Multidomain intervention for the prevention of cognitive decline after stroke - a pooled patient-level data analysis

Background and purpose

The aim of this pooled patient‐level data analysis was to test if multidomain interventions, addressing several modifiable vascular risk factors simultaneously, are more effective than usual post‐stroke care for the prevention of cognitive decline after stroke.

Methods

This pooled patient‐level data analysis included two randomized controlled trials using a multidomain approach to target vascular risk factors in stroke patients and cognition as primary outcome. Changes from baseline to 12 months in the trail making test (TMT)‐A, TMT‐B and 10‐words test were analysed using stepwise backward linear mixed models with study as random factor. Two analyses were based on the intention‐to‐treat (ITT) principle using different imputation approaches and one was based on complete cases.

Results

Data from 322 patients (157 assigned to multidomain intervention and 165 to standard care) were analysed. Differences between randomization groups for TMT‐A scores were found in one ITT model (P = 0.014) and approached significance in the second ITT model (P = 0.087) and for complete cases (P = 0.091). No significant intervention effects were found for any of the other cognitive variables.

Conclusion

We found indications that multidomain interventions compared with standard care can improve the scores in TMT‐A at 1 year after stroke but not those for TMT‐B or the 10‐words test. These results have to be interpreted with caution due to the small number of patients.

The changing panorama of cerebral palsy in Sweden. X. Prevalence and origin in the birth-year period 1999-2002

AIM

The aim of the study was to describe the prevalence and origin of cerebral palsy (CP), which is the tenth report from the western Swedish study.

METHODS

A population-based study covering 85,737 live births in the area in 1999-2002. Birth characteristics and neuroimaging findings were recorded, prevalence of CP was calculated and aetiology was analysed.

RESULTS

CP was found in 186 children. The crude prevalence was 2.18 per 1000 live births. The gestational age-specific prevalence for <28 gestational weeks was 55.6 per 1000 live births, whereas it was 43.7 for 28-31 weeks, 6.1 for 32-36 weeks and 1.43 per 1000 for >36 weeks. There was a female majority among children born at term and a male predominance in children born preterm. Hemiplegia accounted for 38%, diplegia for 32%, tetraplegia for 7%, whereas 17% had dyskinetic CP and 5% ataxia. Neuroimaging showed white-matter lesions in 31% and cortical/subcortical lesions in 29%. The aetiology was considered to be prenatal in 36%, peri/neonatal in 42%, whereas it remained unclassified in 21%.

CONCLUSION

The decrease in CP prevalence observed since the 1980s had ceased. An increase in children born at term and in dyskinetic CP was found. In children born before 28 weeks of gestation, the prevalence decreased significantly. White-matter and cortical/subcortical lesions dominated on neuroimaging.

Dyskinetic cerebral palsy in Europe: trends in prevalence and severity

OBJECTIVE

To describe the trends for and severity of dyskinetic cerebral palsy in a European collaborative study between cerebral palsy registers, the Surveillance of Cerebral Palsy in Europe (SCPE).

METHODS

The prevalence of dyskinetic cerebral palsy was calculated in children born in 1976-1996. Walking ability, accompanying impairments and perinatal adverse events were analysed.

RESULTS

578 children had dyskinetic cerebral palsy, of whom 70% were born at term. The prevalence per 1000 live births increased from 0.08 in the 1970s to 0.14 in the 1990s. For the 386 children (70%) with a birth weight of > or =2500 g, the increase was significant (0.05 to 0.12). There was a concurrent decrease in neonatal mortality among children with a birth weight of > or =2500 g. Overall, 16% of the children walked without aids, 24% with aids and 59% needed a wheelchair. Severe learning disability was present in 52%, epilepsy in 51% and severe visual and hearing impairment in 19% and 6%, respectively. Accompanying impairments increased with motor severity. In children born in 1991-1996, perinatal adverse events, that is an Apgar score of <5 at 5 min and convulsions before 72 h, had occurred more frequently compared with children with bilateral spastic cerebral palsy (BSCP, n = 4746). Children with dyskinetic cerebral palsy had more severe cognitive and motor impairments than children with BSCP.

CONCLUSIONS

The prevalence of dyskinetic cerebral palsy appears to have increased in children with a normal birth weight. They have frequently experienced perinatal adverse events. Most children have a severe motor impairment and several accompanying impairments.

