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1.
Mov Disord ; 39(1): 53-63, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37955157

RESUMO

BACKGROUND: Reduced gastric motility in Parkinson's disease (PD) has been reported, but hardly any study exists in subjects with isolated rapid-eye-movement (REM) sleep behavior disorder (iRBD), a specific prodrome of α-synucleinopathies. OBJECTIVES: We compared the gastric motility of 17 iRBD subjects with that of 18 PD subjects (15 drug naive, 3 early treated in defined off) and 15 healthy controls (HC) with real-time magnetic resonance imaging (rtMRI). METHODS: After overnight fasting, participants consumed a standardized breakfast and underwent a 3-T rtMRI of the stomach. Amplitude and velocity of the peristaltic waves were analyzed under blinded conditions. Gastric motility index (GMI) was calculated. The procedure was repeated in 12 of 17 iRBD subjects ~2.5 years later. Nine of these 12 iRBD subjects were hyposmic. RESULTS: In iRBD and PD subjects the amplitude of the peristaltic waves was significantly reduced compared with HCs (iRBD vs. HC: 8.7 ± 3.7 vs. 11.9 ± 4.1 mm, P = 0.0097; PD vs. HC: 6.8 ± 2.2 vs. 11.9 ± 4.1 mm, P = 0.0001). The amplitude in iRBD and PD subjects was decreased to the same extent. The GMI was reduced in only PD subjects (PD vs. HC: P = 0.0027; PD vs. iRBD: P = 0.0203). After ~2.5 years the amplitude in iRBD subjects did not significantly decrease further. CONCLUSION: The amplitude of the peristaltic waves was markedly reduced in iRBD, a prodrome of α-synucleinopathies. This reduction was similar to the extent observed already in manifest early PD. This finding implies that the α-synuclein pathology affects the innervation of the stomach already in the prodromal stage. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.


Assuntos
Doença de Parkinson , Transtorno do Comportamento do Sono REM , Sinucleinopatias , Humanos , Doença de Parkinson/complicações , Doença de Parkinson/patologia , Transtorno do Comportamento do Sono REM/patologia , Estômago/patologia , Sono
2.
Epilepsia ; 65(4): 1107-1114, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38305932

RESUMO

OBJECTIVE: The aim of the study was to evaluate the benefits of morphometric magnetic resonance imaging (MRI) postprocessing in patients presenting with a first seizure and negative MRI results and to investigate these findings in the context of the clinical and electroencephalographic data, seizure recurrence rates, and epilepsy diagnosis in these patients. METHODS: We retrospectively reviewed 97 MRI scans of patients with first unprovoked epileptic seizure and no evidence of epileptogenic lesion on clinical routine MRI. Morphometric Analysis Program (MAP; v2018), automated postprocessing software, was used to identify subtle, potentially epileptogenic lesions in the three-dimensional T1-weighted MRI data. The resulting probability maps were examined together with the conventional MRI images by a reviewer who remained blinded to the patients' clinical and electroencephalographical data. Clinical data were prospectively collected between February 2018 and May 2023. RESULTS: Among the apparently MRI-negative patients, a total of 18 of 97 (18.6%) showed cortical changes suggestive of focal cortical dysplasia. Within the population with positive MAP findings (MAP+), seizure recurrence rates were 61.1% and 66.7% at 1 and 2 years after the first unprovoked seizure, respectively. Conversely, patients with negative MAP findings (MAP-) had lower seizure recurrence rates of 27.8% and 34.2% at 1 and 2 years after the first unprovoked seizure, respectively. Patients with MAP+ findings were significantly more likely to be diagnosed with epilepsy than those patients with MAP- findings (χ2 [1, n = 97] = 14.820, p < .001, odds ratio = 21.371, 95% CI = 2.710-168.531) during a mean follow-up time of 22.51 months (SD = 16.7 months, range = 1-61 months). SIGNIFICANCE: MRI postprocessing can be a valuable tool for detecting subtle epileptogenic lesions in patients with a first seizure and negative MRI results. Patients with first seizure and MAP+ findings had high seizure recurrence rates, meeting the criteria for beginning epilepsy.


