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1.
Front Nutr ; 10: 1173316, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37955018

RESUMEN

Using ultra-high field (7 Tesla) functional MRI (fMRI), we conducted the first in-vivo functional neuroimaging study of the normal human brainstem specifically designed to examine neural signals in the Nucleus Tractus Solitarius (NTS) in response to all basic taste stimuli. NTS represents the first relay station along the mammalian taste processing pathway which originates at the taste buds in the oral cavity and passes through the thalamus before reaching the primary taste cortex in the brain. In our proof-of-concept study, we acquired data from one adult volunteer using fMRI at 1.2 mm isotropic resolution and performed a univariate general linear model analysis. During fMRI acquisition, three shuffled injections of sweet, bitter, salty, sour, and umami solutions were administered following an event-related design. We observed a statistically significant blood oxygen level-dependent (BOLD) response in the anatomically predicted location of the NTS for all five basic tastes. The results of this study appear statistically robust, even though they were obtained from a single volunteer. The information derived from a similar experimental strategy may inspire novel research aimed at clarifying important details of central nervous system involvement in eating disorders, at designing and monitoring tailored therapeutic strategies.

2.
Eur J Neurosci ; 58(3): 2868-2873, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37369968

RESUMEN

Childhood maltreatment (CM) is associated with distinct clinical and biological characteristics in people with eating disorders (EDs). The measurement of local gyrification index (lGI) may help to better characterize the impact of CM on cortical structure. Thus, the present study investigated the association of CM with lGI in women with EDs. Twenty-six women with anorexia nervosa (AN) and 24 with bulimia nervosa (BN) underwent a 3T MRI scan. All participants filled in the Childhood Trauma Questionnaire. All neuroimaging data were processed by FreeSurfer. LGI maps underwent a general linear model to evaluate differences between groups with or without CM. People with AN and BN were merged together. Based on the Childhood Trauma Questionnaire cutoff scores, 24 participants were identified as maltreated and 26 as non-maltreated. Maltreated people with EDs showed a significantly lower lGI in the left middle temporal gyrus compared with non-maltreated people, whereas no differences emerged in the right hemisphere between groups. The present study showed that in people with EDs, CM is associated with reduced cortical folding in the left middle temporal gyrus, an area that could be involved in ED psychopathology. This finding corroborates the hypothesis of a 'maltreated ecophenotype', which argues that CM may allow to biologically, other than clinically, distinguish individuals with the same psychiatric disorder.


Asunto(s)
Anorexia Nerviosa , Bulimia Nerviosa , Maltrato a los Niños , Trastornos de Alimentación y de la Ingestión de Alimentos , Humanos , Femenino , Niño , Trastornos de Alimentación y de la Ingestión de Alimentos/patología , Anorexia Nerviosa/diagnóstico por imagen , Anorexia Nerviosa/patología , Lóbulo Temporal
3.
Eur Arch Psychiatry Clin Neurosci ; 273(2): 459-466, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35852616

RESUMEN

Childhood maltreatment (CM) is a non-specific risk factor for eating disorders (ED) and is associated with a greater severity in their clinical presentation and poorer treatment outcome. These data suggest that maltreated people with ED may be biologically other than clinically different from non-maltreated people. The aim of the present study was to investigate cortical thickness (CT), a possible biomarker of neurodevelopment, in people with ED with or without history of CM and in healthy women. Twenty-four healthy women, 26 with anorexia nervosa and 24 with bulimia nervosa underwent a 3T MRI scan. All participants filled in the childhood trauma questionnaire. All neuroimaging data were processed by FreeSurfer. Twenty-four participants with ED were identified as maltreated and 26 participants with ED as non-maltreated. All healthy women were non-maltreated. Compared to healthy women, maltreated people with ED showed lower CT in the left rostral anterior cingulate gyrus, while compared to people with ED without history of CM showed lower CT values in the left superior frontal and in right caudal middle frontal and superior parietal gyri. No significant differences emerged in CT measures between healthy women and people with ED without history of CM. The present findings show for the first time that in adult people with ED childhood maltreatment is associated with cortical thinning in areas implicated in the modulation of brain processes that are acknowledged to play a role in the psychopathology of ED.


