Biomedical subjects

Liisa Metsähonkala

Publications and source records attributed to Liisa Metsähonkala.

12 recordsLinked to original sources

PubMed2006

Strength and mobility of the neck-shoulder region in adolescent headache.

The significance of the musculoskeletal function of the neck-shoulder region in different headache types in children and adolescents is not clear. The purpose of this study was to investigate the association between different types of headache and the strength and mobility of the neck-shoulder region in 13-year-old schoolchildren. A structured questionnaire on headache was sent to all 1,409 children in the sixth grade in the city of Turku. Of the 1,135 (81%) children who completed the questionnaire, a sample from different headache groups was randomly selected for clinical examination. The study consisted of 59 children with migraine, 65 with episodic tension-type headache (TTHA), and 59 headache-free controls. Dynamic muscle strength of the upper extremities (UE endurance), mobility of both shoulders (UE mobility), and the cervical range of motion (CROM) were measured. Girls with episodic TTHA had lower UE endurance of both dominant and nondominant sides than girls in the other study groups. Girls with migraine had lower UE endurance of nondominant side than girls in the control group. In boys, no significant differences were observed. An interesting association between the function of the neck-shoulder region and headache complaints in adolescents was ascertained.

Adolescent↗

PubMed2006

Long-term trends in the incidence of headache in Finnish schoolchildren.

OBJECTIVE: To study changes over time in the incidence of migraine and frequent headache. METHODS: A population-based study on migraine and other headaches in Finnish children starting school at age 7 years in the city of Turku was conducted in 1974, 1992, and 2002. The study design used in each study was virtually identical. The study population included 1927 children in 1974, 1436 children in 1992, and 1066 children in 2002. The corresponding response rates were 90%, 96%, and 81%. RESULTS: An increasing trend in the incidence of migraine was found from 1974 to 2002 in both boys and girls. The incidence rates of migraine with aura increased from 5.2 per 1000 person-years in 1974 to 41.3 per 1000 person-years in 2002. The increase in the rates of migraine without aura was from 14.5 per 1000 person-years in 1974 to 91.9 in 2002. Similarly, a significant increase over time was seen in the incidence of frequent headache from 1974 to 2002 in both boys and girls. CONCLUSIONS: The incidence of childhood migraine and frequent headache has substantially increased over the last 30 years. The increased incidence is alarming and reflects untoward changes in children's lifestyles. Additional studies are needed on causal associations with life changes.

Child↗

PubMed2005

Regression analysis utilizing subjective evaluation of emotional experience in PET studies on emotions.

A methodological study on subject-specific regression analysis (SSRA) exploring the correlation between the neural response and the subjective evaluation of emotional experience in eleven healthy females is presented. The target emotions, i.e., amusement and sadness, were induced using validated film clips, regional cerebral blood flow (rCBF) was measured using positron emission tomography (PET), and the subjective intensity of the emotional experience during the PET scanning was measured using a category ratio (CR-10) scale. Reliability analysis of the rating data indicated that the subjects rated the intensity of their emotional experience fairly consistently on the CR-10 scale (Cronbach alphas 0.70-0.97). A two-phase random-effects analysis was performed to ensure the generalizability and inter-study comparability of the SSRA results. Random-effects SSRAs using Statistical non-Parametric Mapping 99 (SnPM99) showed that rCBF correlated with the self-rated intensity of the emotional experience mainly in the brain regions that were identified in the random-effects subtraction analyses using the same imaging data. Our results give preliminary evidence of a linear association between the neural responses related to amusement and sadness and the self-evaluated intensity of the emotional experience in several regions involved in the emotional response. SSRA utilizing subjective evaluation of emotional experience turned out a feasible and promising method of analysis. It allows versatile exploration of the neurobiology of emotions and the neural correlates of actual and individual emotional experience. Thus, SSRA might be able to catch the idiosyncratic aspects of the emotional response better than traditional subtraction analysis.

Adolescent↗

PubMed2005

Subanesthetic ketamine does not affect 11C-flumazenil binding in humans.

