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1.
J Neural Transm (Vienna) ; 123(12): 1387-1393, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27619658

RESUMEN

Dorsal pre-motor cortex (PMd) is thought to play a role in fine motor control. The aim of the present study was to investigate whether inhibitory or excitatory stimulation of PMd would have an impact on manual dexterity in Parkinson's disease (PD). Fifteen patients with PD participated in this study. High resolution structural MRI was used for neuro-navigated TBS. Participants were targeted with one train of TBS in three experimental sessions: sham stimulation over vertex, continuous TBS (cTBS) over PMd and intermittent TBS (iTBS) over PMd, respectively. Dexterity was measured by a coin rotation task (CRT), which is a valid measure to detect limb kinetic apraxia (LKA). Neither cTBS or iTBS significantly interfered with CRT. Post hoc sub-analysis in a group of PD patients (n = 5) with stronger baseline impairment, indicating LKA, revealed further deterioration of dexterous performance for the cTBS condition (p = 0.04). This sham controlled pilot study demonstrates that TBS over PMd does not significantly interfere with dexterity in PD. However, patients with dexterous impairment qualifying for LKA may be more susceptible to TBS.


Asunto(s)
Lateralidad Funcional/fisiología , Corteza Motora/fisiología , Enfermedad de Parkinson/terapia , Desempeño Psicomotor/fisiología , Ritmo Teta/fisiología , Estimulación Magnética Transcraneal/métodos , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Potenciales Evocados Motores/fisiología , Femenino , Humanos , Imagenología Tridimensional , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Corteza Motora/diagnóstico por imagen , Enfermedad de Parkinson/fisiopatología
2.
Brain ; 135(Pt 11): 3426-39, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22831781

RESUMEN

Left-sided spatial neglect is a common neurological syndrome following right-hemispheric stroke. The presence of spatial neglect is a powerful predictor of poor rehabilitation outcome. In one influential account of spatial neglect, interhemispheric inhibition is impaired and leads to a pathological hyperactivity in the contralesional hemisphere, resulting in a biased attentional allocation towards the right hemifield. Inhibitory transcranial magnetic stimulation can reduce the hyperactivity of the contralesional, intact hemisphere and thereby improve spatial neglect symptoms. However, it is not known whether this improvement is also relevant to the activities of daily living during spontaneous behaviour. The primary aim of the present study was to investigate whether the repeated application of continuous theta burst stimulation trains could ameliorate spatial neglect on a quantitative measure of the activities of daily living during spontaneous behaviour. We applied the Catherine Bergego Scale, a standardized observation questionnaire that can validly and reliably detect the presence and severity of spatial neglect during the activities of daily living. Eight trains of continuous theta burst stimulation were applied over two consecutive days on the contralesional, left posterior parietal cortex in patients suffering from subacute left spatial neglect, in a randomized, double-blind, sham-controlled design, which also included a control group of neglect patients without stimulation. The results showed a 37% improvement in the spontaneous everyday behaviour of the neglect patients after the repeated application of continuous theta burst stimulation. Remarkably, the improvement persisted for at least 3 weeks after stimulation. The amelioration of spatial neglect symptoms in the activities of daily living was also generally accompanied by significantly better performance in the neuropsychological tests. No significant amelioration in symptoms was observed after sham stimulation or in the control group without stimulation. These results provide Class I evidence that continuous theta burst stimulation is a viable add-on therapy in neglect rehabilitation that facilitates recovery of normal everyday behaviour.


