Ozone alters the chemical signal required for plant - insect pollination: The case of the Mediterranean fig tree and its specific pollinator

Tropospheric ozone (O3) is likely to affect the chemical signal emitted by flowers to attract their pollinators through its effects on the emission of volatile organic compounds (VOCs) and its high reactivity with these compounds in the atmosphere. We investigated these possible effects using a plant-pollinator interaction where the VOCs responsible for pollinator attraction are known and which is commonly exposed to high O3 concentration episodes: the Mediterranean fig tree (Ficus carica) and its unique pollinator, the fig wasp (Blastophaga psenes). In controlled conditions, we exposed fig trees bearing receptive figs to a high-O3 episode (5 h) of 200 ppb and analyzed VOC emission. In addition, we investigated the chemical reactions occurring in the atmosphere between O3 and pollinator-attractive VOCs using real-time monitoring. Finally, we tested the response of fig wasps to the chemical signal when exposed to increasing O3 mixing ratios (0, 40, 80, 120 and 200 ppb). The exposure of the fig tree to high O3 levels induced a significant decrease in leaf stomatal conductance, a limited change in the emission by receptive figs of VOCs not involved in pollinator attraction, but a major change in the relative abundances of the compounds among pollinator-attractive VOCs in O3-enriched atmosphere. Fig VOCs reacted with O3 in the atmosphere even at the lowest level tested (40 ppb) and the resulting changes in VOC composition significantly disrupted the attraction of the specific pollinator. These results strongly suggest that current O3 episodes are probably already affecting the interaction between the fig tree and its specific pollinator.

Predicting ablation zones with multislice volumetric 2-D magnetic resonance thermal imaging

BACKGROUND

High-intensity focused ultrasound (HIFU) serves as a noninvasive stereotactic system for the ablation of brain metastases; however, treatments are limited to simple geometries and energy delivery is limited by the high acoustic attenuation of the calvarium. Minimally-invasive magnetic resonance-guided robotically-assisted (MRgRA) needle-based therapeutic ultrasound (NBTU) using multislice volumetric 2-D magnetic resonance thermal imaging (MRTI) overcomes these limitations and has potential to produce less collateral tissue damage than current methods.

OBJECTIVE

To correlate multislice volumetric 2-D MRTI volumes with histologically confirmed regions of tissue damage in MRgRA NBTU.

METHODS

Seven swine underwent a total of 8 frontal MRgRA NBTU lesions. MRTI ablation volumes were compared to histologic tissue damage on brain sections stained with 2,3,5-triphenyltetrazolium chloride (TTC). Bland-Altman analyses and correlation trends were used to compare MRTI and TTC ablation volumes.

RESULTS

Data from the initial and third swine's ablations were excluded due to sub-optimal tissue staining. For the remaining ablations (n = 6), the limits of agreement between the MRTI and histologic volumes ranged from -0.149 cm³ to 0.252 cm³ with a mean difference of 0.052 ± 0.042 cm³ (11.1%). There was a high correlation between the MRTI and histology volumes (r² = 0.831) with a strong linear relationship (r = 0.868).

CONCLUSION

We used a volumetric MRTI technique to accurately track thermal changes during MRgRA NBTU in preparation for human trials. Improved volumetric coverage with MRTI enhanced our delivery of therapy and has far-reaching implications for focused ultrasound in the broader clinical setting.

