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1.
J Affect Disord ; 294: 679-685, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34333176

RESUMEN

BACKGROUND: Noninvasive neurostimulation with transcranial Pulsed Electromagnetic Fields (tPEMF) may be a promising method for treatment resistant depression (TRD). Studies shown substantial improvement of depressive symptoms in patients with TRD, but there is no information on long-term antidepressant effects. The aim of this study was to investigate the short- and long-term efficacy of tPEMF in participants with TRD. METHODS: Eligible participants with TRD in this sham-controlled double-blind multicenter trial were randomly assigned to five weeks either daily active or sham tPEMF. Severity of depression and anxiety was assessed pre- and directly post-treatment and five and fifteen weeks post-treatment. Primary outcome was change on the 17-item Hamilton depression rating scale directly post-treatment. Secondary outcome was change on the Hamilton-17 during follow-up and change on the Inventory of Depressive Symptomatology Self-Report and the Beck Anxiety Index. RESULTS: Of the 55 included participants, 50 completed the treatment protocol. Depressive symptoms improved over time in both groups. The improvement continued until the last follow-up measure. There was no difference in outcome between the active and the sham group on change in depression post-treatment or on any secondary measure. CONCLUSION: Treatment with this type of active tPEMF was not superior to sham in patients with TRD. This is in contrast to a previous study using a similar design and power calculation, but a higher magnetic field strength, that reported improvement of depression after treatment with tPEMF compared to sham. An important limitation of our study was the fact that no different dosing regimens were tried.


Asunto(s)
Trastorno Depresivo Resistente al Tratamiento , Antidepresivos/uso terapéutico , Trastorno Depresivo Resistente al Tratamiento/tratamiento farmacológico , Método Doble Ciego , Campos Electromagnéticos , Humanos , Estimulación Magnética Transcraneal , Resultado del Tratamiento
2.
Neurosci Lett ; 699: 212-216, 2019 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-30710664

RESUMEN

BACKGROUND: Neuromodulation is nowadays investigated as a promising method for pain relief. Research indicates that a single 30-minute stimulation with transcranial pulsed electromagnetic fields (tPEMF) can induce analgesic effects. However, it is unknown whether tPEMF can induce analgesia in neuropathic pain patients. OBJECTIVE: To evaluate the effect of tPEMF on spontaneous pain and heat pain in neuropathic pain patients. METHODS: This study had a randomized double-blind crossover design. Twenty neuropathic pain patients received 30-minutes of tPEMF and 30-minutes sham stimulation. Primary outcomes were pain intensity, pain aversion and heat pain. Secondary outcomes included affect, cognition, and motor function, to investigate safety, tolerability and putative working mechanisms of tPEMF. Outcomes were assessed before, during and after stimulation. RESULTS: No differences in analgesic effects between tPEMF and sham stimulation were found for pain intensity, pain aversion or heat pain. No differences between tPEMF and sham stimulation were observed for affect, motor, and cognitive outcomes. CONCLUSION: A single 30-minute tPEMF stimulation did not induce analgesic effects in neuropathic pain patients, compared to sham. Further study is needed to determine whether prolonged stimulation is necessary for analgesic effects.


Asunto(s)
Analgesia/métodos , Neuralgia/terapia , Estimulación Magnética Transcraneal , Adolescente , Adulto , Afecto , Anciano , Anciano de 80 o más Años , Cognición , Estudios Cruzados , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Destreza Motora , Dimensión del Dolor , Estimulación Magnética Transcraneal/efectos adversos , Adulto Joven
3.
Br J Psychiatry ; 208(2): 108-13, 2016 02.
Artículo en Inglés | MEDLINE | ID: mdl-26834167

RESUMEN

BACKGROUND: Recent studies with intravenous (i.v.) application of ketamine show remarkable but short-term success in patients with MDD. Studies in patients with chronic pain have used different ketamine applications for longer time periods. This experience may be relevant for psychiatric indications. AIMS: To review the literature about the dosing regimen, duration, effects and side-effects of oral, intravenous, intranasal and subcutaneous routes of administration of ketamine for treatment-resistant depression and pain. METHOD: Searches in PubMed with the terms 'oral ketamine', 'depression', 'chronic pain', 'neuropathic pain', 'intravenous ketamine', 'intranasal ketamine' and 'subcutaneous ketamine' yielded 88 articles. We reviewed all papers for information about dosing regimen, number of individuals who received ketamine, number of ketamine days per study, results and side-effects, as well as study quality. RESULTS: Overall, the methodological strength of studies investigating the antidepressant effects of ketamine was considered low, regardless of the route of administration. The doses for depression were in the lower range compared with studies that investigated analgesic use. Studies on pain suggested that oral ketamine may be acceptable for treatment-resistant depression in terms of tolerability and side-effects. CONCLUSIONS: Oral ketamine, given for longer time periods in the described doses, appears to be well tolerated, but few studies have systematically examined the longer-term negative consequences. The short- and longer-term depression outcomes as well as side-effects need to be studied with rigorous randomised controlled trials.