Asunto(s)
Bulimia Nerviosa , Maltrato a los Niños , Trastornos de Alimentación y de la Ingestión de Alimentos , Adulto , Humanos , Femenino , Niño , Adelgazamiento de la Corteza Cerebral/patología , Trastornos de Alimentación y de la Ingestión de Alimentos/diagnóstico por imagen , Trastornos de Alimentación y de la Ingestión de Alimentos/etiología , Trastornos de Alimentación y de la Ingestión de Alimentos/patología , Giro del Cíngulo/patología , Bulimia Nerviosa/diagnóstico por imagen
4.
Front Neurosci ; 16: 971809, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36117618

RESUMEN

In Kallmann syndrome (KS), the peculiar phenomenon of bimanual synkinesis or mirror movement (MM) has been associated with a spectral shift, from lower to higher frequencies, of the resting-state fMRI signal of the large-scale sensorimotor brain network (SMN). To possibly determine whether a similar frequency specificity exists across different functional connectivity SMN states, and to capture spontaneous transitions between them, we investigated the dynamic spectral changes of the SMN functional connectivity in KS patients with and without MM symptom. Brain MRI data were acquired at 3 Tesla in 39 KS patients (32 without MM, KSMM-, seven with MM, KSMM+) and 26 age- and sex-matched healthy control (HC) individuals. The imaging protocol included 20-min rs-fMRI scans enabling detailed spectro-temporal analyses of large-scale functional connectivity brain networks. Group independent component analysis was used to extract the SMN. A sliding window approach was used to extract the dynamic spectral power of the SMN functional connectivity within the canonical physiological frequency range of slow rs-fMRI signal fluctuations (0.01-0.25 Hz). K-means clustering was used to determine (and count) the most recurrent dynamic states of the SMN and detect the number of transitions between them. Two most recurrent states were identified, for which the spectral power peaked at a relatively lower (state 1) and higher (state 2) frequency. Compared to KS patients without MM and HC subjects, the SMN of KS patients with MM displayed significantly larger spectral power changes in the slow 3 canonical sub-band (0.073-0.198 Hz) and significantly fewer transitions between state 1 (less recurrent) and state 2 (more recurrent). These findings demonstrate that the presence of MM in KS patients is associated with reduced spontaneous transitions of the SMN between dynamic functional connectivity states and a higher recurrence and an increased spectral power change of the high-frequency state. These results provide novel information about the large-scale brain functional dynamics that could help to understand the pathologic mechanisms of bimanual synkinesis in KS syndrome and, potentially, other neurological disorders where MM may also occur.

5.
Front Aging Neurosci ; 14: 976340, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36118711

RESUMEN

Functional and metabolic neural changes in Type 2 diabetes mellitus (T2DM) can be associated with poor cognitive performances. Here we analyzed the functional-metabolic neurovascular coupling (NVC) in the brain of T2DM patients. Thirty-three patients (70 ± 6 years, 15 males) with recent T2DM diagnosis and 18 healthy control (HC) subjects (65 ± 9 years, 9 males) were enrolled in a brain MRI study to identify the potential effects of T2DM on NVC. T2DM patients were either drug-naive (n = 19) or under treatment with metformin (n = 14) since less than 6 months. Arterial spin labeling and blood oxygen level dependent resting-state functional MRI (RS-fMRI) images were combined to derive NVC measures in brain regions and large-scale networks in a standard brain parcelation. Altered NVC values in T2DM patients were correlated with cognitive performances spanning several neurological domains using Spearman correlation coefficients. Compared to HC, T2DM patients had reduced NVC in the default mode network (DMN) and increased NVC in three regions of the dorsal (DAN) and salience-ventral (SVAN) attention networks. NVC abnormalities in DAN and SVAN were associated with reduced visuo-spatial cognitive performances. A spatial pattern of NVC reduction in the DMN, accompanied by isolated regional NVC increases in DAN and SVAN, could reflect the emergence of (defective) compensatory processes in T2DM patients in response to altered neurovascular conditions. Overall, this pattern is reminiscent of neural abnormalities previously observed in Alzheimer's disease, suggesting that similar neurobiological mechanisms, secondary to insulin resistance and manifesting as NVC alterations, might be developing in T2DM pathology.

