11 research outputs found
Why can spontaneous intracranial hypotension cause behavioral changes? A case report and multimodality neuroimaging comparison with frontotemporal dementia
No full textFrontotemporal Brain Sagging Syndrome (FBSS) is a rare condition characterized by the presence of spontaneous intracranial hypotension associated with behavioural disturbances mimicking the behavioural variant of Frontotemporal dementia (bvFTD). It has been suggested that behavioural symptoms are caused by damage to the connectivity of the frontal lobes due to the brain sagging. However, no studies have directly explored brain connectivity in patients with FBSS. Here, we report a new case of FBSS with persistent behavioural disturbances, whom we compared to 20 patients with bvFTD and to 13 cognitively healthy controls using Magnetic Resonance Imaging (MRI). We explored differences related to grey matter (GM) volume with voxel-based morphometry, functional connectivity with seed-based analysis, and white matter (WM) microstructural integrity with tract-based spatial statistics. We found that the FBSS patient, like the controls, had greater GM volume relative to the bvFTD patients. Moreover, the FBSS patient had greater functional connectivity from a left inferior frontal gyrus seed than both the bvFTD patients and healthy controls groups in dorsolateral frontal areas. Like the bvFTD group the FBSS patient had decreased WM integrity relative to the controls, especially in the posterior part of the corpus callosum, and the magnitude of these abnormalities correlated with measures of apathy across the FBSS and bvFTD patients. Our results suggest that behavioural changes associated with SIH are mainly due to altered WM connectivity
Olfactory Testing and Gray Matter Volume: A Combined Approach to Predict the Conversion to Alzheimer
No full text: Background/Objectives: Olfactory decline is common in normal aging and frequent in neurodegenerative diseases such as Alzheimer's disease (AD). Therefore, it has been suggested as a marker for the Mild Cognitive Impairment (MCI) progression to AD. Although suggested, the relationship between olfactory deficits and cerebral atrophy in MCI conversion to AD is still debated. This study aims at investigating the olfaction-related morphological and behavioural alterations in MCI in order to understand whether they can predict the progression to AD. Methods: Twenty-seven MCI patients and thirty-five healthy controls (HCs) took part in the study, with follow-up showing conversion to AD in thirteen patients (converter-MCI, cMCI). The Burgarth Sniffin' Sticks Tests (threshold-TT, discrimination-DT, identification-IT) assessed the olfactory capacities. The Voxel-Based Morphometry (VBM) analysis investigated the atrophic patterns. Results: The Receiving Operating Characteristics analyses demonstrated that DT and IT could distinguish HC from MCI (DT Area Under Curve-AUC = 0.8; IT AUC = 0.8), as well as cMCI from sMCI (stable) patients (DT AUC = 0.7; IT AUC = 0.6), similarly to memory and executive functions tests. Olfactory performance positively correlated with memory tests in sMCI (all rhos ≥ 0.8, all ps < 0.01), whereas it positively correlated with executive functions in cMCI (all rhos ≥ 0.6, all ps < 0.05). VBM results revealed distinct atrophic patterns in cMCI, especially in the olfactory cortex, that were already present at the MCI diagnosis, before AD conversion. A larger volume of the olfactory cortex was associated with better memory and executive functions. Conclusions: Quantitative olfactory and morphological patterns represent non-invasive, predictive biomarkers of the MCI progression to AD; thus, their assessments at MCI onset allows earlier interventions for MCI patients
Role of metal-nanostructure features on tip-enhanced photoluminescence of single molecules
No full textTip-enhanced photoluminescence (TEPL) experiments have recently reached the ability to investigate single molecules exploiting resolution at the submolecular level. Localized surface plasmon resonances of metallic nanostructures have the capability of enhancing an impinging electromagnetic radiation in the proximity of their surface, with evident consequences both on absorption and emission of molecules placed in the same region. We propose a theoretical analysis of these phenomena in order to interpret TEPL experiments on single molecules, including a quantum mechanical description of the target molecule equilibrated with the presence of two nanostructures representative of the nanocavity usually employed in STMs. The approach has been applied to the zinc phthalocyanine molecule, previously considered in recent TEPL experiments [Yang et al., Nat. Photonics 14, 693–699 (2020)]. This work has the aim of providing a comprehensive theoretical understanding of the experimental results, particularly focusing on the investigation of the tip features that majorly influence the excitation and fluorescence processes of the molecule, such as the geometry, the dielectric function, and the tip–molecule distanceAccepted manuscript after peer-review. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in J. Chem. Phys. 155, 214304 (2021) and may be found at https://aip.scitation.org/doi/10.1063/5.0066758. License can be found here: https://publishing.aip.org/resources/researchers/rights-and-permissions/author-licenses