Cerebral palsy and restricted growth status at birth: population-based case-control study

OBJECTIVE

To evaluate the association between growth status at birth and subsequent development of cerebral palsy in preterm and term infants.

DESIGN

Population-based case-controlled study.

SETTING

Cerebral palsy register in Western Sweden. Subjects Cohort of 334 singletons born between 1983 and 1990, with cerebral palsy diagnosed from age 4, and 668 singletons matched for gestation, gender and delivery unit.

METHOD

Growth status at birth was determined using small for gestational age (SGA) categories, with customised birthweight percentiles (SGAcust) based on the Swedish population.

MAIN OUTCOME MEASURES

Proportion of babies that were SGAcust, comparing cases and controls in three gestational age categories: early preterm (24-33 weeks), late preterm (34-36 weeks) and term (37+ weeks).

RESULTS

Of the 334 children with cerebral palsy, 87 (26.6%) were born early preterm, 27 (8.1%) late preterm and 218 (66%) at term. Children who had been born at term were more likely to have been SGA <1st customised percentile (SGAcust1) than their matched controls (OR 6.6, 95% CI 2.3-18.6). In contrast, children with cerebral palsy born preterm were not more likely to have been SGAcust1 (OR 0.9, 95% CI 0.4-1.9), and this applied to early preterm as well as late preterm births. For less severely small babies (SGA between 1st and 5th customised percentiles), the association with cerebral palsy remained significant for term births (OR 5.2, 95% CI 2.7-10.1) but was again not significant for preterm births.

CONCLUSIONS

Term singletons with severely SGA birthweights had a five- to seven-fold risk of developing cerebral palsy compared with gestational age-matched infants with birthweights within normal limits. For children born preterm, SGA was not more likely to be present in cases than in controls. These findings support the concept of cerebral palsy as a multifactorial condition and highlight the importance of antenatal surveillance of fetal growth.

Dyskinetic cerebral palsy: a population-based study of children born between 1991 and 1998

The aim of this study was to describe the epidemiology, aetiology, and clinical findings in dyskinetic cerebral palsy (CP)in a population-based follow-up study of children born between 1991 and 1998. Age range at ascertainment was 4 to 8 years and prevalence was 0.27 per 1000 live-births. Forty-eight children were examined (27 males, 21 females; mean age 9y, range 5-13y). Thirty-nine had dystonic CP and nine a choreo-athetotic subtype. Primitive reflexes were present in 43 children and spasticity in 33. Gross Motor Function Classification System levels were: Level IV, n= 10 and Level V, n= 28. The rate of learning disability (n= 35) and epilepsy (n= 30) increased with the severity of the motor disability. Thirty-eight children had anarthria. Peri- or neonatal adverse events had been present in 34 of 42 children born at >or=34 weeks' gestation. Motor impairment was most severe in this group. Placental abruption or uterine rupture had occurred in 8 participants and 19 of the 42 near-term/term children required assisted ventilation, compared with 1% and 12% respectively in other CP types. Neuroimaging in 39 children born at >or=34 weeks revealed isolated, late third trimester lesions in 24 and a combination of early and late third trimester lesions in seven. Dyskinetic CP is the dominant type of CP found in term-born, appropriate-for-gestational-age children with severe impairments who have frequently experienced adverse perinatal events.

Disabilities in children with hydrocephalus--a population-based study of children aged between four and twelve years

BACKGROUND

Children with hydrocephalus represent a heterogeneous group with various aetiologies and disability profiles. Over the years, continuous changes in medical care have occurred and updated information is important.

AIM

To study disability profiles in aetiological and gestational age subgroups of children with hydrocephalus in the 1990s.

METHOD

A population-based series of 114 children, 70 with infantile hydrocephalus and 44 with hydrocephalus associated with MMC. All the children were examined clinically and interviewed.

RESULTS

Learning disabilities were present in 47 % of children with infantile hydrocephalus compared with 16 % of those with MMC, cerebral palsy in 27 % vs. zero and epilepsy in 34 vs. 11 %. Even after excluding children with cerebral palsy, the majority had abnormal tendon reflexes and scored below the 5th centile on a motor test. Hydrocephalus overt at birth, low gestational age, a perinatal origin, enlarged ventricles at follow-up and several shunt revisions all indicated risk factors for a poor outcome.

