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1.
Child Neuropsychol ; 26(1): 100-112, 2020 01.
Article En | MEDLINE | ID: mdl-31111792

Previous studies have evidenced cognitive difficulties across various domains in Type 1 Diabetes Mellitus (T1DM) children, but the implicit memory system has not yet been systematically explored.Taking into account that the interplay between memory and perception may be modulated by the semantic category of the stimuli and their salience, we explored explicit and implicit memory using both object and food stimuli to verify whether for T1DM children there is a feebleness in performing the function of memory as a function of the stimuli used.Eighteen T1DM children and 47 healthy children performed an explicit recognition task in which they were requested to judge whether the presented image had already been shown ("old") or not ("new") and an identification priming task in which they were asked to name new and old pictures presented at nine ascending levels of spatial filtering.Results did not reveal any differences between controls and T1DM children in the explicit memory recognition task, whereas some differences between the two groups were found in the identification priming task. In T1DM children, the priming effect was observed only for food images.The dissociation between implicit and explicit memory observed in children with diabetes seems to be modulated by the category of the stimuli, and these results underscore the relevance of taking into account this variable when exploring cognitive functions.


Diabetes Mellitus, Type 1/complications , Child , Female , Humans , Male
2.
Acta Crystallogr B Struct Sci Cryst Eng Mater ; 75(Pt 2): 127-133, 2019 Apr 01.
Article En | MEDLINE | ID: mdl-32830736

A new (N2H4)WO3 compound has been obtained by mixing WO3 and aqueous hydrazine solution at room temperature for 24 h. The reaction is catalyzed by the presence of lithium. X-ray, synchrotron and neutron diffraction techniques have shown that the material crystallizes in trigonal space group P3221 (No. 154). Chains of distorted WO4 tetrahedra extend along the a axis of the unit cell, linked by a corner-sharing oxygen atom: the N2H4 are in the voids between them. The thermal characterization shows that this new compound is stable up to 220°C, greatly beyond the boiling point of N2H4 (114°C); thus making it a promising candidate for catalysis or trapping applications.

3.
Acta Neurol Scand ; 137(6): 618-622, 2018 Jun.
Article En | MEDLINE | ID: mdl-29624640

Over last fifty years, intravenous (iv) phenytoin (PHT) loading dose has been the treatment of choice for patients with benzodiazepine-resistant convulsive status epilepticus and several guidelines recommended this treatment regimen with simultaneous iv diazepam. Clinical studies have never shown a better efficacy of PHT over other antiepileptic drugs. In addition, iv PHT loading dose is a complex and time-consuming procedure which may expose patients to several risks, such as local cutaneous reactions (purple glove syndrome), severe hypotension and cardiac arrhythmias up to ventricular fibrillation and death, and increased risk of severe allergic reactions. A further disadvantage of PHT is that it is a strong enzymatic inducer and it may make ineffective several drugs that need to be used simultaneously with antiepileptic treatment. In patients with a benzodiazepine-resistant status epilepticus, we suggest iv administration of levetiracetam as soon as possible. If levetiracetam would be ineffective, a further antiepileptic drug among those currently available for iv use (valproate, lacosamide, or phenytoin) can be added before starting third line treatment.


Anticonvulsants/administration & dosage , Phenytoin/administration & dosage , Piracetam/analogs & derivatives , Status Epilepticus/drug therapy , Administration, Cutaneous , Administration, Intravenous , Anticonvulsants/adverse effects , Exanthema/chemically induced , Humans , Infusions, Intravenous , Levetiracetam , Phenytoin/adverse effects , Piracetam/administration & dosage , Piracetam/adverse effects , Status Epilepticus/diagnosis , Treatment Outcome
4.
Acta Psychol (Amst) ; 185: 229-234, 2018 Apr.
Article En | MEDLINE | ID: mdl-29550693

The positivity effect in the elderly consists of an attentional preference for positive information as well as avoidance of negative information. Extant theories predict either that the positivity effect depends on controlled attentional processes (socio-emotional selectivity theory), or on an automatic gating selection mechanism (dynamic integration theory). This study examined the role of automatic and controlled attention in the positivity effect. Two dot-probe tasks (with the duration of the stimuli lasting 100 ms and 500 ms, respectively) were employed to compare the attentional bias of 35 elderly people to that of 35 young adults. The stimuli used were expressive faces displaying neutral, disgusted, fearful, and happy expressions. In comparison to young people, the elderly allocated more attention to happy faces at 100 ms and they tended to avoid fearful faces at 500 ms. The findings are not predicted by either theory taken alone, but support the hypothesis that the positivity effect in the elderly is driven by two different processes: an automatic attention bias toward positive stimuli, and a controlled mechanism that diverts attention away from negative stimuli.