Long-term effects of subthalamic nucleus deep brain stimulation on speech in Parkinson's disease
No full text: Bilateral subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment in advanced Parkinson's Disease (PD). However, the effects of STN-DBS on speech are still debated, particularly in the long-term follow-up. The objective of this study was to evaluate the long-term effects of bilateral STN-DBS on speech in a cohort of advanced PD patients treated with bilateral STN-DBS. Each patient was assessed before surgery through a neurological evaluation and a perceptual-acoustic analysis of speech and re-assessed in the long-term in different stimulation and drug conditions. The primary outcome was the percentage change of speech intelligibility obtained by comparing the postoperative on-stimulation/off-medication condition with the preoperative off-medication condition. Twenty-five PD patients treated with bilateral STN-DBS with a 5-year follow-up were included. In the long-term, speech intelligibility stayed at the same level as preoperative values when compared with preoperative values. STN-DBS induced a significant acute improvement of speech intelligibility (p < 0.005) in the postoperative assessment when compared to the on-stimulation/off-medication and off-stimulation/off-medication conditions. These results highlight that STN-DBS may handle speech intelligibility even in the long-term
Cerebral Amyloid-β Deposition, Axial Features, and Cognitive Alterations in Patients with Parkinson’s Disease Treated with Bilateral STN-DBS: A Long-Term Cohort Study
No full textObjectives: Our aim was to evaluate the possible long-term cerebral deposition of amyloid-β in patients with PD treated with subthalamic nucleus deep brain stimulation (STN-DBS) and its possible influence on axial and cognitive variables. Methods: Consecutive PD patients treated with bilateral STN-DBS with a long-term follow-up were included. The amyloid-β deposition was evaluated postoperatively through an 18F-flutemetamol positron emission tomography (PET) study. Axial symptoms were assessed using a standardized clinical–instrumental approach. The speech was assessed by perceptual and acoustic analysis, while gait was assessed by means of the instrumented Timed Up and Go test (iTUG). Motor severity was evaluated by applying the UPDRS part III score and subscores, while cognitive functions were assessed through a complete neuropsychological assessment. Different stimulation and drug conditions were assessed: on-stimulation/off-medication, off-stimulation/off-medication, and on-stimulation/on-medication conditions (single- and dual-task). Results: In total, 19 PD patients (male: 11; age: 63.52 years; on-stimulation/on-medication UPDRS-III: 17.05) with a five-year postoperative follow-up were included. The amyloid-β deposition was found in 21% of patients (4/19) with a prevalent involvement of prefrontal, limbic, and parietal areas. Compared with patients without amyloid-β deposition, PD patients with positive 18F-flutemetamol in the PET study showed a higher preoperative UPDRS-I (p = 0.037) score. Conclusions: Our results suggest that in the long term, after STN-DBS, a significant percentage of PD patients may present brain amyloid-β deposition. However, larger samples are needed to evaluate the possible role of amyloid-β deposition in the development of axial and cognitive alterations after surgery
Catarina Benincasa de Siena: a escrita de si
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Literatura, Florianópolis, 2011A escritora italiana Catarina Benincasa de Siena (1347-1380) manifestou a sua criação literária especialmente nas missivas que redigiu ao longo de sua vida. Destacam-se 381 cartas, as quais foram enviadas a diversas pessoas, como papas, cardeais, reis, rainhas, entre outros. Neste estudo, busca-se compreender, portanto, a escrita de si de Catarina e sua contribuição literária. Realizou-se, para tanto, um estudo de caso com suporte teorico da Teopoética através da análise das suas litter?rum, indicando a literalidade do seu Epistolário, n'O Diálogo e nas Orações. Observou-se, no decorrer deste estudo, que essas obras incluem textos e cartas escritos a partir de 1367 e redigidos até 1380, nos quais Benincasa não foi somente religiosa e mística, mas demonstra que sua experiência epistolar e também litarária ultrapassando fronteiras, tempo e espaço. Nota-se, ainda, que ela conjugava a espiritualidade com atividade social e política, alimentada por uma conoscenza di sé e guiada por sua intuição, com amor e testemunhada pela paixão, pelo Divino e pelo mundo. Catarina ficou conhecida como uma mulher enérgica, autodidata, ativa, que viveu numa época em que os limitados espaços oferecidos à mulher eram ou a casa doméstica ou a conventual. Conclui-se, com base em seus escritos, que ela tratava em pé de igualdade os poderosos da época, disposta a predicar ou, então, a criticar políticos e prelados. Esteve empenhada, com efeito, em prol da reforma da Igreja, da reconciliação pela paz, e sempre escrevendo em nome de Jesus Cristo, registrando, assim, a sua criação literária
