Pain-related Somato Sensory Evoked Potentials: A potential new tool to improve the prognostic prediction of coma after cardiac arrest

INTRODUCTION: Early prediction of a good outcome in comatose patients after cardiac arrest still remains an unsolved problem. The main aim of the present study was to examine the accuracy of middle-latency SSEP triggered by a painful electrical stimulation on median nerves to predict a favorable outcome. METHODS: No- and low-flow times, pupillary reflex, Glasgow motor score and biochemical data were evaluated at ICU admission. The following were considered within 72 h of cardiac arrest: highest creatinine value, hyperthermia occurrence, EEG, SSEP at low- (10 mA) and high-intensity (50 mA) stimulation, and blood pressure reactivity to 50 mA. Intensive care treatments were also considered. Data were compared to survival, consciousness recovery and 6-month CPC (Cerebral Performance Category). RESULTS: Pupillary reflex and EEG were statistically significant in predicting survival; the absence of blood pressure reactivity seems to predict brain death within 7 days of cardiac arrest. Middle- and short-latency SSEP were statistically significant in predicting consciousness recovery, and middle-latency SSEP was statistically significant in predicting 6-month CPC outcome. The prognostic capability of 50 mA middle-latency-SSEP was demonstrated to occur earlier than that of EEG reactivity. CONCLUSIONS: Neurophysiological evaluation constitutes the key to early information about the neurological prognostication of postanoxic coma. In particular, the presence of 50 mA middle-latency SSEP seems to be an early and reliable predictor of good neurological outcome, and its absence constitutes a marker of poor prognosis. Moreover, the absence 50 mA blood pressure reactivity seems to identify patients evolving towards the brain death

Pain-related somatosensory evoked potentials and functional brain magnetic resonance in the evaluation of neurologic recovery after cardiac arrest: a case study of three patients

This case series investigates whether painful electrical stimulation increases the early prognostic value of both somatosensory-evoked potentials and functional magnetic resonance imaging in comatose patients after cardiac arrest. Three single cases with hypoxic-ischemic encephalopathy were considered. A neurophysiological evaluation with an electroencephalogram and somatosensory-evoked potentials during increased electrical stimulation in both median nerves was performed within five days of cardiac arrest. Each patient also underwent a functional magnetic resonance imaging evaluation with the same neurophysiological protocol one month after cardiac arrest. One patient, who completely recovered, showed a middle latency component at a high intensity of stimulation and the activation of all brain areas involved in cerebral pain processing. One patient in a minimally conscious state only showed the cortical somatosensory response and the activation of the primary somatosensory cortex. The last patient, who was in a vegetative state, did not show primary somatosensory evoked potentials; only the activation of subcortical brain areas occurred. These preliminary findings suggest that the pain-related somatosensory evoked potentials performed to increase the prognosis of comatose patients after cardiac arrest are associated with regional brain activity showed by functional magnetic resonance imaging during median nerves electrical stimulation. More importantly, this cases report also suggests that somatosensory evoked potentials and functional magnetic resonance imaging during painful electrical stimulation may be sensitive and complementary methods to predict the neurological outcome in the acute phase of coma. Thus, pain-related somatosensory-evoked potentials may be a reliable and a cost-effective tool for planning the early diagnostic evaluation of comatose patients

White-Matter Hyperintensity Load and Differences in Resting-State Network Connectivity Based on Mild Cognitive Impairment Subtype.

