RESUMEN
Resting-state (rs) fMRI has been shown to be useful for preoperative mapping of functional areas in patients with brain tumors and epilepsy. However, its lack of standardization limits its widespread use and hinders multicenter collaboration. The American Society of Functional Neuroradiology, American Society of Pediatric Neuroradiology, and the American Society of Neuroradiology Functional and Diffusion MR Imaging Study Group recommend specific rs-fMRI acquisition approaches and preprocessing steps that will further support rs-fMRI for future clinical use. A task force with expertise in fMRI from multiple institutions provided recommendations on the rs-fMRI steps needed for mapping of language, motor, and visual areas in adult and pediatric patients with brain tumor and epilepsy. These were based on an extensive literature review and expert consensus.Following rs-fMRI acquisition parameters are recommended: minimum 6-minute acquisition time; scan with eyes open with fixation; obtain rs-fMRI before both task-based fMRI and contrast administration; temporal resolution of ≤2 seconds; scanner field strength of 3T or higher. The following rs-fMRI preprocessing steps and parameters are recommended: motion correction (seed-based correlation analysis [SBC], independent component analysis [ICA]); despiking (SBC); volume censoring (SBC, ICA); nuisance regression of CSF and white matter signals (SBC); head motion regression (SBC, ICA); bandpass filtering (SBC, ICA); and spatial smoothing with a kernel size that is twice the effective voxel size (SBC, ICA).The consensus recommendations put forth for rs-fMRI acquisition and preprocessing steps will aid in standardization of practice and guide rs-fMRI program development across institutions. Standardized rs-fMRI protocols and processing pipelines are essential for multicenter trials and to implement rs-fMRI as part of standard clinical practice.
Asunto(s)
Neoplasias Encefálicas , Epilepsia , Humanos , Niño , Adulto , Mapeo Encefálico/métodos , Imagen por Resonancia Magnética/métodos , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/cirugía , Epilepsia/diagnóstico por imagen , Epilepsia/cirugía , Lenguaje , Encéfalo/diagnóstico por imagenRESUMEN
Medial temporal lobe epilepsy (TLE), a condition known to affect the integrity and function of medial temporal lobe structures such as the hippocampus, has been shown to disrupt memory for real-life episodes. Here, patients with unilateral TLE, patients who received a unilateral temporal lobe resection to cure TLE, and healthy controls produced free narratives of autobiographical memories (AMs). To assess temporal resolution, narratives were segmented into bits of information, or details, which were classified according to how precisely they could be located within the time course of the AM. Categories included details corresponding to the entire AM, to parts or subevents within the AM, and to actions taking place within seconds to minutes. The number of details per category was tallied and compared between patients and controls. Temporal order was assessed by determining the correct (internally consistent) chronological order of the sequence of events within the narrative. Results indicate that while patients' memory for the parts or subevents of personal episodes was intact, as was their temporal order, their memory for the minute-by-minute unraveling of the episode was impaired. We believe this loss of temporally specific details may contribute to the reduced vividness of AM recollection in TLE patients. Our findings provide further evidence that patients with hippocampal damage retrieve skeletal AMs for which the gist of the memory is maintained, but the specific details are lost.
Asunto(s)
Epilepsia del Lóbulo Temporal , Hipocampo/fisiopatología , Trastornos de la Memoria/fisiopatología , Recuerdo Mental/fisiología , Lóbulo Temporal , Adulto , Estudios de Casos y Controles , Epilepsia del Lóbulo Temporal/fisiopatología , Epilepsia del Lóbulo Temporal/cirugía , Femenino , Lateralidad Funcional/fisiología , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Lóbulo Temporal/fisiopatología , Lóbulo Temporal/cirugíaRESUMEN
Patients with mesial temporal lobe epilepsy (mTLE) show structural and functional abnormalities in hippocampus and surrounding mesial temporal structures. Brain signal complexity appears to be a marker of functional integrity or capacity. We examined complexity in 8 patients with intracranial hippocampal electrodes during performance of memory tasks (scene encoding and recognition) known to be sensitive to mesial temporal integrity. Our patients were shown to have right mesial temporal seizure onsets, permitting us to evaluate both epileptogenic (right) and healthy (left) hippocampi. Using multiscale entropy (MSE) as a measure of complexity, we found that iEEG from the epileptogenic hippocampus showed less complexity than iEEG from the healthy hippocampus. This difference was reliable for encoding but not for recognition. Our results indicate that both functional integrity and cognitive demands influence hippocampal signal complexity.
