Hearts and Minds: Emotion Recognition and Mentalizing in Parkinson's Disease and Progressive Supranuclear Palsy

OBJECTIVE

There are scarce data comparing Parkinson's disease (PD) and Progressive Supranuclear Palsy (PSP) in social cognition (SC). We aimed to compare patients with PSP and PD in SC.

METHODS

We included three groups: PD (n = 18), PSP (n = 20) and controls (n = 23). Participants underwent neuropsychological exams, including the mini-version of the Social and Emotional Assessment, which is composed of the facial emotion recognition test (FERT) and the modified faux-pas (mFP) test, which assesses Theory of Mind (ToM).

RESULTS

Patients with PD scored lower than controls in the FERT, but not in the mFP test. Patients with PSP performed worse than controls in both the mFP and FERT. PD and PSP groups did not differ in the FERT, but PSP performed worse than PD in the mFP test. The mFP test distinguished PSP from PD with 89% accuracy.

CONCLUSION

The assessment of ToM may contribute to the differentiation between PD and PSP.

Pro-inflammatory interleukin-6 signaling links cognitive impairments and peripheral metabolic alterations in Alzheimer's disease

Alzheimer's disease (AD) is associated with memory impairment and altered peripheral metabolism. Mounting evidence indicates that abnormal signaling in a brain-periphery metabolic axis plays a role in AD pathophysiology. The activation of pro-inflammatory pathways in the brain, including the interleukin-6 (IL-6) pathway, comprises a potential point of convergence between memory dysfunction and metabolic alterations in AD that remains to be better explored. Using T2-weighted magnetic resonance imaging (MRI), we observed signs of probable inflammation in the hypothalamus and in the hippocampus of AD patients when compared to cognitively healthy control subjects. Pathological examination of post-mortem AD hypothalamus revealed the presence of hyperphosphorylated tau and tangle-like structures, as well as parenchymal and vascular amyloid deposits surrounded by astrocytes. T2 hyperintensities on MRI positively correlated with plasma IL-6, and both correlated inversely with cognitive performance and hypothalamic/hippocampal volumes in AD patients. Increased IL-6 and suppressor of cytokine signaling 3 (SOCS3) were observed in post-mortem AD brains. Moreover, activation of the IL-6 pathway was observed in the hypothalamus and hippocampus of AD mice. Neutralization of IL-6 and inhibition of the signal transducer and activator of transcription 3 (STAT3) signaling in the brains of AD mouse models alleviated memory impairment and peripheral glucose intolerance, and normalized plasma IL-6 levels. Collectively, these results point to IL-6 as a link between cognitive impairment and peripheral metabolic alterations in AD. Targeting pro-inflammatory IL-6 signaling may be a strategy to alleviate memory impairment and metabolic alterations in the disease.

The Timed Inspiratory Effort Index as a Weaning Predictor: Analysis of Intra- and Interobserver Reproducibility

BACKGROUND

Prolonged ventilatory weaning may expose patients to unnecessary discomfort, increase the risk of complications, and raise the costs of hospital treatment. In this scenario, indexes that reliably predict successful liberation can be helpful.

OBJECTIVE

To evaluate the intra- and interobserver reproducibility of the timed inspiratory effort index as a weaning predictor.

METHODS

This prospective observational study included subjects judged as able to start liberation from mechanical ventilation. For the intra-observer analysis, the same investigator performed 2 measurements in each selected patient with an interval of 30 min a rest. For interobserver analysis, 2 measurements were obtained in another sample of subjects, also with an interval of 30 min rest, but each of one performed by a different investigator. The Bland-Altman diagram, the coefficient concordance of kappa, and the Pearson correlation coefficient were used to compare the measurements. The performance of the timed inspiratory effort index was assessed by receiver operating characteristic curves. Values of P < .05 were considered significant.