Asunto(s)
Analgésicos/uso terapéutico , Dolor Crónico/tratamiento farmacológico , Trastorno Depresivo Resistente al Tratamiento/tratamiento farmacológico , Ketamina/efectos adversos , Ketamina/uso terapéutico , Administración Oral , Antidepresivos/uso terapéutico , Humanos , Dimensión del Dolor , Escalas de Valoración Psiquiátrica , Resultado del Tratamiento
4.
Depress Anxiety ; 33(1): 35-44, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26378742

RESUMEN

BACKGROUND: Abnormal brain activations during processing of emotional facial expressions in depressed patients have been demonstrated. We investigated the natural course of brain activation in response to emotional faces in depression, indexed by functional magnetic resonance imaging (fMRI) scans preceding and following change in depressive state. We hypothesized a decrease in activation in the amygdala, anterior cingulate cortex (ACC), and insula with a decrease in depressive pathology. METHODS: A 2-year longitudinal fMRI study was conducted as part of the Netherlands Study of Depression and Anxiety. We included 32 healthy controls and 49 depressed patients. During the second scan, 27 patients were in remission (remitters), the other 22 were not (nonremitters). All participants viewed faces with emotional expressions during scanning. RESULTS: Rostral ACC activation during processing of happy faces was predictive of a decrease in depressive state (PFWE = .003). In addition, remitters showed decreased activation of the insula over time (PFWE = .016), specifically during happy faces. Nonremitters displayed increased abnormalities in emotion recognition circuitry during the second scan compared to the first. No effect of selective serotonin reuptake inhibitor use was observed. CONCLUSIONS: Our results demonstrate that rostral ACC activation may predict changes in depressive state even at 2-year outcome. The association between change in depressed state and change in insula activation provides further evidence for the role of the insula in a network maintaining emotional and motivational states.


Asunto(s)
Encéfalo/fisiopatología , Trastorno Depresivo/fisiopatología , Imagen por Resonancia Magnética , Adulto , Mapeo Encefálico , Trastorno Depresivo/psicología , Emociones , Expresión Facial , Femenino , Humanos , Estudios Longitudinales , Masculino , Países Bajos
5.
J Sex Med ; 12(9): 1865-77, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26293889

RESUMEN

INTRODUCTION: Spina bifida (SB) causes low spinal lesions, and patients often have absent genital sensation and a highly impaired sex life. TOMAX (TO MAX-imize sensation, sexuality and quality of life) is a surgical procedure whereby the penis is newly innervated using a sensory nerve originally targeting the inguinal area. Most TOMAX-treated SB patients initially experience penile stimulation as inguinal sensation, but eventually, the perception shifts to penis sensation with erotic feelings. The brain mechanisms mediating this perceptual shift, which are completely unknown, could hold relevance for understanding the brain's role in sexual development. AIM: The aim of this study was to study how a newly perceived penis would be mapped onto the brain after a lifelong disconnection. METHODS: Three TOMAX-treated SB patients participated in a functional magnetic resonance imagery experiment while glans penis, inguinal area, and index finger were stimulated with a paint brush. MAIN OUTCOME MEASURE: Brush stimulation-induced activation of the primary somatosensory cortex (SI) and functional connectivity between SI and remote cerebral regions. RESULTS: Stimulation of the re-innervated side of the glans penis and the intact contralateral inguinal area activated a very similar location on SI. Yet, connectivity analysis identified distinct SI functional networks. In all three subjects, the middle cingulate cortex (MCC) and the parietal operculum-insular cortex (OIC) were functionally connected to SI activity during glans penis stimulation, but not to SI activity induced by inguinal stimulation. CONCLUSIONS: Investigating central somatosensory network activity to a de novo innervated penis in SB patients is feasible and informative. The consistent involvement of MCC and OIC above and beyond the brain network expected on the basis of inguinal stimulation suggests that these areas mediate the novel penis sensation in these patients. The potential role of MCC and OIC in this process is discussed, along with recommendations for further research.