Asunto(s)
Actividades Cotidianas/psicología , Mapeo Encefálico/psicología , Trastornos de la Percepción/psicología , Trastornos de la Percepción/rehabilitación , Estimulación Magnética Transcraneal/psicología , Mapeo Encefálico/métodos , Evaluación de la Discapacidad , Método Doble Ciego , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas/estadística & datos numéricos , Lóbulo Parietal/patología , Lóbulo Parietal/fisiología , Trastornos de la Percepción/complicaciones , Trastornos de la Percepción/patología , Índice de Severidad de la Enfermedad , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/psicología , Rehabilitación de Accidente Cerebrovascular , Estimulación Magnética Transcraneal/métodos
3.
Neurocrit Care ; 14(1): 4-10, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20878265

RESUMEN

BACKGROUND: Refractory status epilepticus (RSE) has a mortality of 16-39%; coma induction is advocated for its management, but no comparative study has been performed. We aimed to assess the effectiveness (RSE control, adverse events) of the first course of propofol versus barbiturates in the treatment of RSE. METHODS: In this randomized, single blind, multi-center trial studying adults with RSE not due to cerebral anoxia, medications were titrated toward EEG burst-suppression for 36-48 h and then progressively weaned. The primary endpoint was the proportion of patients with RSE controlled after a first course of study medication; secondary endpoints included tolerability measures. RESULTS: The trial was terminated after 3 years, with only 24 patients recruited of the 150 needed; 14 subjects received propofol, 9 barbiturates. The primary endpoint was reached in 43% in the propofol versus 22% in the barbiturates arm (P = 0.40). Mortality (43 vs. 34%; P = 1.00) and return to baseline clinical conditions at 3 months (36 vs. 44%; P = 1.00) were similar. While infections and arterial hypotension did not differ between groups, barbiturate use was associated with a significantly longer mechanical ventilation (P = 0.03). A non-fatal propofol infusion syndrome was detected in one patient, while one subject died of bowel ischemia after barbiturates. DISCUSSION: Although undersampled, this trial shows significantly longer mechanical ventilation with barbiturates and the occurrence of severe treatment-related complications in both arms. We describe practical issues necessary for the success of future studies needed to improve the current unsatisfactory state of evidence.


Asunto(s)
Coma/inducido químicamente , Cuidados Críticos/métodos , Propofol/administración & dosificación , Propofol/efectos adversos , Estado Epiléptico/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Barbitúricos/administración & dosificación , Barbitúricos/efectos adversos , Femenino , Humanos , Hipnóticos y Sedantes/administración & dosificación , Hipnóticos y Sedantes/efectos adversos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Estado Epiléptico/mortalidad , Resultado del Tratamiento , Adulto Joven
4.
Neuroimage Clin ; 16: 88-97, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28765808

RESUMEN

Parkinson's disease (PD) patients frequently suffer from dexterous deficits impeding activities of daily living. There is controversy whether impaired fine motor skill may stem from limb kinetic apraxia (LKA) rather than bradykinesia. Based on classical models of limb praxis LKA is thought to result when premotor transmission of time-space information of skilled movements to primary motor representations is interrupted. Therefore, using functional magnetic resonance imaging (fMRI) we tested the hypothesis that dexterous deficits in PD are associated with altered activity and connectivity in left parieto-premotor praxis network. Whole-brain analysis of fMRI activity during a task for LKA (coin rotation) showed increased activation of superior and inferior parietal lobule (SPL, IPL) and ventral premotor cortex (vPM) in PD patients compared to controls. For bradykinesia (assessed by finger tapping) a decreased fMRI activity could be detected in patients. Additionally, psychophysical interaction analysis showed increased functional connectivity between IPL and the posterior hippocampi in patients with PD. By contrast, functional connectivity to the right dorsolateral prefrontal cortex was decreased in patients with PD compared to controls. In conclusion, our data demonstrates that dexterous deficits in PD were associated with enhanced fMRI activation of the left praxis network upstream to primary motor areas, mirroring a neural correlate for the behavioral dissociation of LKA and bradykinesia. Furthermore, the findings suggest that patients recruit temporal areas of motor memory as an attempt to compensate for impaired motor skills. Finally, dysexecutive function may contribute to the deficit.