RESULTS

We selected 113 subjects (43 males; mean ± SD age, 77 ± 14 y). Fifty-six (49.6%) achieved successful liberation, and 33 (29%) died in the ICU. The mean ± SD duration of mechanical ventilation was 14.4 ± 6.7 d. The Bland-Altman diagrams that addressed intra- and interobservers agreement showed low variability between measurements. Values of the concordance coefficients of kappa were 0.82 (0.68-0.95) and 0.80 (0.65-0.94), and of the linear correlation coefficients, 0.86 (0.77-0.91) and 0.89 (0.82-0.93) for the intra- and interobservers measurements, respectively. The mean ± SD values for the area under the curve for each pair of the intra- and interobserver measurements were 0.96 ± 0.07 versus 0.94 ± 0.07 (P = .41) and 0.94 ± 0.05 versus 0.90 ± 0.07 (P = .14), respectively.

CONCLUSIONS

The variability of the measurement of the timed inspiratory effort index by intra- and interobservers showed very high reproducibility, which reinforced the index as a sensible, accurate, and reliable outcome predictor of liberation from mechanical ventilation.

Cerebrospinal Fluid Levels of Angiotensin-Converting Enzyme Are Associated with Amyloid-β42 Burden in Alzheimer's Disease

This study was designed to determine whether the levels of renin-angiotensin system (RAS) components are associated with Alzheimer's disease (AD) pathology. Cerebrospinal fluid levels of Angiotensin (Ang) II, Ang-(1-7), angiotensin-converting enzyme (ACE), ACE2, Amyloid-β (Aβ)40, Aβ42, total tau (hTau), and phospho-tau (pTau) were measured in 18 patients with AD and 10 controls. Patients with AD presented decreased levels of ACE when compared with controls. We found a significant positive correlation between ACE and Aβ42 levels among patients. Our results strengthen the hypothesis that ACE is associated with Aβ pathology in AD.

BsmI polymorphism in the vitamin D receptor gene is associated with 25-hydroxy vitamin D levels in individuals with cognitive decline

ABSTRACT Elderly people are at a high risk of developing vitamin D (VitD) deficiency due to both decreased intake and cutaneous synthesis. Most of the biological actions of VitD are mediated by the vitamin D receptor (VDR), which is present in neurons and glial cells of the hippocampus, and in the cortex and subcortical nuclei, essential areas for cognition. It is known that VDR gene polymorphisms may decrease the VDR affinity for VitD. Objective: The present study aimed to investigate the influence of VitD levels on cognitive decline in patients with dementia due to Alzheimer's disease (AD, n = 32) and mild cognitive impairment (MCI, n = 15) compared to cognitively healthy elderly (n = 24). We also evaluated the association of VDR gene polymorphisms with cognitive disturbance. Methods: Four polymorphisms on the VDR gene were studied, namely, BsmI, ApaI, FokI and TaqI, by polymerase chain reaction-restriction fragment length polymorphism. Serum levels of 25-hydroxy vitamin D (25(OH)D) were determined by high performance liquid chromatography. Results: No significant difference in 25(OH)D levels or genotypic/allelic frequencies was observed between the groups. Deficiency of 25(OH)D was more frequently observed in women. The AA/AG genotypes of the BsmI polymorphism was associated with sufficient 25(OH)D levels, while the GG genotype of this same polymorphism was associated to insufficient levels in the cognitively-impaired group (individuals with AD or MCI). Conclusions: The data obtained do not confirm the relationship between reductions of VitD levels, polymorphisms in the VDR gene, and altered cognitive function in this sample. However, the data indicate that BsmI polymorphism in the VDR gene is associated with the VitD levels in individuals with cognitive decline.

Frontal lobe neurology and the creative mind

Concepts from cognitive neuroscience strongly suggest that the prefrontal cortex (PFC) plays a crucial role in the cognitive functions necessary for creative thinking. Functional imaging studies have repeatedly demonstrated the involvement of PFC in creativity tasks. Patient studies have demonstrated that frontal damage due to focal lesions or neurodegenerative diseases are associated with impairments in various creativity tasks. However, against all odds, a series of clinical observations has reported the facilitation of artistic production in patients with neurodegenerative diseases affecting PFC, such as frontotemporal dementia (FTD). An exacerbation of creativity in frontal diseases would challenge neuroimaging findings in controls and patients, as well as the theoretical role of prefrontal functions in creativity processes. To explore this paradox, we reported the history of a FTD patient who exhibited the emergence of visual artistic productions during the course of the disease. The patient produced a large amount of drawings, which have been evaluated by a group of professional artists who were blind to the diagnosis. We also reviewed the published clinical cases reporting a change in the artistic abilities in patients with neurological diseases. We attempted to reconcile these clinical observations to previous experimental findings by addressing several questions raised by our review. For instance, to what extent can the cognitive, conative, and affective changes following frontal damage explain changes in artistic abilities? Does artistic exacerbation truly reflect increased creative capacities? These considerations could help to clarify the place of creativity—as it has been defined and explored by cognitive neuroscience—in artistic creation and may provide leads for future lesion studies.