Asunto(s)
Corteza Cerebral/fisiopatología , Giro del Cíngulo/fisiopatología , Pene/inervación , Pene/cirugía , Disrafia Espinal/fisiopatología , Procedimientos Quirúrgicos Urológicos Masculinos , Adulto , Anciano , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Calidad de Vida , Recuperación de la Función , Umbral Sensorial , Disrafia Espinal/psicología , Disrafia Espinal/cirugía , Tacto
6.
J Psychiatr Res ; 61: 150-7, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25533973

RESUMEN

The gene Disrupted-In-Schizophrenia-1 (DISC1) has been indicated as a determinant of psychopathology, including affective disorders, and shown to influence prefrontal cortex (PFC) and hippocampus functioning, regions of major interest for affective disorders. We aimed to investigate whether DISC1 differentially modulates brain function during executive and memory processing, and morphology in regions relevant for depression and anxiety disorders (affective disorders). 128 participants, with (n = 103) and without (controls; n = 25) affective disorders underwent genotyping for Ser704Cys (with Cys-allele considered as risk-allele) and structural and functional (f) Magnetic Resonance Imaging (MRI) during visuospatial planning and emotional episodic memory tasks. For both voxel-based morphometry and fMRI analyses, we investigated the effect of genotype in controls and explored genotypeXdiagnosis interactions. Results are reported at p < 0.05 FWE small volume corrected. In controls, Cys-carriers showed smaller bilateral (para)hippocampal volumes compared with Ser-homozygotes, and lower activation in the anterior cingulate cortex (ACC) and dorsolateral PFC during visuospatial planning. In anxiety patients, Cys-carriers showed larger (para)hippocampal volumes and more ACC activation during visuospatial planning. In depressive patients, no effect of genotype was observed and overall, no effect of genotype on episodic memory processing was detected. We demonstrated that Ser704Cys-genotype influences (para)hippocampal structure and functioning the dorsal PFC during executive planning, most prominently in unaffected controls. Results suggest that presence of psychopathology moderates Ser704Cys effects.


Asunto(s)
Función Ejecutiva , Hipocampo/fisiopatología , Imagen por Resonancia Magnética , Trastornos del Humor/genética , Trastornos del Humor/fisiopatología , Proteínas del Tejido Nervioso/genética , Adulto , Emociones , Femenino , Genotipo , Giro del Cíngulo/fisiopatología , Humanos , Masculino , Memoria , Persona de Mediana Edad , Trastornos del Humor/psicología , Polimorfismo de Nucleótido Simple , Corteza Prefrontal/fisiopatología
7.
Front Hum Neurosci ; 8: 866, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25386133

RESUMEN

Through education, a social group transmits accumulated knowledge, skills, customs, and values to its members. So far, to the best of our knowledge, the association between educational attainment and neural correlates of emotion processing has been left unexplored. In a retrospective analysis of The Netherlands Study of Depression and Anxiety (NESDA) functional magnetic resonance imaging (fMRI) study, we compared two groups of fourteen healthy volunteers with intermediate and high educational attainment, matched for age and gender. The data concerned event-related fMRI of brain activation during perception of facial emotional expressions. The region of interest (ROI) analysis showed stronger right amygdala activation to facial expressions in participants with lower relative to higher educational attainment (HE). The psychophysiological interaction analysis revealed that participants with HE exhibited stronger right amygdala-right insula connectivity during perception of emotional and neutral facial expressions. This exploratory study suggests the relevance of educational attainment on the neural mechanism of facial expressions processing.

8.
Soc Cogn Affect Neurosci ; 9(5): 601-9, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-23482625

RESUMEN

Neuropeptide Y (NPY) has been associated with stress reactivity in affective disorders and is most densely expressed in the amygdala. An important stressor associated with affective disorders is the experience of childhood emotional maltreatment (CEM). We investigated whether the interaction of NPY risk genotype and CEM would affect brain activation. From The Netherlands Study of Depression and Anxiety, 33 healthy controls and 85 patients with affective disorders were scanned with functional magnetic resonance imaging while making gender decisions of emotional facial expressions. Results showed interactions between genotype and CEM, within carriers of the risk genotype, CEM was associated with higher amygdala activation, whereas CEM did not influence activation in non-risk carriers. In the posterior cingulate cortex (PCC), less activation was seen in those with CEM and the risk genotype, whereas genotype did not influence PCC activation in those without CEM. In addition, those carrying the risk genotype and with experience of CEM made a faster gender decision than those without CEM. Thus, the combined effect of carrying NPY risk genotype and a history of CEM affected amygdala and PCC reactivity, areas related to emotion, self-relevance processing and autobiographical memory. These results are consistent with the notion that the combination of risk genotype and CEM may cause hypervigilance.


