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Biomedical subjects

P G Larsson

Publications and source records attributed to P G Larsson.

At least 19 recordsLinked to original sources
PubMed2006

The value of multichannel MEG and EEG in the presurgical evaluation of 70 epilepsy patients.

OBJECTIVE: To evaluate the sensitivity of a simultaneous whole-head 306-channel magnetoencephalography (MEG)/70-electrode EEG recording to detect interictal epileptiform activity (IED) in a prospective, consecutive cohort of patients with medically refractory epilepsy that were considered candidates for epilepsy surgery. METHODS: Seventy patients were prospectively evaluated by simultaneously recorded MEG/EEG. All patients were surgical candidates or were considered for invasive EEG monitoring and had undergone an extensive presurgical evaluation at a tertiary epilepsy center. MEG and EEG raw traces were analysed individually by two independent reviewers. RESULTS: MEG data could not be evaluated due to excessive magnetic artefacts in three patients (4%). In the remaining 67 patients, the overall sensitivity to detect IED was 72% (48/67 patients) for MEG and 61% for EEG (41/67 patients) analysing the raw data. In 13% (9/67 patients), MEG-only IED were recorded, whereas in 3% (2/67 patients) EEG-only IED were recorded. The combined sensitivity was 75% (50/67 patients). CONCLUSION: Three hundred and six-channel MEG has a similarly high sensitivity to record IED as EEG and appears to be complementary. In one-third of the EEG-negative patients, MEG can be expected to record IED, especially in the case of lateral neocortical epilepsy and/or cortical dysplasia.

Adolescent↗
PubMed2005

3T phased array MRI improves the presurgical evaluation in focal epilepsies: a prospective study.

BACKGROUND: Although detection of concordant lesions on MRI significantly improves postsurgical outcomes in focal epilepsy (FE), many conventional MR studies remain negative. The authors evaluated the role of phased array surface coil studies performed at 3 Tesla (3T PA MRI). METHODS: Forty patients with medically intractable focal epilepsies were prospectively imaged with 3T PA-MRI including high matrix TSE T2, fluid attenuated inversion recovery, and magnetization prepared rapid gradient echo. All patients were considered candidates for epilepsy surgery. 3T PA-MRIs were reviewed by a neuroradiologist experienced in epilepsy imaging with access to clinical information. Findings were compared to reports of prior standard 1.5T MRI epilepsy studies performed at tertiary care centers. RESULTS: Experienced, unblinded review of 3T PA-MRI studies yielded additional diagnostic information in 48% (19/40) compared to routine clinical reads at 1.5T. In 37.5% (15/40), this additional information motivated a change in clinical management. In the subgroup of patients with prior 1.5T MRIs interpreted as normal, 3T PA-MRI resulted in the detection of a new lesion in 65% (15/23). In the subgroup of 15 patients with known lesions, 3T PA-MRI better defined the lesion in 33% (5/15). CONCLUSION: Phased array surface coil studies performed at 3 Tesla read by an experienced unblinded neuroradiologist can improve the presurgical evaluation of patients with focal epilepsy when compared to routine clinical 1.5T studies read at tertiary care centers.

Adolescent↗
PubMed2005

Comparison of traditional Chinese acupuncture, minimal acupuncture at non-acupoints and conventional treatment for chronic sinusitis.

OBJECTIVES: To compare traditional Chinese acupuncture, minimal acupuncture at non-acupoints and conventional treatment for chronic sinusitis. DESIGN: A three-armed single blind randomised controlled study. SETTING: In an outpatient specialist clinic, we recruited 65 patients with symptoms of sinusitis >3 months and signs of sinusitis on computed tomography (CT). INTERVENTIONS: We randomised patients to one of three study arms: (1) 2-4 weeks of medication with antibiotics, corticosteroids, 0.9% sodium chloride solution, and local decongestants (n=21), (2) 10 treatments with traditional Chinese acupuncture (n=25), or (3) 10 treatments with minimal acupuncture at non-acupoints (n=19). OUTCOME MEASURES: Change in sinus soft tissue swelling on CT, symptoms of sinusitis, and health-related quality of life (HRQoL), using the two component summary scales of the Short Form 36 and a rating scale. RESULTS: In the conventional treatment group, sinus soft tissue swelling was reduced over 4 weeks (p=0.04), and HRQoL improved over 12 weeks (p=0.01-0.05). Pairwise comparisons of changes in total symptom score between the groups showed signs of a difference between conventional medication and sham over 4 weeks (p=0.06). CONCLUSION: Sinus soft tissue swelling was reduced in the conventional treatment group over 4 weeks, and HRQoL improved over 12 weeks. Only a non-significant difference in symptom score change over 4 and 12 weeks was shown between conventional medication and traditional Chinese acupuncture.