CONCLUSIONS

In spite of major advances in management, hydrocephalus in children still has a considerable impact on outcome. Being born very preterm and with a hydrocephalus that is already overt at birth involve the highest risk of a poor outcome. Apart from major impairments, the children frequently have definite motor problems.

Gross and fine motor function and accompanying impairments in cerebral palsy

The aim of this study was to describe and analyze gross and fine motor function and accompanying neurological impairments in children with cerebral palsy (CP) born between 1991 and 1998 in western Sweden. A population-based study comprised 411 children with a diagnosis of CP ascertained at 4 to 8 years of age. Gross Motor Function Classification System (GMFCS) levels were documented in 367 children (205 males, 162 females). Bimanual Fine Motor Function (BFMF) classification levels of 345 of the children and information on learning disability, epilepsy, visual and hearing impairments, and hydrocephalus from 353 children were obtained. For spastic CP, a new classification according to the Surveillance of Cerebral Palsy in Europe of uni- and bilateral spastic CP was applied. GMFCS was distributed at Level I in 32%, Level II in 29%, Level III in 8%, Level IV in 15%, and Level V in 16%. The corresponding percentages for BFMF were 30.7%, 31.6%, 12.2%, 11.9%, and 13.6% respectively. Learning disability was present in 40%, epilepsy in 33%, and severe visual impairment in 19% of the children. Motor function differed between CP types. More severe GMFCS levels correlated with larger proportions of accompanying impairments and, in children born at term, to the presence of adverse peri/neonatal events in the form of intracranial haemorrhage/stroke, cerebral infection, and hypoxic-ischaemic encephalopathy. GMFCS Level I correlated positively to increasing gestational age. We conclude that the classification of CP should be based on CP type and motor function, as the two combine to produce an indicator of total impairment load.

The changing panorama of cerebral palsy in Sweden. IX. Prevalence and origin in the birth-year period 1995-1998

AIM

This is the ninth report from the western-Swedish study of the prevalence and origin of cerebral palsy.

METHODS

A population-based study covering the 88 371 live births in the area in 1995-1998. Birth characteristics, neuroimaging findings and risk factors in children with cerebral palsy were recorded, prevalence was calculated, and aetiology was analysed.

RESULTS

The study comprised 170 children with cerebral palsy, i.e. a prevalence of 1.92 per 1000 live births. Excluding eight post-neonatally derived cases, the gestational age-specific prevalences were 77 per 1000 for children born before 28 wk of gestation, 40 for children born at 28-31 wk, 7 for children born at 32-36 wk and 1.1 for children born after 36 wk of gestation. Spastic hemiplegia, diplegia and tetraplegia accounted for 38%, 35% and 6%, respectively, dyskinetic cerebral palsy for 15%, and ataxia for 6%. For the first time, hemiplegia was now most common, due to the decline in preterm diplegia. There was a further increase in full-term dyskinetic cerebral palsy. The origin of cerebral palsy in children born at term was considered to be prenatal in 38%, peri/neonatal in 35% and unclassifiable in 27%, while in children born preterm it was 17%, 49% and 33%, respectively.

CONCLUSION

The decreasing trend from the period 1991-1994 continued, both in children born at term and especially in those born preterm. However, the increase in dyskinetic cerebral palsy in children born at term was a matter of concern. In this group, a perinatal hypoxic ischaemic encephalopathy had been present in 71%.

Cerebral palsy in preterm infants: a population-based case-control study of antenatal and intrapartal risk factors

Previous studies have indicated that foetomaternal infection increases the risk of spastic cerebral palsy (CP) in term infants, whereas this association appears to be less evident in preterm infants. The aim of this study was to analyse infection-related risk factors for spastic CP in preterm infants. A population-based series of preterm infants with spastic CP, 91 very preterm (<32 wk) and 57 moderately preterm (32-36 wk), born in 1983-90, were included and matched with a control group (n = 296). In total, 154 maternal, antenatal and intrapartal variables were retrieved from obstetric records. In the entire group, histological chorioamnionitis/pyelonephritis, long interval between rupture of membranes and birth, admission-delivery interval <4 h and Apgar scores of <7 at 1 min just significantly increased the risk of CP, and Apgar scores of <7 at 5 and 10 min were strongly associated with an increased risk. Abruptio placentae, Apgar scores <7 at 1 min and pathological non-stress test (reason for delivery) were significant risk factors of CP only in the moderately preterm and hemiplegic groups, whereas fever before delivery was a significant risk factor in the very preterm and spastic diplegic groups. Antibiotics during pregnancy was associated with CP only in the spastic diplegic CP group.