Asunto(s)
Encéfalo/fisiopatología , Maltrato a los Niños , Emociones/fisiología , Trastornos del Humor/genética , Trastornos del Humor/fisiopatología , Neuropéptido Y/genética , Adulto , Amígdala del Cerebelo/fisiopatología , Mapeo Encefálico , Niño , Expresión Facial , Femenino , Genotipo , Giro del Cíngulo/fisiopatología , Humanos , Imagen por Resonancia Magnética , Masculino , Reconocimiento Visual de Modelos/fisiología , Riesgo , Estrés Psicológico/genética
10.
Psychiatry Res ; 214(3): 269-76, 2013 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-24148912

RESUMEN

Emotional deficits are among the core features of schizophrenia and both associative emotional learning and the related ability to verbalize emotions can be reduced. We investigated whether schizophrenia patients demonstrated impaired function of limbic and prefrontal areas during associative emotional learning. Patients and controls filled out an alexithymia questionnaire and performed an associative emotional learning task with positive, negative and neutral picture-word pairs during fMRI scanning. After scanning, they indicated for each pair whether they remembered it. We conducted standard GLM analysis and Independent Component Analysis (ICA). Both the GLM results and task-related ICA components were compared between groups. The alexithymia questionnaire indicated more cognitive-emotional processing difficulties in patients than controls, but equal experienced intensity of affective states. Patients remembered less picture-word pairs, irrespective of valence. GLM analysis showed significant visual, temporal, amygdalar/hippocampal, and prefrontal activation in all subjects. ICA identified a network of brain areas similar to GLM, mainly in response to negative stimuli. Neither analysis showed differences between patients and controls during learning. Although in previous studies schizophrenia patients showed abnormalities in both memory and emotion processing, neural circuits involved in cross-modal associative emotional learning may remain intact to a certain degree, which may have potential consequences for treatment.


Asunto(s)
Encéfalo/fisiología , Emociones , Aprendizaje/fisiología , Esquizofrenia , Adulto , Síntomas Afectivos/fisiopatología , Mapeo Encefálico , Estudios de Casos y Controles , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Esquizofrenia/fisiopatología , Encuestas y Cuestionarios
11.
PLoS One ; 8(9): e73290, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24069183

RESUMEN

Major depressive disorder (MDD) has been associated with abnormal prefrontal-limbic interactions and altered catecholaminergic neurotransmission. The val158met polymorphism on the catechol-O-methyltransferase (COMT) gene has been shown to influence prefrontal cortex (PFC) activation during both emotional processing and working memory (WM). Although COMT-genotype is not directly associated with MDD, it may affect MDD pathology by altering PFC activation, an endophenotype associated with both COMT and MDD. 125 participants, including healthy controls (HC, n=28) and MDD patients were genotyped for the COMT val158met polymorphism and underwent functional magnetic resonance imaging (fMRI-neuroimaging) during emotion processing (viewing of emotional facial expressions) and a WM task (visuospatial planning). Within HC, we observed a positive correlation between the number of met-alleles and right inferior frontal gyrus activation during emotional processing, whereas within patients the number of met-alleles was not correlated with PFC activation. During WM a negative correlation between the number of met-alleles and middle frontal gyrus activation was present in the total sample. In addition, during emotional processing there was an effect of genotype in a cluster including the amygdala and hippocampus. These results demonstrate that COMT genotype is associated with relevant endophenotypes for MDD. In addition, presence of MDD only interacts with genotype during emotional processing and not working memory.