6.
Chem Senses ; 472022 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-35749468

RESUMEN

The central gustatory pathway encompasses multiple subcortical and cortical regions whose neural functional connectivity can be modulated by taste stimulation. While gustatory perception has been previously linked to sex, whether and how the gustatory network differently responds to basic tastes between men and women is unclear. Here, we defined the regions of the central gustatory network by a meta-analysis of 35 fMRI taste activation studies and then analyzed the taste-evoked functional connectivity between these regions in 44 subjects (19 women) in a separate 3 Tesla activation study where sweet and bitter solutions, at five concentrations each, were administered during scanning. From the meta-analysis, a network model was set up, including bilateral anterior, middle and inferior insula, thalamus, precentral gyrus, left amygdala, caudate and dorsolateral prefrontal cortex. Higher functional connectivity than in women was observed in men between the right middle insula and bilateral thalami for bitter taste. Men exhibited higher connectivity than women at low bitter concentrations and middle-high sweet concentrations between bilateral thalamus and insula. A graph-based analysis expressed similar results in terms of nodal characteristics of strength and centrality. Our findings add new insights into the mechanisms of taste processing by highlighting sex differences in the functional connectivity of the gustatory network as modulated by the perception of sweet and bitter tastes. These results shed more light on the neural origin of sex-related differences in gustatory perception and may guide future research on the pathophysiology of taste perception in humans.


Asunto(s)
Caracteres Sexuales , Gusto , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Gusto/fisiología , Percepción del Gusto/fisiología , Tálamo
7.
Sci Rep ; 12(1): 8565, 2022 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-35595790

RESUMEN

The recently introduced orientation selective deep brain stimulation (OS-DBS) technique freely controls the direction of the electric field's spatial gradient by using multiple contacts with independent current sources within a multielectrode array. The goal of OS-DBS is to align the electrical field along the axonal track of interest passing through the stimulation site. Here we utilized OS-DBS with a planar 3-channel electrode for stimulating the rat entorhinal cortex (EC) and medial septal nucleus (MSN), two promising areas for DBS treatment of Alzheimer's disease. The brain responses to OS-DBS were monitored by whole brain functional magnetic resonance imaging (fMRI) at 9.4 T with Multi-Band Sweep Imaging with Fourier Transformation (MB-SWIFT). Varying the in-plane OS-DBS stimulation angle in the EC resulted in activity modulation of multiple downstream brain areas involved in memory and cognition. Contrary to that, no angle dependence of brain activations was observed when stimulating the MSN, consistent with predictions based on the electrode configuration and on the main axonal directions of the targets derived from diffusion MRI tractography and histology. We conclude that tuning the OS-DBS stimulation angle modulates the activation of brain areas relevant to Alzheimer's disease, thus holding great promise in the DBS treatment of the disease.


Asunto(s)
Enfermedad de Alzheimer , Estimulación Encefálica Profunda , Núcleos Septales , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/terapia , Animales , Encéfalo , Cognición , Estimulación Encefálica Profunda/métodos , Corteza Entorrinal/diagnóstico por imagen , Corteza Entorrinal/fisiología , Imagen por Resonancia Magnética/métodos , Ratas
8.
Neurobiol Aging ; 111: 1-13, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34915240

