Lucas Drucaroff

Higher autonomic activation predicts better performance in Iowa Gambling Task

ObjectiveTo evaluate the relationship between the autonomic nervous system basal state and performance in decision-making tasks. BackgroundThe link between performance in decision-making tasks and acute changes in autonomic parameters during their execution has been extensively investigated. However, there is lacking evidence regarding the relationship between decision making and basal autonomic state. MethodsResting autonomic nervous system activity in 18 healthy individuals was assessed by means of heart rate variability (HRV) analysis before conducting 3 different decision-making tasks: an ambiguous one, the Iowa Gambling Task; a test that assesses risk-taking behavior, the Game of Dice Task; and a test that assesses reversal learning behavior, the Reversal Learning Task. The tasks were administered in a random manner. ResultsThere was a direct correlation between the Iowa Gambling Task net score and the resting low frequency HRV (r=0.73; P<0.001), which is strongly influenced by sympathetic activity. No correlations were found between HRV and the Game of Dice Task net score or the Reversal Learning Task last error trial. ConclusionsThe results are compatible with the idea that a higher basal activation of autonomic nervous system is beneficial for subsequent decision-making process.

Olfactory Dysfunction Evaluation Is Not Affected by Comorbid Depression in Parkinson's Disease.

Olfactory function assessment is an important screening tool for Parkinsons disease (PD) diagnosis. It is debated whether olfaction is affected by comorbid depression. We assessed the relationship between depression and olfaction in PD and determined whether depression may limit the usefulness of olfactory testing for PD diagnosis.

Brain activation induced by psychological stress in patients with schizophrenia

Environmental influences are critical for the expression of genes putatively related to the behavioral and cognitive phenotypes of schizophrenia. Among such factors, psychosocial stress has been proposed to play a major role in the expression of symptoms. However, it is unsettled how stress interacts with pathophysiological pathways to produce the disease. We studied 21 patients with schizophrenia and 21 healthy controls aged 18 to 50years with 3T-fMRI, in which a period of 6min of resting state acquisition was followed by a block design, with three blocks of 1-min control-task, 1-min stress-task and 1-min rest after-task. Self-report of stress and PANSS were measured. Limbic structures were activated in schizophrenia patients by simple tasks and remained active during, and shortly after stress. In controls, stress-related brain activation was more time-focused, and restricted to the stressful task itself. Negative symptom severity was inversely related to activation of anterior cingulum and orbitofrontal cortex. Results might represent the neurobiological aspect of hyper-reactivity to normal stressful situations previously described in schizophrenia, thus providing evidence on the involvement of limbic areas in the response to stress in schizophrenia. Patients present a pattern of persistent limbic activation probably contributing to hypervigilance and subsequent psychotic thought distortions.

Short apraxia screening test

Background: Limb apraxia comprises many different and common disorders, which are largely unrecognized essentially because there is no easy-to-use screening test sensitive enough to identify all types of limb praxis deficits. Method: We evaluated 70 right-handed patients with limb apraxia due to a single focal lesion of the left hemisphere and 40 normal controls, using a new apraxia screening test. The test covered 12 items including: intransitive gestures, transitive gestures elicited under verbal, visual, and tactile modalities, imitation of meaningful and meaningless postures and movements, and a multiple object test. Results: Interrater reliability was maximum for a cutoff of >2 positive items identifying apraxia on the short battery (Cohen’s kappa .918, p < .0001), and somewhat less for >3 items (Cohen’s kappa .768, p < .0001). Although both results were statistically significant, >2 was higher, indicating greater apraxia diagnosis agreement between raters at this cutoff value. Conclusions: The screening test proved to have high specificity and sensitivity to diagnose every type of upper limb praxis deficit, thus showing advantages over previously published tests.

Cluster B personality symptoms in persons at genetic risk for schizophrenia are associated with social competence and activation of the right temporo-parietal junction during emotion processing

Personality disorders are common in nonpsychotic siblings of patients with schizophrenia, and some personality traits in this group may be associated with an increased risk for full-blown psychosis. We sought to establish if faulty right-hemisphere activation induced by social cognitive tasks, as previously described in patients with schizophrenia, is associated with specific personality symptoms in their unaffected siblings. We observed that cluster B personality symptoms in this group were inversely related to activation in the right temporo parietal junction (rTPJ, a structure critical in social cognitive processing) in response to a basic emotion processing task and also to social competence, whereas in contrast to our initial hypothesis, cluster A traits were not associated with right hemisphere activation during emotion processing or with social competence. These findings suggest the existence of clinical traits in at-risk individuals which share a common neurobiological substrate with schizophrenia, in regards to social performance.

Failure to Recover from Proactive Semantic Interference and Abnormal Limbic Connectivity in Asymptomatic, Middle-Aged Offspring of Patients with Late-Onset Alzheimer’s Disease