Asunto(s)
Encéfalo/fisiología , Emociones/fisiología , Memoria a Corto Plazo/fisiología , Adulto , Encéfalo/metabolismo , Catecol O-Metiltransferasa/metabolismo , Femenino , Genotipo , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Corteza Prefrontal/fisiología
12.
PLoS One ; 8(4): e61926, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23620795

RESUMEN

UNLABELLED: The 'complex neural pulse'(TM) (CNP) is a neuromodulation protocol employing weak pulsed electromagnetic fields (PEMF). A pioneering paper reported an analgesic effect in healthy humans after 30 minutes of CNP-stimulation using three nested whole head coils. We aimed to devise and validate a stimulator with a novel design entailing a multitude of small coils at known anatomical positions on a head cap, to improve applicability. The main hypothesis was that CNP delivery with this novel device would also increase heat pain thresholds. Twenty healthy volunteers were enrolled in this double-blind, sham-controlled, crossover study. Thirty minutes of PEMF (CNP) or sham was applied to the head. After one week the other treatment was given. Before and after each treatment, primary and secondary outcomes were measured. Primary outcome was heat pain threshold (HPT) measured with thermal quantitative sensory testing. Other outcomes were warmth detection threshold, and aspects of cognition, emotion and motor performance. As hypothesized heat pain threshold was significantly increased after the PEMF stimulation. All other outcomes were unaltered by the PEMF but there was a trend level reduction of cognitive performance after PEMF stimulation as measured by the digit-symbol substitution task. Results from this pilot study suggest that our device is able to stimulate the brain and to modulate its function. This is in agreement with previous studies that used similar magnetic field strengths to stimulate the brain. Specifically, pain control may be achieved with PEMF and for this analgesic effect, coil design does not appear to play a dominant role. In addition, the flexible configuration with small coils on a head cap improves clinical applicability. TRIAL REGISTRATION: Dutch Cochrane Centre NTR1093.


Asunto(s)
Salud , Magnetismo/instrumentación , Umbral del Dolor/fisiología , Adulto , Estudios Cruzados , Demografía , Método Doble Ciego , Campos Electromagnéticos , Emociones/fisiología , Femenino , Humanos , Masculino , Actividad Motora/fisiología , Fenómenos Fisiológicos de la Piel , Adulto Joven
13.
Neurobiol Aging ; 34(4): 1277-86, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23063645

RESUMEN

Brain microvasculature plays a critical role in the regulation of homeostasis of neural tissues. The present study focuses on characteristic microvascular basement membrane (bm) aberrations in the midbrain periaqueductal gray matter (PAG) and their relation to aging. The PAG can be considered a caudal extension of the limbic system and is a key structure in the regulation of a myriad of autonomic and motor control functions. In an ultrastructural study, morphologic changes in mesencephalic PAG capillaries were assessed in aged and young hamster and compared with those in caudal brainstem areas. Bm aberrations were studied in 1200 capillaries (n = 600 young hamsters; n = 600 aged hamsters). A new, never reported variant of bm degeneration was found that presented itself as foamy-like structures accumulating within the lamina densa of notably PAG capillaries. We classified these foamy structures as 'spumiform basement membrane degenerations' (sbmd) in which we could distinguish 4 stages depending on the size and intramembranous localization, ranging from split bm (stage I), intermediate stages II and III, to extensive stage IV, affecting almost the complete capillary bm outline. In the PAG of senescent animals various stages of sbmd were observed in 92 ± 3% of all capillaries. Stage II was most prominently present (59%), followed by stage III (20%), and stage IV (13%). These bm aberrations were clearly age-dependent because in young animals, only 5% of the PAG capillaries showed characteristics of sbmd. For comparison, in the pontine reticular formation at the PAG-level, 41% of the capillaries showed a form of sbmd, but these defects were significantly less severe (stages I-II, 98%), and caudal brainstem structures displayed no sbmd at all. In addition to sbmd, diffuse endothelial changes, disrupted tight junctions, thickening of the bm, pericyte degeneration, and gliosis were observed in PAG capillaries. It is hypothesized that selective bm permeability of PAG capillaries results in a sequence of bm damage events that start with split bm, gradually changing into more and more extensive sbmd accumulations that eventually almost completely surround the capillary. Progressive sbmd in PAG capillaries might lead to a loss of blood-brain barrier function and consequently to impairment of autonomic and motor control functions exerted by the PAG.