Insights into the Intraspecific Variability of the above and Belowground Emissions of Volatile Organic Compounds in Tomato

The in-vivo monitoring of volatile organic compound (VOC) emissions is a potential non-invasive tool in plant protection, especially in greenhouse cultivation. We studied VOC production from above and belowground organs of the eight parents of the Multi-Parent Advanced Generation Intercross population (MAGIC) tomato population, which exhibits a high genetic variability, in order to obtain more insight into the variability of constitutive VOC emissions from tomato plants under stress-free conditions. Foliage emissions were composed of terpenes, the majority of which were also stored in the leaves. Foliage emissions were very low, partly light-dependent, and differed significantly among genotypes, both in quantity and quality. Soil with roots emitted VOCs at similar, though more variable, rates than foliage. Soil emissions were characterized by terpenes, oxygenated alkanes, and alkenes and phenolic compounds, only a few of which were found in root extracts at low concentrations. Correlation analyses revealed that several VOCs emitted from foliage or soil are jointly regulated and that above and belowground sources are partially interconnected. With respect to VOC monitoring in tomato crops, our results underline that genetic variability, light-dependent de-novo synthesis, and belowground sources are factors to be considered for successful use in crop monitoring.

Plant Secondary Compounds in Soil and Their Role in Belowground Species Interactions

Knowledge of the effect of plant secondary compounds (PSCs) on belowground interactions in the more diffuse community of species living outside the rhizosphere is sparse compared with what we know about how PSCs affect aboveground interactions. We illustrate here that PSCs from foliar tissue, root exudates, and leaf litter effectively influence such belowground plant-plant, plant-microorganism, and plant-soil invertebrate interactions. Climatic factors can induce PSC production and select for different plant chemical types. Therefore, climate change can alter both quantitative and qualitative PSC production, and how these compounds move in the soil. This can change the soil chemical environment, with cascading effects on both the ecology and evolution of belowground species interactions and, ultimately, soil functioning.

Insect Odorscapes: From Plant Volatiles to Natural Olfactory Scenes

Olfaction is an essential sensory modality for insects and their olfactory environment is mostly made up of plant-emitted volatiles. The terrestrial vegetation produces an amazing diversity of volatile compounds, which are then transported, mixed, and degraded in the atmosphere. Each insect species expresses a set of olfactory receptors that bind part of the volatile compounds present in its habitat. Insect odorscapes are thus defined as species-specific olfactory spaces, dependent on the local habitat, and dynamic in time. Manipulations of pest-insect odorscapes are a promising approach to answer the strong demand for pesticide-free plant-protection strategies. Moreover, understanding their olfactory environment becomes a major concern in the context of global change and environmental stresses to insect populations. A considerable amount of information is available on the identity of volatiles mediating biotic interactions that involve insects. However, in the large body of research devoted to understanding how insects use olfaction to locate resources, an integrative vision of the olfactory environment has rarely been reached. This article aims to better apprehend the nature of the insect odorscape and its importance to insect behavioral ecology by reviewing the literature specific to different disciplines from plant ecophysiology to insect neuroethology. First, we discuss the determinants of odorscape composition, from the production of volatiles by plants (section "Plant Metabolism and Volatile Emissions") to their filtering during detection by the olfactory system of insects (section "Insect Olfaction: How Volatile Plant Compounds Are Encoded and Integrated by the Olfactory System"). We then summarize the physical and chemical processes by which volatile chemicals distribute in space (section "Transportation of Volatile Plant Compounds and Spatial Aspects of the Odorscape") and time (section "Temporal Aspects: The Dynamics of the Odorscape") in the atmosphere. The following sections consider the ecological importance of background odors in odorscapes and how insects adapt to their olfactory environment. Habitat provides an odor background and a sensory context that modulate the responses of insects to pheromones and other olfactory signals (section "Ecological Importance of Odorscapes"). In addition, insects do not respond inflexibly to single elements in their odorscape but integrate several components of their environment (section "Plasticity and Adaptation to Complex and Variable Odorscapes"). We finally discuss existing methods of odorscape manipulation for sustainable pest insect control and potential future developments in the context of agroecology (section "Odorscapes in Plant Protection and Agroecology").