Positron emission tomography (PET) studies suggest that propofol and inhaled anesthetics increase (11)C-flumazenil binding in the living human brain, thus supporting the involvement of gamma-aminobutyric acid type A (GABA(A)) receptors in the mechanism of action of these drugs. Ketamine produces its anesthetic effects primarily by N-methyl-d-aspartate receptor antagonism, but it may also have GABA(A) receptor agonistic properties. By using PET, we studied the cerebral (11)C-flumazenil binding in 10 healthy subjects before and during a subanesthetic racemic ketamine infusion reaching a serum concentration of 350 +/- 42 ng/mL. Ketamine did not affect (11)C-flumazenil binding to GABA(A) receptor in the brain, indicating that this mechanism is of minor importance in the actions of subanesthetic ketamine.

Adult↗

PubMed2004

Increased presynaptic dopamine function in Asperger syndrome.

The etiology of Asperger syndrome is essentially unknown, but abnormality of the dopamine system has been shown in clinically overlapping disorders. The present study was designed to investigate the presynaptic dopamine function in Asperger syndrome. Eight healthy, drug-free males with Asperger syndrome and five healthy male controls were examined with positron emission tomography using 6-[18F]fluoro-L-DOPA ([18F]FDOPA) as a tracer. In the Asperger syndrome group, the [18F]FDOPA influx (Ki) values were increased in the striatum, i.e. in the putamen and caudate nucleus and in the frontal cortex. The results indicate that the dopamine system is affected in subjects with Asperger syndrome. Partially similar results have also been obtained in schizophrenia, suggesting an overlap not only of the clinical features but also of pathogenesis.

Adult↗

PubMed2004

Psychiatric symptoms in children with primary headache.

OBJECTIVE: To examine the association of psychiatric symptoms with migraine and tension-type headache in children. METHOD: A questionnaire completed by 1,135 Finnish children in the sixth grade identified 154 children with migraine, 138 with tension-type headache, and 407 children who were headache-free. Seventy children were randomly selected from each group and evaluated by a structured interview to confirm headache type, resulting in a sample of 59 children with migraine, 65 with tension-type headache, and 59 without headache. The children completed the Children's Depression Inventory, and the parents completed the Child Behavior Checklist and General Functioning scale of the McMaster Family Assessment Device. RESULTS: Children with migraine had significantly higher levels of total, internalizing, and somatic symptoms, as well as social and family problems, than those without headache and had higher levels of somatic symptoms than children with tension-type headache. Children with tension-type headache had significantly higher levels of somatic symptoms and family problems than those without headache. CONCLUSIONS: The association between psychiatric symptoms and headaches shows differences between different headache types. However, a minority of children with migraine or tension-type headache have high levels of psychiatric symptoms.

Adolescent↗

PubMed2004

Sevoflurane and propofol increase 11C-flumazenil binding to gamma-aminobutyric acidA receptors in humans.

Based on in vitro studies and animal data, most anesthetics are supposed to act via gamma-aminobutyric acid type A (GABA(A)) receptors. However, this fundamental characteristic has not been extensively investigated in humans. We studied (11)C-flumazenil binding to GABA(A) receptors during sevoflurane and propofol anesthesia in the living human brain using positron emission tomography (PET). Fourteen healthy male subjects underwent 2 60-min dynamic PET studies with (11)C-labeled flumazenil, awake and during anesthesia. Anesthesia was maintained with 2% end-tidal sevoflurane (n = 7) or propofol at a target plasma concentration of 9.0 +/- 3.0 (mean +/- sd) microg/mL (n = 7). The depth of anesthesia was measured with bispectral index (BIS). Values of regional distribution volumes (DV) of (11)C-flumazenil were calculated in several brain areas using metabolite-corrected arterial plasma curves and a two-compartment model. Separate voxel-based statistical analysis using parametric DV images was performed for detailed visualization. The average BIS index was 35 +/- 6 in the sevoflurane group and 28 +/- 8 in the propofol group (P = 0.02). Sevoflurane increased the DV of (11)C-flumazenil significantly (P < 0.05) in all brain areas studied except the pons and the white matter. In the propofol group the increases were significant (P < 0.05) in the caudatus, putamen, cerebellum, thalamus and the frontal, temporal, and parietal cortices. Furthermore, the DV increases in the frontal, occipital, parietal, and temporal cortical areas and in the putamen were statistically significantly larger in the sevoflurane than in the propofol group. Our findings support the involvement of GABA(A) receptors in the mechanism of action of both anesthetics in humans.

Adult↗

PubMed2004

Externalizing problem behaviors and headache: a follow-up study of adolescent Finnish twins.