RESUMEN

Age-related sensorineural hearing loss (HL) leads to localized brain changes in the primary auditory cortex, long-range functional alterations, and is considered a risk factor for dementia. Nonhuman studies have repeatedly highlighted cross-modal brain plasticity in sensorial brain networks other than those primarily involved in the peripheral damage, thus in this study, the possible cortical alterations associated with HL have been analyzed using a whole-brain multimodal connectomic approach. Fifty-two HL and 30 normal hearing participants were examined in a 3T MRI study along with audiological and neurological assessments. Between-regions functional connectivity and whole-brain probabilistic tractography were calculated in a connectome-based manner and graph theory was used to obtain low-dimensional features for the analysis of brain connectivity at global and local levels. The HL condition was associated with a different functional organization of the visual subnetwork as revealed by a significant increase in global efficiency, density, and clustering coefficient. These functional effects were mirrored by similar (but more subtle) structural effects suggesting that a functional repurposing of visual cortical centers occurs to compensate for age-related loss of hearing abilities.


Asunto(s)
Conectoma/métodos , Plasticidad Neuronal , Presbiacusia/diagnóstico , Presbiacusia/fisiopatología , Anciano , Corteza Auditiva/patología , Corteza Auditiva/fisiopatología , Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatología , Imagen de Difusión Tensora , Femenino , Audición , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Vías Nerviosas/fisiopatología , Corteza Visual/fisiopatología
9.
Orphanet J Rare Dis ; 16(1): 349, 2021 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-34353346

RESUMEN

BACKGROUND: Sensorineural hearing loss in beta-thalassemia is common and it is generally associated with iron chelation therapy. However, data are scarce, especially on adult populations, and a possible involvement of the central auditory areas has not been investigated yet. We performed a multicenter cross-sectional audiological and single-center 3Tesla brain perfusion MRI study enrolling 77 transfusion-dependent/non transfusion-dependent adult patients and 56 healthy controls. Pure tone audiometry, demographics, clinical/laboratory and cognitive functioning data were recorded. RESULTS: Half of patients (52%) presented with high-frequency hearing deficit, with overt hypoacusia (Pure Tone Average (PTA) > 25 dB) in 35%, irrespective of iron chelation or clinical phenotype. Bilateral voxel clusters of significant relative hypoperfusion were found in the auditory cortex of beta-thalassemia patients, regardless of clinical phenotype. In controls and transfusion-dependent (but not in non-transfusion-dependent) patients, the relative auditory cortex perfusion values increased linearly with age (p < 0.04). Relative auditory cortex perfusion values showed a significant U-shaped correlation with PTA values among hearing loss patients, and a linear correlation with the full scale intelligence quotient (right side p = 0.01, left side p = 0.02) with its domain related to communication skills (right side p = 0.04, left side p = 0.07) in controls but not in beta-thalassemia patients. Audiometric test results did not correlate to cognitive test scores in any subgroup. CONCLUSIONS: In conclusion, primary auditory cortex perfusion changes are a metabolic hallmark of adult beta-thalassemia, thus suggesting complex remodeling of the hearing function, that occurs regardless of chelation therapy and before clinically manifest hearing loss. The cognitive impact of perfusion changes is intriguing but requires further investigations.


Asunto(s)
Corteza Auditiva , Pérdida Auditiva Sensorineural , Talasemia beta , Audiometría de Tonos Puros , Estudios Transversales , Pérdida Auditiva Sensorineural/etiología , Humanos
10.
Ann Clin Transl Neurol ; 8(9): 1774-1785, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34342169

