Ramping down a clinical 3 T scanner: a journey into MRI and MRS at 0.75 T.

Object: Lower-field MR is reemerging as a viable, potentially cost-effective alternative to high-field MR, thanks to advances in hardware, sequence design, and reconstruction over the past decades. Evaluation of lower field strengths, however, is limited by the availability of lower-field systems on the market and their considerable procurement costs. In this work, we demonstrate a low-cost, temporary alternative to purchasing a dedicated lower-field MR system.

Temporarily Out of Order: Temporal Perspective Taking in Language in Children With Autism Spectrum Disorder.

Clinical reports suggest that children with autism spectrum disorder (ASD) struggle with time perception, but few studies have investigated this. This is the first study to examine these children's understanding of and . These temporal conjunctions have been argued to require additional cognitive effort when conjoining two events in a clause order that is incongruent with their order in time.

Children with autism spectrum disorder show pronoun reversals in interpretation.

Pronoun reversals, saying you when meaning I, in children with autism spectrum disorder (ASD) are generally viewed as manifesting in early development and speech production only. This study investigates pronoun reversals in later development (age 6-12) in interpretation in 48 Dutch-speaking children with ASD and 43 typically developing (TD) peers. We contrasted children's interpretation of I and you in indirect and direct speech reports, with the latter type requiring an additional perspective shift.

A high-performance gradient insert for rapid and short-T imaging at full duty cycle.

Purpose: The goal of this study was to devise a gradient system for MRI in humans that reconciles cutting-edge gradient strength with rapid switching and brings up the duty cycle to 100% at full continuous amplitude. Aiming to advance neuroimaging and short-T techniques, the hardware design focused on the head and the extremities as target anatomies.

Methods: A boundary element method with minimization of power dissipation and stored magnetic energy was used to design anatomy-targeted gradient coils with maximally relaxed geometry constraints.

Individualised prediction model of seizure recurrence and long-term outcomes after withdrawal of antiepileptic drugs in seizure-free patients: a systematic review and individual participant data meta-analysis.

Background: People with epilepsy who became seizure-free while taking antiepileptic drugs might consider discontinuing their medication, with the possibility of increased quality of life because of the elimination of adverse events. The risk with this action, however, is seizure recurrence. The objectives of our study were to identify predictors of seizure recurrence and long-term seizure outcomes and to produce nomograms for estimation of individualised outcomes.

Cross-linguistic patterns in the acquisition of quantifiers.

Learners of most languages are faced with the task of acquiring words to talk about number and quantity. Much is known about the order of acquisition of number words as well as the cognitive and perceptual systems and cultural practices that shape it. Substantially less is known about the acquisition of quantifiers.

Installation of the 1.5 T MRI accelerator next to clinical accelerators: impact of the fringe field.

In the UMC Utrecht a prototype MRI accelerator has been installed to investigate the feasibility of real-time, MRI guided radiotherapy. The system consists of a 6 MV Elekta (Crawley, UK) accelerator and a 1.5 T Philips (Best, The Netherlands) MRI system.

Integrating a 1.5 T MRI scanner with a 6 MV accelerator: proof of concept.

At the UMC Utrecht, The Netherlands, we have constructed a prototype MRI accelerator. The prototype is a modified 6 MV Elekta (Crawley, UK) accelerator next to a modified 1.5 T Philips Achieva (Best, The Netherlands) MRI system.

MRI/linac integration.

Purpose/objectives: In radiotherapy the healthy tissue involvement still poses serious dose limitations. This results in sub-optimal tumour dose and complications. Daily image guided radiotherapy (IGRT) is the key development in radiation oncology to solve this problem.

Eight-channel transmit/receive body MRI coil at 3T.

Multichannel transmit magnetic resonance imaging (MR) systems have the potential to compensate for signal-intensity variations occurring at higher field strengths due to wave propagation effects in tissue. Methods such as RF shimming and local excitation in combination with parallel transmission can be applied to compensate for these effects. Moreover, parallel transmission can be applied to ease the excitation of arbitrarily shaped magnetization patterns.

A multicenter, randomized clinical study to evaluate the effect on cognitive function of topiramate compared with valproate as add-on therapy to carbamazepine in patients with partial-onset seizures.

Purpose: This study compares the cognitive effects of topiramate (TPM) with those of valproate (VPA) using efficacious doses of each drug when used as adjunctive therapy to carbamazepine (CBZ). A key question of the study is to what extent a more gradual introduction of TPM improves tolerability and prevents cognitive impairment.

Methods: The study is a multicenter, randomized, observer-blinded, parallel-group clinical trial with VPA or TPM given as first-line add-on therapy to steady-state treatment with CBZ.

[Antiepileptics].

Despite introduction of new antiepileptic drugs the established drugs phenytoin, carbamazepine and valproate still provide the treatment of choice in most forms of epilepsy, being efficacious in approximately two-thirds of all newly referred patients. In 20-60% of patients resistant to treatment with the older drugs, a 50% reduction of seizure frequency can be achieved by adding ethosuximide, clobazam, vigabatrine, oxcarbazepine, lamotrigine, felbamate, tiagabine or topiramate to the classic treatment. The majority of the new drugs are free of the problematic enzyme induction of the older compounds, making monotherapy as well as combination therapy much easier.

