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Biomedical subjects

G Hagberg

Publications and source records attributed to G Hagberg.

At least 37 records · Page 2Linked to original sources
PubMed1998

Infantile hydrocephalus: declining prevalence in preterm infants.

The prevalence and aetiological panorama of infantile hydrocephalus in western Sweden have been followed since the late 1960s. A significant increase in the live birth prevalence of very preterm infants with infantile hydrocephalus was found, from 6.99 per 1000 in the birth year period 1973-78 to 25.37 in 1983-86, and owing to an increased survival of very preterm infants with a high risk of hydrocephalus, secondary to an intraventricular haemorrhage occurring in the perinatal period. In the present study covering the birth years 1991-94, a declining prevalence to 13.69 per 1000 very preterm infants was found. In moderately preterm and term groups, mostly with prenatal aetiologies, the prevalence was unchanged. Outcome in surviving children with infantile hydrocephalus remained essentially the same as in previous studies, indicating that the underlying aetiology is the most decisive factor with respect to ensuing neuroimpairments.

Gestational Age↗
PubMed1998

Intractable epilepsy in a population-based series of mentally retarded children.

PURPOSE: The characteristics of intractable epilepsy were analyzed in a population-based study of active epilepsy in mentally retarded children aged 6-13 years. METHODS: Diagnostic registers, EEG laboratory registers, and registers for the Education of the Subnormal were searched. Medical files were scrutinized. Clinical examinations and interviews with parents and caregivers or both were performed. EEG recordings, computed tomography (CT) and magnetic resonance imaging (MRI) of the CNS were reevaluated. RESULTS: Forty-five percent (44 of 98) of the children with mental retardation (MR) and active epilepsy had intractable seizures, defined as one or more seizures every day or week. The median age at onset was 0.8 years, as compared with 3.0 years for those with controlled epilepsy. Predictive factors for frequent seizures were the number of seizure types, severe MR, status epilepticus (SE) and tonic seizures. Epileptiform EEG activity was present in 91%, and focal activity in 65%. Brain lesions were detected on CT and MRI in 70%, with generalized lesions in 60%. Concurrent focal epileptiform activity and focal brain lesions on CT/MRI were detected in 26%. The percentages and prevalence rates for infantile spasms (IS) and Lennox-Gastaut syndrome (LGS) were 18% (0.25 in 1,000) and 7% (0.06 in 1,000), respectively. One of 8 children with IS had had previous neonatal seizures, 3 had SE and 1 later developed LGS. CONCLUSIONS: Children with MR and intractable epilepsy have a high frequency of severe MR and additional major neuroimpairments. EEG recordings frequently showed focal changes despite generalized lesions in neuroradiology.

Adolescent↗
PubMed1997

Assignment of glial brain tumors in humans by in vivo 1H-magnetic resonance spectroscopy and multidimensional metabolic classification.

This study presents a simple approach for the noninvasive assignment of glial brain tumors according to malignancy by single-voxel proton magnetic resonance spectroscopy at short echo times (TE < or = 50 milliseconds). Based on peak area ratios, a five-dimensional data set was obtained for each investigated subject. This vector was then projected along metabolic coordinates in a two-dimensional metabolic space. These coordinates had been determined in a previous study (Hagberg G et al., 1995, Magn Reson Med 34: 242-252). Tumor assignment was done without any knowledge of histology by comparing the location of the new cases to the features of the previous study. All 11 investigated glioblastomas multiforme, as well as 4 of 5 astrocytomas grade II, could easily be assigned to the groups of high- and low-grade tumors, respectively. Classification was more difficult in the case of a cystic astrocytoma grade II and one astrocytoma grade III. Two spectra measured in normal-appearing matter of glioblastoma patients were not classified as healthy. Using single-voxel proton magnetic resonance spectroscopy at short echo times with the knowledge of a base study, a straightforward, fast, and noninvasive differential diagnosis of glial brain tumors is possible.