Attention/physiology , Emotions/physiology , Facial Expression , Orientation/physiology , Photic Stimulation/methods , Adult , Aged , Aged, 80 and over , Fear/physiology , Fear/psychology , Female , Humans , Male , Orientation, Spatial/physiology , Reaction Time/physiology , Young Adult
5.
Neuroscience ; 372: 266-272, 2018 02 21.
Article En | MEDLINE | ID: mdl-29337234

Electrophysiological and neuroimaging studies suggest that our actions are initiated by unconscious mental processes long before awareness of intention to act. The time window between the awareness of the intention to move and the movement onset, which normally permits to exert a conscious "veto" on the impending action, is modulated by individual differences in trait impulsivity. In particular, trait impulsive people show a delayed awareness of the intention to act, probably exceeding the "point of no return", after which the action can no longer be inhibited. In order to investigate if individual differences in the "veto" interval might be explained by differences in the readiness potential (RP) dynamics, nineteen healthy participants underwent an impulsivity trait assessment using the Barratt Impulsiveness Scale (BIS-11) and performed a task based on Libet's clock paradigm, during EEG recordings of pre-movement neural activity. We observed a positive relationship between impulsive personality trait and motor system excitability during the preparation of self-initiated movements. In particular, the RP showed an earlier negative rising phase and a greater amplitude, with the increasing of BIS-11 scores. Based on present results, we conclude hypothesizing that trait impulsivity might be characterized by less effective preparatory inhibition mechanisms, which have a fundamental role in the control of behavior.


Brain/physiology , Impulsive Behavior/physiology , Motor Activity/physiology , Personality/physiology , Adult , Electroencephalography , Female , Humans , Male , Neuropsychological Tests , Young Adult
6.
Eur J Neurosci ; 44(7): 2455-2459, 2016 10.
Article En | MEDLINE | ID: mdl-27521184

Deficient voluntary control of behaviour and impulsivity are key aspects of impulse control disorders. The objective of the present study was to evaluate the relationship between behavioural measures of impulsivity and the awareness of voluntary action. Seventy-four healthy volunteers completed the Barratt Impulsiveness Scale (BIS), a questionnaire used to measure impulsive personality traits, and a go/no-go task. Moreover, all participants performed a behavioural task based on the Libet's clock paradigm in which they were requested to report the time of a self-initiated movement (M-judgement) or the time they first feel their intention to move (W-judgement). A positive relationship between the time in which subjects reported the intention to move (W-judgement) and impulsivity measures emerged. Namely, the higher was the score in the attentional and motor impulsivity subscales of the BIS and the number of inhibitory failure responses in the go/no-go task, the lower was the difference between the W-judgement and the actual movement (i.e. the awareness of intention to move was closer to the voluntary movement execution). In contrast, no relationship emerged with M-judgement. The present findings suggest that impulsivity is related to a delayed awareness of voluntary action. We hypothesize that in impulse control disorders, the short interval between conscious intention and actual movement may interfere with processes underlying the conscious 'veto' of the impending action.


Attention/physiology , Awareness/physiology , Impulsive Behavior/physiology , Intention , Movement/physiology , Female , Humans , Judgment/physiology , Male , Neuropsychological Tests , Reaction Time/physiology , Young Adult
7.
Brain Stimul ; 9(4): 574-6, 2016.
Article En | MEDLINE | ID: mdl-27033011

BACKGROUND: Recent neuroimaging data support the hypothesis of a multisensory interplay at low-level sensory-specific cortex. OBJECTIVE: We used an on-line interference approach by rTMS to investigate the role of the left lateral occipital cortex (LOC) in audio-visual (AV) object recognition process. METHODS: Fifteen healthy volunteers performed a visual identification task of degraded pictures presented alone or simultaneously to coherent or non-coherent sounds. Focal 10-Hz rTMS at an intensity of 100% resting motor threshold was delivered simultaneously to the picture. Two blocks of 60 pictures were randomly displayed in two different experimental conditions: rTMS of the left LOC and over Cz. RESULTS: rTMS of the left LOC produced a worsening of the accuracy compared to rTMS over Cz specifically in the coherent AV condition. CONCLUSION: These data support the view that audio-visual interaction effect may occur at early stage of recognition processing.