Asunto(s)
Cognición/fisiología , Epilepsia del Lóbulo Temporal/patología , Lateralidad Funcional/fisiología , Hipocampo/fisiopatología , Memoria/fisiología , Adulto , Electroencefalografía/métodos , Entropía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Lóbulo Temporal/fisiopatologíaRESUMEN
Encoding and retrieval of relational information requires interaction between the hippocampus and various neocortical regions, but it is unknown whether the connectivity of hippocampal-neocortical networks is different at input and output stages. To examine this, we conducted a network analysis of event-related fMRI data collected during a face-recognition, remember/know paradigm. Directed analyses in the medial temporal lobe identified a small region in the left hippocampus that showed differential activation for encoding and retrieval of recollected versus familiar items. Multivariate seed partial least squares (PLS) analysis was used to identify brain regions that were functionally connected to this hippocampal region at encoding and retrieval of 'remembered' items. Anatomically based structural equation modeling (SEM) was then used to test for differences in effective connectivity of network nodes between these two memory stages. The SEM analysis revealed a reversal of directionality between the left hippocampus (LHC) and left inferior parietal cortex (LIPC) at encoding and retrieval. During encoding, activation of the LHC had a positive influence on the LIPC, whereas during retrieval the reverse pattern was found, i.e., the LIPC activation positively influenced LHC activation. These findings emphasize the importance of hippocampal-parietal connections and underscore the complexity of their interactions in initial binding and retrieval/reintegration of relational memory. We also found that, during encoding, the right hippocampus had a positive influence on the right retrospenial cortex, whereas during retrieval this influence was significantly weaker. We submit that examining patterns of connectivity can be important both to elaborate and constrain models of memory involving hippocampal-neocortical interactions.
Asunto(s)
Hipocampo/fisiología , Memoria/fisiología , Neocórtex/fisiología , Red Nerviosa/fisiología , Adulto , Mapeo Encefálico , Interpretación Estadística de Datos , Cara , Femenino , Humanos , Análisis de los Mínimos Cuadrados , Imagen por Resonancia Magnética , Masculino , Modelos Psicológicos , Modelos Estadísticos , Vías Nerviosas , Oxígeno/sangre , Estimulación Luminosa , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología , Reconocimiento en Psicología/fisiología , Lóbulo Temporal/fisiologíaRESUMEN
The contribution of the Wada test (intracarotid amytal procedure, IAP) to predicting postoperative memory outcome in left temporal lobe epilepsy (LTLE) is becoming increasingly controversial when preoperative neuropsychological evaluation and MRI findings are available. We retrospectively analyzed 59 patients with LTLE who underwent en bloc temporal lobe resection. All patients had valid bilateral IAP test results, complete pre- and postoperative neuropsychological evaluation, and MRI grading on a 5-point scale integrating T 2 signal increase and degree of atrophy. Thirty percent of patients showed postoperative memory decline. Multiple regression analysis revealed that significant predictors of decline [F(2.56)=22.71, P<0.001, r(2)=0.448] included preoperative memory learning score [t=-5.89, P<0.001] and MRI classification [t=3.10, P<0.003], but not IAP scores. The IAP is of no added value in the prediction of postoperative memory outcome in LTLE in the presence of comprehensive neuropsychological and MRI data.