Astrocytoma↗
PubMed1996

Proton chemical shift imaging, metabolic maps, and single voxel spectroscopy of glial brain tumors.

Seventeen patients with presumed glial brain tumors were examined with proton chemical shift imaging and single voxel spectroscopy that used different echo times. Metabolite resonances were evaluated by metabolic ratios and absolutely by correcting for coil load and comparison to phantom measurements. Metabolic images were created to visualize the metabolic changes. All patients showed spectra that were different from those measured in healthy control subjects. Spectral changes were also present in normal-appearing matter (NAM) that was distant from lesions. The resonance at 3.55 ppm which is usually assigned to both myo-inositol and glycine, was the only one to allow a discrimination between healthy volunteers, astrocytoma grade II, and glioblastoma multiforme (GBM) (p < 0.02). From the different echo times used we conclude that an increase in this resonance has to be assigned to glycine rather than myo-inositol. This resonance might be used to grade human gliomas more reliably. Total creatine (Cr) decreased more drastically with malignancy than N-acetylated metabolites (NA). This led to a higher NA/Cr ratio in GBM compared to astrocytoma grade II. NA/Cr was thus pseudonormal in GBM due to a change in both nominator and denominator. This study reveals the importance of comparing magnetic resonance spectroscopy data of lesions to spectra measured in identical localizations in healthy control subjects instead of NAM and the importance of quantifying single metabolic peaks instead of creating metabolic ratios in clinical magnetic resonance spectroscopy.

Adult↗
PubMed1996

Non-progressive ataxia: origins, brain pathology and impairments in 78 swedish children.

This population-based study refers to 78 Swedish children with non-progressive ataxia from a total population of 3.1 million inhabitants. Inclusion criteria were ataxic gait without any signs of spasticity, dyssynergia, dysmetria and intention tremor. CT and/or MRI studies were available from 70 patients (90%). Infratentorial pathology was revealed in 27%, and findings were considered normal in 61%. If CT was normal, of recent date and of good quality, MRI did not add any new information. In half of the cases with pathological CT, however, MRI provided new information. The origin was considered prenatal in 45% (familial in 17%), perinatal in 4% and unclassifiable in 51%. 60% were mentally retarded; in the rest, cognitive development was near normal (18%) or normal (22%). Speech development was delayed in 88%, and 58% had visual dysfunction.

Adolescent↗
PubMed1996

Characteristics of seizures in a population-based series of mentally retarded children with active epilepsy.

PURPOSE: The characteristics of seizures were analysed in a population-based study of active epilepsy in 6- to 13-year-old mentally retarded children. METHODS: The search procedure included diagnostic registers, EEG registers, and registers of the Education of the Subnormal. Medical files were scrutinized, and clinical examinations and interviews with parents or caretakers or both were performed. RESULTS: The median age of seizure onset was 1.3 years, 3.1 for children with mild retardation and 0.8 for children with severe retardation. Among the 98 children identified, current seizure groups were partial in 20, generalized in 59, and mixed in 19. The prevailing seizure types were tonic-clonic, myoclonic, atypical absences, and partial complex seizures, present in 42, 33, 23, and 23 children, respectively. A total of 46 children had more than one seizure type. Seizures every day/week occurred in 44 children. There was a constancy between seizure type at onset and later seizure type. Neonatal seizures (n = 25), infantile spasms (n = 12), and status epilepticus (n = 37) occurred independent of one another. Prognostic factors for poor neurologic outcome were early onset of epilepsy, infantile spasms as onset type, and prior neonatal seizures. Children with only partial seizures less frequently had severe mental retardation, cerebral palsy, and visual impairment than those with only generalized seizures. CONCLUSIONS: Epilepsies in children with mental retardation are characterized by severe seizure manifestations. The brain damage giving rise to mental retardation and epilepsy is probably the main factor in terms of seizure outcome.