Auditory Perception/physiology , Occipital Lobe/physiology , Pattern Recognition, Visual/physiology , Psychomotor Performance/physiology , Adult , Female , Humans , Male , Pilot Projects , Transcranial Magnetic Stimulation/methods , Young Adult
8.
Eur J Neurosci ; 42(4): 2051-60, 2015 Aug.
Article En | MEDLINE | ID: mdl-26061279

In healthy subjects (HS), transcranial magnetic stimulation (TMS) applied during 'linguistic' tasks discloses excitability changes in the dominant hemisphere primary motor cortex (M1). We investigated 'linguistic' task-related cortical excitability modulation in patients with adductor-type spasmodic dysphonia (ASD), a speech-related focal dystonia. We studied 10 ASD patients and 10 HS. Speech examination included voice cepstral analysis. We investigated the dominant/non-dominant M1 excitability at baseline, during 'linguistic' (reading aloud/silent reading/producing simple phonation) and 'non-linguistic' tasks (looking at non-letter strings/producing oral movements). Motor evoked potentials (MEPs) were recorded from the contralateral hand muscles. We measured the cortical silent period (CSP) length and tested MEPs in HS and patients performing the 'linguistic' tasks with different voice intensities. We also examined MEPs in HS and ASD during hand-related 'action-verb' observation. Patients were studied under and not-under botulinum neurotoxin-type A (BoNT-A). In HS, TMS over the dominant M1 elicited larger MEPs during 'reading aloud' than during the other 'linguistic'/'non-linguistic' tasks. Conversely, in ASD, TMS over the dominant M1 elicited increased-amplitude MEPs during 'reading aloud' and 'syllabic phonation' tasks. CSP length was shorter in ASD than in HS and remained unchanged in both groups performing 'linguistic'/'non-linguistic' tasks. In HS and ASD, 'linguistic' task-related excitability changes were present regardless of the different voice intensities. During hand-related 'action-verb' observation, MEPs decreased in HS, whereas in ASD they increased. In ASD, BoNT-A improved speech, as demonstrated by cepstral analysis and restored the TMS abnormalities. ASD reflects dominant hemisphere excitability changes related to 'linguistic' tasks; BoNT-A returns these excitability changes to normal.


Dysphonia/pathology , Dysphonia/physiopathology , Evoked Potentials, Motor/physiology , Linguistics , Motor Cortex/physiopathology , Adult , Aged , Analysis of Variance , Botulinum Toxins, Type A/therapeutic use , Case-Control Studies , Dysphonia/drug therapy , Electric Stimulation , Electromyography , Evoked Potentials, Motor/drug effects , Female , Functional Laterality , Hand , Humans , Male , Middle Aged , Neuromuscular Agents/therapeutic use , Reading , Speech , Statistics, Nonparametric , Transcranial Magnetic Stimulation
9.
Neuroscience ; 278: 302-12, 2014 Oct 10.
Article En | MEDLINE | ID: mdl-25168726

In time processing, the role of different cortical areas is still under investigation. Event-related potentials (ERPs) represent valuable indices of neural timing mechanisms in the millisecond-to-second domain. We used an interference approach by repetitive TMS (rTMS) on ERPs and behavioral performance to investigate the role of different cortical areas in processing basic temporal information. Ten healthy volunteers were requested to decide whether time intervals between two tones (S1-S2, probe interval) were shorter (800ms), equal to, or longer (1200ms) than a previously listened 1000-ms interval (target interval) and press different buttons accordingly. This task was performed at the baseline and immediately after a 15-min-long train of 1-Hz rTMS delivered over the supplementary motor area, right posterior parietal cortex, right superior temporal gyrus, or an occipital control area. Task accuracy, reaction time, and ERPs during (contingent negative variation, CNV) and after the presentation of probe intervals were analyzed. At the baseline, CNV amplitude was modulated by the duration of the probe interval. RTMS had no significant effect on behavioral or ERP measures. These preliminary data suggest that stimulated cortical areas are less crucially involved than other brain regions (e.g. subcortical structures) in the explicit discrimination of auditory time intervals in the range of hundreds of milliseconds.