Asunto(s)
Apraxias/diagnóstico por imagen , Apraxias/etiología , Extremidades/fisiopatología , Imagen por Resonancia Magnética , Enfermedad de Parkinson/complicaciones , Anciano , Encéfalo/diagnóstico por imagen , Estudios de Casos y Controles , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Escala del Estado Mental , Persona de Mediana Edad , Trastornos de la Destreza Motora/diagnóstico por imagen , Trastornos de la Destreza Motora/etiología , Movimiento/fisiología , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/patología , Oxígeno/sangre
5.
Neuropsychologia ; 71: 158-64, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25841335

RESUMEN

According to the direct matching hypothesis, perceived movements automatically activate existing motor components through matching of the perceived gesture and its execution. The aim of the present study was to test the direct matching hypothesis by assessing whether visual exploration behavior correlate with deficits in gestural imitation in left hemisphere damaged (LHD) patients. Eighteen LHD patients and twenty healthy control subjects took part in the study. Gesture imitation performance was measured by the test for upper limb apraxia (TULIA). Visual exploration behavior was measured by an infrared eye-tracking system. Short videos including forty gestures (20 meaningless and 20 communicative gestures) were presented. Cumulative fixation duration was measured in different regions of interest (ROIs), namely the face, the gesturing hand, the body, and the surrounding environment. Compared to healthy subjects, patients fixated significantly less the ROIs comprising the face and the gesturing hand during the exploration of emblematic and tool-related gestures. Moreover, visual exploration of tool-related gestures significantly correlated with tool-related imitation as measured by TULIA in LHD patients. Patients and controls did not differ in the visual exploration of meaningless gestures, and no significant relationships were found between visual exploration behavior and the imitation of emblematic and meaningless gestures in TULIA. The present study thus suggests that altered visual exploration may lead to disturbed imitation of tool related gestures, however not of emblematic and meaningless gestures. Consequently, our findings partially support the direct matching hypothesis.


Asunto(s)
Movimientos Oculares , Gestos , Conducta Imitativa , Percepción de Movimiento , Reconocimiento Visual de Modelos , Accidente Cerebrovascular , Adulto , Anciano , Medidas del Movimiento Ocular , Femenino , Lateralidad Funcional , Humanos , Rayos Infrarrojos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Accidente Cerebrovascular/patología , Accidente Cerebrovascular/psicología , Tomografía Computarizada por Rayos X , Grabación en Video , Adulto Joven
6.
J Int AIDS Soc ; 17(4 Suppl 3): 19745, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25397490

RESUMEN

INTRODUCTION: HIV-1 viral escape in the cerebrospinal fluid (CSF) despite viral suppression in plasma is rare [1,2]. We describe the case of a 50-year-old HIV-1 infected patient who was diagnosed with HIV-1 in 1995. Antiretroviral therapy (ART) was started in 1998 with a CD4 T cell count of 71 cells/ìL and HIV-viremia of 46,000 copies/mL. ART with zidovudine (AZT), lamivudine (3TC) and efavirenz achieved full viral suppression. After the patient had interrupted ART for two years, treatment was re-introduced with tenofovir (TDF), emtricitabin (FTC) and ritonavir boosted atazanavir (ATVr). This regimen suppressed HIV-1 in plasma for nine years and CD4 cells stabilized around 600 cells/ìL. Since July 2013, the patient complained about severe gait ataxia and decreased concentration. MATERIALS AND METHODS: Additionally to a neurological examination, two lumbar punctures, a cerebral MRI and a neuropsycological test were performed. HIV-1 viral load in plasma and in CSF was quantified using Cobas TaqMan HIV-1 version 2.0 (Cobas Ampliprep, Roche diagnostic, Basel, Switzerland) with a detection limit of 20 copies/mL. Drug resistance mutations in HIV-1 reverse transcriptase and protease were evaluated using bulk sequencing. RESULTS: The CSF in January 2014 showed a pleocytosis with 75 cells/ìL (100% mononuclear) and 1,184 HIV-1 RNA copies/mL, while HIV-1 in plasma was below 20 copies/mL. The resistance testing of the CSF-HIV-1 RNA showed two NRTI resistance-associated mutations (M184V and K65R) and one NNRTI resistance-associated mutation (K103N). The cerebral MRI showed increased signal on T2-weighted images in the subcortical and periventricular white matter, in the basal ganglia and thalamus. Four months after ART intensification with AZT, 3TC, boosted darunavir and raltegravir, the pleocytosis in CSF cell count normalized to 1 cell/ìL and HIV viral load was suppressed. The neurological symptoms improved; however, equilibrium disturbances and impaired memory persisted. The neuro-psychological evaluation confirmed neurocognitive impairments in executive functions, attention, working and nonverbal memory, speed of information processing, visuospatial abilities and motor skills. CONCLUSIONS: HIV-1 infected patients with neurological complaints prompt further investigations of the CSF including measurement of HIV viral load and genotypic resistance testing since isolated replication of HIV with drug resistant variants can rarely occur despite viral suppression in plasma. Optimizing ART by using drugs with improved CNS penetration may achieve viral suppression in CSF with improvement of neurological symptoms.