Asunto(s)
Membrana Basal/ultraestructura , Tronco Encefálico/irrigación sanguínea , Tronco Encefálico/ultraestructura , Capilares/ultraestructura , Trastornos Cerebrovasculares/patología , Animales , Cricetinae , Femenino , Mesocricetus
14.
PLoS One ; 7(8): e43526, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22927981

RESUMEN

Due to the lack of a specific diagnostic tool for neuropathic pain, a grading system to categorize pain as 'definite', 'probable', 'possible' and 'unlikely' neuropathic was proposed. Somatosensory abnormalities are common in neuropathic pain and it has been suggested that a greater number of abnormalities would be present in patients with 'probable' and 'definite' grades. To test this hypothesis, we investigated the presence of somatosensory abnormalities by means of Quantitative Sensory Testing (QST) in patients with a clinical diagnosis of neuropathic pain and correlated the number of sensory abnormalities and sensory profiles to the different grades. Of patients who were clinically diagnosed with neuropathic pain, only 60% were graded as 'definite' or 'probable', while 40% were graded as 'possible' or 'unlikely' neuropathic pain. Apparently, there is a mismatch between a clinical neuropathic pain diagnosis and neuropathic pain grading. Contrary to the expectation, patients with 'probable' and 'definite' grades did not have a greater number of abnormalities. Instead, similar numbers of somatosensory abnormalities were identified for each grade. The profiles of sensory signs in 'definite' and 'probable' neuropathic pain were not significantly different, but different from the 'unlikely' grade. This latter difference could be attributed to differences in the prevalence of patients with a mixture of sensory gain and loss and with sensory loss only. The grading system allows a separation of neuropathic and non-neuropathic pain based on profiles but not on the total number of sensory abnormalities. Our findings indicate that patient selection based on grading of neuropathic pain may provide advantages in selecting homogenous groups for clinical research.


Asunto(s)
Neuralgia/diagnóstico , Neuralgia/patología , Células Receptoras Sensoriales/patología , Adulto , Anciano , Estudios de Casos y Controles , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
15.
PLoS One ; 7(5): e37524, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22629414

RESUMEN

In patients who experience unilateral chronic pain, abnormal sensory perception at the non-painful side has been reported. Contralateral sensory changes in these patients have been given little attention, possibly because they are regarded as clinically irrelevant. Still, bilateral sensory changes in these patients could become clinically relevant if they challenge the correct identification of their sensory dysfunction in terms of hyperalgesia and allodynia. Therefore, we have used the standardized quantitative sensory testing (QST) protocol of the German Research Network on Neuropathic Pain (DFNS) to investigate somatosensory function at the painful side and the corresponding non-painful side in unilateral neuropathic pain patients using gender- and age-matched healthy volunteers as a reference cohort. Sensory abnormalities were observed across all QST parameters at the painful side, but also, to a lesser extent, at the contralateral, non-painful side. Similar relative distributions regarding sensory loss/gain for non-nociceptive and nociceptive stimuli were found for both sides. Once a sensory abnormality for a QST parameter at the affected side was observed, the prevalence of an abnormality for the same parameter at the non-affected side was as high as 57% (for Pressure Pain Threshold). Our results show that bilateral sensory dysfunction in patients with unilateral neuropathic pain is more rule than exception. Therefore, this phenomenon should be taken into account for appropriate diagnostic evaluation in clinical practice. This is particularly true for mechanical stimuli where the 95% Confidence Interval for the prevalence of sensory abnormalities at the non-painful side ranges between 33% and 50%.


Asunto(s)
Hiperalgesia/fisiopatología , Neuralgia/fisiopatología , Umbral del Dolor/fisiología , Trastornos de la Sensación/diagnóstico , Adulto , Anciano , Femenino , Humanos , Hiperalgesia/diagnóstico , Masculino , Persona de Mediana Edad , Dimensión del Dolor/métodos , Estimulación Física , Trastornos de la Sensación/fisiopatología
16.
Soc Cogn Affect Neurosci ; 7(6): 660-6, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22563009

RESUMEN

Alexithymia is a trait characterized by a diminished capacity to describe and distinguish emotions and to fantasize; it is associated with reduced introspection and problems in emotion processing. The default mode network (DMN) is a network of brain areas that is normally active during rest and involved in emotion processing and self-referential mental activity, including introspection. We hypothesized that connectivity of the DMN might be altered in alexithymia. Twenty alexithymic and 18 non-alexithymic healthy volunteers underwent a resting state fMRI scan. Independent component analysis was used to identify the DMN. Differences in connectivity strength were compared between groups. Within the DMN, alexithymic participants showed lower connectivity within areas of the DMN (medial frontal and temporal areas) as compared to non-alexithymic participants. In contrast, connectivity in the high-alexithymic participants was higher for the sensorimotor cortex, occipital areas and right lateral frontal cortex than in the low-alexithymic participants. These results suggest a diminished connectivity within the DMN of alexithymic participants, in brain areas that may also be involved in emotional awareness and self-referential processing. On the other hand, alexithymia was associated with stronger functional connections of the DMN with brain areas involved in sensory input and control of emotion.