Auditory Perception/physiology , Cerebral Cortex/physiology , Time Perception/physiology , Transcranial Direct Current Stimulation , Adult , Discrimination, Psychological/physiology , Evoked Potentials, Auditory , Female , Humans , Male , Middle Aged , Pilot Projects , Reaction Time , Young Adult
10.
Monaldi Arch Chest Dis ; 79(1): 20-6, 2013 Mar.
Article En | MEDLINE | ID: mdl-23741942

The morbidity and mortality rates attributed to smoking are substantial and cigarette smoke remains the first preventable cause of premature death worldwide. Despite the knowledge of the adverse consequences of smoking, many smokers struggle to quit. Cigarette smoking is the primary cause of chronic obstructive pulmonary disease, and smoking cessation represents the most effective way of stopping its progression. Varenicline is one of the first-line smoking cessation aids recommended in many Clinical Practice Guidelines and its efficacy and safety have been demonstrated in several clinical trials. Varenicline has a unique mechanism of action and clinical trials support its use as an effective and generally well-tolerated therapy. This article reviews the clinical pharmacological trials on smoking cessation published in recent years on varenicline, with particular attention to the outcomes used in the studies. MedLine, the Cochrane database and Embase were evaluated. Almost all the trials have, as a primary endpoint, the abstinence from cigarettes at 9-12 weeks of treatment. Only one study considers lung function spirometric changes as a secondary endpoint. No study has evaluated lung function. This marker could be very important as a way of evaluating, objectively, an improvement in lung function, which correlates also with subjective parameters, as dyspnea and fatigue.


Benzazepines/therapeutic use , Nicotinic Agonists/therapeutic use , Outcome Assessment, Health Care , Quinoxalines/therapeutic use , Smoking Cessation/methods , Benzazepines/adverse effects , Benzazepines/pharmacology , Clinical Trials as Topic , Humans , Lung/drug effects , Lung/physiology , Quinoxalines/adverse effects , Quinoxalines/pharmacology , Smoking/epidemiology , Varenicline
11.
Eur J Neurol ; 20(8): 1204-11, 2013 Aug.
Article En | MEDLINE | ID: mdl-23607817

BACKGROUND AND PURPOSE: To identify adverse events (AEs) significantly associated with perampanel treatment in double-blind clinical studies (RCTs). Serious AEs, study withdrawals due to AEs and dose-effect responses of individual AEs were also investigated. METHODS: All placebo controlled, double-blind RCTs investigating therapeutic effects of oral perampanel were searched. AEs were assessed for their association with perampanel after exclusion of synonyms, rare AEs and non-assessable AEs. Risk difference (RD) was used to evaluate the association of any AE (99% confidence intervals) and withdrawals or serious AEs (95% confidence intervals) with perampanel. RESULTS: Nine RCTs (five in pharmacoresistant epilepsy and four in Parkinson's disease) were included in our study. Almost 4000 patients had been recruited, 2627 of whom were randomized to perampanel and treated with drug doses of 0.5 mg/day (n = 68), 1 mg/day (n = 65), 2 mg/day (n = 753), 4 mg/day (n = 1017), 8 mg/day (n = 431) or 12 mg/day (n = 293). Serious AEs were not significantly associated with perampanel treatment. The experimental drug was significantly associated with an increased risk of AE-related study withdrawals at 4 mg/day [RD (95% confidence interval) 0.03 (0.00, 0.06)] and 12 mg/day [RD (95% confidence interval) 0.13 (0.07, 0.18)]. Of 15 identified AEs, five (dizziness, ataxia, somnolence, irritability and weight increase) were found to be significantly associated with perampanel and one (seizure worsening) was significantly associated with placebo. CONCLUSIONS: Vestibulocerebellar AEs (dizziness, ataxia), sedative effects (somnolence), irritability and weight increase were significantly associated with perampanel treatment.


