Cognitive and Behavioral Neurology最新文献

Background: Impulsivity resulting in unrestrained eating has been implicated as a contributing factor for obesity. Delay discounting (DD) tasks where individuals choose between a smaller immediate reward and a larger delayed reward provide useful data to describe impulsive decision-making and to determine the extent to which delayed rewards are discounted.

Objective: To study the association between body mass index(BMI) and delay discounting for food and money in adult women.

Methods: We used a DD task with real food rewards to investigate impulsive decision-making as related to BMI in participants who self-identified as women. Participants in group A had a mean BMI of 21.4 (n = 14), and participants in group B had a mean BMI of 32.2 (n = 14). Each group was tested in a hungry state during a single session. We performed fMRI during a DD task requiring participants to choose between a food item (one sandwich) constituting a smaller immediate reward and multiple food items (two, three, or four sandwiches) constituting a series of larger delayed rewards available at different intervals. The steepness of the discounting curve for food was determined from these decisions. Participants then completed a monetary discounting task to facilitate a comparison of the discounting of food and monetary rewards.

Results: Participants in group B discounted food rewards more steeply than monetary rewards. Decisions for delayed rewards led to increased activations of brain areas related to executive control on fMRI, such as the head of the caudate nucleus and the anterior cingulate cortex (ACC) in group A, but not group B participants.

Conclusion: Our findings suggest that group B had difficulty deciding against the immediate food rewards due to insufficient recruitment of cortical control areas. Therefore, impulsivity is an important target for behavioral interventions in individuals with obesity.

Background: Antisocial behaviors occur in up to 91% of individuals with behavioral variant frontotemporal dementia (bvFTD). Prior work has shown that antisocial behaviors can be differentiated into aggressive and nonaggressive rule-breaking behavioral subtypes. Socioemotional dysfunction is common in bvFTD and unique compared to other types of dementia.

Objective: To determine whether socioemotional dysfunction relates to general antisocial behaviors in individuals with bvFTD, or whether different types of socioemotional dysfunction relate to aggressive versus rule-breaking behaviors.

Methods: Informants for 28 participants with bvFTD and 21 participants with Alzheimer disease (AD) completed the Social Behavior Questionnaire (SBQ) and the Interpersonal Reactivity Index (IRI). The SBQ measures the presence and severity of 26 antisocial behaviors, including subscales for aggressive behaviors (SBQ-AGG) and nonaggressive rule-breaking behaviors (SBQ-RB). The IRI measures cognitive and emotional empathy capabilities, including subscales for Empathic Concern (IRI-EC) and Perspective-taking (IRI-PT).

Results: As expected, participants with bvFTD had higher scores on the SBQ in total than participants with AD, as well as on the SBQ-AGG and SBQ-RB separately. Participants with bvFTD had lower scores on the IRI-EC and IRI-PT than participants with AD (P < 0.0001 for all measures). Lower scores on the IRI-PT correlated with higher scores on the SBQ-AGG-but not with higher scores on the SBQ-RB-across the combined group of participants (P = 0.007), and within participants in the bvFTD group (P = 0.01) specifically, after controlling for covariates of age, sex, dementia severity, and IRI-EC scores. Lower scores on the IRI-EC correlated with higher scores on the SBQ-AGG-but not with higher scores on the SBQ-RB-across the combined group of participants (P = 0.02) after controlling for covariates of age, sex, dementia severity, and IRI-PT scores.

Conclusion: Our results suggest that socioemotional dysfunction relates to antisocial behaviors in individuals with bvFTD, but that the mechanisms leading to aggressive and rule-breaking behaviors are differentiable, providing meaningful implications for distinct approaches to treatment and prevention.

Background: Individuals with idiopathic adult-onset isolated cervical dystonia (CD) may have cognitive difficulties and increased mood challenges. Social cognition and executive functioning may be particularly affected.

Objective: To explore social cognition and executive functioning performance in individuals with CD, using the Cambridge Neuropsychological Test Automated Battery (CANTAB), as previous research has used traditional, nondigital neuropsychological assessments. We sought to investigate the relationships between social cognition, executive functioning, mood, and disability in individuals with CD.

Methods: We recruited 37 individuals with CD, including 26 women with an age range of 33 to 69 years (M = 56.64, SD = 8.31) from a dystonia clinic in a hospital neurology department. The individuals completed selected tasks from the CANTAB measuring social cognition and executive functioning. We compared the individuals' performance with CANTAB normative data. Depression, anxiety, disease severity, and disability were measured.