Assuntos
Epilepsia , Processamento de Imagem Assistida por Computador , Humanos , Estudos Retrospectivos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Convulsões/diagnóstico por imagem , Epilepsia/diagnóstico por imagem , Epilepsia/patologia
3.
Hum Brain Mapp ; 44(2): 496-508, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36098483

RESUMO

Assessment of regional language lateralization is crucial in many scenarios, but not all populations are suited for its evaluation via task-functional magnetic resonance imaging (fMRI). In this study, the utility of structural connectome features for the classification of language lateralization in the anterior temporal lobes (ATLs) was investigated. Laterality indices for semantic processing in the ATL were computed from task-fMRI in 1038 subjects from the Human Connectome Project who were labeled as stronger rightward lateralized (RL) or stronger leftward to bilaterally lateralized (LL) in a data-driven approach. Data of unrelated subjects (n = 432) were used for further analyses. Structural connectomes were generated from diffusion-MRI tractography, and graph theoretical metrics (node degree, betweenness centrality) were computed. A neural network (NN) and a random forest (RF) classifier were trained on these metrics to classify subjects as RL or LL. After classification, comparisons of network measures were conducted via permutation testing. Degree-based classifiers produced significant above-chance predictions both during cross-validation (NN: AUC-ROC[CI] = 0.68[0.64-0.73], accuracy[CI] = 68.34%[63-73.2%]; RF: AUC-ROC[CI] = 0.7[0.66-0.73], accuracy[CI] = 64.81%[60.9-68.5]) and testing (NN: AUC-ROC[CI] = 0.69[0.53-0.84], accuracy[CI] = 68.09[53.2-80.9]; RF: AUC-ROC[CI] = 0.68[0.53-0.84], accuracy[CI] = 68.09[55.3-80.9]). Comparison of network metrics revealed small effects of increased node degree within the right posterior middle temporal gyrus (pMTG) in subjects with RL, while degree was decreased in the right posterior cingulate cortex (PCC). Above-chance predictions of functional language lateralization in the ATL are possible based on diffusion-MRI connectomes alone. Increased degree within the right pMTG as a right-sided homologue of a known semantic hub, and decreased hubness of the right PCC may form a structural basis for rightward-lateralized semantic processing.


Assuntos
Conectoma , Semântica , Humanos , Conectoma/métodos , Mapeamento Encefálico , Lobo Temporal/diagnóstico por imagem , Idioma , Imageamento por Ressonância Magnética/métodos , Imagem de Tensor de Difusão , Lateralidade Funcional
4.
Epilepsia ; 62(6): 1354-1361, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33939185

RESUMO

OBJECTIVE: This study was undertaken to identify temporal encephaloceles (TEs) and examine their characteristics in patients with temporal lobe epilepsy (TLE) and extratemporal lobe epilepsy (ETLE), as well as in asymptomatic cases. METHODS: Four hundred fifty-eight magnetic resonance imaging scans were examined retrospectively to identify TE in 157 patients with TLE, 150 patients with ETLE, and 151 healthy controls (HCs). RESULTS: At least one TE was identified in 9.6% of the TLE patients (n = 15, 95% confidence interval [CI] = 5.3%-15.3%), in 3.3% of patients with ETLE (n = 5, 95% CI = 1.1%-7.6%), and in 2.0% of the HCs (n = 3, 95% CI = .4%-5.7%), indicating a significantly higher frequency in patients with TLE compared to ETLE and HC subjects (p = .027, p = .005). Examining the characteristics of TEs in both asymptomatic and epilepsy patients, we found that TEs with a diameter of less than 6.25 mm were more likely to be asymptomatic, with a sensitivity of 91.7% and a specificity of 73.3% (area under the curve = .867, 95% CI = .723-1.00, p = .001). SIGNIFICANCE: Temporal encephaloceles may occur without presenting any clinical symptoms. Patients with TLE show a higher frequency of TEs compared to the ETLE and HC groups. According to our study, TE size could be used to suggest potential epileptogenicity.


Assuntos
Encefalocele/etiologia , Epilepsia do Lobo Temporal/complicações , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia/complicações , Epilepsia/diagnóstico por imagem , Lobo Temporal/diagnóstico por imagem , Adolescente , Adulto , Idoso , Eletroencefalografia , Encefalocele/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
5.
Epilepsy Behav ; 76: 56-62, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28927715

RESUMO

OBJECTIVE: Juvenile myoclonic epilepsy (JME) is the most common idiopathic generalized epilepsy syndrome. Neuropsychological, electrophysiological, and neuroimaging studies have led to the hypothesis that JME is related to dysfunction of frontal brain regions and mainly frontal thalamocortical networks. METHODS: We investigated possible microstructural white matter abnormalities of 20 patients with JME as compared with 20 healthy control subjects using diffusion tensor imaging (DTI). We analyzed whole-head DTI scans without an a-priori hypothesis using Tract-Based Spatial Statistics (TBSS). To analyze associated gray matter changes, we applied voxel-based morphometry (VBM) to a 3D T1 magnetization prepared rapid gradient echo (MPRAGE) sequence. Neuropsychological testing and personality trait tests were performed to bridge the gap between structure and function. RESULTS: In patients, DTI revealed microstructural white matter changes in anterior parts of the Corpus callosum, anterior parts of the cingulate gyrus, and widespread frontal white matter bilaterally as well as in anterior parts of the right thalamus, which were not accompanied by gray matter changes in VBM. Microstructural changes in the cingulum correlated with personality traits. Neuropsychological test results showed impaired attention and executive functions and reduced short-term memory in the patient group. Also, there was a tendency toward alexithymia and significantly higher scores on depression. SIGNIFICANCE: The present study results showed neuropsychological deficits including frontal lobe cognitive performance and a tendency toward alexithymia as well as accompanying microstructural neuroimaging changes in patients with JME, which all point to alterations in frontal brain regions and frontal thalamocortical networks in these patients.