Acupuncture↗
PubMed2005

Bacterial vaginosis--a microbiological and immunological enigma.

The development of bacterial vaginosis (BV) among women of childbearing age and the resulting quantitative and qualitative shift from normally occurring lactobacilli in the vagina to a mixture of mainly anaerobic bacteria is a microbiological and immunological enigma that so far has precluded the formulation of a unifying generally accepted theory on the aetiology and clinical course of BV. This critical review highlights some of the more important aspects of BV research that could help in formulating new basic ideas respecting the biology of BV, not least the importance of the interleukin mediators of local inflammatory responses and the bacterial shift from the normally occurring lactobacilli species: L. crispatus, L. gasseri, L. jensenii, and L. iners to a mixed flora dominated by anaerobic bacteria.

Animals↗
PubMed2005

Bacterial vaginosis--a laboratory and clinical diagnostics enigma.

Diagnosing bacterial vaginosis (BV) has long been based on the clinical criteria of Amsel et al., whereby three of four defined criteria must be satisfied. Though there are other criteria and scoring methods which function well in comparison (i.e. Nugent scoring), it is not certain that they will always identify the same category of patients. Point-of-care methods based on various combinations of microbial products, presence of RNA, or more complex laboratory instrumentations such as sensor arrays, have also been introduced for the diagnosis of BV. No method for diagnosing BV can at present be regarded as the best. It could be that--based partly on tacit knowledge on the part of the clinical investigators scoring in the clinic--various scoring systems have been chosen to fit a particular BV-related problem in a particular population. In this review we critically examine these pertinent issues influencing clinical scoring and laboratory diagnostics of BV.

Clinical Laboratory Techniques↗
PubMed2005

Bacterial vaginosis. Transmission, role in genital tract infection and pregnancy outcome: an enigma.

Whether bacterial vaginosis (BV) is acquired from an endogenous or an exogenous source is subject to controversy. Despite findings of an association between sexual behaviour and BV, some data indicate that BV is not a sexually transmitted infection in the traditional sense, while other data indicate that BV is an exogenous infection. A third aspect of BV is its tendency to go unnoticed by affected women. All of this will have a strong impact on how physicians view the risks of asymptomatic BV. This review focuses on whether or not BV should be regarded as a sexually transmitted infection (STI), its role in postoperative infections and pelvic inflammatory disease (PID), and on whether or not treatment of BV during pregnancy to reduce preterm delivery should be recommended. The reviewed studies do not lend unequivocal support to an endogenous or exogenous transmission of the bacteria present in BV. For women undergoing gynaecological surgery such as therapeutic abortion, the relative risk of postoperative infection is clearly elevated (approx. 2.3-2.8). A weaker association exists between BV and pelvic inflammatory disease. Data on treatment of BV as a way of reducing preterm delivery are inconclusive and do not support recommendations for general treatment of BV during pregnancy. The discrepant associations between BV and preterm birth found in recent studies may be explained by variations in immunological response to BV. Genetic polymorphism in the cytokine response--both regarding the TNF alleles and in interleukin production--could make women more or less susceptible to BV, causing different risks of preterm birth. Thus, studies on the vaginal inflammatory response to microbial colonization should be given priority.

Anti-Bacterial Agents↗
PubMed2005

Bacterial vaginosis--a disturbed bacterial flora and treatment enigma.

The syndrome bacterial vaginosis (BV) is characterized by a disturbed vaginal microflora in which the normally occurring lactobacilli yield quantitatively to an overgrowth of mainly anaerobic bacteria. As BV is a possible cause of obstetrics complications and gynaecological disease--as well as a nuisance to the affected women--there is a strong impetus to find a cure. In BV treatment studies, the diagnosis criteria for diagnosis of BV vary considerably and different methods are used for cure evaluation. The design of study protocols varies and there is no consensus respecting a suitable time for follow-up visits. For the purpose of this review, available data were recalculated for 4-week post treatment cure rates. For oral metronidazole the 4-week cure rate was found not to exceed 60-70%. Treatment regimens with topical clindamycin or topical metronidazole have the same cure rates. It can thus be said that no sound scientific basis exists for recommending any particular treatment. There is no evidence of beneficial effects on BV engendered by partner treatment, or by addition of probiotics or buffered gel. Long-term follow-up (longer than 4 weeks) shows a relapse rate of 70%. With a primary cure rate of 60-70%, and a similar relapse rate documented in the reviewed literature, clinicians simply do not have adequate data for determining treatment or designing clinical studies. This is unfortunate since--apart from the obvious patient benefits--clinical studies can often serve as a guide for more basic studies in the quest for underlying disease mechanisms. In the case of BV there is still a need for continued basic studies on the vaginal flora, local immunity to the flora and host-parasite interactions as an aid when designing informative clinical studies.