CONCLUSION

Antenatal infections marginally increased the risk of CP. Low Apgar score and abruptio placentae were associated with CP, especially in moderately preterm infants with hemiplegic CP.

In vivo multiple spin echoes imaging of trabecular bone on a clinical 1.5 T MR scanner

In vivo multiple spin echoes (MSE) images of bone marrow in trabecular bone were obtained for the first time on a clinical 1.5 T scanner. Despite of a reduced sensitivity of the MSE trabecular bone images with respect to the cerebral matter ones, it is possible to observe some features in the MSE trabecular bone images that may be useful in the diagnosis of osteopenic states. Two different CRAZED-type MSE imaging sequences based on spin-echo and EPI imaging modalities were applied in phantom and in vivo. Preliminary experimental results indicate that EPI imaging readout seems to conceal the MSE contrast correlated with pore dimension in porous media. However it is still possible to detect anisotropy effects related to the bone structure in MSE-EPI images. Some strategies are suggested to optimize the quality of MSE trabecular bone images.

Head growth in Rett syndrome

The longitudinal development of head growth was investigated in girls with Rett syndrome (RS). Growth retardation was expressed in standard deviation (SD) scores. In classic types, the mean head circumference fell successively to 2 SD scores below the norm at the age of 4 years. After the age of 8 it stabilized close to -3 SD scores. In forme fruste variants, the mean head circumference was within normal limits; however, it was significantly below the norm, -0.8 SD scores. In girls with classic RS, head growth had decelerated by less than 1 SD score in 20% of the girls at the age of 6 years and in 10% at the age of 12 years. In forme fruste variants only a small decline in head growth occurred. Head growth decline may thus be very small in classic RS and is usually not present at all in forme fruste variants. In the future, it should, therefore, neither be regarded as a necessary diagnostic criterion for classic RS, nor as a valid one for forme fruste variants.

PET with 11C-deuterium-deprenyl and 18F-FDG in focal epilepsy

OBJECTIVES

This study compares positron emission tomography (PET) using 11C-deuterium-deprenyl (DED) with PET using 18F-fluorodeoxyglucose(18F-FDG) for examining epileptogenic regions in patients with focal epilepsy.

MATERIAL AND METHODS

Twenty-three patients undergoing evaluation for epilepsy surgery were subjected to PET with DED. Fourteen patients had mesial temporal lobe epilepsy (TLE) and 9 patients had seizures of neocortical origin. In addition, 6 healthy control subjects were examined. Pixel-by-pixel analysis was used to generate graphical images of tracer distribution volume (intercept) and the accumulation rate (slope). Asymmetries with respect to relative intercept and slope were compared in patients with temporal lobe epilepsy (TLE), in patients with extra-temporal lobe epilepsy (exTLE), and in the control subjects. The results were compared with 18F-FDG-PET.

RESULTS

Among the patients with TLE, significant differences between the epileptogenic and the contralateral lobe were found with DED intercept and FDG-uptake. No significant differences were found with DED slope. The exTLE and the control groups showed no significant differences between sides or lobes.

CONCLUSIONS

This study indicates that PET with 11C-deuterium-deprenyl is a useful method for identifying TLE and is equivalent to PET with 18F-FDG in this sense. The method has little localizing value in seizures originating from neocortical structures.

Cerebral hemodynamics in asymptomatic patients with internal carotid artery occlusion: a dynamic susceptibility contrast MR and transcranial Doppler study

BACKGROUND AND PURPOSE

Perfusion imaging with dynamic susceptibility contrast MR imaging (DSC-MRI) has been used to evaluate hemodynamic status in patients with symptomatic occlusive cerebrovascular disease. The aim of the present study was to determine the hemodynamic changes occurring in asymptomatic patients with unilateral internal carotid artery (ICA) occlusion by use of DSC-MRI with transcranial Doppler (TCD) measurement of the breath-holding index (BHI).