Compartment specific chiral pinene emissions identified in a Maritime pine forest

To track unknown sources and sinks of volatile organic compounds (VOCs) inside forest canopies we measured diel cycles of VOC exchanges in a temperate maritime forest at the branch, stem and ground level with special focus on the chiral signatures of pinenes. All compartments released day and night α- and β-pinene as major compounds. In addition, strong light dependent emissions of ocimene and linalool from branches occurred during hot summer days. In all compartments the overall emission strength of pinenes varied from day to day spanning 1 to 2 orders of magnitude. The highest pinene emissions from ground and stem were observed during high moisture conditions. Despite this variability stem emissions consistently expressed a different chiral composition than branch emissions, the former containing a much larger fraction of (-)-enantiomers than the latter. Pinene emissions from dead needle litter and soil were mostly enriched in (-)-enantiomers, while the chiral signatures of the ambient air inside the forest showed mostly intermediate levels compared to the emission signatures. These findings suggest that different organ-specific pinene producing enzymes exist in Maritime pine, and indicate that emissions from ground and stem compartments essentially contribute to the canopy VOC flux. Overall the results open new perspectives to explore chirality as a possible marker to recognize shifts in the contributions of different VOC sources present within forest ecosystems and to explain observed temporal changes in the chiral signature of pinenes in the atmosphere.

Differences in peripheral myelin antigen-specific T cell responses and T memory subsets in atypical versus typical CIDP

Background

Chronic inflammatory demyelinating polyneuropathy (CIDP) is presented by a large heterogeneity of clinical phenotypes. Around 50% of patients suffer from typical CIDP and show better therapy response than atypical variants. The goal of our study was to search for cellular immunological differences in typical versus atypical CIDP in comparison to controls.

Methods

We evaluated 26 (9 typical, 17 atypical) patients with mainly active-unstable CIDP using clinical and immunological examinations (enzyme-linked immunospot assay ELISPOT, fluorescence-activated cell sorting FACS) in comparison to 28 healthy, age-matched controls (HC). Typical or atypical CIDP measurements were compared with HC using Kruskal-Wallis test.

Results

Atypical CIDP patients showed increased frequencies of T cell subsets, especially CD4+ effector memory T cells (TEM) and CD4+ central memory T cells (TCM) as well as a tendency of higher T cell responses against the peripheral myelin antigens of PMP-22, P2, P0 and MBP peptides compared to typical CIDP. Searching for novel auto-antigens, we found that T cell responses against P0 180-199 as well as MBP 82-100 were significantly elevated in atypical CIDP patients vs. HC.

Conclusions

Our results indicate differences in underlying T cell responses between atypical and typical CIDP characterized by a higher peripheral myelin antigen-specific T cell responses as well as a specific altered CD4+ memory compartment in atypical CIDP. Larger multi-center studies study are warranted in order to characterize T cell auto-reactivity in atypical CIDP subgroups in order to establish immunological markers as a diagnostic tool.

Water shortage and quality of fleshy fruits--making the most of the unavoidable

Extreme climatic events, including drought, are predicted to increase in intensity, frequency, and geographic extent as a consequence of global climate change. In general, to grow crops successfully in the future, growers will need to adapt to less available water and to take better advantage of the positive effects of drought. Fortunately, there are positive effects associated with drought. Drought stimulates the secondary metabolism, thereby potentially increasing plant defences and the concentrations of compounds involved in plant quality, particularly taste and health benefits. The role of drought on the production of secondary metabolites is of paramount importance for fruit crops. However, to manage crops effectively under conditions of limited water supply, for example by applying deficit irrigation, growers must consider not only the impact of drought on productivity but also on how plants manage the primary and secondary metabolisms. This question is obviously complex because during water deficit, trade-offs among productivity, defence, and quality depend upon the intensity, duration, and repetition of events of water deficit. The stage of plant development during the period of water deficit is also crucial, as are the effects of other stressors. In addition, growers must rely on relevant indicators of water status, i.e. parameters involved in the relevant metabolic processes, including those affecting quality. Although many reports on the effects of drought on plant function and crop productivity have been published, these issues have not been reviewed thus far. Here, we provide an up-to-date review of current knowledge of the effects of different forms of drought on fruit quality relative to the primary and secondary metabolisms and their interactions. We also review conventional and less conventional indicators of water status that could be used for monitoring purposes, such as volatile compounds. We focus on fruit crops owing to the importance of secondary metabolism in fruit quality and the importance of fruits in the human diet. The issue of defence is also briefly discussed.