Prospective study of the prevalence of Alzheimer-type dementia in institutionalized individuals with Down syndrome.

Institutionalized patients with Down syndrome (n = 307) were monitored for 5 to 10 years prospectively to determine prevalence of Alzheimer-type dementia. Clinical signs, cognitive functioning, and EEGs were assessed. When possible, postmortem neuropathological examinations were conducted.

Use of electroencephalography to detect Alzheimer's disease in Down's syndrome.

We studied the role of electroencephalography (EEG) in the diagnosis of Alzheimer-type dementia in patients with Down's syndrome. 197 patients with Down's syndrome were monitored for 5 to 8 years. Aspects of cognitive functioning were assessed twice yearly.

Effect of epilepsy, seizures and epileptiform EEG discharges on cognitive function.

Patients with an established diagnosis of epilepsy were included in three groups on the basis of the absence (Group 2) or presence (Group 3) of epileptiform EEG discharges or subtle seizures (Group 4) during the cognitive assessment procedure. A separate age-matched non-epileptic control group (Group 1) was formed. Twenty-five patients were included in each of the four groups.

Withdrawal of antiepileptic drugs (AEDs) in seizure-free patients, risk factors for relapse with special attention for the EEG.

When a patient has remained free from seizures for several years while taking antiepileptic drugs (AED) the question arises whether or not the medication can be withdrawn. Therefore it would be desirable to be able to identify reliably those patients who will remain seizure-free without treatment. Numerous variables might be of prognostic importance but our knowledge about the significance of demographic, genetic, aetiological, pathophysiological and treatment-related factors remains extremely poor.

Effect of sabeluzole (R 58,735) on memory functions in patients with epilepsy.

Sabeluzole, a new benzothiazol derivative, has shown positive effects on memory function in animals and in normal volunteers. The present study reports the results of sabeluzole, in memory-impaired patients with localization-related (partial) epilepsy. A randomized, double-blind placebo-controlled parallel-group design was used.

Gamma-vinyl GABA (vigabatrin) and mood disturbances.

We explored factors that may predispose patients to adverse mood effects during treatment with vigabatrin (gamma-vinyl GABA; VGB): mood disorders before VGB treatment, type of epilepsy, seizure type and seizure frequency, type and number of comedication, and VGB dose. The clinical relevance of such a study is that it may help identify circumstances in which VGB should be administered with caution. Seventy-three patients (40 males, 33 females), all with refractory epilepsies, who received VGB as add-on therapy, were assessed by the Amsterdamse Stemmingslyst (ASL), a mood-rating scale, before the start of treatment, and demographic and clinical data were recorded.

Cognitive side-effects of phenytoin compared with carbamazepine in patients with localization-related epilepsy.

In continuation of an earlier study of our group (Neurology, 43 (1) (1993) 41-51), we present the results of an investigation of the adverse effects of carbamazepine versus phenytoin on cognitive function. Two groups of twenty-five patients are compared in an open, parallel group and non-randomized clinical investigation: a group of patients on carbamazepine (CBZ) monotherapy versus a group of similar size on phenytoin (PHT) monotherapy. The two groups do not show significant differences on variables that could confound the comparison of drug-specific adverse effects: age, gender, intelligence, type of epilepsy, seizure type, seizure frequency, EEG focus and age at onset of the epilepsy.

Home EEG and video monitoring in epilepsy: first experiences.

In an out-patient epilepsy clinic methods were developed for mobile epilepsy diagnosis and treatment. One of the diagnostic facilities is long-term EEG/video monitoring at home. Method and first results are presented together with a case report of an 8-year-old boy with persistent seizures.

Memory complaints, memory disorders and focus localization in patients with partial epilepsy.

Our study aimed at analysing effects of epileptic foci on memory function in patients with partial epilepsy. Twenty-eight patients with spontaneous memory complaints and psychometrically established memory disorders were assessed by 21-channel electroencephalography recorded both during cognitive testing and during 99mTc-HMPAO single photon emission computed tomography (SPECT). Computed tomography (CT) was performed on the same day.

Focus localization in patients with partial epilepsy with 99Tcm-HMPAO SPECT under continuous surface EEG monitoring.

Our study was aimed at determining the validity of 99Tcm-HMPAO single photon emission computed tomography (SPECT) in the localization of the epileptogenic focus by correlating this diagnostic method with other auxiliary investigations such as surface EEG and X-ray transmission computed tomography (CT). Twenty-eight patients with partial epilepsy and spontaneous memory complaints were assessed with a 21-channel EEG recorded during psychometric evaluation of the memory complaints and with a 12-channel EEG during 99Tcm-HMPAO SPECT. No significant agreement was observed for total focus localization by the two EEGs, CT or SPECT.