"Mild cognitive impairment" (MCI) is a diagnosis characterised by deficits in episodic memory (aMCI) or in other non-memory domains (naMCI). Although the definition of subtypes is helpful in clinical classification, it provides little insight on the variability of neurofunctional mechanisms (i.e., resting-state brain networks) at the basis of symptoms. In particular, it is unknown whether the presence of a high load of white-matter hyperintensities (WMHs) has a comparable effect on these functional networks in aMCI and naMCI patients. This question was addressed in a cohort of 123 MCI patients who had completed an MRI protocol inclusive of T1-weighted, fluid-attenuated inversion recovery (FLAIR) and resting-state fMRI sequences. T1-weighted and FLAIR images were processed with the Lesion Segmentation Toolbox to quantify whole-brain WMH volumes. The CONN toolbox was used to preprocess all fMRI images and to run an independent component analysis for the identification of four large-scale haemodynamic networks of cognitive relevance (i.e., default-mode, salience, left frontoparietal, and right frontoparietal networks) and one control network (i.e., visual network). Patients were classified based on MCI subtype (i.e., aMCI vs. naMCI) and WMH burden (i.e., low vs. high). Maps of large-scale networks were then modelled as a function of the MCI subtype-by-WMH burden interaction. Beyond the main effects of MCI subtype and WMH burden, a significant interaction was found in the salience and left frontoparietal networks. Having a low WMH burden was significantly more associated with stronger salience-network connectivity in aMCI (than in naMCI) in the right insula, and with stronger left frontoparietal-network connectivity in the right frontoinsular cortex. Vice versa, having a low WMH burden was significantly more associated with left-frontoparietal network connectivity in naMCI (than in aMCI) in the left mediotemporal lobe. The association between WMH burden and strength of connectivity of resting-state functional networks differs between aMCI and naMCI patients. Although exploratory in nature, these findings indicate that clinical profiles reflect mechanistic interactions that may play a central role in the definition of diagnostic and prognostic statuses

Patient with corticobasal syndrome showing disease-associated biomarkers of dementia with Lewy Bodies: a Treviso Dementia (TREDEM) registry case report

Background: An 82-year-old right-handed man, a retired teacher, reported the occurrence, three years earlier, of difficulties in moving his left arm and foot, tremor in his left hand, and gestures of the left upper limb that appeared to be independent of the patient's will.Objective: We describe an unusual case of corticobasal syndrome (CBS) showing disease-associated biomarkers of dementia with Lewy bodies (DLB).Methods: Clinical, neuropsychological, imaging, and biomarker evaluations were conducted, including tau and amyloid-beta levels in the cerebrospinal fluid (CSF) and a RT-QuIC assay for alpha-synuclein both in the CSF and olfactory mucosa (OM), as well as a QEEG assessment.Results: The patient presented resting tremor, mild extrapyramidal hypertonus, mild bradykinesia on the left side, and severe apraxia on the left upper limb. Brain MRI showed a diffuse right hemisphere atrophy which was prominent in the posterior parietal and temporal cortices, and moderate in the frontal cortex and the precuneus area. F-18-FDG PET imaging showed reduced glucose metabolism in the right lateral parietal, temporal, and frontal cortices with involvement of the right precuneus. The putamen did not appear to be pathological at DaTQUANT. Neuropsychological tests showed memory and visual-perceptual deficits. CSF tau and amyloid measurements did not show clear pathological values. RT-QuIC for alpha-synuclein in CSF and OM samples were positive. The QEEG analysis showed a pre-alpha dominant frequency in posterior derivations, typical of early stages of DLB.Conclusion: Although in the present patient the clinical diagnosis was of probable CBS, unexpectedly positive biomarkers for DLB suggested the co-presence of multiple pathologies

More atypical than atypical Alzheimer's disease phenotypes: a Treviso Dementia (TREDEM) registry case report

Background: A 57-year-old right-handed man was admitted to the Treviso Memory Clinic due to the presence of memory forgetfulness, repetition of the same questions, episodes of confusion, initial difficulties in performing complex tasks and easy distraction over the past two years, as well as recurrent and never-happened-before car accidents.Objective: We report a peculiar case of an early onset Alzheimer's disease (AD) with an unusual symptomatology, apparently not fitting in any of the categorized atypical forms of AD nor being representative of a typical amnestic AD.Methods: The patient underwent a neuropsychological, structural, and metabolic cerebral evaluation by MRI and F-18-FDG PET, together with the search for cerebral amyloid (amyloid PET), a genetic testing for dementia related genes and the dosage of CSF protein biomarkers of neurodegenerative conditions.Results: We observed a convergence of predominant frontal (dysexecutive, verbal disinhibition) and posterior (visuospatial) features of cognitive impairment. Structural MRI sequences showed subarachnoid spaces of the vault enlarged in the frontoparietal region with anterior and posterior cortical atrophy. The hippocampus appeared preserved. The 18F-FDG PET scans showed hypometabolism in the prefrontal, lateral temporal, posterior parietal, and occipital regions bilaterally. The F-18-Flutemetamol scan showed a diffused uptake of the amyloid tracer at the cerebral cortex. CSF biomarkers were compatible with Alzheimer's disease (AD).Conclusion: This case report presented with clinical phenotypic aspects atypical of AD, both frontal and posterior, never described as concomitant in the most accredited criteria for atypical AD, and appeared therefore more atypical than each of the atypical AD phenotypes already reported