First long-term experience with the orphan drug rufinamide in children with myoclonic-astatic epilepsy (Doose syndrome)

INTRODUCTION

We evaluated the long-term efficacy and tolerability of the orphan drug rufinamide (RUF) in children with pharmacoresistant myoclonic-astatic epilepsy (MAE, Doose syndrome).

METHODS

This was a retrospective European multicenter study on eight patients who had started an intention-to-treat trial of RUF between July 2007 and June 2010. Clinical information was collected via questionnaire. Responder rate was defined as reduction of seizure frequency ≥50% in comparison to four weeks before starting RUF. Maximum follow-up was eighteen months.

RESULTS

Responder rates were 7/8 patients after 3 months, 6/8 patients after 6 months and 5/8 patients after 12 months. RUF seemed particularly effective in the prevention of myoclonic-astatic seizures (comparable with drop attacks in Lennox-Gastaut-Syndrome, for which RUF is particularly effective). Some loss of efficacy was noticed in the long-term observation. Side-effects occurred in two patients. Seizure aggravation was not observed.

CONCLUSION

RUF seems to be a promising therapeutic option in children with MAE. Further studies are warranted to confirm these first observations.

The diversification of terpene emissions in Mediterranean oaks: lessons from a study of Quercus suber, Quercus canariensis and its hybrid Quercus afares

Interspecific gene flow is common in oaks. In the Mediterranean, this process produced geographical differentiations and new species, which may have contributed to the diversification of the production of volatile terpenes in the oak species of this region. The endemic North African deciduous oak Quercus afares (Pomel) is considered to be a stabilized hybrid between the evergreen Quercus suber (L.) and the deciduous Quercus canariensis (Willd.), presumably being monoterpene and isoprene emitters, respectively. In a common garden experiment, we examined the terpene emission capacities, terpene synthase (TPS) activities and nuclear genetic markers in 52 trees of these three oak species. All but one of the Q. suber and Q. canariensis trees were found to be genetically pure, whereas most Q. afares trees possessed a mixed genotype with a predominance of Q. suber alleles. Analysis of the foliar terpene emissions and TPS activities revealed that all the Q. canariensis trees strongly produced isoprene while all the Q. suber trees were strong monoterpene producers. Quercus afares trees produced monoterpenes as well but at more variable and significantly lower rates, and with a monoterpene pattern different than that observed in Q. suber. Among 17 individuals tested, one Q. afares tree emitted only an insignificant amount of terpenes. No mixed isoprene/monoterpene emitter was detected. Our results suggest that the capacity and pattern of volatile terpene production in Algerian Q. afares populations have strongly diverged from those of its parental species and became quantitatively and qualitatively reduced, including the complete suppression of isoprene production.

Low long-term efficacy and tolerability of add-on rufinamide in patients with Dravet syndrome

In this retrospective European multicenter study we evaluated the efficacy and tolerability of rufinamide in patients with Dravet syndrome and refractory seizures. Twenty patients were included; in 16 patients a SCN1A mutation was detected. The responder rate after 6 months was 20%, and after 34 months, 5%. The retention rate was 45% after 6 months and 5% after 34 months. Rufinamide treatment was stopped because of aggravation of seizures (30%), no effect (45%), and side effects (10%). The efficacy and long-term retention rate were low in our patients with Dravet syndrome and refractory seizures, far lower than in patients with Lennox-Gastaut syndrome; one-third of our patients experienced seizure aggravation. Therefore, rufinamide does not seem to be a suitable option for long-term treatment in patients with Dravet syndrome.