METHODS

Nine patients with asymptomatic unilateral ICA occlusion underwent DSC-MRI and TCD examination. One patient was excluded from final analysis because of severe movement artifacts. On a separate workstation, regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and regional mean time to peak (rMTT) were calculated on the basis of signal decay rate during the passage of gadolinium bolus through the sampled volume in the territory of the middle cerebral artery. TCD-BHI was calculated in all patients. Six healthy subjects underwent the same MR protocol as the patients.

RESULTS

Compared with control subjects, patients with unilateral ICA occlusions had hemodynamic changes in the ipsilateral hemisphere: rCBF was significantly lower than in controls (P <.01), and r MTT was significantly increased in both white (WM) and gray matter (GM) in the affected side (WM: P <.01; GM: P <.05). No statistically significant difference in rCBV was found in the group of patients (occluded versus contralateral, P <.1) or between the patient and control groups (occluded side versus controls, P <.1). The correlation of rCBV and BHI showed a strong relation of the two variables, showing a decrease of the latter when the former increased.

CONCLUSION

DSC-MRI is a valuable tool for measuring hemodynamic changes in the presence of carotid disease with hemodynamic impairment. In our opinion, hemodynamic changes and efficiency of collateral pathways can be evaluated in occlusive carotid disease by using paired measurement of BHI and DSC-MRI. In the patient group, MR-determined rCBV and TCD-determined BHI showed a significant inverse correlation, suggesting similar significance of the two indices.

Epilepsy in a representative series of Rett syndrome

In a representative series of 53 females with Rett syndrome (RS), aged 5-55 y, a history of epilepsy was present in 50 (94%), 45 of whom had 5-y active epilepsy. Compared with severe mental retardation in general, the median age of seizure onset was significantly later (4 vs 0.8 y) and partial complex seizures were more frequent (54% vs 23%). Neonatal seizures had occurred in only one and infantile spasms in none compared with 26% and 12%. After teenage, the severity of epilepsy tended to decrease, i.e. lower seizure frequency and relatively more partial seizures. The rate of being seizure-free for 1 y was 8% after 10 y and 40% after 27 y of epilepsy duration. Frequent seizures were associated with smaller head circumference.

CONCLUSION

This epilepsy profile could fit in with present-day knowledge of RS as a form of dendrito-synaptogenic developmental failure with mainly late postnatal consequences, as well as being a relatively stationary condition in adulthood.

Correlation between ICIDH handicap code and Gross Motor Function Classification System in children with cerebral palsy

The aim of this study was to apply the International Classification of Impairments, Disabilities and Handicap (ICIDH; WHO 1980) parallel to the Gross Motor Function Classification System (GMFCS; Palisano et al. 1997) in a population-based series of children with cerebral palsy (CP). Of the 116 children studied, birth characteristics, data on gross motor function, and level of handicap at 5 to 6 years of age, were retrospectively collected from medical records and documentation made by rehabilitation team members. Low handicap scores and mild levels of gross motor disability were present in children with hemiplegic CP, moderate scores in children with diplegic CP, simple ataxia, and athetotic CP, and high scores in children with dystonic CP and tetraplegic CP. A significant correlation was found between high handicap scores as well as high levels on the GMFCS and the presence of learning disability, epilepsy, and obvious aetiology of CP. A strong correlation was found between the handicap code and the GMFCS, the strongest concerning the dimension of mobility (r = 0.95,p<0.0001). A striking similarity in the grading of disability was present between the ICIDH handicap code and the GMFCS. The GMFCS is considerably less time-consuming and can be evaluated retrospectively. The handicap code requires more detailed information and is more useful for a comprehensive profile of the child.

Serial proton MR spectroscopy of contrast-enhancing multiple sclerosis plaques: absolute metabolic values over 2 years during a clinical pharmacological study

BACKGROUND AND PURPOSE

The time courses of total creatine (Cr), N-acetylaspartate (NAA), choline (Cho), and myo-inositol have not previously been investigated in the follow-up of contrast-enhancing multiple sclerosis (MS) plaques. Therefore, over a period of 2 years, we compared the absolute concentrations of these metabolites between patients treated with a placebo or 15 +/- deoxyspergualin (DSG) and between clinical groups with relapsing-remitting or secondary-progressive MS.

METHODS

Sixteen patients, recruited from a pharmacological study of DSG, and 11 healthy control subjects were investigated by a stimulated-echo acquisition mode sequence (TR/TE = 3000/20). The selected volume initially contained a contrast-enhancing plaque, which was followed up for a period of 2 years.