Blindsight is sensitive to stimulus numerosity and configuration: Evidence from the redundant signal effect

One important, yet relatively unexplored question is whether blindsight, i.e., unconscious visually guided behavior in hemianopic patients, is endowed with basic perceptual properties such as detecting stimulus numerosity and overall configuration. Rather than a forced-choice procedure in which patients are supposed to guess about stimuli presented to the blind hemifield, we used a redundant signal effect paradigm, i.e., the speeding of simple reaction time (RT) when presenting multiple versus single similar stimuli. The presence of an effect of numerosity for the (unseen) stimuli presented to the blind field was indirectly assessed by measuring RT to bilateral versus unilateral stimuli presented to the intact hemifield. Chronic hemianopic patients were tested with unilateral or bilateral black dots, both of which could be either single or quadruple. The latter could either have a fixed spatial configuration representing a diamond or be randomly spatially assembled on every trial. Both configurations covered the same extent of visual field and had the overall same luminance. We found that a numerosity effect as a result of increasing the number of stimuli in the blind field was indeed present but only with the diamond configuration. This is a convincing evidence that this form of blindsight does not depend upon stimulus numerosity per se but is likely to be related to the presence of structured and memorized rather than meaningless changing stimuli. Keywords: Blindsight Hemianopia Redundancy gain Subcortical visual pathways Reaction tim

Application of a multidisciplinary approach for the evaluation of traceability of extra virgin olive oil

In this work, a multidisciplinary approach for the evaluation of extra virgin olive oil traceability (geographical provenience and botanical differentiation) is presented. Conventional techniques such as major chemical component determination (triacylglycerols, TAG and fatty acids) and other novel approaches as stable isotopic ratio (13C/12C in combination with 18O/16O) and thermal properties obtained from cooling curves and their deconvoluted peaks by means of differential scanning calorimetry were compared. Fifty-three samples from different Italian regions, diverse cultivars, and two Mediterranean areas (Italy and Croatia) were analyzed with all the three techniques. The oils exhibited different values especially for d18O and thermal properties of the deconvoluted peaks of crystallization according to Italian regions and/or cultivars. Data were treated by means of linear discriminant analysis inserting all parameters as predictors in models where the potentiality to discriminate oils was tested. All models revealed a good resolution among categories with selected TAG, d18O values, and thermal properties of the deconvoluted peak set at the highest temperature exhibiting the highest weight for the discriminant functions. These findings could give strength to the utilization of new analytical techniques supporting those traditionally employed, also sustained by proper chemometric procedures, as suitable for the resolution of extra virgin olive traceability

Application of a multidisciplinary approach for the evaluation of traceability of extra virgin olive oil

In this work, a multidisciplinary approach for the evaluation of extra virgin olive oil traceability (geographical provenience and botanical differentiation) is presented. Conventional techniques such as major chemical component determination (triacylglycerols, TAG and fatty acids) and other novel approaches as stable isotopic ratio ((13)C/(12)C in combination with (18)O/(16)O) and thermal properties obtained from cooling curves and their deconvoluted peaks by means of differential scanning calorimetry were compared. Fifty-three samples from different Italian regions, diverse cultivars, and two Mediterranean areas (Italy and Croatia) were analyzed with all the three techniques. The oils exhibited different values especially for delta(18)O and thermal properties of the deconvoluted peaks of crystallization according to Italian regions and/or cultivars. Data were treated by means of linear discriminant analysis inserting all parameters as predictors in models where the potentiality to discriminate oils was tested. All models revealed a good resolution among categories with selected TAG, delta(18)O values, and thermal properties of the deconvoluted peak set at the highest temperature exhibiting the highest weight for the discriminant functions. These findings could give strength to the utilization of new analytical techniques supporting those traditionally employed, also sustained by proper chemometric procedures, as suitable for the resolution of extra virgin olive traceability