Advancing research diagnostic criteria for Alzheimer's disease: the IWG-2 criteria

In the past 8 years, both the International Working Group (IWG) and the US National Institute on Aging-Alzheimer's Association have contributed criteria for the diagnosis of Alzheimer's disease (AD) that better define clinical phenotypes and integrate biomarkers into the diagnostic process, covering the full staging of the disease. This Position Paper considers the strengths and limitations of the IWG research diagnostic criteria and proposes advances to improve the diagnostic framework. On the basis of these refinements, the diagnosis of AD can be simplified, requiring the presence of an appropriate clinical AD phenotype (typical or atypical) and a pathophysiological biomarker consistent with the presence of Alzheimer's pathology. We propose that downstream topographical biomarkers of the disease, such as volumetric MRI and fluorodeoxyglucose PET, might better serve in the measurement and monitoring of the course of disease. This paper also elaborates on the specific diagnostic criteria for atypical forms of AD, for mixed AD, and for the preclinical states of AD.

Distinct patterns of antiamyloid-β antibodies in typical and atypical Alzheimer disease

OBJECTIVE

To compare serum antiamyloid-β (Aβ) antibodies in typical and atypical Alzheimer disease (AD).

DESIGN

Preliminary observations.

SUBJECTS

Thirteen patients with AD, 8 patients with posterior cortical atrophy with evidence of AD (PCA-AD) pathophysiological process by both cerebrospinal fluid (CSF) biomarkers and amyloid imaging, and 12 age-matched control individuals.

INTERVENTIONS

The class and subclass levels of serum anti-Aβ antibodies were measured using an oligomer-based enzyme-linked immunosorbent assay. This method allowed measuring both free antibodies and, after acidic treatment, the total fraction that includes all antibodies complexed with circulating Aβ40/42 and any cross-reacting antigen.

RESULTS

Anti-Aβ IgG were restricted to the IgG1 and IgG3 subclasses. Their total levels were strikingly lower and more homogeneous in patients with PCA compared with both typical AD and controls, while biomarkers of amyloid deposition (CSF Aβ42 and positron emission tomography amyloid imaging) were similar in patients with AD and patients with PCA.

CONCLUSIONS

Serum anti-Aβ IgG1 and IgG3 antibodies differ between distinct forms of AD. Its significance is discussed for possible implications as immune effectors in the specific pathophysiology of AD variants.

Brain networks in posterior cortical atrophy: a single case tractography study and literature review

Posterior cortical atrophy (PCA) is rare neurodegenerative dementia, clinically characterized by a progressive decline in higher-visual object and space processing. After a brief review of the literature on the neuroimaging in PCA, here we present a study of the brain structural connectivity in a patient with PCA and progressive isolated visual and visuo-motor signs. Clinical and cognitive data were acquired in a 58-years-old patient (woman, right-handed, disease duration 18 months). Brain structural and diffusion tensor (DT) magnetic resonance imaging (MRI) were obtained. A voxel-based morphometry (VBM) study was performed to explore the pattern of gray matter (GM) atrophy, and a fully automatic segmentation was assessed to obtain the hippocampal volumes. DT MRI-based tractography was used to assess the integrity of long-range white matter (WM) pathways in the patient and in six sex- and age-matched healthy subjects. This PCA patient had a clinical syndrome characterized by left visual neglect, optic ataxia, and left limb apraxia, as well as mild visuo-spatial episodic memory impairment. VBM study showed bilateral posterior GM atrophy with right predominance; DT MRI tractography demonstrated WM damage to the right hemisphere only, including the superior and inferior longitudinal fasciculi and the inferior fronto-occipital fasciculus, as compared to age-matched controls. The homologous left-hemisphere tracts were spared. No difference was found between left and right hippocampal volumes. These data suggest that selective visuo-spatial deficits typical of PCA might not result from cortical damage alone, but by a right-lateralized network-level dysfunction including WM damage along the major visual pathways.