BACKGROUND We have obtained previous evidence of limbic dysfunction in middle-aged, asymptomatic offspring of late-onset Alzheimers disease (LOAD) patients, and failure to recover from proactive semantic interference has been shown to be a sensitive cognitive test in other groups at risk for LOAD. OBJECTIVE To assess the effects of specific proactive semantic interference deficits as they relate to functional magnetic resonance imaging (fMRI) neocortical and limbic functional connectivity in middle aged offspring of individuals with LOAD (O-LOAD) and age-equivalent controls. METHODS We examined 21 O-LOAD and 20 controls without family history of neurodegenerative disorders (CS) on traditional measures of cognitive functioning and the LASSI-L, a novel semantic interference test uniquely sensitive to the failure to recover from proactive interference (frPSI). Cognitive tests then were correlated to fMRI connectivity of seeds located in entorhinal cortex and anterodorsal thalamic nuclei among O-LOAD and CS participants. RESULTS Relative to CS, O-LOAD participants evidenced lower connectivity between entorhinal cortex and orbitofrontal, anterior cingulate, and anterior temporal cortex. In the offspring of LOAD patients, LASSI-L measures of frPSI were inversely associated with connectivity between anterodorsal thalamus and contralateral posterior cingulate. Intrusions on the task related to frPSI were inversely correlated with a widespread connectivity network involving hippocampal, insular, posterior cingulate, and dorsolateral prefrontal cortices, along with precunei and anterior thalamus in this group. Different patterns of connectivity associated with frPSI were observed among controls. CONCLUSION The present results suggest that both semantic interference deficits and connectivity abnormalities might reflect limbic circuit dysfunction as a very early clinical signature of LOAD pathology, as previously demonstrated for other limbic phenotypes, such as sleep and circadian alterations.

Brain Structural and Amyloid Correlates of Recovery From Semantic Interference in Cognitively Normal Individuals With or Without Family History of Late-Onset Alzheimer’s Disease

Failure to recover from proactive semantic interference (frPSI) has been shown to be more sensitive than traditional cognitive measures in different populations with preclinical Alzheimers disease. The authors sought to characterize the structural and amyloid in vivo correlates of frPSI in cognitively normal offspring of patients with late-onset Alzheimers disease (O-LOAD), compared with individuals without a family history of neurodegenerative disorders (CS). The authors evaluated the LASSI-L, a test tapping frPSI and other types of semantic interference and delayed recall on the RAVLT, along with 3-T MRI volumetry and positron emission tomography Pittsburgh compound B, in 27 O-LOAD and 18 CS with equivalent age, sex, years of education, ethnicity, premorbid intelligence, and mood symptoms. Recovery from proactive semantic interference (frPSI) and RAVLT delayed recall were lower in O-LOAD cases. Structural correlates of both cognitive dimensions were different in CS and O-LOAD, involving brain regions concerned with autonomic, motor, and motivational control in the former, and regions traditionally implicated in Alzheimers disease in the latter. Better recovery from retroactive semantic interference was associated with less amyloid load in the left temporal lobe in O-LOAD but not CS. In middle-aged cognitively normal individuals with one parent affected with LOAD, frPSI was impaired compared with persons without a family history of LOAD. The neuroimaging correlates of such cognitive measure in those with one parent with LOAD involve Alzheimers-relevant brain regions even at a relatively young age.

Hemispheric specialization of mood processing is abnormal in patients with schizophrenia

Abnormalities of brain lateralization are among the most consistent neurobiological signatures of the schizophrenia syndrome (Schweitzer et al., 1978; Hirnstein and Hugdahl, 2014). Most studies have focused on alterations in the lateralization of language, sensory processing,macroscopic brain morphology, and motor dexterity, which have been long known to exhibit hemispheric specialization in H. sapiens (Newcombe and Ratcliff, 1973). In fact, it has been proposed that language and psychosismight share a common origin related to the development of brain lateralization in H. sapiens, presumably when our species diverged from other hominins some160,000 years ago (Crow, 2008). Implicit language functions and social cognition have also been proposed to stem from lateralization deficits (Guinjoan et al., 2015), whichmight bear significant clinical value in schizophrenia as the syndrome presents remarkable disturbances in mood processing and social behavior. Healthy individuals display hemispheric specialization in emotion processing (e.g., Craig, 2009; Costanzo et al., 2015). We hypothesized that development of abnormal brain lateralization in schizophrenia involves emotion processing in addition to language and motor dexterity, and specifically predicted that patients with schizophrenia would display deficits in left hemisphere activation during language tasks and impairments in right hemisphere activation during the induction of sadness, as evidence of an overall deficit in hemispheric specialization in this group. We studied 15 right-handed medicated patients with chronic stable schizophrenia (31± 9 years, 47%women) and 20 right-handed healthy individuals (26 ± 5 years, 55% women) with a functional magnetic resonance imaging paradigm of phonological fluency and sadness induction described in detail elsewhere (Costanzo et al., 2015). Briefly, a block design was employed in a GE Hx 3T for both word generation

Assessment of Arterial Stiffness by 24-Hour Ambulatory Blood Pressure Monitoring in Nocturnal Hypertensive or Normotensive Subjects

Background: Nocturnal hypertension, male gender, age and arterial stiffness are important risk factors for cardiovascular morbidity and mortality. The objective of this study was to assess arterial stiffness in nocturnal hypertensive or normotensive men and women >40 years of age. Methods: Twenty-four-hour ambulatory blood pressure monitoring was performed in 144 men and 137 women. Eighty-eight subjects were between 40 and 49 years old (53% men), 98 were between 50 and 59 years old (55% men) and 95 were >60 years old (45% men). They were classified as nocturnal hypertensive if their average night systolic blood pressure and/or diastolic blood pressure was >120/70 mm/Hg. Arterial stiffness was assessed by the Ambulatory Arterial Stiffness Index (AASI), which is calculated as 1 minus the slope of diastolic on systolic blood pressure during the 24-hour recording period. Results were analyzed by analysis of covariance and were adjusted for 24-hour mean arterial pressure, the presence of antihypertensive treatment, height and heart rate. Results: Women showed a higher AASI compared to men, independently of age. In men, the AASI increased with age, being higher in nocturnal hypertensive than in nocturnal normotensive subjects, independently of age. Nocturnal hypertensive women showed higher AASI values than their respective nocturnal normotensive controls in the 50- to 59-year and >60-year age groups only. Conclusion: The results show that arterial stiffness is higher among nocturnal hypertensive subjects, especially in women >50 years old.