RESUMEN

OBJECTIVE: To assess the performance of a combination of three quantitative MRI markers (iron deposition, basal neuronal metabolism, and regional atrophy) for differential diagnosis between amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS). METHODS: In total, 33 ALS, 12 PLS, and 28 healthy control (HC) subjects underwent a 3T MRI study including single- and multi-echo sequences for gray matter (GM) volumetry and quantitative susceptibility mapping (QSM) and a pseudo-continuous arterial spin labeling (ASL) sequence for cerebral blood flow (CBF) measurement. Mean values of QSM, CBF, and GM volumes were extracted in the motor cortex, basal ganglia, thalamus, amygdala, and hippocampus. A generalized linear model was applied to the three measures to binary discriminate between groups. The diagnostic performances were evaluated via receiver operating characteristic analyses. RESULTS: A significant discrimination was obtained: between ALS and HCs in the left and right motor cortex, where QSM increases were respectively associated with disability scores and disease duration; between PLS and ALS in the left motor cortex, where PLS patients resulted significantly more atrophic; between ALS and HC in the right motor cortex, where GM volumes were associated with upper motor neuron scores. Significant discrimination between ALS and HC was achieved in subcortical structures only combining all three parameters. INTERPRETATION: While increased QSM values in the motor cortex of ALS patients is a consolidated finding, combining QSM, CBF, and GM volumetry shows higher diagnostic potential for differentiating ALS patients from HC subjects and, in the motor cortex, between ALS and PLS.


Asunto(s)
Sustancia Gris/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Corteza Motora/diagnóstico por imagen , Enfermedad de la Neurona Motora/diagnóstico por imagen , Adulto , Anciano , Esclerosis Amiotrófica Lateral/diagnóstico por imagen , Esclerosis Amiotrófica Lateral/metabolismo , Esclerosis Amiotrófica Lateral/patología , Esclerosis Amiotrófica Lateral/fisiopatología , Biomarcadores , Circulación Cerebrovascular/fisiología , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de la Neurona Motora/metabolismo , Enfermedad de la Neurona Motora/patología , Enfermedad de la Neurona Motora/fisiopatología
11.
Magn Reson Med ; 86(4): 2137-2145, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34002880

RESUMEN

PURPOSE: Electrical epidural spinal cord stimulation (SCS) is used as a treatment for chronic pain as well as to partially restore motor function after a spinal cord injury. Monitoring the spinal cord activity during SCS with fMRI could provide important and objective measures of integrative responses to treatment. Unfortunately, spinal cord fMRI is severely challenged by motion and susceptibility artifacts induced by the implanted electrode and bones. This pilot study introduces multi-band sweep imaging with Fourier transformation (MB-SWIFT) technique for spinal cord fMRI during SCS in rats. Given the close to zero acquisition delay and high bandwidth in 3 dimensions, MB-SWIFT is demonstrated to be highly tolerant to motion and susceptibility-induced artifacts and thus holds promise for fMRI during SCS. METHODS: MB-SWIFT with 0.78 × 0.78 × 1.50 mm3 spatial resolution and 3-s temporal resolution was used at 9.4 Tesla in rats undergoing epidural SCS at different frequencies. Its performance was compared with spin echo EPI. The origin of the functional contrast was also explored using suppression bands. RESULTS: MB-SWIFT was tolerant to electrode-induced artifacts and respiratory motion, leading to substantially higher fMRI sensitivity than spin echo fMRI. Clear stimulation frequency-dependent responses to SCS were detected in the rat spinal cord close to the stimulation site. The origin of MB-SWIFT fMRI signals was consistent with dominant inflow effects. CONCLUSION: fMRI of the rat spinal cord during SCS can be consistently achieved with MB-SWIFT, thus providing a valuable experimental framework for assessing the effects of SCS on the central nervous system.


Asunto(s)
Estimulación de la Médula Espinal , Animales , Artefactos , Imagen por Resonancia Magnética , Proyectos Piloto , Ratas , Médula Espinal/diagnóstico por imagen
12.
Front Syst Neurosci ; 15: 641121, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33716681