Results: The individuals with CD had significantly lower scores than the CANTAB normative data in both social cognition and executive functioning tasks, with the largest differences evident in problem-solving, attention, and positive emotion bias tasks. Poorer emotion recognition was associated with increased difficulties in problem-solving tasks. The individuals demonstrated a bias toward identifying happiness in facial affect, which was related to a poorer recognition of emotions. Cognitive performance was not related to CD severity or disability or to current mood symptoms.

Conclusion: Difficulties with both social cognition and executive functioning were identified in the individuals with CD, and are likely important targets for clinical interventions.

Phonemic paraphasia, a common characteristic of conduction aphasia, has traditionally been attributed to phonological representation dysfunction. An alternative hypothesis posits that phonemic paraphasia arises from difficulty converting phonemes into their corresponding articulatory maneuvers. However, detailed case studies supporting this theory have been lacking. In this report, we present the case of a 61-year-old right-handed man with right temporo-parietal infarction who exhibited crossed aphasia characterized by typical conduction aphasia symptoms (eg, relatively fluent speech with intact comprehension, frequent phonemic paraphasia, and pronounced difficulties in oral repetition) in the absence of distorted articulation, syllable segmentation, and prosody impairment. Despite the frequent occurrence of phonemic paraphasia and articulatory challenges, our patient's phonological representations remained relatively intact. His phonemic paraphasia was often self-corrected to produce correct responses, a feature known as conduit d'approche. During the oral repetition of individual mora (ie, the smallest unit of speech in Japanese), we observed that the patient consistently traced the corresponding Hiragana phonetic symbol accurately, despite his difficulties in articulation. We substantiated this phenomenon through objective assessment and posit that it resulted from an unusual separation of language functions in crossed aphasia-specifically, a disconnection between phonological representations in the right temporo-parietal cortex and speech articulation engrams in the left hemisphere. In this case of conduction aphasia, articulatory-based phonemic paraphasia may be viewed as an inability to convert phonemes into the appropriate articulatory maneuvers rather than as phonological representation dysfunction or apraxia of speech.

Background: Impairment in semantic knowledge contributes to Alzheimer disease (AD)-related decline. However, the particulars of the impact AD has on specific domains of knowledge remain debatable.

Objective: To investigate the impact of AD on specific semantic categories that are integral to daily functions-living things and man-made objects.

Method: We administered a free-listing task (written version) to 19 individuals with AD and 15 cognitively normal older adults and assessed the task's relationship with other cognitive and functional tests in clinical use. We compared the contents of the lists of salient concepts generated by the AD and control groups.

Results: Group membership (AD or control), after controlling for age, sex, formal education, and an estimate of premorbid intellectual ability, predicted the groups' performance on the free-listing task across two categories. Functional status was inversely related to performance on the free-listing task, holding demographic variables constant. Based on a comparison of the contents of the free lists that were generated by the two groups, it was possible to conclude that, in individuals with AD, conceptual knowledge central to the respective categories was well preserved, whereas the peripheral conceptual material showed evidence of degradation.

Conclusion: The free-listing task, which is an easy-to-administer and cost-effective tool, could aid in the preliminary detection of semantic knowledge dysfunction, revealing concepts that are better preserved and, possibly, the characterization of AD. Cognitive assessment tools that can be applied across cultures are needed, and the free-listing task has the potential to address this gap.

Background: The rubber hand illusion (RHI) is a well-established method for studying body ownership: Given adequate concordance of visual, sensory, and proprioceptive stimuli, the individual experiences a rubber hand as his or her own.

Objective: To study the effects of a threat to the rubber hand.

Methods: We created a typical RHI paradigm but added threatening pain: Both the real hand of an individual and the rubber hand were stroked with a brush, either synchronously (RHI-inducing condition) or asynchronously (control condition), but only the rubber hand was then pricked with a needle to create a threatening pain condition. Event-related potentials (ERPs) were recorded in a group of 23 typically-developed individuals. ERP effects were source-localized using low-resolution electromagnetic tomography.

Results: The individuals consistently reported experience of the RHI during the experiment when the brush strokes were applied synchronously to both the real hand and the rubber hand. ERP analysis revealed that synchronous brush stroking gave rise to higher amplitude of frontal ERPs in the 100-200 ms range than asynchronous brush stroking, which was interpreted as reflecting the RHI. In the threatening pain condition, ERPs showed a greater positivity at frontocentral electrodes, source localized in the supplementary motor area (SMA).