Assuntos
Imagem de Tensor de Difusão/métodos , Imageamento por Ressonância Magnética/métodos , Epilepsia Mioclônica Juvenil/complicações , Testes Neuropsicológicos , Substância Branca/fisiopatologia , Adulto , Encéfalo , Corpo Caloso , Epilepsia Generalizada , Função Executiva/fisiologia , Feminino , Lobo Frontal , Humanos , Masculino , Memória de Curto Prazo/fisiologia , Pessoa de Meia-Idade , Neuroimagem , Adulto Jovem
6.
J Stroke Cerebrovasc Dis ; 25(7): 1671-1677, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27067881

RESUMO

BACKGROUND: Cerebral microbleeds (CMB) are associated with an increased risk for ischemic and especially hemorrhagic stroke. The aim of the present study is to identify patients at high risk for the development of new CMB after initiation of an antiplatelet drug therapy. METHODS: Patients received magnetic resonance imaging (MRI) within 1 week after initiation of an antiplatelet drug treatment due to a first ischemic stroke (n = 58) and after a follow-up period of 6 months (n = 40). We documented the presence and the number of CMB at baseline and follow-up and analyzed the influence of possible risk factors including vascular risk factors, stroke etiology, and number of CMB at baseline using stepwise logistic regression and Spearman's correlation coefficient. We compared progression rates of CMB in relation to each risk factor using the Mann-Whitney U-test. RESULTS: The logistic regression model could correctly predict the presence of CMB in 70.7% of patients at baseline and 80% at follow-up. The model correctly identified 85% of patients with new CMB. We observed progression of CMB in 40% of the patients. The overall progression rate was .8 CMB per patient. The progression rate was significantly influenced by age more than 70 years and atherothrombotic stroke. The number of new CMB correlated significantly with the number of CMB at baseline. CONCLUSIONS: We found several predictors of CMB after initiation of antiplatelet drug therapy. The results help to identify patients who need closer monitoring and thorough control of risk factors in order to lower the risk of new CMB and associated complications.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Hemorragias Intracranianas/induzido quimicamente , Inibidores da Agregação Plaquetária/efeitos adversos , Acidente Vascular Cerebral/tratamento farmacológico , Adulto , Idoso , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Feminino , Humanos , Hemorragias Intracranianas/diagnóstico por imagem , Modelos Logísticos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Inibidores da Agregação Plaquetária/administração & dosagem , Valor Preditivo dos Testes , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico por imagem , Fatores de Tempo , Resultado do Tratamento
7.
Epilepsia ; 56(9): 1408-14, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26216711

RESUMO

OBJECTIVE: To evaluate the tolerability and efficacy of the ictal and immediate postictal application of intranasal midazolam (in-MDZ) in adolescents and adults during video-electroencephalography (EEG) monitoring. METHODS: Medical records of all patients treated with in-MDZ between 2008 and 2014 were reviewed retrospectively. For each single patient, the time span until recurrence of seizures was analyzed after an index seizure with and without in-MDZ application. To prevent potential bias, we defined the first seizure with application of in-MDZ as the in-MDZ index seizure. The control index seizure was the preceding, alternatively the next successive seizure without application of in-MDZ. RESULTS: In total, 75 epilepsy patients (mean age 34 ± 14.7 years; 42 male, 33 female) were treated with in-MDZ (mean dose 5.1 mg). Adverse events were observed in four patients (5.3%), and no serious adverse events occurred. The median time after EEG seizure onset before administration of in-MDZ was 2.17 min (interquartile range [IQR] 03.82; range 0.13-15.0 min). Over the next 12 h after in-MDZ, the number of seizures was significantly lower (p = 0.031). The median seizure-free interval was significantly longer following treatment with in-MDZ (5.83 h; IQR 6.83, range 0.4-23.87) than it was for those with no in-MDZ treatment (2.37 h; IQR 4.87, range 0.03-21.87; p = 0.015). Conversely, the likelihood of the patient developing a subsequent seizure was four times higher (odds ratio [OR] 4.33, 95% confidence interval [CI] 1.30-14.47) in the first hour and decreased gradually after 12 h (OR 1.5, 95% CI 1.06-2.12). The occurrence of generalized tonic-clonic seizures was lower in the in-MDZ group in the 24-h observation period (OR 4.67, 95% CI 1.41-15.45; p = 0.009). SIGNIFICANCE: Ictal and immediate postictal administration of in-MDZ was well tolerated and not associated with serious adverse events. We demonstrated a significant reduction of subsequent seizures (all seizure types) for a 12 h period and of generalized tonic-clonic seizures for 24 h following in-MDZ.