Anticonvulsants/adverse effects , Anticonvulsants/therapeutic use , Pyridones/adverse effects , Pyridones/therapeutic use , Anticonvulsants/administration & dosage , Confidence Intervals , Dose-Response Relationship, Drug , Double-Blind Method , Drug Resistance , Epilepsies, Partial/drug therapy , Epilepsy/drug therapy , Humans , Nitriles , Parkinson Disease/drug therapy , Pyridones/administration & dosage , Randomized Controlled Trials as Topic , Risk Assessment , Seizures/drug therapy
12.
Neurology ; 76(3): 260-4, 2011 Jan 18.
Article En | MEDLINE | ID: mdl-21242494

OBJECTIVE: DCC is the receptor for netrin, a protein that guides axon migration of developing neurons across the body's midline. Mutations in the DCC gene were recently identified in 2 families with congenital mirror movements (MM). The objective was to study clinical and genetic characteristics of 3 European families with MM and to test whether this disorder is genetically homogeneous. METHODS: We studied 3 MM families with a total of 13 affected subjects. Each patient had a standardized interview and neurologic examination, focusing on the phenomenology and course of the MM. The severity of MM was also assessed. Molecular analysis of DCC was performed in the index cases. In addition, linkage analysis of the DCC locus was performed in a large French family. RESULTS: The clinical expression and course of MM were very similar in all the affected subjects, regardless of DCC mutational status. However, slight intersubject variability in the severity of MM was noted within each family. Onset always occurred in infancy or early childhood, and MM did not deteriorate over time. Motor disability due to MM was mild and restricted to activities that require independent movements of the 2 hands. We found a novel mutation in the DCC gene in an Italian family with MM associated with abnormal ipsilateral corticospinal projection. The DCC locus was excluded in the French family. CONCLUSION: DCC has a crucial role in the development of corticospinal tracts in humans. Congenital MM is genetically heterogeneous, despite its clinical homogeneity.


Genes, DCC/genetics , Genetic Heterogeneity , Mutation , Stereotypic Movement Disorder/genetics , Adult , Age of Onset , Aged , Dyskinesias/genetics , Female , France , Humans , Male , Middle Aged , Pain/etiology , Pedigree , Phenotype , Severity of Illness Index , Stereotypic Movement Disorder/complications , Stereotypic Movement Disorder/physiopathology , Upper Extremity/physiopathology
13.
Epilepsy Res ; 89(1): 66-71, 2010 Mar.
Article En | MEDLINE | ID: mdl-20129761

PURPOSE: Malformations of cortical development are often accompanied by an abnormal cortical pattern. Due to its propensity to involve discrete cortical areas, polymicrogyria represents an interesting model for assessing the reorganization of cortical function in relation to the disrupted anatomy. Functional MRI, TMS and SEPs can provide a highly complementary, multimodal approach to map noninvasively the functional rearrangement of sensorimotor functions in the polymicrogyric cortex, and to obtain a coherent modelling. We report here an illustrative case which is included in a patients series under study using a block design 3T fMRI, short-latency SEPs as identified on the basis of their latency, polarity, and scalp distribution and an assessment of the area and volume of the motor maps and the relative position of the center of gravity and hot spot. RESULTS: A 15 years old girl, with drug-resistant epilepsy and left perisylvian polymicrogyria that was part of a large epileptogenic network including also the mesial aspect of the left frontal lobe, exhibited a normal distribution of somatomotor responses in the expected anatomic sites, with a dissociation between motor functions, which were slightly impaired in the malformed hemisphere, and bilaterally normal sensory responses. In this patient, a large resection of epileptogenic zone, sparing eloquent areas as previously identified, should be planned in order to improve seizure outcome. CONCLUSIONS: An integrated fMRI, TMS and SEP mapping approach helps defining the relationship between epileptogenic zones and somatomotor areas. Studies of greater number of patients will be necessary in order to identify the general rules that determine the functional representation in the malformed cortex.


Cerebral Cortex/physiopathology , Epilepsy/physiopathology , Malformations of Cortical Development/physiopathology , Nerve Net/physiopathology , Adolescent , Brain Mapping , Electroencephalography , Epilepsy/complications , Evoked Potentials, Somatosensory/physiology , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Malformations of Cortical Development/complications , Signal Processing, Computer-Assisted , Transcranial Magnetic Stimulation
14.
Neurology ; 72(10): 928-34, 2009 Mar 10.
Article En | MEDLINE | ID: mdl-19273828