Asunto(s)
Amobarbital , Epilepsia del Lóbulo Temporal/fisiopatología , Epilepsia del Lóbulo Temporal/cirugía , Memoria/fisiología , Pruebas Neuropsicológicas/normas , Adulto , Lobectomía Temporal Anterior/métodos , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Periodo Posoperatorio , Valor Predictivo de las Pruebas , Estadística como Asunto , Adulto JovenRESUMEN
We investigated the relationship between ear advantage scores on the Fused Dichotic Words Test (FDWT), and laterality of activation in fMRI using a verb generation paradigm in fourteen children with epilepsy. The magnitude of the laterality index (LI), based on spatial extent and magnitude of activation in classical language areas (BA 44/45, 21/22, 39) differed significantly for patients classified with unilateral left, compared to bilateral, language representation based on FDWT scores. Concordance with fMRI was higher for those classified with unilateral left, than bilateral language representation on the FDWT. Of note, asymmetry in temporal lobe, rather than frontal lobe, activation was more strongly related to the LI from the dichotic listening test. This study shows that the FDWT can provide a quick and valid estimate of lateralization in pre-surgical candidates, which can be readily adopted for other clinical or research purposes when an estimate of language dominance is desired.
Asunto(s)
Pruebas de Audición Dicótica , Dominancia Cerebral/fisiología , Epilepsia del Lóbulo Frontal/fisiopatología , Epilepsia del Lóbulo Temporal/fisiopatología , Lóbulo Frontal/fisiopatología , Lenguaje , Imagen por Resonancia Magnética , Lóbulo Temporal/fisiopatología , Mapeo Encefálico , Niño , Epilepsia del Lóbulo Frontal/cirugía , Epilepsia del Lóbulo Temporal/cirugía , Femenino , Humanos , Masculino , Pruebas Neuropsicológicas , Pronóstico , Habla/fisiología , Percepción del Habla/fisiología , Conducta Verbal/fisiología , Pruebas de Asociación de PalabrasRESUMEN
Mild cognitive impairment (MCI) is a term for nondemented individuals with memory complaints and deficits greater than age-adjusted normal performance. Functional MRI (fMRI) may be a more sensitive method than other techniques to reveal functional abnormalities in individuals with MCI, only a proportion of whom progress to Alzheimer's disease (AD). fMRI was carried out while subjects (four MCI, five age-matched normal controls, and one AD) performed incidental encoding (deep and shallow) and recognition tasks for colored and black and white photographs contrasted to baseline fixation. fMRI revealed interesting dissociations between activation patterns and behavioral performance when comparing the MCI and AD to the NC.
Asunto(s)
Enfermedad de Alzheimer/fisiopatología , Mapeo Encefálico , Trastornos del Conocimiento/fisiopatología , Cognición/fisiología , Trastornos de la Memoria/fisiopatología , Envejecimiento/fisiología , Enfermedad de Alzheimer/etiología , Análisis de Varianza , Trastornos del Conocimiento/complicaciones , Progresión de la Enfermedad , Humanos , Imagen por Resonancia Magnética , Análisis por Apareamiento , Trastornos de la Memoria/complicaciones , Valores de Referencia , Índice de Severidad de la EnfermedadRESUMEN
Phonological and semantic aspects of language were examined in patients with unilateral temporal lobe epilepsy (TLE) and healthy controls using functional MRI. We expected to replicate previous findings in healthy individuals showing relatively greater activation in frontal regions for phonological compared with semantic processing, and greater activation in temporal regions for semantic compared with phonological processing. We hypothesized that differences between patients with left TLE and healthy controls would be found in the pattern of left temporal cortical activation associated specifically with semantic processing. Patients with right TLE were included as a seizure control group. All TLE patients previously showed left hemisphere language dominance on intracarotid sodium amytal studies. Greater blood oxygen level dependent activation was found during phonological processing compared with semantic processing in frontal regions for healthy participants but, contrary to expectation, semantic processing did not lead to increased temporal lobe activity relative to phonological processing. Furthermore, no differences between left temporal patients and controls were found specifically in left temporal cortex. Rather, patients with left temporal seizure foci showed significantly greater left dorsolateral prefrontal activity compared with controls, as well as increased signal change in left inferior frontal and right middle temporal gyrus. Surprisingly, patients with right, but not left, TLE showed poorer performance on the linguistic tasks compared with controls, as well as a decrease in right superior temporal activation. The results converge with studies of dyslexic patients showing increased left frontal activity in the presence of left temporal dysfunction and are suggestive of both inter- and intra-hemispheric functional reorganization of language representation in left TLE.
