CT) both in children and adults (r = 0.84 and r = 0.86, respectively). In adults, a fairly large proportion (46.3%) of the patients where lateral ventricle echoes could be recorded, apparently had essentially normal ventricle systems, although there was evidence that these echoes could be recorded more easily from widened ventricles.

Adolescent↗