Adolescent↗
PubMed1996

The changing panorama of cerebral palsy in Sweden. VII. Prevalence and origin in the birth year period 1987-90.

This seventh Swedish population-based cerebral palsy (CP) report comprises 216 children born between 1987 and 1990. The crude live birth prevalence was 2.36 per 1000, indicating a break in the continuous increase since 1970. Excluding 10 postnatally-derived cases, gestational-age specific prevalences were 80 for extremely, 54 for very and 8 for moderately preterms and 1.4 for term children per 1000. Birth weight-specific prevalences were 57 for birth weights < 1000 g, 68 for 1000-1499 g, 14 for 1500-2499 g and 1.4 for > or = 2500 g per 1000. The aetiology was considered prenatal in 8%, peri/neonatal in 54% and unclassifiable in 38% of preterms and 33, 28 and 39% of term children. Hemiplegic, diplegic and tetraplegic syndromes accounted for 22, 66 and 7% of preterms and 44, 29 and 10% of term children. Non-walking, mental retardation, epilepsy, severe visual impairment and infantile hydrocephalus were present in 39, 39, 26, 18 and 23% of preterms; and 38, 44, 36, 14 and 5% of term children, respectively. The entire series of 1408 cases born in 1954-90 revealed three distinct trend eras for preterms, clearly related to changes in perinatal care and shifts in type of CP manifestations.

Cerebral Palsy↗
PubMed1996

The changing panorama of cerebral palsy--bilateral spastic forms in particular.

Our Swedish population-based cerebral palsy (CP) project started 25 years ago and today covers the birth years 1954-1990, with over 1400 CP cases. This large series (1, 2, 3) has opened new perspectives on time trends and aetiological background factors, where two areas of successively increasing knowledge stand out as particularly helpful. One is the growing amount of biological and clinical data from the continuously increasing cohorts of surviving very preterm infants, the other is the rapidly expanding and refined information from neuroimaging. Bilateral spastic CP (BSCP), including spastic and ataxic diplegia, tetraplegia and spastic-dyskinetic CP, is the most prevalent clinical group of CP syndromes, present in around 75% of preterm and 45% of term CP, and has shown the most significant prevalence changes over time. In this presentation we, therefore, focus on BSCP, also analysed in a collaborative study between southwest Germany and western Sweden and recently presented in a series of four papers (4, 5, 6, 7).

Cerebral Palsy↗
PubMed1995

Proton MRS of gadolinium-enhancing MS plaques and metabolic changes in normal-appearing white matter.

Localized short echo time (TE = 20 ms), stimulated echo acquisition mode, and double spin echo (TE = 135 ms) proton spectroscopy were performed in clearly defined, acute Gadolinium (Gd)-enhancing multiple sclerosis (MS) plaques of 22 patients with clinically definite MS. The resonances of N-acetylated metabolites (NA), creatine/phosphocreatine (Cr), choline-containing compounds (Cho), glycine/myo-inositol (Ino), and lactate were evaluated. The ratios of NA/Cr and NA/Cho were significantly decreased, Cho/Cr increased, and Ino/Cr remained unchanged. No marker peaks or elevated lactate levels were found. The measured metabolic changes were practically independent of the relative plaque size within the volume of interest (8 ml). Thus, the spectral changes measured with 1H MRS in acute Gd-enhancing MS plaques originate not only from the lesion as depicted by MRI, but also from the surrounding normal-appearing white matter.

Adult↗
PubMed1995

In vivo proton MR spectroscopy of human gliomas: definition of metabolic coordinates for multi-dimensional classification.

Several multi-dimensional statistical evaluation methods were applied to single-voxel proton MR spectra of glial brain tumors and of healthy volunteers. Metabolic coordinates with histological relevance for future diagnosis were found by which spectra from controls, low-grade tumors, and high-grade tumors were completely separated. Significant differences between low-grade and high-grade glioma patients and controls were found for several metabolic ratios by variance analysis. Cluster analysis both with and without principal component analysis was applied. The outcome of these two approaches depended mainly on the lipid-to-creatine ratio. Two other approaches, discriminant factor analysis and the orthonormal discriminant vector method were then used to find discriminatory metabolic coordinates. It turned out that a linear combination of all evaluable metabolic ratios made it possible to separate the three groups completely. On the basis of these results, a classification method that uses the entire proton MRS spectrum is proposed.