Asunto(s)
Síntomas Afectivos/patología , Encéfalo/patología , Modelos Neurológicos , Vías Nerviosas/patología , Descanso , Adolescente , Adulto , Encéfalo/irrigación sanguínea , Femenino , Lateralidad Funcional , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Modelos Estadísticos , Vías Nerviosas/irrigación sanguínea , Oxígeno/sangre , Análisis de Componente Principal , Escalas de Valoración Psiquiátrica , Tiempo de Reacción , Encuestas y Cuestionarios , Adulto Joven
17.
Neurobiol Aging ; 33(12): 2920-34, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22445324

RESUMEN

UNLABELLED: The nucleus pararetroambiguus (NPRA) and the commissural nucleus of the solitary tract (NTScom) show estrogen nuclear receptor-α immunoreactivity (nuclear ER-α-IR). Both cell groups are involved in estrous cycle related adaptations. We examined in normally cycling aged hamsters the occurrence/amount/frequency of age-related degenerative changes in NPRA and NTScom during estrus and diestrus. In 2640 electron microscopy photomicrographs plasticity reflected in the ratio of axon terminal surface/dendrite surface (t/d) was morphometrically analyzed. Medial tegmental field (mtf, nuclear ER-α-IR poor), served as control. In aged animals, irrespective of nuclear ER-α-IR+ or nuclear ER-α-IR- related cell groups, extensive diffuse degenerative structural aberrations were observed. The hormonal state had a strong influence on t/d ratios in NPRA and NTScom, but not in mtf. In NPRA and NTScom, diestrous hamsters had significantly smaller t/d ratios (NPRA, 0.750 ± 0.050; NTScom, 0.900 ± 0.039) than the estrous hamsters (NPRA, 1.083 ± 0.075; NTScom, 1.204 ± 0.076). Aging affected axodendritic ratios only in mtf (p < 0.001). IN CONCLUSION: in the female hamster brain, estrous cycle-induced structural plasticity is preserved in NPRA and NTScom during aging despite the presence of diffuse age-related neurodegenerative changes.


Asunto(s)
Envejecimiento , Tronco Encefálico/citología , Estrógenos/metabolismo , Neuronas/metabolismo , Conducta Sexual Animal/fisiología , Factores de Edad , Animales , Tronco Encefálico/metabolismo , Cricetinae , Receptor alfa de Estrógeno/metabolismo , Ciclo Estral/metabolismo , Femenino , Masculino , Microscopía Electrónica de Transmisión , Neuronas/ultraestructura , Factores de Tiempo
18.
Eur Neuropsychopharmacol ; 22(6): 387-400, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22300864

RESUMEN

Decreased prefrontal activation (hypofrontality) in schizophrenia is thought to underlie negative symptoms and cognitive impairments, and may contribute to poor social outcome. Hypofrontality does not always improve during treatment with antipsychotics. We hypothesized that antipsychotics, which share antagonism at dopamine receptors, with a relatively low dopamine receptor affinity and high serotonin receptor affinity may have a sparing effect on prefrontal function compared to strong dopamine receptor antagonists. We systematically investigated the relation between serotonin and dopamine antagonism of antipsychotics and prefrontal functioning by reviewing neuroimaging studies. The weight of the evidence was consistent with our hypothesis that antipsychotics with low dopaminergic receptor affinity and moderate to high serotonergic affinity were associated with higher activation of the prefrontal cortex. However, clozapine, a weak dopamine and strong serotonin antagonist, was associated with decrease in prefrontal activation. Future studies should further elucidate the link between prefrontal activation and negative symptoms using prospective designs and advanced neuroimaging techniques, which may ultimately benefit the development of treatments for disabling negative symptoms.