CSF tau markers are correlated with hippocampal volume in Alzheimer's disease

Hippocampal atrophy as assessed by magnetic resonance imaging (MRI) and abnormal cerebrospinal fluid (CSF) biomarkers are supportive features for the diagnosis of Alzheimer's disease (AD) and are assumed to be indirect pathological markers of the disease. In AD patients, antemortem MRI hippocampal volumes (HVs) correlate with the density of neurofibrillary tangles (but not with senile plaques) at autopsy suggesting that HVs may better correlate with CSF tau and hyperphosphorylated tau (P-tau) levels than CSF amyloid beta protein (Aβ)(42) level. Here, we tested this hypothesis in a well-defined AD group. Patients were selected according to the New Research Criteria for AD, including specific episodic memory deficit and CSF AD profile (defined as abnormal ratio of Aβ(42):tau). MRI was performed within 6 months of lumbar puncture. HVs were obtained using automated segmentation software. Thirty-six patients were included. Left HV correlated with CSF tau (R = -0.53) and P-tau (R = -0.56) levels. Mean HVs correlated with the CSF P-tau level (R = -0.52). No correlation was found between any brain measurement and CSF Aβ(42) level. The CSF tau and P-tau levels, but not the CSF Aβ(42) level, correlated with HV, suggesting that CSF tau markers reflect the neuronal loss associated with the physiopathological process of AD.

Visual neglect in posterior cortical atrophy

BACKGROUND

In posterior cortical atrophy (PCA), there is a progressive impairment of high-level visual functions and parietal damage, which might predict the occurrence of visual neglect. However, neglect may pass undetected if not assessed with specific tests, and might therefore be underestimated in PCA. In this prospective study, we aimed at establishing the side, the frequency and the severity of visual neglect, visual extinction, and primary visual field defects in an unselected sample of PCA patients.

METHODS

Twenty-four right-handed PCA patients underwent a standardized battery of neglect tests. Visual fields were examined clinically by the confrontation method.

RESULTS

Sixteen of the 24 patients (66%) had signs of visual neglect on at least one test, and fourteen (58%) also had visual extinction or hemianopia. Five patients (21%) had neither neglect nor visual field defects. As expected, left-sided neglect was more severe than right-sided neglect. However, right-sided neglect resulted more frequently in this population (29%) than in previous studies on focal brain lesions.

CONCLUSION

When assessed with specific visuospatial tests, visual neglect is frequent in patients with PCA. Diagnosis of neglect is important because of its negative impact on daily activities. Clinicians should consider the routine use of neglect tests to screen patients with high-level visual deficits. The relatively high frequency of right-sided neglect in neurodegenerative patients supports the hypothesis that bilateral brain damage is necessary for right-sided neglect signs to occur, perhaps because of the presence in the right hemisphere of crucial structures whose damage contributes to neglect.

Frontotemporal dementia: pathology of gait?

The main diagnostic criteria of the behavioural variant of frontotemporal degeneration (bvFTD) include neurobehavioral and dysexecutive syndromes, but not specific gait characteristics although strong relationship between gait and prefrontal functions are increasingly recognized. Accordingly, we tested the hypothesis that patients with bvFTD would have more gait changes than older healthy controls and demented patients with Alzheimer's disease (AD). Sixty subjects were included in the study: 19 with bvFTD, 19 with AD and 22 healthy controls. Mean values and coefficients of variation (CV) of stride time while just walking (i.e., single tasking) and while walking with backward counting (i.e., dual tasking) were measured using the SMTEC-footswitch system. Stride time, mean value, and CV were significantly increased in both patient groups compared with healthy controls during single task or walking alone (P < 0.001) and during dual tasking (P < 0.001). After adjusting for age, Mini-mental examination, psychoactive drugs, gender, and history of previous fall, only the patients with bvFTD group was associated with an increase of CV of stride time during single walking (P < 0.001) and dual tasking (P < 0.001). These data suggest that gait instability during single and dual tasking could represent a supportive argument for bvFTD. In clinical practice, such a diagnosis should be at least considered in any demented patient with gait instability.