RESUMEN

Prolonged mastication may induce an asymmetric modification of the local perfusion of the trigeminal principal nucleus. The aim of the present study was to evaluate the possible influence of vitamin C (vit. C) on such effect. Four groups of healthy volunteers underwent arterial spin labeling magnetic resonance imaging (ASL-MRI) to evaluate the local perfusion of the trigeminal nuclei after a vit. C-enriched lunch or a control lunch. Two ASL-MRI scans were acquired, respectively, before and after a 1 h-long masticating exercise or a 1 h long resting period. The results showed (i) an increased global perfusion of the brain in the vit. C-enriched lunch groups, (ii) an increased local perfusion of the right principal trigeminal nucleus (Vp) due to mastication, and (iii) a reduction of the rightward asymmetry of the Vp perfusion, due to mastication, after the vit C-enriched meal compared to the control meal. These results confirmed a long-lasting effect of prolonged mastication on Vp perfusion and also suggest a possible effect of vit. C on cerebral vascular tone regulation. Moreover, the data strongly draw attention on the side-to-side relation in Vp perfusion as a possible physiological parameter to be considered to understand the origin of pathological conditions like migraine.

13.
Sci Rep ; 11(1): 5504, 2021 03 09.
Artículo en Inglés | MEDLINE | ID: mdl-33750822

RESUMEN

Epidural spinal cord stimulation (ESCS) is widely used for chronic pain treatment, and is also a promising tool for restoring motor function after spinal cord injury. Despite significant positive impact of ESCS, currently available protocols provide limited specificity and efficiency partially due to the limited number of contacts of the leads and to the limited flexibility to vary the spatial distribution of the stimulation field in respect to the spinal cord. Recently, we introduced Orientation Selective (OS) stimulation strategies for deep brain stimulation, and demonstrated their selectivity in rats using functional MRI (fMRI). The method achieves orientation selectivity by controlling the main direction of the electric field gradients using individually driven channels. Here, we introduced a similar OS approach for ESCS, and demonstrated orientation dependent brain activations as detected by brain fMRI. The fMRI activation patterns during spinal cord stimulation demonstrated the complexity of brain networks stimulated by OS-ESCS paradigms, involving brain areas responsible for the transmission of the motor and sensory information. The OS approach may allow targeting ESCS to spinal fibers of different orientations, ultimately making stimulation less dependent on the precision of the electrode implantation.


Asunto(s)
Imagen por Resonancia Magnética , Traumatismos de la Médula Espinal , Estimulación de la Médula Espinal , Animales , Electrodos Implantados , Espacio Epidural/diagnóstico por imagen , Espacio Epidural/fisiopatología , Masculino , Ratas , Ratas Sprague-Dawley , Traumatismos de la Médula Espinal/diagnóstico por imagen , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/terapia
14.
Brain Imaging Behav ; 15(4): 2017-2030, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32989650

RESUMEN

Traumatic events can produce emotional, cognitive and autonomous physical responses. This may ultimately lead to post-traumatic stress disorder (PTSD), a psychiatric syndrome which requires comprehensive treatment. Trauma exposure alters functional connectivity; however, onset and nature of these changes are unknown. Here, we explore functional connectivity changes at rest directly after experimental trauma exposure. Seventy-three healthy subjects watched either a trauma or a control film. Resting state functional magnetic resonance imaging measurements were conducted before and directly after the film. Seed-based analyses revealed trauma-related changes in functional connectivity, specifically including decreases of connectivity between amygdala and middle temporal gyrus and increases between hippocampus and precuneus. These central effects were accompanied by trauma-related increases in heart rate. Moreover, connectivity between the amygdala and middle temporal gyrus predicted subsequent trauma-related valence. Our results demonstrate rapid functional connectivity changes in memory-related brain regions at rest after experimental trauma, selectively relating to changes in emotions evoked by the trauma manipulation. Results could represent an early predictive biomarker for the development of trauma-related PTSD and thus provide an indication for the need of early targeted preventive interventions.