Asunto(s)
Epilepsia del Lóbulo Temporal/fisiopatología , Lóbulo Frontal/fisiopatología , Trastornos del Lenguaje/fisiopatología , Lóbulo Temporal/fisiopatología , Conducta Verbal/fisiología , Adolescente , Adulto , Afasia/etiología , Afasia/patología , Afasia/fisiopatología , Trastornos de la Articulación/etiología , Trastornos de la Articulación/patología , Trastornos de la Articulación/fisiopatología , Mapeo Encefálico , Epilepsia del Lóbulo Temporal/patología , Femenino , Lóbulo Frontal/patología , Lateralidad Funcional/fisiología , Humanos , Trastornos del Lenguaje/etiología , Trastornos del Lenguaje/patología , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Plasticidad Neuronal/fisiología , Pruebas Neuropsicológicas , Desempeño Psicomotor/fisiología , Tiempo de Reacción/fisiología , Recuperación de la Función/fisiología , Caracteres Sexuales , Lóbulo Temporal/patologíaRESUMEN
OBJECTIVES: Studies indicate that men with prostate cancer (MPC) adopt passive roles in cancer management; however, increasing public awareness of prostate cancer and advocacy by MPC and their allies suggest otherwise. This study looks at the information that is important to MPC; their preferred participation in decision making; and the influence of sociodemographic, disease, and psychological factors on information needs and decision preferences. METHOD: Consecutive men diagnosed with prostate cancer and attending two tertiary care cancer clinics completed questionnaires on information needs and decision preferences. Questions included demographic information, health and disease status, psychosocial functioning, optimism, and decisional preferences and information preferences for content, type, focus, format, and amount. RESULTS: Questionnaires were completed by 101 MPC. Their mean age was 70 years and most were married and well-educated. Over 70% wanted detailed information at all illness stages focusing on their disease, treatment, survival, self-care, and empowerment. Over 60% of MPC wanted shared decision making with their physician. Psychological variables were found to influence information needs but not involvement in decision making. CONCLUSION: These results represent a challenge to health-care providers for accomodating the informational needs and decision preferences of individual MPC.
Asunto(s)
Educación del Paciente como Asunto , Participación del Paciente , Neoplasias de la Próstata/psicología , Trastornos Psicofisiológicos/psicología , Rol del Enfermo , Adaptación Psicológica , Anciano , Necesidades y Demandas de Servicios de Salud , Humanos , MasculinoRESUMEN
The nature of remote memory impairment in patients with medial temporal lobe damage is the subject of some debate. While some investigators have found that retrograde amnesia in such patients is temporally graded, with relative sparing of remote memories (Squire and Alvarez, 1995), others contend that impairment is of very long duration and that remote memories are not necessarily spared (Sanders and Warrington, 1971; Nadel and Moscovitch, 1997). In this study, remote memory was assessed in 25 patients with unilateral temporal lobe epilepsy and 22 non-neurologically impaired controls using the Autobiographical Memory Interview (Kopelman et al., 1989). Results indicate that patients have impaired personal episodic memory but intact personal semantic memory. The impairment extends even to the most remote time periods in early childhood, long before seizure onset in many patients. As well, patients awaiting temporal lobectomy for control of seizures perform as poorly as those who have already undergone resective surgery. These results support the hypothesis that temporal lobe damage or dysfunction, caused by recurrent seizures or surgical excision, results in extensive retrograde amnesia for personal episodic memories. Interestingly, patients with radiological evidence of hippocampal sclerosis were not significantly more impaired than those without obvious sclerosis. These results indicate that even minimal damage to medial temporal lobes results in significant impairment to autobiographical episodic memory. These findings are more compatible with a memory loss or retrieval deficit rather than a consolidation account of remote memory impairment.