BACKGROUND: In amnestic mild cognitive impairment (aMCI), functional neuronal connectivity may be altered, as suggested by quantitative EEG and neuroimaging data. In young healthy humans, the execution of linguistic tasks modifies the excitability of the hand area of the dominant primary motor cortex (M1(hand)), as tested by transcranial magnetic stimulation (TMS). We used TMS to investigate functional connectivity between language-related cortical areas and M1(hand) in aMCI. METHODS: Ten elderly women with aMCI and 10 age-matched women were recruited. All participants were right handed and underwent a neuropsychological evaluation. In the first TMS experiment, participants performed three different tasks: reading aloud, viewing of non-letter strings (baseline), and nonverbal oral movements. The second experiment included the baseline condition and three visual searching/matching tasks using letters, geometric shapes, or digits as target stimuli. RESULTS: In controls, motor evoked potentials (MEP) elicited by suprathreshold TMS of the left M1(hand) were significantly larger during reading aloud (170% baseline) than during nonverbal oral movements, whereas no difference was seen for right M1(hand) stimulation. Similarly, MEP elicited by left M1(hand) stimulation during letter and shape searching/matching tasks were significantly larger compared to digit task. In contrast, linguistic task performance did not produce any significant MEP modulation in patients with aMCI, although neuropsychological evaluation showed normal language abilities. CONCLUSIONS: Findings suggest that functional connectivity between the language-related brain regions and the dominant M1(hand) may be altered in amnestic mild cognitive impairment. Follow-up studies will reveal whether transcranial magnetic stimulation application during linguistic tasks may contribute to characterize the risk of conversion to Alzheimer disease.


Cerebral Cortex/physiology , Cognition Disorders/physiopathology , Cognition Disorders/psychology , Motor Cortex/physiology , Psychomotor Performance/physiology , Reading , Aged , Cognition/physiology , Data Interpretation, Statistical , Electroencephalography , Evoked Potentials, Motor/physiology , Female , Form Perception/physiology , Humans , Language , Movement/physiology , Neuropsychological Tests , Photic Stimulation , Transcranial Magnetic Stimulation
15.
Int J Clin Pract ; 63(2): 207-16, 2009 Feb.
Article En | MEDLINE | ID: mdl-19196359

OBJECTIVE: To provide an overview of current habits, priorities, perceptions and knowledge of cardiologists with regard to hypertension and stroke prevention in outpatient practice. METHODS: A sample of 203 cardiologists operating in outpatient clinics and randomly selected amongst members of the largest Italian Outpatient Cardiologist Association were interviewed by e-mail, in April-May 2007. RESULTS: The interviewed cardiologists reported that hypertensive outpatients represent a large percentage of their practice population, in which the clinical priority was blood pressure (BP) reduction. Stroke was identified as the most important event to prevent and it was also perceived as the most preventable hypertension-related cardiovascular event. A remarkably high rate of achieved BP control was reported, to a degree that it is inconsistent with current epidemiological reports and with the relatively low percentage use of combination therapies declared by cardiologists. Additional risk factors, organ damage, diabetes mellitus and atrial fibrillation were consistently reported in hypertensive patients. Among antihypertensive drug classes, a preference for angiotensin-converting enzyme inhibitors has been expressed by the majority of physicians; this choice was generally justified by evidence derived from international trials or by the antihypertensive efficacy of this drug class. CONCLUSIONS: The results confirm the presence of weaknesses in the current services for patients with hypertension, even when being managed by cardiologists. Discrepancies between perceptions and reality, or clinical practice and guideline recommendations are also highlighted. An analysis of these aspects may help to identify current areas of potential improvement for stroke prevention in the clinical management of hypertension in cardiology practice.


Cardiology/statistics & numerical data , Hypertension/therapy , Professional Practice/statistics & numerical data , Stroke/prevention & control , Ambulatory Care/statistics & numerical data , Antihypertensive Agents/therapeutic use , Blood Pressure , Cardiovascular Diseases/etiology , Health Surveys , Humans , Hypertension/physiopathology , Italy , Primary Prevention , Risk Factors , Treatment Outcome
16.
Exp Brain Res ; 175(4): 633-40, 2006 Nov.
Article En | MEDLINE | ID: mdl-16794846