Adult↗
PubMed1995

Bilateral spastic cerebral palsy--a collaborative study between southwest Germany and western Sweden. III: Aetiology.

In this third report from the collaborative study of children with bilateral spastic cerebral palsy born between 1975 and 1986, aetiology was analysed. Evidence for a prenatal aetiology increased with gestational age, whereas evidence for a peri-/neonatal aetiology decreased. The largest subgroup, the leg-dominated subtype, showed the same distribution of aetiology as the total group. A prenatal aetiology was found mainly among term and moderately preterm children with a four-limb-dominated subtype; a peri-/neonatal aetiology among very preterm children with a three- or four-limb-dominated subtype or among term children with a dyskinetic-spastic subtype. The findings support the hypothesis generated from the authors' epidemiological results of a peri-/neonatal aetiology being predominant among preterm, and a prenatal aetiology among term, children with bilateral spastic cerebral palsy.

Cerebral Palsy↗
PubMed1995

Bilateral spastic cerebral palsy--MRI pathology and origin. Analysis from a representative series of 56 cases.

MRI of the brain was performed on 56 children with bilateral spastic cerebral palsy (CP) at a mean age of 10.7 years. Specific pathology was found in 91 per cent; periventricular leukomalacia was present in 42 per cent of term- and 87 per cent of preterm-born children. Parasagittal subcorticocortical injury, multicystic encephalomalacia and basal ganglia lesions were identified in 16 per cent, in all but one associated with severe peri-/neonatal events at term or near term. Maldevelopment comprised 9 per cent, all but one found in term-born children. MRI morphology correlated strikingly with outcome. Periventricular leukomalacia was associated with more severe disability in term- than preterm-born children.

Adolescent↗
PubMed1995

Active epilepsy in mentally retarded children. I. Prevalence and additional neuro-impairments.

A population-based study of active epilepsy was conducted in 6-13-year-old mentally retarded children born between 1975 and 1986. The population at risk comprised 48,873 children. Ninety-eight children were identified, 35 mildly and 63 severely retarded. The prevalence was 2.0 per 1000; 0.7 per 1000 for mildly and 1.3 per 1000 for severely retarded children. Sixty-nine children had at least one additional neuroimpairment. Cerebral palsy was found in 42 children with a majority of spastic/dystonic tetraplegias; visual impairment was present in 24 and autism in 24. Thirty-three children had only a mild or no gross motor disability and mild mental retardation, while 23 had IQs < 20 and a very severe gross motor disability. This study underlines the fact that active epilepsy in mentally retarded children is often associated with additional neuroimpairments, especially a combination of severe cerebral palsy and severe visual impairment.

Adolescent↗
PubMed1995

Active epilepsy in mentally retarded children. II. Etiology and reduced pre- and perinatal optimality.

A population-based study of active epilepsy in mentally retarded children identified 98 children, 6-13 years old. A biopathological origin was established in 66% of mildly and 92% of severely retarded children: a prenatal etiology was considered in 51% and 57%, a perinatal in 9% and 19%, a postnatal in 6% and 16% and an untraceable etiology in 34% and 8%, respectively. Severe mental retardation was more frequent in the peri- and postnatal groups (80% and 83%) than in the prenatal and untraceable groups (67% and 29%). Thirty-four pre- and perinatal optimal items were defined. Children with a prenatal etiology did not differ from controls in any of the periods. Children with a perinatal etiology had, compared with controls, higher proportions of non-optimal items successively increasing through the pre- and perinatal periods showing the accumulation of negative events.

Adolescent↗