OBJECTIVE: To examine the association of teacher- and parent-rated behavior with headache in a prospective follow-up study of adolescent Finnish twins. METHODS: Questionnaire data were collected during 1995-2001 from a nationwide sample of Finnish families of 11-year-old twins who were born 1983-1987 (n = 5393) and again at age of 14. Psychological factors were measured by using parents' and teachers' ratings of a 37-item multidimensional rating instrument at the ages of 11 and 14. RESULTS: At age 11, headache frequency (5 categories) was associated with total scales of externalizing and internalizing problem behaviors and adaptive behaviors, assessed by parents, but only with externalizing problem behaviors assessed by teachers. Results were similar at age 14. The incidence of at least monthly headache between the ages of 11 and 14 years was predicted by externalizing problem behaviors and 2 subscales of adaptive behaviors: constructiveness and poor compliance. In twin pairs discordant for headache, externalizing and internalizing problem behaviors were more common among headache sufferers than among headache-nonsufferers. Headache-discordant monozygotic co-twins confirmed the association of externalizing problem behaviors with headache. CONCLUSIONS: The frequency of adolescents' headache is predicted by psychological factors, especially by externalizing problem behaviors. This seems to be independent of genetic or familial influences on behavior and headache. Behavioral problems may be a sign of worsening of headache or vice versa.

Adolescent↗

PubMed2003

Changes in cerebral blood flow in Asperger syndrome during theory of mind tasks presented by the auditory route.

Lack of theory of mind (ToM) has been considered to be a key feature in Asperger syndrome (AS). The main aim of the present study was to determine whether an exclusively auditory input of ToM stories activated the same brain areas as demonstrated previously using visual stimuli. Eight right-handed otherwise healthy men with AS and eight healthy right-handed male controls participated in a PET activation study using auditory given ToM stories and stories about physical events for induction. Both subjects with AS and controls showed increased activation in the occipitotemporal area bilaterally and in thalamus during ToM tasks. Both groups also showed activation in the medial frontal area during ToM tests.However, this activation was more intensive and extensive in the control group, especially when a more sensitive analysis method was used. As a group, unrelated to the tasks, the AS subjects showed increased activation of the cerebellum. It was concluded that the activation pattern was mainly in agreement with earlier studies using comparable stimuli administered differently. There was no support for a right hemisphere specific dysfunction.

Adult↗

PubMed2003

Effects of sevoflurane, propofol, and adjunct nitrous oxide on regional cerebral blood flow, oxygen consumption, and blood volume in humans.

BACKGROUND: Anesthetic agents, especially volatile anesthetics and nitrous oxide (N2O), are suspected to perturb cerebral homeostasis and vascular reactivity. The authors quantified the effects of sevoflurane and propofol as sole anesthetics and in combination with N2O on regional cerebral blood flow (rCBF), metabolic rate of oxygen (rCMRO2), and blood volume (rCBV) in the living human brain using positron emission tomography. METHODS: 15O-labeled water, oxygen, and carbon monoxide were used as positron emission tomography tracers to determine rCBF, rCMRO2 and rCBV, respectively, in eight healthy male subjects during the awake state (baseline) and at four different anesthetic regimens: (1) sevoflurane alone, (2) sevoflurane plus 70% N2O (S+N), (3) propofol alone, and (4) propofol plus 70% N2O (P+N). Sevoflurane and propofol were titrated to keep a constant hypnotic depth (Bispectral Index 40) throughout anesthesia. End-tidal carbon dioxide was strictly kept at preinduction level. RESULTS: The mean +/- SD end-tidal concentration of sevoflurane was 1.5 +/- 0.3% during sevoflurane alone and 1.2 +/- 0.3% during S+N (P < 0.001). The measured propofol concentration was 3.7 +/- 0.7 microg/ml during propofol alone and 3.5 +/- 0.7 microg/ml during P+N (not significant). Sevoflurane alone decreased rCBF in some (to 73-80% of baseline, P < 0.01), and propofol in all brain structures (to 53-70%, P < 0.001). Only propofol reduced also rCBV (in the cortex and cerebellum to 83-86% of baseline, P < 0.05). Both sevoflurane and propofol similarly reduced rCMRO2 in all brain areas to 56-70% and 50-68% of baseline, respectively (P < 0.05). The adjunct N2O counteracted some of the rCMRO2 and rCBF reductions caused by drugs alone, and especially during S+N, a widespread reduction (P < 0.05 for all cortex and cerebellum vs. awake) in the oxygen extraction fraction was seen. Adding of N2O did not alter the rCBV effects of sevoflurane and propofol alone. CONCLUSIONS: Propofol reduced rCBF and rCMRO2 comparably. Sevoflurane reduced rCBF less than propofol but rCMRO2 to an extent similar to propofol. These reductions in flow and metabolism were partly attenuated by adjunct N2O. S+N especially reduced the oxygen extraction fraction, suggesting disturbed flow-activity coupling in humans at a moderate depth of anesthesia.