A distributed cortical network enables the lateralization of intended unimanual movements, i.e., the transformation from a default mirror movement to a unimanual movement. Little is known about the exact functional organization of this "non-mirror transformation" network. Involvement of the right dorsal premotor cortex (dPMC) was suggested because its virtual lesion by high-frequency repetitive transcranial magnetic stimulation (rTMS) increased the excitability of the left primary motor cortex (M1) during unilateral isometric contraction of a left hand muscle (Cincotta et al., Neurosci Lett 367: 189-93, 2004). However, no behavioural effects were observed in that experimental protocol. Here we tested behaviourally twelve healthy volunteers to find out whether focal disruption of the right dPMC by "off-line" One Hz rTMS (900 pulses, 115% of resting motor threshold) enhances "physiological" mirroring. This was measured by an established protocol (Mayston et al., Ann Neurol 45: 583-94, 1999) that quantifies the mirror increase in the electromyographic (EMG) level in the isometrically contracting abductor pollicis brevis (APB) muscle of one hand during brief phasic contractions performed with the APB of the other hand. Mirroring in the right APB significantly increased after real rTMS of the right dPMC. In contrast, no change in mirroring was seen with sham rTMS of the right dPMC, real rTMS of the right M1, or real rTMS of the left dPMC. These findings strongly support the hypothesis that the right dPMC is part of the non-mirror transformation cortical network.


Evoked Potentials, Motor/physiology , Frontal Lobe/physiology , Imitative Behavior/physiology , Motor Cortex/physiology , Muscle Contraction/physiology , Muscle, Skeletal/physiology , Neural Pathways/physiology , Action Potentials/physiology , Adult , Efferent Pathways/physiology , Electromyography/methods , Female , Functional Laterality/physiology , Hand/innervation , Hand/physiology , Humans , Male , Membrane Potentials/physiology , Middle Aged , Motor Cortex/anatomy & histology , Motor Neurons/physiology , Muscle, Skeletal/innervation , Nerve Net/physiology , Neural Pathways/anatomy & histology
17.
Exp Brain Res ; 171(4): 490-6, 2006 Jun.
Article En | MEDLINE | ID: mdl-16369790

In healthy subjects, suprathreshold repetitive transcranial magnetic stimulation (rTMS) at frequencies >2 Hz prolongs the cortical silent period (CSP) over the course of the train. This progressive lengthening probably reflects temporal summation of the inhibitory interneurons in the stimulated primary motor cortex (M1). In this study, we tested whether high-frequency rTMS also modulates the ipsilateral silent period (ISP). In nine normal subjects, suprathreshold 10-pulse rTMS trains were delivered to the right M1 at frequencies of 3, 5, and 10 Hz during maximal isometric contraction of both first dorsal interosseous muscles. At 10 Hz, the second pulse of the train increased the area of the ISP; the other stimuli did not increase it further. During rTMS at 3 and 5 Hz, the ISP remained significantly unchanged. Control experiments showed that 10-Hz rTMS delivered at subthreshold intensity also increased the ISP. rTMS over the hand motor area did not facilitate ISPs in the biceps muscles. Finally, rTMS-induced ISP facilitation did not outlast the 10-Hz rTMS train. These findings suggest that rTMS at a frequency of 10 Hz potentiates the interhemispheric inhibitory mechanisms responsible for the ISP, partly through temporal summation. The distinct changes in the ISP and CSP suggest that rTMS facilitates intrahemispheric and interhemispheric inhibitory phenomena through separate neural mechanisms. The ISP facilitation induced by high-frequency rTMS is a novel, promising tool to investigate pathophysiological abnormal interhemispheric inhibitory transfer in various neurological diseases.


Electric Stimulation , Evoked Potentials, Motor/radiation effects , Functional Laterality/physiology , Motor Cortex/radiation effects , Transcranial Magnetic Stimulation , Adult , Analysis of Variance , Dose-Response Relationship, Radiation , Electromyography/methods , Female , Humans , Male , Middle Aged , Neural Inhibition , Reaction Time , Time Factors
18.
Int J Clin Pharmacol Res ; 25(2): 57-63, 2005.
Article En | MEDLINE | ID: mdl-16060395