Asunto(s)
Epilepsia del Lóbulo Temporal/fisiopatología , Trastornos de la Memoria/fisiopatología , Recuerdo Mental/fisiología , Adulto , Análisis de Varianza , Epilepsia del Lóbulo Temporal/cirugía , Hipocampo/fisiopatología , Humanos , Trastornos de la Memoria/cirugía , Persona de Mediana Edad , Pruebas Neuropsicológicas/estadística & datos numéricos , Variaciones Dependientes del Observador , Lóbulo Temporal/fisiopatología , Lóbulo Temporal/cirugíaRESUMEN
OBJECTIVES: Studies show that women with cancer want more information about and participation in all aspects of their healthcare including decision-making. However, most studies have been done on women with breast cancer, which often runs a lengthy course and has strong patient-advocacy groups. Little is known about the preferences of women with ovarian cancer, the fifth leading cause of cancer death in women, which often has a more rapidly fatal course. METHODS: This study of women with ovarian cancer investigates what information is most vital for women with ovarian cancer, their preferred role in decision-making, and the influence of sociodemographic, disease-related, and psychological factors. RESULTS: Questionnaires were completed by 105 women with ovarian cancer in two Canadian university hospital oncology clinics. Their mean age was 55.8 +/- 14. 9 years. Most were married, well-educated, and considered their health status to be excellent or good, even though over 60% had metastatic disease. Over 80% of these women wanted detailed information about ovarian cancer during the diagnosis, treatment, and posttreatment stages of their disease. In particular, they wanted information pertaining to the disease, treatment, and self-care issues. Approximately 60% of women preferred to share decision-making with their doctors at every stage of the illness. Psychological variables and disease severity were found to influence information needs and decisional preferences. In general, the more psychologically distressed the women, the more information they wanted about coping strategies and the more serious the illness, the more shared decision-making was desired. CONCLUSION: These results present a challenge to health care providers in more adequately meeting the individual information needs of women with ovarian cancer and involving them to the extent that they wish in the decision-making process.
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Servicios de Información , Neoplasias Ováricas/psicología , Educación del Paciente como Asunto , Adulto , Anciano , Toma de Decisiones , Demografía , Femenino , Humanos , Salud Mental , Persona de Mediana Edad , Neoplasias Ováricas/terapia , Satisfacción del Paciente , Índice de Severidad de la Enfermedad , Clase SocialRESUMEN
Attentional control in children and adolescents with unilateral temporal-lobe excisions was examined using two experimental tasks, a lexical-decision and a spatial-cue task, and a standardized vigilance task. Participants with left temporal excisions took longer than controls to reorient their attention after invalid cues compared to neutral cues in the lexical task and they made more errors on all three of the tasks. Participants with right temporal excisions differed from controls in the number of errors made on the spatial task. No differences were found between the lesion and control groups on reaction-time measures of the spatial task. The results suggest that a material-specific inhibition impairment, as well as a more general sustained attention deficit, may result after a left temporal excision in childhood or adolescence. These deficits are considered in the context of neuroanatomical models of attentional control.
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Trastorno por Déficit de Atención con Hiperactividad/etiología , Trastorno por Déficit de Atención con Hiperactividad/psicología , Inteligencia/fisiología , Lóbulo Temporal/fisiología , Adolescente , Nivel de Alerta/fisiología , Niño , Señales (Psicología) , Toma de Decisiones , Epilepsia/cirugía , Femenino , Humanos , Pruebas de Inteligencia , Lenguaje , Masculino , Proyectos Piloto , Desempeño Psicomotor/fisiología , Percepción Espacial/fisiología , Lóbulo Temporal/cirugíaRESUMEN
This study examined the distribution of alcohol-related and other dementias in a sample of 130 cognitively impaired residents of long-term care facilities in a Northern Ontario community. Study procedures entailed standardized psychiatric, neurological, and neuropsychological evaluations. Diagnoses of dementia of the Alzheimer type (DAT) and vascular dementia were based on criteria of the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association. The diagnosis of alcohol-related dementia (ARD) was based on extensive review of medical history to assess before alcohol abuse and stabilization or improvement in cognitive functioning following institutionalization in conjunction with no other identifiable cause of dementia. ARD comprised 24% of this population compared with DAT (35%), vascular dementia (19%), and other causes (22%). The ARD group was, on average, 10 years younger than the other groups. It had nearly twice the average length of institutionalization and had milder cognitive impairment on both clinical ratings and neuropsychological tests. A diagnosis of ARD was present in the medical records for only 25% of patients in this group. These findings suggest that ARD may be more common than previously suspected in the distribution of dementias in long-term care facilities.