7.
Clin Neurophysiol ; 125(3): 457-62, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24054467

RESUMEN

OBJECTIVE: Neuro-imaging studies have suggested that the ability to imitate meaningless and meaningful gestures may differentially depend on superior (SPL) and inferior (IPL) parietal lobule. Therefore, we hypothesized that imaging-guided neuro-navigated continuous theta burst stimulation (cTBS) over left SPL mainly affects meaningless and over left IPL predominantly meaningful gestures. METHODS: Twelve healthy subjects participated in this study. High resolution structural MRI was used for imaging guided neuro-navigation cTBS. Participants were targeted with one train of cTBS in three experimental sessions: sham stimulation over vertex and real cTBS over left SPL and IPL, respectively. An imitation task, including 24 meaningless and 24 meaningful gestures, was performed 'offline'. RESULTS: cTBS over both left IPL and SPL significantly interfered with gestural imitation. There was no differential effect of SPL and IPL cTBS on gesture type (meaningless versus meaningful). CONCLUSIONS: Our findings confirm that left posterior parietal cortex plays a predominant role in gestural imitation. However, the hypothesis based on the dual route model suggesting a differential role of SPL and IPL in the processing of meaningless and meaningful gestures could not be confirmed. SIGNIFICANCE: Left SPL and IPL play a common role within the posterior-parietal network in gestural imitation regardless of semantic content.


Asunto(s)
Gestos , Conducta Imitativa/fisiología , Lóbulo Parietal/fisiología , Ritmo Teta , Estimulación Magnética Transcraneal/métodos , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Adulto Joven
8.
Clin Neurophysiol ; 122(6): 1197-202, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21130031

RESUMEN

OBJECTIVE: The traditional view of a predominant inferior parietal representation of gestures has been recently challenged by neuroimaging studies demonstrating that gesture production and discrimination may critically depend on inferior frontal lobe function. The aim of the present work was therefore to investigate the effect of transient disruption of these brain sites by continuous theta burst stimulation (cTBS) on gesture production and recognition. METHODS: Fourteen healthy subjects participated in the study. A repeated measures design was employed with three experimental sessions: baseline (BSL), left inferior parietal (IPL) and inferior frontal (IFG) TBS. Gesture production and recognition was assessed in an off-line approach using a new test of upper limb apraxia (TULIA) and a modified version of postural knowledge test (PKT). RESULTS: TBS of the left IFG significantly lowered total TULIA scores. The effect was even more prominent when contrasted with IPL than with BSL. However, TBS over either stimulation site did not significantly influence PKT measures. CONCLUSIONS: The interference of the left inferior frontal cTBS with gesture production emphasizes the role this brain region has in the control of gestures. SIGNIFICANCE: The study demonstrated that gesture performance is amenable to modulation with TBS.


Asunto(s)
Fenómenos Biofísicos/fisiología , Dominancia Cerebral/fisiología , Lóbulo Frontal/fisiología , Gestos , Desempeño Psicomotor/fisiología , Adulto , Análisis de Varianza , Mapeo Encefálico , Estimulación Eléctrica/métodos , Electroencefalografía , Femenino , Antebrazo/inervación , Humanos , Masculino , Tiempo de Reacción/fisiología , Factores de Tiempo
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