RESULTS

In contrast-enhancing plaques, Cho was significantly elevated and showed a significant reduction after both 3 and 12 months. The initially normal Cr significantly increased between 3 and 12 months, and was negatively correlated with plaque volume on T1-weighted MR images. NAA initially showed normal values, a significant decrease at 1 month, and a slow recovery over 2 years. Myo-inositol did not show a clear tendency. The placebo group did not differ from the treated group, nor did the relapsing-remitting group differ from the secondary-progressive group.

CONCLUSION

The contradictory time courses of Cr and NAA show that an absolute quantification in proton MR spectroscopy in MS is necessary to avoid a false interpretation of reduced NAA/Cr ratios. The increase in Cr is probably due to remyelination. The initial dip and later recovery of NAA seem to be related to diminishing edema and remyelination.

The effect of isoniazid on BCG-induced toxicity in patients with superficial bladder cancer

The use of bacillus Calmette-Guérin in the treatment of transitional cell cancer of the bladder has caused concern because of its associated adverse effects. We conducted a randomized prospective, double-blind, multicentre study to determine whether isoniazid prophylaxis could reduce BCG-induced toxicity without compromising its immunotherapeutic effects. Patients (n = 160) with histologically documented urothelial cancer (pTa-T1, pTis, G1-3) were treated with 6 weekly instillations of BCG Connaught strain, 81 mg, administered concomitantly with a 3-day course of isoniazid (300 mg o.d.) or placebo. Side-effects were recorded with each treatment and at follow-up. Of the patients treated with isoniazid, 19% remained free from side-effects, compared with 16% of the placebo group. Local side-effects confined to the bladder were significantly lower among those receiving isoniazid (35% vs. 48%, p < 0.01). Local side-effects together with systemic adverse effects such as fever, nausea or skin rash were experienced by 30% of patients in each arm. There were no differences in tumour recurrence between the two patient groups. Concomitant isoniazid reduces the local, but not the systemic side-effects of topically applied BCG without compromising the antitumour effect on superficial, transitional cell cancer of the bladder during a follow-up period that now exceeds 2 years.

Head growth in Rett syndrome

The longitudinal development of head growth was investigated in girls with Rett syndrome. Measurements were taken retrospectively from different kinds of records. Growth retardation was expressed in standard deviation (SD) scores. In classic types, the mean head circumference fell successively to 2 SD scores below the norm at the age of 4 y. After the age of 8 y it stabilized close to -3 SD scores. The degree of deceleration correlated strongly to the age at which a deceleration of 1 SD score had occurred. In forme fruste variants, the mean head circumference was within normal limits; however, it was significantly below the norm (-0.8 SD scores). Body height deviated to -2 SD scores at the age of 6 y and was highly correlated to decline in head growth. When head growth was related to the severity of motor disability, there was a continuum from almost normal head growth with well-preserved gross motor function and some preserved fine motor function to a marked deceleration in head growth with maximum gross and fine motor disability.

Increased dopamine synthesis rate in medial prefrontal cortex and striatum in schizophrenia indicated by L-(beta-11C) DOPA and PET

BACKGROUND

The aim of the present study was to investigate dopamine synthesis in the brain of drug-free schizophrenic patients, not only in the striatum but also in extrastriatal areas like the prefrontal cortex, brain areas that for a long time has been in focus of interest in the pathophysiology of schizophrenia.

METHODS

PET was performed in 12 drug-free (10 drug-naive) psychotic schizophrenic patients and 10 healthy volunteers matched for age and gender using 11C-labelled L-DOPA as the tracer. The time-radioactivity curve from occipital cortex (located within Brodman area 17 and 18) was used as input function to calculate L-DOPA influx rate, Ki images, that were matched to a common brain atlas. A significant overall increase of the Ki values was found in the schizophrenic group as compared with healthy controls.

RESULTS

In particular, significantly higher Ki were found in the schizophrenic patients compared to the controls in the caudate nucleus, putamen and in parts of medial prefrontal cortex (Brod 24). The Ki value reflect an increased utilization of L-DOPA, presumably due to increased activity of the amino acid decarboxylate enzyme.

CONCLUSIONS

The results indicate that the synthesis of dopamine is elevated within the striatum and parts of medial prefrontal cortex in schizophrenia.