Asunto(s)
Demencia/epidemiología , Institucionalización/estadística & datos numéricos , Psicosis Alcohólicas/epidemiología , Anciano , Anciano de 80 o más Años , Consumo de Bebidas Alcohólicas/efectos adversos , Consumo de Bebidas Alcohólicas/epidemiología , Enfermedad de Alzheimer/clasificación , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/epidemiología , Enfermedad de Alzheimer/psicología , Estudios Transversales , Demencia/clasificación , Demencia/diagnóstico , Demencia/psicología , Demencia Vascular/clasificación , Demencia Vascular/diagnóstico , Demencia Vascular/epidemiología , Demencia Vascular/psicología , Diagnóstico Diferencial , Femenino , Humanos , Incidencia , Cuidados a Largo Plazo/estadística & datos numéricos , Masculino , Escala del Estado Mental/estadística & datos numéricos , Persona de Mediana Edad , Pruebas Neuropsicológicas/estadística & datos numéricos , Ontario/epidemiología , Psicometría , Psicosis Alcohólicas/clasificación , Psicosis Alcohólicas/diagnóstico , Psicosis Alcohólicas/psicologíaRESUMEN
Patients with unilateral frontal- or temporal-lobe excisions and normal control subjects made relative-recency decisions about objects presented sequentially. Several objects within each series were presented in the context of actions to be performed using them, such as "squeeze the sponge", whereas others had only to be named. Both left and right frontal-lobe groups were impaired on order judgements for named items, but their performance was normal for action items. The results suggest that providing salient and distinctive items, involving meaningful actions and multimodal cues, helps compensate for deficits in memory for temporal information associated with frontal-lobe damage.
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Lóbulo Frontal/fisiopatología , Memoria/fisiología , Lóbulo Temporal/fisiopatología , Adolescente , Adulto , Análisis de Varianza , Discriminación en Psicología , Epilepsia/fisiopatología , Epilepsia/psicología , Epilepsia/cirugía , Femenino , Lóbulo Frontal/cirugía , Humanos , Masculino , Persona de Mediana Edad , Tiempo de Reacción , Lóbulo Temporal/cirugíaAsunto(s)
Lóbulo Frontal/fisiología , Memoria/fisiología , Adolescente , Adulto , Discriminación en Psicología , Lóbulo Frontal/anatomía & histología , Lóbulo Frontal/cirugía , Humanos , Persona de Mediana Edad , Lóbulo Temporal/anatomía & histología , Lóbulo Temporal/fisiología , Lóbulo Temporal/cirugía , TiempoRESUMEN
This experiment investigated the durability of implicit memory for a single episode in normal and amnesic subjects. The target materials consisted of sentence puzzles that were difficult to comprehend in the absence of a key word or phrase. Sentences were re-presented at delays ranging from one minute to one week, and implicit memory was indicated by facilitation in solving previously incomprehensible sentences on subsequent exposures. Patients with severe memory impairments on tests of explicit recall and recognition showed substantial and robust facilitation, or priming, from a single prior presentation and there was no evidence of a systematic decay of facilitation over retention intervals up to one week. The long-lasting implicit memory observed in the sentence puzzle task contrasts with previous findings of rapid decay of priming effects in amnesic patients.
Asunto(s)
Amnesia/fisiopatología , Memoria/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Tiempo , Aprendizaje Verbal/fisiologíaAsunto(s)
Afecto , Autoimagen , Estado de Conciencia , Femenino , Humanos , Masculino , Factores SexualesRESUMEN
Twenty-four young (M = 28 years) and 24 old (M = 70 years) adults completed a lexical decision task in which they saw two strings of letters on each trial and were asked to respond "yes" only if both strings were words. For both ages, decisions were faster when the words were associated than when they were not. This pattern emerged for both ages, regardless of whether the associated pairs were category-member or descriptive-property associates. The same participants were also presented with a list of words to free recall. There was a decline with age both in the number of words recalled and in the degree of categorical clustering, particularly of low frequency category exemplars. Viewed from the perspective of two-process semantic activation models, these results place constraints on processing-deficit theories, and are consistent with the hypothesis that effortful processes change with aging, whereas automatic processes do not.