Adult↗

PubMed2002

Metabolic characterization of childhood brain tumors: comparison of 18F-fluorodeoxyglucose and 11C-methionine positron emission tomography.

BACKGROUND: Positron emission tomography (PET) scans of primary brain tumors were performed in pediatric patients to examine whether metabolic characteristics could be used as an index of clinical aggressiveness. METHODS: Twenty-seven pediatric patients with untreated primary central nervous system neoplasms were studied with PET scans using 2-[(18)F] fluoro-2-deoxy-D-glucose (FDG) and/or L-[methyl-(11)C] methionine (MET). Metabolic characteristics as assessed with FDG and MET standardized uptake values (SUV) and SUV-to-normal brain ratios were compared with histopathology and selected histochemical features such as proliferation activity (Ki-67(MIB-1)) and apoptotic, vascular, and cell density indices. The median followup time was 43 months. RESULTS: The accumulation of both FDG and MET was significantly higher in high-grade than in low-grade tumors, but a considerable overlap was found. The accumulation of both tracers was associated positively with age. High-grade tumors showed higher proliferative activity and vascularity than the low-grade tumors. In univariate analysis, FDG-PET, MET-PET, and apoptotic index were independent predictors of event-free survival. CONCLUSION: We found that both FDG and MET uptake in pediatric brain tumors are associated with malignancy grade. However, no clear limits of SUVs and SUV-to-normal brain ratios can be set between low-grade and high-grade tumors, which makes the assessment of malignancy grade using metabolic imaging with PET scan difficult in individual cases. Although FDG-PET and MET-PET do not compensate for histopathologic evaluation, they may give valuable additional information especially if invasive procedures to obtain histopathologic samples are not feasible.

Adolescent↗

PubMed2002

Effects of surgical levels of propofol and sevoflurane anesthesia on cerebral blood flow in healthy subjects studied with positron emission tomography.

BACKGROUND: The authors report a positron emission tomography (PET) study on humans with parallel exploration of the dose-dependent effects of an intravenous (propofol) and a volatile (sevoflurane) anesthetic agent on regional cerebral blood flow (rCBF) using quantitative and relative (Statistical Parametric Mapping [SPM]) analysis. METHODS: Using H(2)(15)O, rCBF was assessed in 16 healthy (American Society of Anesthesiologists [ASA] physical status I) volunteers awake and at three escalating drug concentrations: 1, 1.5, and 2 MAC/EC(50), or specifically, at either 2, 3, and 4% end-tidal sevoflurane (n = 8), or 6, 9, and 12 microg/ml plasma concentration of propofol (n = 8). Rocuronium was used for muscle relaxation. RESULTS: Both drugs decreased the bispectral index and blood pressure dose-dependently. Comparison between adjacent levels showed that sevoflurane initially (0 vs. 1 MAC) reduced absolute rCBF by 36-53% in all areas, then (1 vs. 1.5 MAC) increased rCBF in the frontal cortex, thalamus, and cerebellum (7-16%), and finally (1.5 vs. 2 MAC) caused a dual effect with a 23% frontal reduction and a 38% cerebellar increase. In the propofol group, flow was also initially reduced by 62-70%, with minor further effects. In the SPM analysis of the "awake to 1 MAC/EC(50)" step, both anesthetic agents reduced relative rCBF in the cuneus, precuneus, posterior limbic system, and the thalamus or midbrain; additionally, propofol reduced relative rCBF in the parietal and frontal cortices. CONCLUSIONS: Both anesthetic agents caused a global reduction of rCBF (propofol > sevoflurane) at the 1 MAC/EC(50) level. The effect was maintained at higher propofol concentrations, whereas 2 MAC sevoflurane caused noticeable flow redistribution. Despite the marked global changes, SPM analysis enabled detailed localization of regions with the greatest relative decreases.

Adult↗