The growing use of guidelines to manage asthmatic patients prompted us to evaluate their impact on clinical practice. This study was performed in two similar groups of asthmatic patients. A retrospective and prospective review of medical records in an asthmatic population was performed. The patients were followed up for a mean period of 2 years before (group 1 [G1]) and after the publication of the Guideline for Asthma Treatment (group 2 [G2]). After evaluation of objective/clinical measurements we noticed a significant difference between both groups. There were 23 and 40 patients who did not complain of any respiratory symptoms in G1 and G2, respectively. The total number of visits to the emergency department decreased by more than 75%, from 26 (G1) to six (G2). The forced expiratory volume in 1 sec improved by a mean of 4% in G1 and 9% in G2. After application of the guidelines there was a redistribution of the degree of disease severity. In G2, there was a 12% increase in the use of long-acting beta2-stimulating sprays; 40% of the patients were using a combination of a long-acting beta2-stimulating drug and an inhaled steroid. In our experience, the use of the Global Initiative for Asthma (GINA) guidelines leads to better management of asthma patients with different degrees of severity. These findings suggest the need to perform a similar analysis in a broader setting such as a national multicenter survey in order to collect information on the challenges of putting these theoretical difficulties into practice and to compare their implementation in distinct centers.


Asthma/drug therapy , Administration, Inhalation , Adult , Asthma/physiopathology , Drug Therapy, Combination , Female , Forced Expiratory Volume , Humans , Length of Stay , Male , Middle Aged , Patient Education as Topic , Prospective Studies , Retrospective Studies
19.
Clin Neurophysiol ; 116(7): 1733-42, 2005 Jul.
Article En | MEDLINE | ID: mdl-15905126

OBJECTIVE: To analyse the interactions between simultaneous or nearly simultaneous focal transcranial magnetic stimulation (TMS) of the motor cortex hand area (M1hand) of both hemispheres. METHODS: In 7 healthy subjects, motor evoked potential (MEP) amplitude and cortical silent period (CSP) duration were elicited in the right hand by bihemispheric focal TMS of M1hand (8-shaped coils, monophasic current waveform, stimulus intensity 120% above motor threshold, TMS of right M1hand preceding TMS of left M1hand by 0-1000 micros), or by unilateral TMS of left M1hand alone. A dipole probe was used to measure the physical interactions between the two stimulating coils. RESULTS: Bihemispheric TMS markedly decreased MEP and CSP at intervals of 0 and 50 micros compared to unilateral TMS, whereas both measures increased at the interval of 150 micros. The dipole probe experiments showed that the physical interactions between the electrical fields of the two coils entirely explained the MEP and CSP findings, but only under the assumption that excitation of M1hand is not point-focal but extends over several centimetres. CONCLUSIONS: First, simultaneous focal TMS of distant brain sites may result in marked 'distortion' of brain excitation through physical interaction between the induced electrical fields. Second, these findings support the notion that excitation of human M1hand is relatively non-focal, even if a 'focal' stimulating coil and low stimulus intensity are used. SIGNIFICANCE: Potentially marked physical interaction between induced electrical fields must be taken into account when testing or disrupting distant brain sites with simultaneous focal TMS.


Artifacts , Cerebral Cortex/radiation effects , Electromagnetic Fields , Evoked Potentials, Motor/radiation effects , Magnetics/instrumentation , Neurons/radiation effects , Adult , Cerebral Cortex/anatomy & histology , Cerebral Cortex/physiology , Electric Stimulation/instrumentation , Electric Stimulation/methods , Evoked Potentials, Motor/physiology , Humans , Middle Aged , Neural Inhibition/physiology , Neural Inhibition/radiation effects , Neurons/physiology , Time Factors
20.
Eur Rev Med Pharmacol Sci ; 7(6): 171-3, 2003.
Article En | MEDLINE | ID: mdl-15206486

BACKGROUND: To understand if relapse, following antimicrobial treatment was due to re-infection or to recrudescence. METHODS: Fifty patients with dyspepsia were studied prospectively. They were followed up by endoscopy and biopsy of antral mucosa before and after treatment with anti-microbial therapy. Gel isoelectrofocusing was used to characterize protein profile of Hp. RESULTS: At baseline 40 patients were affected by chronic gastritis associated with Hp. At the end of treatment 75% patients given omeprazole, amoxicillin and clarithromycin were Hp infected: 43% showed the same protein profile and 57% different. CONCLUSIONS: Our data suggest that the relapse is due to recrudescence or to reinfection.


Bacterial Proteins/chemistry , Gastritis/metabolism , Helicobacter Infections/metabolism , Helicobacter pylori/chemistry , Adult , Aged , Chronic Disease , Female , Helicobacter Infections/microbiology , Humans , Isoelectric Focusing , Male , Middle Aged , Prospective Studies , Recurrence
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