Anti-Bacterial Agents↗
PubMed2002

An international study of the interobserver variation between interpretations of vaginal smear criteria of bacterial vaginosis.

An international workshop on vaginal smear-based diagnosis of bacterial vaginosis was organized where 13 investigators scoring 258 slides with smears from vaginal fluid. Interobserver reproducibility of interpretations of Nugent scores, Hay/Ison scores and wet smear scores for the diagnosis of bacterial vaginosis was shown to be high. Detailed analysis of individual scoring results however indicated that basic standards of quality control to ensure robust individual readings of slides must be adhered to.

Bacteriological Techniques↗
PubMed2001

Laparoscopy reduces unnecessary appendicectomies and improves diagnosis in fertile women. A randomized study.

BACKGROUND: The aim of this study was to study the value of diagnostic laparoscopy prospectively in fertile women scheduled for acute appendectomy. METHODS: For this study, 110 women, with acute abdominal pain ages 15 to 47 years, in whom the surgeon had decided to perform an appendectomy, were randomized to either open appendectomy or diagnostic laparoscopy, then open appendectomy if necessary. RESULTS: Appendicitis was diagnosed in 66% of the women after open surgery, and in 73% after laparoscopy. During laparoscopy, was appendicitis misdiagnosed in only 7% of the women, from whom the appendix unnecessarily removed, whereas 34% in the open surgery group had a healthy appendix removed. No appendicitis was missed in the laparoscopic group. The relative risk of removing a healthy appendix in open surgery was 6.6 relative risk (range, 2-21 C.I.) as compared with laparoscopy. Among the women with a healthy appendix, a gynecologic diagnosis was found in 73% after laparoscopy, as compared with 17% after open surgery. CONCLUSIONS: Laparoscopy reduces unnecessary appendectomies and improves diagnosis in fertile women.

Adolescent↗
PubMed2001

Analysis of bacterial vaginosis-related amines in vaginal fluid by gas chromatography and mass spectrometry.

The presence of various amines in vaginal fluid from women with malodorous vaginal discharge has been reported before. The investigations have used several techniques to identify the amines. However, an optimized quantification, together with a sensitive analysis method in connection with a diagnostic procedure for vaginal discharge, including the syndrome of bacterial vaginosis, as defined by the accepted "gold standard," has not been done before. We now report a sensitive gas chromatographic and mass spectrometric method for identifying the amines isobutylamine, phenethylamine, putrescine, cadaverine, and tyramine in vaginal fluid. We used weighted samples of vaginal fluid to obtain a correct quantification. In addition, a proper diagnosis was obtained using Gram-stained smears of the vaginal fluid that were Nugent scored according to the method of Nugent et al. (R. P. Nugent et al., J. Clin. Microbiol., 29:297-301, 1991). We found that putrescine, cadaverine, and tyramine occurred in high concentrations in vaginal fluid from 24 women with Nugent scores between 7 and 10. These amines either were not found or were found only in very low concentrations in vaginal fluid from women with Nugent scores of 0 to 3. There is a strong correlation between bacterial vaginosis and the presence of putrescine, cadaverine, and tyramine in high concentrations in vaginal fluid.

Adult↗
PubMed2000

Acupuncture in intractable epilepsy: lack of effect on health-related quality of life.

The objective of this study was to assess the effect on health-related quality of life of acupuncture and sham acupuncture as adjunctive treatment in intractable epilepsy. We performed a randomized controlled trail with two parallel treatment arms at The National Center for Epilepsy in Norway, a comprehensive epilepsy center. Thirty-four patients with long-standing drug resistant epilepsy completed the study. The intervention consisted of 20 acupuncture treatments (bilateral needling of three acupoints plus one or two individually chosen points) or sham acupuncture (bilateral needling with smaller needles of three points outside the traditional meridians) over 8 weeks. The main outcome measures were changes in mean health-related quality of life scores for the two groups after 8 weeks, using the 89-item Quality of Life in Epilepsy (QOLIE-89) questionnaire. We found no difference between the acupuncture and sham acupuncture groups in score changes in any dimension of the QOLIE-89 questionnaire, despite testing a large number of dimensions. We also found no change in QOLIE-89 scores between baseline and 8 weeks in either groups. In conclusion, we could not demonstrate a significant effect of traditional acupuncture or sham acupuncture on the health-related quality of life of patients with intractable epilepsy.