Regulation of dopaminergic activity in early Parkinson's disease

Parkinson's disease (PD) is characterized by an uneven and progressive loss of nigrostriatal dopaminergic neurons. It is hypothesized that the physiological basis for the therapeutic response in early stages of PD is the ability for the partially and unevenly denervated dopaminergic system to restore and normalize dopaminergic influence in functionally segregated subregions of the basal ganglia. To investigate this hypothesis, patients with early and uncomplicated PD were investigated with positron emission tomography by using a two-tracer protocol yielding a measure of dopamine transporter-corrected dopamine synthesis capacity. Compared with controls, patients with PD exhibited a considerable increase in dopamine transporter-corrected dopamine synthesis capacity. The increase showed an inverse dependence on the structural integrity in as much as the highest rate was measured in the most denervated region, the dorsal part of putamen (198% of control value). A therapeutic challenge with antiparkinsonian medication state-dependently decreased dopaminergic activity. Thus, it is demonstrated that dopaminergic degeneration in PD is accompanied by a conspicuous acceleration of presynaptic dopaminergic activity, which is state-dependently down-regulated by dopaminomimetic treatment. It is suggested that homeostatic mechanisms acting to maintain congruity within the dopaminergic system are functionally intact in early PD.

Synthesis and characterization of binding of 5-[76Br]bromo-3-[[2(S)-azetidinyl]methoxy]pyridine, a novel nicotinic acetylcholine receptor ligand, in rat brain

5-[76Br]Bromo-3-[[2(S)-azetidinyl]methoxy]pyridine ([76Br]BAP), a novel nicotinic acetylcholine receptor ligand, was synthesized using [76Br]bromide in an oxidative bromodestannylation of the corresponding trimethylstannyl compound. The radiochemical yield was 25%, and the specific radioactivity was on the order of 1 Ci/micromol. The binding properties of [76Br]BAP were characterized in vitro and in vivo in rat brain, and positron emission tomography (PET) experiments were performed in two rhesus monkeys. In association experiments on membranes of the cortex and thalamus, >90% of maximal specific [76Br]BAP binding was obtained after 60 min. The dissociation half-life of [76Br]BAP was 51 +/- 6 min in cortical membranes and 56 +/- 3 min in thalamic membranes. Saturation experiments with [76Br]BAP revealed one population of binding sites with dissociation constant (K(D)) values of 36 +/- 9 and 30 +/- 9 pM in membranes of cortex and thalamus, respectively. The maximal binding site density (Bmax) values were 90 +/- 17 and 207 +/- 33 fmol/mg in membranes of cortex and thalamus, respectively. Scatchard plots were nonlinear, and the Hill coefficients were <1, suggesting the presence of a lower-affinity binding site. In vitro autoradiography studies showed that binding of [76Br]BAP was high in the thalamus and presubiculum, moderate in the cortex and striatum, and low in the cerebellum and hippocampus. A similar pattern of [76Br]BAP accumulation was observed by ex vivo autoradiography. In vivo, binding of [76Br]BAP in whole rat brain was blocked by preinjection of (S)(-)-nicotine (0.3 mg/kg) by 27, 52, 68, and 91% at survival times of 10, 25, 40, 120, and 300 min, respectively. In a preliminary PET study in rhesus monkeys, the highest [76Br]BAP uptake was found in the thalamus, and radioactivity was displaceable by approximately 60% with cytisine and by 50% with (S)(-)-nicotine. The data of this study indicate that [76Br]BAP is a promising radioligand for the characterization of nicotinic acetylcholine receptors in vivo.

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.

N-[11C]methylspiperone PET, in contrast to [11C]raclopride, fails to detect D2 receptor occupancy by an atypical neuroleptic