Asunto(s)
Imagen por Resonancia Magnética , Trastornos por Estrés Postraumático , Amígdala del Cerebelo , Encéfalo/diagnóstico por imagen , Hipocampo/diagnóstico por imagen , Humanos , Trastornos por Estrés Postraumático/diagnóstico por imagen
15.
Neuroimage ; 224: 117357, 2021 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-32916285

RESUMEN

Functional MRI (fMRI) has become an important tool for probing network-level effects of deep brain stimulation (DBS). Previous DBS-fMRI studies have shown that electrical stimulation of the ventrolateral (VL) thalamus can modulate sensorimotor cortices in a frequency and amplitude dependent manner. Here, we investigated, using a swine animal model, how the direction and orientation of the electric field, induced by VL-thalamus DBS, affects activity in the sensorimotor cortex. Adult swine underwent implantation of a novel 16-electrode (4 rows x 4 columns) directional DBS lead in the VL thalamus. A within-subject design was used to compare fMRI responses for (1) directional stimulation consisting of monopolar stimulation in four radial directions around the DBS lead, and (2) orientation-selective stimulation where an electric field dipole was rotated 0°-360° around a quadrangle of electrodes. Functional responses were quantified in the premotor, primary motor, and somatosensory cortices. High frequency electrical stimulation through leads implanted in the VL thalamus induced directional tuning in cortical response patterns to varying degrees depending on DBS lead position. Orientation-selective stimulation showed maximal functional response when the electric field was oriented approximately parallel to the DBS lead, which is consistent with known axonal orientations of the cortico-thalamocortical pathway. These results demonstrate that directional and orientation-selective stimulation paradigms in the VL thalamus can tune network-level modulation patterns in the sensorimotor cortex, which may have translational utility in improving functional outcomes of DBS therapy.


Asunto(s)
Estimulación Encefálica Profunda , Corteza Motora/fisiología , Vías Nerviosas/fisiología , Núcleo Subtalámico/fisiología , Animales , Estimulación Encefálica Profunda/métodos , Estimulación Eléctrica/métodos , Femenino , Imagen por Resonancia Magnética/métodos , Porcinos , Tálamo/fisiología , Núcleos Talámicos Ventrales/fisiología
16.
Diabetes ; 69(11): 2458-2466, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32839347

RESUMEN

Even though well known in type 2 diabetes, the existence of brain changes in type 1 diabetes (T1D) and both their neuroanatomical and clinical features are less well characterized. To fill the void in the current understanding of this disease, we sought to determine the possible neural correlate in long-duration T1D at several levels, including macrostructural, microstructural cerebral damage, and blood flow alterations. In this cross-sectional study, we compared a cohort of 61 patients with T1D with an average disease duration of 21 years with 54 well-matched control subjects without diabetes in a multimodal MRI protocol providing macrostructural metrics (cortical thickness and structural volumes), microstructural measures (T1-weighted/T2-weighted [T1w/T2w] ratio as a marker of myelin content, inflammation, and edema), and cerebral blood flow. Patients with T1D had higher T1w/T2w ratios in the right parahippocampal gyrus, the executive part of both putamina, both thalami, and the cerebellum. These alterations were reflected in lower putaminal and thalamic volume bilaterally. No cerebral blood flow differences between groups were found in any of these structures, suggesting nonvascular etiologies of these changes. Our findings implicate a marked nonvascular disruption in T1D of several essential neural nodes engaged in both cognitive and motor processing.


Asunto(s)
Encéfalo/patología , Diabetes Mellitus Tipo 1/patología , Adolescente , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
17.
Neuroimage ; 213: 116750, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32198048

RESUMEN

Deep brain stimulation (DBS) has become an important tool in the management of a wide spectrum of diseases in neurology and psychiatry. Target selection is a vital aspect of DBS so that only the desired areas are stimulated. Segmented leads and current steering have been shown to be promising additions to DBS technology enabling better control of the stimulating electric field. Recently introduced orientation selective DBS (OS-DBS) is a related development permitting sensitization of the stimulus to axonal pathways with different orientations by freely controlling the primary direction of the electric field using multiple contacts. Here, we used OS-DBS to stimulate the subthalamic nucleus (STN) in healthy rats while simultaneously monitoring the induced brain activity with fMRI. Maximal activation of the sensorimotor and basal ganglia-thalamocortical networks was observed when the electric field was aligned mediolaterally in the STN pointing in the lateral direction, while no cortical activation was observed with the electric field pointing medially to the opposite direction. Such findings are consistent with mediolateral main direction of the STN fibers, as seen with high resolution diffusion imaging and histology. The asymmetry of the OS-DBS dipolar field distribution using three contacts along with the potential stimulation of the internal capsule, are also discussed. We conclude that OS-DBS offers an additional degree of flexibility for optimization of DBS of the STN which may enable a better treatment response.