Direct and indirect impact of sewage sludge compost spreading on Quercus coccifera monoterpene emissions in a Mediterranean shrubland

Monoterpene emissions of Quercus coccifera L. were repeatedly measured during the two years following the spreading of a sewage sludge compost at rates of 50 Mg ha⁻¹ and 100 Mg ha⁻¹, in a twelve-year-old post-fire Mediterranean shrubland. We also monitored the patterns of change in soil and leaf nutrient content, plant water potential, chlorophyll fluorescence, and plant growth. Compost spreading resulted in weak changes in leaf nutrient content and plant water status, and therefore no significant effect on monoterpene emissions at leaf scale, except during one summer sampling, probably related to advanced leaf maturity with the highest compost rate. However, compost increased plant growth, particularly the leaf biomass. The results suggest that compost spreading in Mediterranean shrublands has no strong short-term effect on Q. coccifera monoterpene emissions at leaf level, but may indirectly increase volatile organic compound fluxes at the stand scale, which may contribute to regional ozone pollution.

Refractory focal epilepsy in a patient with methylmalonic aciduria: case report on positive and long-lasting effect of rufinamide

We report on a 5-year-old boy with methylmalonic aciduria, an autosomal recessive inborn error of metabolism leading to accumulation of methylmalonic-CoA and thereby causing intoxication with leading symptoms of hyperammonaemia and metabolic acidosis. Hyperammonemia itself causes brain oedema. In our patient, this led to a vast metabolic stroke of the left hemisphere and subsequent pharmacoresistant epilepsy. Guided by his main seizures--drop attacks--the orphan drug rufinamide (RUF) was introduced as "off-label use" and led to freedom of drop attacks and tonic-clonic seizures over a period of 14 months as well as normalisation of the electroencephalogramm. Only once during an episode of fever and diarrhoea with reduced level of RUF did some provoked seizures with focal complex semiology for the time period of infection occur. In the 16 months follow-up, the patient also improved in his development, showing a more stable gait with the hemiparesis and understanding more complex sentences.

Determinants of survival in patients with brain metastases from cutaneous melanoma

Background:

This retrospective study aimed to identify prognostic factors in patients with brain metastases from cutaneous melanoma.

Methods:

In all, 265 patients under regular screening according to valid national surveillance guidelines were included in the study. Kaplan–Meier analyses were performed to estimate and to compare overall survival. Cox modeling was used to identify independent determinants of the overall survival, which were used in explorative classification and regression tree analysis to define meaningful prognostic groups.

Results:

In total, 55.5% of our patients presented with two or less brain metastases, 82.6% had concurrent extracranial metastasis and 64% were asymptomatic and diagnosed during surveillance scans. In all, 36.7% were candidates for local treatment (neurosurgery or stereotactic radiosurgery (SRS)). The median overall survival of the entire collective was 5.0 months (95% confidence interval: 4.3–5.7). Favourable independent prognostic factors were: normal pre-treatment level of serum lactate dehydrogenase (P<0.001), administered therapy (neurosurgery or SRS vs other, P=0.002), number of brain metastases (single vs multiple, P=0.032) and presence of bone metastasis (false vs true, P=0.044). Three prognostic groups with significantly different overall survival were identified. Candidates for local treatment (group I) had the longer median survival (9 months). Remaining patients could be further classified in two groups on the basis of serum lactate dehydrogenase.

Conclusion:

Applied treatment and serum lactate dehydrogenase levels were independent predictors of survival of patients with brain metastases from cutaneous melanoma. Patients receiving local therapy have overall survival comparable with general stage IV melanoma patients.

BVOCs and global change

Biogenic volatile organic compounds (BVOCs) produced by plants are involved in plant growth, reproduction and defense. They are emitted from vegetation into the atmosphere and have significant effects on other organisms and on atmospheric chemistry and physics. Here, we review current knowledge on the alteration of BVOC emission rates due to climate and global changes: warming, drought, land use changes, high atmospheric CO(2) concentrations, ozone and enhanced UV radiation. These alterations are very variable depending on the doses, timing, BVOC and species, but in overall terms are likely to increase BVOC emissions. These changed emissions can lead to unforeseeable consequences for the biosphere structure and functioning, and can disturb biosphere feedback on atmospheric chemistry and climate with a direction and intensity that warrants in-depth investigation.