The occupancy of the atypical neuroleptic quetiapine (Seroquel) at the D2 dopamine receptor was investigated using the PET tracers [11C]raclopride and N-[11C]methylspiperone in a group of five schizophrenic patients. A steady-state treatment condition was ensured by dosing the patients with 750 mg quetiapine daily during 3 weeks followed by a period of tapering off the dose. For each patient, PET examinations were performed with both tracers at two of the following doses: 750, 450, 300 and/or 150 mg. As control, a group of six healthy untreated volunteers was investigated. The D2 binding potential in the putamen and the caudate nucleus was determined by using an evaluation method based on the method proposed by Patlak and Blasberg. The receptor occupancy was determined by assuming that the group of healthy volunteers is representative of untreated drug-naive schizophrenic patients. While a significant linear trend of increasing occupancy with increasing quetiapine dose (reaching 51% +/- 10% occupancy at the 750 mg dose) was detected with [11C]raclopride (P < 0.01), no such trend was apparent for N-[11C]methylspiperone (P > 0.09, maximal occupancy values were 2% +/- 3%, measured for the group of three patients on 450 mg). The study suggests that N-[11C]methylspiperone cannot be used for the assessment of D2 receptor occupancy induced by quetiapine. The result is discussed in terms of endogenous dopamine, tracer kinetics and equilibrium dissociation constants.

From magnetic resonance spectroscopy to classification of tumors. A review of pattern recognition methods

This article reviews the wealth of different pattern recognition methods that have been used for magnetic resonance spectroscopy (MRS) based tumor classification. The methods have in common that the entire MR spectra is used to develop linear and non-linear classifiers. The following issues are addressed: (i) pre-processing, such as normalization and digitization, (ii) extraction of relevant spectral features by multivariate methods, such as principal component analysis, linear discriminant analysis (LDA), and optimal discriminant vector, and (iii) classification by LDA, cluster analysis and artificial neural networks. Different approaches are compared and discussed in view of practical and theoretical considerations.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

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.

Gross motor disability and head growth in Rett syndrome--a preliminary report

Growth of head circumference was measured in 99 RS girls and compared to gross motor function. The degree of head growth deceleration correlated to the severity of gross motor disability at 12 years of age.

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.

Bilateral spastic cerebral palsy--a comparative study between southwest Germany and western Sweden. II: Epidemiology

Epidemiological data of a collaborative study on children with bilateral spastic cerebral palsy (BSCP) between south-west Germany and western Sweden are reported. The study period covered the birth years 1975 to 1986. Overall, the rate of BSCP increased during the birth year periods 1975-77 and 1978-80, but decreased thereafter. The rise was due to an increase of BSCP in low-birthweight (LBW) children, especially very LBW (VLBW) children. Mortality rates in LBW, and particularly VLBW, children decreased significantly during the whole study period in both countries. The BSCP rate, after the initial increase, showed a decrease during the second half of the study period in LBW children. Results are interpreted in favour of a predominantly prenatal aetiology in normal-birthweight and of a predominantly peri- and neonatal aetiology in LBW children.

Infantile hydrocephalus epidemiology: an indicator of enhanced survival

The epidemiology of infantile hydrocephalus in the birth years 1973-90 was investigated in west Sweden. The study revealed a significant increase in prevalence from 1973-8 and 1979-82 considered due to the enhanced survival of very and extremely preterm infants. The increase did not continue from 1983-90. This could indicate an improved outcome in preterm survivors as the neonatal survival rate continued to increase. The striking predominance of a perinatal/neonatal aetiology in very preterm hydrocephalic infants could be confirmed: 89% born from 1983-90 had suffered a confirmed postpartum intraventricular haemorrhage. In infants born at term, prenatal origins, mainly maldevelopments, dominated. The outcome in very preterm surviving infants with infantile hydrocephalus was poor: 73% had cerebral palsy, 52% epilepsy, 22% severe visual disability, and 55% were mentally retarded. Despite the increased survival resulting in a majority of healthy infants, there is an accumulating cohort of hydrocephalic children.

Bilateral spastic cerebral palsy--a comparative study between south-west Germany and western Sweden. I: Clinical patterns and disabilities

The results of a collaborative study of bilateral spastic cerebral palsy (BSCP) between south-west Germany and western Sweden are reported, comprising 249 children in south-west Germany and 264 children in western Sweden. A severe gross motor disability was present in 65 per cent of the German and 62 per cent of the Swedish children; learning difficulties or mental retardation in 73 and 76 per cent; active epilepsy in 28 and 26 per cent; and severe visual disability in 20 and 19 per cent, respectively. Severe disabilities were especially pronounced in children with normal birthweights, in whom the most severe subtypes of BSCP were also found. Leg-dominated BSCP was the predominant subtype among low-birthweight children, but also occurred in more than half of the normal-birthweight children. The authors conclude that the two series were comparable, and that reliable results between countries can be obtained if clear-cut classifications and definitions are used.