Asunto(s)
Antipsicóticos/farmacología , Neuroimagen , Corteza Prefrontal/efectos de los fármacos , Receptores Dopaminérgicos/metabolismo , Animales , Bases de Datos Factuales/estadística & datos numéricos , Humanos , Corteza Prefrontal/diagnóstico por imagen , Corteza Prefrontal/metabolismo , Corteza Prefrontal/patología , Radiografía , Cintigrafía , Receptores de Serotonina/metabolismo , Esquizofrenia/tratamiento farmacológico , Esquizofrenia/patología
19.
Neurobiol Aging ; 33(3): 625.e1-9, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21550695

RESUMEN

Lipofuscin accumulation is a characteristic feature of senescent postmitotic neuronal cells but estrogen may have protecting effects by inhibiting its formation. In the present ultrastructural study, lipofuscin accumulation was studied in 2 estrogen-α-receptive brainstem areas: nucleus pararetroambiguus (NPRA) and the commissural part of the solitary tract nucleus/A2 catecholaminergic group (NTScom/A2) and compared with the estrogen-insensitive medial tegmental field (mtf), in young (23 weeks) and aged (95 weeks) female hamsters. In the aged animals, extensive intracytoplasmic lipofuscin accumulation was observed. A total number of 6450 neurons were classified in 4 categories. Levels were significantly elevated in each of the brain areas studied. Lipofuscin accumulation was strongest in the mtf, less in NPRA, and remarkably less in the area of NTScom/A2. In conclusion, the observed differences in lipofuscin accumulation suggest: (1) considerable regional differences in the degree of neuronal vulnerability; and (2) a possible neuroprotective role for estrogen, because the degree of accumulation is inversely related to the density of the estrogen receptors, varying from nonreceptive (mtf) to NPRA and NTScom/A2 (most receptive).


Asunto(s)
Envejecimiento/metabolismo , Tronco Encefálico/metabolismo , Lipofuscina/metabolismo , Neuronas/metabolismo , Envejecimiento/fisiología , Animales , Tronco Encefálico/fisiología , Senescencia Celular/fisiología , Cricetinae , Gránulos Citoplasmáticos/metabolismo , Gránulos Citoplasmáticos/fisiología , Receptor alfa de Estrógeno/metabolismo , Femenino , Masculino , Mesocricetus , Neuronas/fisiología
20.
Biol Psychiatry ; 71(7): 593-602, 2012 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-22206877

RESUMEN

BACKGROUND: Major depressive disorder (MDD), panic disorder, and social anxiety disorder are among the most prevalent and frequently co-occurring psychiatric disorders in adults and may be characterized by a common deficiency in processing of emotional information. METHODS: We used functional magnetic resonance imaging during the performance of an emotional word encoding and recognition paradigm in patients with MDD (n = 51), comorbid MDD and anxiety (n = 59), panic disorder and/or social anxiety disorder without comorbid MDD (n = 56), and control subjects (n = 49). In addition, we studied effects of illness severity, regional brain volume, and antidepressant use. RESULTS: Patients with MDD, prevalent anxiety disorders, or both showed a common hyporesponse in the right hippocampus during positive (>neutral) word encoding compared with control subjects. During negative encoding, increased insular activation was observed in both depressed groups (MDD and MDD + anxiety), whereas increased amygdala and anterior cingulate cortex activation during positive word encoding were observed as depressive state-dependent effects in MDD only. During recognition, anxiety patients showed increased inferior frontal gyrus activation. Overall, effects were unaffected by medication use and regional brain volume. CONCLUSIONS: Hippocampal blunting during positive word encoding is a generic effect in depression and anxiety disorders, which may constitute a common vulnerability factor. Increased insular and amygdalar involvement during negative word encoding may underlie heightened experience of, and an inability to disengage from, negative emotions in depressive disorders. Our results emphasize a common neurobiological deficiency in both MDD and anxiety disorders, which may mark a general insensitiveness to positive information.


Asunto(s)
Ansiedad/fisiopatología , Trastorno Depresivo Mayor/fisiopatología , Neuroimagen Funcional/psicología , Imagen por Resonancia Magnética/psicología , Memoria/fisiología , Trastorno de Pánico/fisiopatología , Reconocimiento en Psicología/fisiología , Adulto , Ansiedad/complicaciones , Ansiedad/psicología , Estudios de Casos y Controles , Trastorno Depresivo Mayor/complicaciones , Trastorno Depresivo Mayor/psicología , Femenino , Neuroimagen Funcional/métodos , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Trastorno de Pánico/complicaciones , Trastorno de Pánico/psicología , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Desempeño Psicomotor/fisiología , Índice de Severidad de la Enfermedad
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