Asunto(s)
Estimulación Encefálica Profunda/métodos , Electrodos Implantados , Núcleo Subtalámico/fisiología , Animales , Imagen por Resonancia Magnética , Masculino , Ratas , Ratas Sprague-Dawley
19.
Psychiatry Res Neuroimaging ; 299: 111069, 2020 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-32203897

RESUMEN

Eating disorders (EDs) have a possible neurodevelopmental pathogenesis. Our study aim was to assess regional cortical thickness (CT), local gyrification index (lGI) and fractal dimensionality (FD), as specific markers of cortical neurodevelopment in ED females. Twenty-two women with acute anorexia nervosa (acuAN), 10 with recovered anorexia nervosa (recAN), 24 with bulimia nervosa (BN) and 35 female healthy controls (HC) underwent a 3T MRI scan. All data were processed by FreeSurfer. Compared to recAN group women with acuAN showed a lower CT in multiple areas, while compared to HC they showed lower CT in temporal regions. BN group showed higher CT values in temporal and paracentral areas compared to HC. In multiple cortical areas, AcuAN group showed greater values of lGI compared to recAN group and lower values of lGI compared to HC. The BN group showed lower lGI in left medial orbitofrontal cortex compared to HC. No significant differences were found in FD among the groups. Present results provide evidence of CT and lGI alterations in patients with AN and, for the first time, in those with BN. Although these alterations could be state-dependent phenomena, they may underlie psychopathological aspects of EDs.


Asunto(s)
Anorexia Nerviosa/patología , Bulimia Nerviosa/patología , Corteza Cerebral/patología , Femenino , Fractales , Lóbulo Frontal/patología , Humanos , Imagen por Resonancia Magnética , Lóbulo Temporal/patología
20.
Orphanet J Rare Dis ; 15(1): 21, 2020 01 20.
Artículo en Inglés | MEDLINE | ID: mdl-31959195

RESUMEN

BACKGROUND: No information is currently available regarding the natural history of asymptomatic intracranial aneurysms in beta-thalassemia, raising several concerns about their proper management. METHODS: We performed a prospective longitudinal three-year-long MR-angiography study on nine beta-thalassemia patients (mean-age 40.3 ± 7.5, six females, 8 transfusion dependent) harboring ten asymptomatic intracranial aneurysms. In addition, we analyzed the clinical files of all adult beta-thalassemia patients (160 patients including those followed with MR-angiography, 121 transfusion dependent) referring to our Centers between 2014 and 2019 searching for history of subarachnoid hemorrhage or history of symptomatic intracranial aneurysms. RESULTS: At the end of the three-year-long follow-up, no patient showed any change in the size and shape of the aneurysms, none presented new intracranial aneurysms or artery stenoses, none showed new brain vascular-like parenchymal lesions or enlargement of the preexisting ones. Besides, in our database of all adult beta-thalassemia patients, no one had history of subarachnoid hemorrhage or history of symptomatic intracranial aneurysms. CONCLUSIONS: Incidental asymptomatic intracranial aneurysms do not seem to be associated, in beta-thalassemia, with an increased risk of complications (enlargement or rupture) at least in the short term period, helping to optimize human and economic resources and patient compliance during their complex long-lasting management.


Asunto(s)
Aneurisma Intracraneal , Talasemia beta , Adulto , Angiografía Cerebral , Femenino , Estudios de Seguimiento , Humanos , Angiografía por Resonancia Magnética , Persona de Mediana Edad , Estudios Prospectivos , Talasemia beta/complicaciones
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