Acupuncture Therapy↗
PubMed2000

Treatment with 2% clindamycin vaginal cream prior to first trimester surgical abortion to reduce signs of postoperative infection: a prospective, double-blinded, placebo-controlled, multicenter study.

BACKGROUND: Bacterial vaginosis (BV) and intermediate flora is known risk-factor for postoperative infection after surgical termination of pregnancy. Vaginal application of 2% clindamycin cream is an efficacious treatment for BV, but it is not known whether preoperative administration of clindamycin cream might reduce the signs of post-abortion infection after surgical termination of pregnancy. AIM: To evaluate whether preoperative treatment with clindamycin cream might reduce the signs of post-abortion infection after legal abortion. DESIGN: Prospective, double-blinded, placebo-controlled, multicenter study. MATERIAL AND METHODS: Consecutive women attending for surgical termination prior to 11+4 gestational weeks were approached. We randomized participants to preoperative vaginal treatment with 2% clindamycin cream or placebo cream in a double-blinded fashion. At all visits vaginal smears were air dried on microscopy slides to be stored. The rate of postoperative pelvic infection according to our definition was the main outcome variable, the cure rates of BV and of intermediate flora were secondary outcome variables. RESULTS: Of 1655 enrolled women, 1102 were evaluable for analyses. Fifty-eight women developed signs of post-abortion infection. Preoperative treatment with clindamycin cream significantly (RR: 4.2, 95% C.I. 1.2-15.9) reduced the risk of post-abortion infection among women with abnormal vaginal flora (BV and intermediate flora). Treatment with clindamycin cream in women with normal lactobacilli flora did not demonstrate any difference compared to the non-treatment group. CONCLUSION: Preoperative treatment for at least three days with clindamycin cream significantly reduced the risk for developing signs of post-abortion infection only among women with preoperative abnormal vaginal flora (BV and intermediate flora).

Abortion, Induced↗
PubMed1999

The effect of acupuncture in chronic intractable epilepsy.

We examined the effect of acupuncture on epileptic seizures in humans in a controlled clinical setting. Treatment was administered by two Chinese professors of acupuncture. Effect was measured by change in seizure frequency. Twenty-nine patients with chronic intractable epilepsy completed the study. They were randomized in two groups; 15 were given classical acupuncture and 14 were given sham acupuncture. There was a reduction in seizure frequency in both groups, which did not reach a level of statistical significance. There was also an increase in the number of seizure-free weeks in both groups, which reached a level of significance in the sham group. Thus, we have not been able to prove a beneficial effect of acupuncture in chronic intractable epilepsy.

Acupuncture Points↗
PubMed1998

Electrophysiological localization of brain regions involved in perceptual memory.

Event-related potentials (ERP) were recorded during perceptual discrimination and short-term memory, varying the interstimulus interval (1-10 s) in delayed spatial frequency discrimination. Accuracy of discrimination remained unimpaired across this time interval, but choice reaction times increased. A brain source localization (BESA) model showed that the activity of the parietal and right temporal sources increased with long retention intervals in a sequential activation pattern where a long-latency component of the parietal source specific to the memory condition was observed, the latency of which matched a memory-related increase in choice reaction times in the cognitive task. It is suggested that the temporal sources are involved in encoding and storage of visual information, and the parietal source is involved in memory retrieval.

Electroencephalography↗
PubMed1997

Does physical exercise influence the occurrence of epileptiform EEG discharges in children?

PURPOSE: To determine if, and how, epileptiform EEG discharges in children were influenced by physical exercise. METHODS: Twenty-six children with intractable partial and generalized epilepsy exercised during video-telemetry recording, aiming at exhaustion after approximately 10 min. RESULTS: During the exercise, epileptiform discharges decreased in 20 of 26 children (17 children had at least 25% reduction) and showed a rebound increase after the exercise (17 of 26 children) compared to baseline conditions. This exercise-induced reduction in epileptiform discharges reached statistical significance only in the 16 patients with localization-related epilepsy. Five patients showed an atypical EEG response to exercise with either unchanged or increased epileptiform activity while exercising. As compared to the other patients, these 5 children had experienced frequent clinical seizures during or immediately after exercise in their leisure time. CONCLUSIONS: In the majority of the tested children, epileptiform EEG discharges decreased during exercise. "Exercise-EEG" may be a helpful diagnostic tool to identify patients who are disposed to have exercise-induced seizures.

Adolescent↗