Conclusion: SMA activation could reflect a control mechanism over reflexive motor activity, facilitating a possible threat-related response. Further studies should address ERP effects and the extent of the RHI to standard and threat stimuli in a correlative fashion to further elucidate the functional significance of the neurophysiological findings.

Background: While the cognitive hallmark of typical Alzheimer disease (AD) is impaired memory consolidation, increasing evidence suggests that the frontal lobes and associated executive functions are also impacted.

Objective: We examined two neurobehavioral executive function tasks and associations with cortical thickness in patients diagnosed with mild cognitive impairment (MCI), suspected AD dementia, and a healthy control group.

Methods: First, we compared group performances on a go/no-go (GNG) task and on Luria's Fist-Edge-Palm (FEP) motor sequencing task. We then examined correlations between neurobehavioral task performance and the thickness of frontal cortical regions, AD signature regions, broader unbiased brain regions, and white matter hyperintensities (WMH).

Results: Participants with MCI performed worse than healthy controls, but better than participants with suspected AD dementia on both tasks. Both GNG and FEP (to a slightly greater extent) tasks showed diffuse associations with most AD signature regions and multiple additional regions within the temporal, parietal, and occipital cortices. Similarly, both tasks showed significant associations with all other cognitive tasks examined. Of the frontal regions examined, only the middle frontal gyrus and pars opercularis were associated with performance on these tasks. Interactions between the precuneus and transtemporal gyri were most predictive of GNG task performance, while the interaction between superior temporal and lingual gyri was most predictive of FEP task performance.

Conclusion: This study replicates difficulties with both GNG and FEP tasks in participants with MCI and AD dementia. Both tasks showed widespread associations with the cortical thickness of various brain structures rather than localizing to frontal regions, consistent with the diffuse nature of AD.

The clinical features of neuropsychiatric systemic lupus erythematosus (NPSLE) are heterogeneous. Furthermore, therapeutic decision-making for NPSLE depends on the recognition of clinical syndromes that have not been sufficiently studied. This report describes the case of a 36-year-old woman with NPSLE who exhibited severe cognitive dysfunction and affective psychosis with persistent nihilistic delusions such as those described in the Cotard delusion. The patient insisted for several months that she was already dead. CSF analysis showed elevated levels of anti-ribosomal P antibodies and a positive determination of oligoclonal bands. Additionally, 18F -FDG PET/CT imaging revealed severe bilateral frontal hypermetabolism suggestive of brain inflammation and occipital hypometabolism. Results from the Systematic Lupus Erythematosus Disease Activity Index 2000 and the Systemic Lupus Erythematosus Disease Activity Score were consistent with an active state of the immunological disease. We then determined by an algorithm that this neuropsychiatric event could be attributed to the activity of the underlying immunological disease. Despite immunosuppressive and symptomatic treatment, only a partial improvement in cognition was achieved. The psychopathological features of the Cotard delusion remained unchanged 4 months after onset. However, we observed rapid remission of affective psychosis and significant improvement in cognition following electroconvulsive therapy. Subsequent follow-up examinations showed a sustained remission. This case describes a protracted form of the Cotard delusion, the diagnostic challenges that arise in the context of SLE, and treatment dilemmas that necessitate collaboration between neurology, psychiatry, and rheumatology.

Behavioral neurology & neuropsychiatry (BNNP) is a field that seeks to understand brain-behavior relationships, including fundamental brain organization principles and the many ways that brain structures and connectivity can be disrupted, leading to abnormalities of behavior, cognition, emotion, perception, and social cognition. In North America, BNNP has existed as an integrated subspecialty through the United Council for Neurologic Subspecialties since 2006. Nonetheless, the number of behavioral neurologists across academic medical centers and community settings is not keeping pace with increasing clinical and research demand. In this commentary, we provide a brief history of BNNP followed by an outline of the current challenges and opportunities for BNNP from the behavioral neurologist's perspective across clinical, research, and educational spheres. We provide a practical guide for promoting BNNP and addressing the shortage of behavioral neurologists to facilitate the continued growth and development of the subspecialty. We also urge a greater commitment to recruit trainees from diverse backgrounds so as to dismantle persistent obstacles that hinder inclusivity in BNNP-efforts that will further enhance the growth and impact of the subspecialty. With rapidly expanding diagnostic and therapeutic approaches across a range of conditions at the intersection of neurology and psychiatry, BNNP is well positioned to attract new trainees and expand its reach across clinical, research, and educational activities.