Do patients with congenital hemiparesis and ipsilateral corticospinal projections respond differently to constraint-induced movement therapy?

This study investigates whether the type of corticospinal reorganization (identified by transcranial magnetic stimulation) influences the efficacy of constraint-induced movement therapy (CIMT). Nine patients (five males, four females; mean age 16y [SD 6y 5mo], range 11-30y) controlling their paretic hand via ipsilateral corticospinal projections from the contralesional hemisphere and seven patients (three males, four females; mean age 17y [SD 7y], range 10-30y) with preserved crossed corticospinal projections from the affected hemisphere to the paretic hand underwent 12 consecutive days of CIMT. A Wolf motor function test applied before and after CIMT revealed a significant improvement in the quality of upper extremity movements in both groups. Only in patients with preserved crossed projections, however, was this amelioration accompanied by a significant gain in speed, whereas patients with ipsilateral projections tended to show speed reduction. These data, although preliminary, suggest that patients with congenital hemiparesis and ipsilateral corticospinal projections respond differently to CIMT.

(Re-)organization of basal ganglia in congenital hemiparesis with ipsilateral cortico-spinal projections

In congenital hemiparesis after pre- or perinatally acquired unilateral brain lesions, many patients control their paretic hand via ipsilateral cortico-spinal projections from the contralesional hemisphere. In order to clarify the pattern of basal ganglia activation in case of such a shift of the primary motor cortical representation (M1) of the paretic hand to the contralesional hemisphere, fMRI was performed in eight patients with congenital hemiparesis due to unilateral periventricular white matter lesions and ipsilateral corticospinal projections to the paretic hand (as determined by focal transcranial magnetic stimulation). FMRI during active movements of the paretic hand yielded basal ganglia activation in the ipsilateral (=contralesional) hemisphere, but not in the contralateral (lesioned) hemisphere. Thus, (re-)organization in congenital hemiparesis with ipsilateral cortico-spinal projections includes, in addition to the ipsilateral primary motor cortex (M1), also the ipsilateral basal ganglia - in contrast to the primary somatosensory cortex (S1), which is typically preserved in the affected hemisphere.

Reorganization of the cerebro-cerebellar network of language production in patients with congenital left-hemispheric brain lesions

Patients with congenital lesions of the left cerebral hemisphere may reorganize language functions into the right hemisphere. In these patients, language production is represented homotopically to the left-hemispheric language areas. We studied cerebellar activation in five patients with congenital lesions of the left cerebral hemisphere to assess if the language network is reorganized completely in these patients, i.e. including also cerebellar language functions. As compared to a group of controls matched for age, sex, and verbal IQ, the patients recruited an area not in the right but in the left cerebellar hemisphere. The extent of laterality of the cerebellar activation correlated significantly with the laterality of the frontal activation. We suggest that the developing brain reacts to early focal lesions in the left hemisphere with a mirror-image organization of the entire cerebro-cerebellar network engaged in speech production.

Volatile organic compound emission from holm oak infested by gypsy moth larvae: evidence for distinct responses in damaged and undamaged leaves