Interplay between speech and gait variables in PD patients treated with STN-DBS: a long-term instrumental assessment
No full textObjective: To evaluate correlations between speech and gait parameters in the long-term and under different medication and subthalamic nucleus deep brain stimulation (STN-DBS) conditions in a cohort of advanced Parkinson's Disease (PD) patients. Methods: This observational study included consecutive PD patients treated with bilateral STN-DBS. Axial symptoms were evaluated using a standardized clinical-instrumental approach. Speech and gait were assessed by perceptual and acoustic analyses and by the instrumented timed up and go test (iTUG) respectively. Disease motor severity was evaluated with the total score and subscores of the UPDRS part III. Different stimulation and drug treatment conditions were assessed: on-stimulation/off-medication, off-stimulation/off-medication, and on-stimulation/on-medication. Results: Twenty-five PD patients with a five-year median follow-up after surgery (range 3-7) were included (18 M; disease duration at surgery:10.44 [sd:4.62] years; age at surgery:58.40 [sd:5.73] years). In the off-stimulation/off-medication and on-stimulation/on-medication conditions, patients who spoke louder had also the greater acceleration of the trunk during gait whereas, in the on-stimulation/on-medication condition only, patients with the poorer voice quality were also the worse to perform sit to stand and gait phases of the iTUG. On the contrary, patients with the higher speech rate performed well the turning and walking phases of the iTUG. Conclusions: This study underlines the presence of different correlations between treatment effects of speech and gait parameters in PD patients treated with bilateral STN-DBS. This may allow us to better understand the common pathophysiological basis of these alterations and to develop a more specific and tailored rehabilitation approach for axial signs after surgery
Author Correction: Long-term effects of subthalamic nucleus deep brain stimulation on speech in Parkinson’s disease
No full textLong-term effects of bilateral subthalamic nucleus deep brain stimulation on gait disorders in Parkinson’s disease: a clinical-instrumental study
No full textObjective
To assess the long-term effects of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) on gait in a cohort of advanced Parkinson’s Disease (PD) patients.
Methods
This observational study included consecutive PD patients treated with bilateral STN-DBS. Different stimulation and drug treatment conditions were assessed: on-stimulation/off-medication, off-stimulation/off-medication, and on-stimulation/on-medication. Each patient performed the instrumented Timed Up and Go test (iTUG). The instrumental evaluation of walking ability was carried out with a wearable inertial sensor containing a three-dimensional (3D) accelerometer, gyroscope, and magnetometer. This device could provide 3D linear acceleration, angular velocity, and magnetic field vector. Disease motor severity was evaluated with the total score and subscores of the Unified Parkinson Disease Rating Scale part III.
Results
Twenty-five PD patients with a 5-years median follow-up after surgery (range 3–7) were included (18 men; mean disease duration at surgery 10.44 ± 4.62 years; mean age at surgery 58.40 ± 5.73 years). Both stimulation and medication reduced the total duration of the iTUG and most of its different phases, suggesting a long-term beneficial effect on gait after surgery. However, comparing the two treatments, dopaminergic therapy had a more marked effect in all test phases. STN-DBS alone reduced total iTUG duration, sit-to-stand, and second turn phases duration, while it had a lower effect on stand-to-sit, first turn, forward walking, and walking backward phases duration.
Conclusions
This study highlighted that in the long-term after surgery, STN-DBS may contribute to gait and postural control improvement when used together with dopamine replacement therapy, which still shows a substantial beneficial effect
Freezing of Gait in Parkinson's Disease Patients Treated with Bilateral Subthalamic Nucleus Deep Brain Stimulation: A Long-Term Overview
No full textBilateral subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment in advanced Parkinson's Disease (PD). However, the effects of STN-DBS on freezing of gait (FOG) are still debated, particularly in the long-term follow-up (≥5-years). The main aim of the current study is to evaluate the long-term effects of STN-DBS on FOG. Twenty STN-DBS treated PD patients were included. Each patient was assessed before surgery through a detailed neurological evaluation, including FOG score, and revaluated in the long-term (median follow-up: 5-years) in different stimulation and drug conditions. In the long term follow-up, FOG score significantly worsened in the off-stimulation/off-medication condition compared with the pre-operative off-medication assessment (z = -1.930; p = 0.05) but not in the on-stimulation/off-medication (z = -0.357; p = 0.721). There was also a significant improvement of FOG at long-term assessment by comparing on-stimulation/off-medication and off-stimulation/off-medication conditions (z = -2.944; p = 0.003). These results highlight the possible beneficial long-term effects of STN-DBS on FOG