Foliage of Quercus ilex L. (holm oak), a widespread Mediterranean species, constitutively emits large quantities of a complex genotype-dependent mixture of volatile organic compounds (VOCs). During a mass outbreak of gypsy moth (Lymantria dispar L.) in southern France, we examined the effects of gypsy moth feeding on VOC production from whole apices and single leaves of Q. ilex. Feeding induced the emission of new VOCs at rates up to 240 ng m(-2) s(-1) (16% of the total VOC release), which mainly consisted of sesquiterpenes, a homoterpene and a monoterpene alcohol. The new compounds were emitted after a delay of several hours following infestation and their production declined rapidly when caterpillars were removed. Undamaged leaves of infested trees emitted new VOCs, but with a different composition to those of damaged leaves and at lower rates. Neither caterpillars nor caterpillar excrement released VOCs. Emission of constitutive VOCs by undamaged leaves of infested trees temporary increased by up to 30%, whereas, in damaged leaves, they remained stable and decreased after some days when necrotic spots occurred around the feeding sites. In continuous light and at constant temperature, emissions of new VOCs showed a marked diurnal cycle, whereas those of constitutive VOCs did not. The results suggest that induced VOCs make a significant contribution to the atmospheric VOC load and may mediate trophic interactions. The observed differential local and systemic responses in composition, quantity and time courses of emissions mirror the existence of several regulation processes triggered by different signaling compounds and elicitors.

Cerebro-muscular and cerebro-cerebral coherence in patients with pre- and perinatally acquired unilateral brain lesions

The cerebral networks involved in motor control were analyzed in four young hemi-paretic patients (21-25 years) with pre- and perinatally acquired brain lesions (3 with left periventricular brain lesions, 1 with left schizencephaly) by means of MEG source coherence analysis. Previous TMS and fMRI studies on the same patients had investigated their residual ability to move the paretic hand by means of a reorganized primary motor cortex (M1) representation in the contralesional hemisphere. The purpose of this study is to identify the effects of such a cerebral reorganization and the related dynamic aspects which allow the patients to move the paretic arm. Patients underwent a pinch grip task (1-N isometric contraction) using their paretic and non-paretic hands in alternation. MEG signals were recorded using a whole-head 151-channel magnetoencephalograph. EMG was simultaneously recorded as a reference for coherence calculations. 3D coherence mapping was performed in the beta frequency range (14-30 Hz). This approach confirmed the relocation of motor functions from the lesioned (left) to the contralesional (right) hemisphere. In case of left, non-paretic pinch grip, coherent activity originated from contralateral (right) M1 exclusively. In the case of right (paretic) grip, coherent activity in ipsilateral M1 as well as significant coherence of ipsilateral cerebellum with both muscle activity and M1 itself was detected in 3 out of 4 subjects. As expected, the patient with no cerebellar involvement during paretic hand contraction showed the worst motor performance in the grip task. Coupling direction analysis demonstrated that throughout pinch grip the coupling direction goes from M1 to cerebellum. The present study verified the assumption that the intact hemisphere takes over motor control from the paretic (ipsilateral) hand in the presence of early unilateral brain lesion. Moreover, the role of cerebellum in motor deficit compensation and its close interaction with ipsilateral primary motor cortex was studied in detail.

Cortical neuromodulation by constraint-induced movement therapy in congenital hemiparesis: an FMRI study

OBJECTIVE

The aim of this study was to assess neuromodulative effects of CIMT in congenital hemiparesis.

PATIENTS AND METHODS

Ten patients (age range: 10-30 years) with congenital hemiparesis due to unilateral cortico-subcortical infarctions in the middle cerebral artery territory, and with preserved cortico-spinal projections from the affected hemisphere to the paretic hand, were included. After a twelve-day period of constraint-induced movement therapy (CIMT), all showed a significant improvement of paretic hand function. Immediately before and after therapy, functional MRI during active and passive hand movements was performed to monitor cortical activation.

RESULTS

Four patients showed consistent increases in cortical activation during movements of the paretic hand in the primary sensorimotor cortex of the affected hemisphere. Of the remaining six patients, three showed similar changes, but these results were potentially contaminated by an improved task performance after therapy. No significant alteration in activation was observed in two patients, and one showed movement artifacts.

CONCLUSIONS

Even a short period of CIMT can induce changes of cortical activation in congenital hemiparesis. In our sample, increases in fMRI activation were consistently observed in the primary sensorimotor cortex of the affected hemisphere. Thus, the potential for neuromodulation is preserved in the affected hemisphere after early brain lesions.