Assuntos
Moduladores GABAérgicos/administração & dosagem , Midazolam/administração & dosagem , Convulsões/tratamento farmacológico , Administração Intranasal , Adolescente , Adulto , Idoso , Criança , Eletroencefalografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica , Recidiva , Convulsões/cirurgia , Gravação em Vídeo , Adulto Jovem
8.
NPJ Parkinsons Dis ; 10(1): 104, 2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38762510

RESUMO

Deep brain stimulation of the subthalamic nucleus (STN-DBS) effectively treats motor and non-motor symptoms in advanced Parkinson's disease (PD). As considerable interindividual variability of outcomes exists, neuroimaging-based biomarkers, including microstructural metrics, have been proposed to anticipate treatment response. In this prospective open-label study, we sought to detect microstructural properties of brain areas associated with short-term non-motor outcomes following STN-DBS. Thirty-seven PD patients underwent diffusion MRI and clinical assessments at preoperative baseline and 6-month follow-up. Whole brain voxel-wise analysis assessed associations between microstructural metrics and non-motor outcomes. Intact microstructure within specific areas, including the right insular cortex, right putamen, right cingulum, and bilateral corticospinal tract were associated with greater postoperative improvement of non-motor symptom burden. Furthermore, microstructural properties of distinct brain regions were associated with postoperative changes in sleep, attention/memory, urinary symptoms, and apathy. In conclusion, diffusion MRI could support preoperative patient counselling by identifying patients with above- or below-average non-motor responses.

9.
Acta Neurol Belg ; 123(3): 1011-1017, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36749466

RESUMO

OBJECTIVE: Functional seizures (FS) or psychogenic, non-epileptic seizures (PNES) are episodic alterations of behaviour with similar semiology to epileptic seizures but which are not caused by epileptic brain activity. Epilepsy patients show a high risk in developing FS; therefore, the purpose of this study is to examine morphometric correlates in patients with FS as well as in epilepsy patients with FS by comparing them separately to healthy controls (HC). METHODS: Twenty-one clinical three-dimensional (3D) T1-magnetic resonance imaging (MRI) scans of patients with FS (FS group) and 15 patients with FS and epilepsy (EFS group) were retrospectively compared with one control group of 21 age- and gender-matched HC. Two separate general linear model analyses were conducted via FreeSurfer version 6.0. RESULTS: The study population consisted of 21 FS patients (66.7% females, n = 14) with a median age at the time of the scan of 24 years (range 17-44 years); 15 EFS patients (80% females, n = 12) with a median age at the time of the scan of 27 years (range 16-43 years); and 21 healthy subjects (66.7% females, n = 14) with a median age at the time of the scan of 24 years (range 19-38 years). Both patient groups showed an increased Cth in the right prefrontal lobe: in the FS group in the right superior frontal, rostral middle frontal gyri and the right orbitofrontal cortex and, in the EFS group, in the right superior frontal gyrus and the right orbitofrontal cortex. Decreases in Cth were present in the right lateral occipital lobe in the FS group, while also in both hemispheres in the EFS group, namely the left paracentral, superior frontal, caudal middle frontal, lateral occipital and right superior frontal gyri. Neither group showed changes in curvature. CONCLUSION: These results suggest alterations in regions of emotional processing and executive control in patients with FS regardless of the presence of epilepsy.


Assuntos
Epilepsia , Convulsões , Feminino , Humanos , Adolescente , Adulto Jovem , Adulto , Masculino , Estudos Retrospectivos , Convulsões/diagnóstico por imagem , Convulsões/psicologia , Epilepsia/complicações , Epilepsia/diagnóstico por imagem , Comorbidade , Córtex Pré-Frontal , Imageamento por Ressonância Magnética/métodos
10.
Front Neurol ; 14: 1209941, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37900611

RESUMO

Objective: To investigate correlates in hippocampal subfield volume and verbal and visual memory function in patients with temporal lobe epilepsy (TLE), mild amnestic cognitive impairment (MCI) and heathy participants (HP). Methods: 50 right-handed participants were included in this study; 11 patients with temporal lobe epilepsy (TLE), 18 patients with mild amnestic cognitive impairment (MCI) and 21 healthy participants (HP). Verbal memory performance was evaluated via the verbal memory test (VLMT) and visual memory performance via the diagnosticum for cerebral damage (DCM). Hippocampal subfield volumes of T1-weighted Magnetic Resonance Imaging (MRI) scans were computed with FreeSurfer version 7.1. Stepwise correlation analyses were performed between the left hippocampal subfield volumes and learning, free recall, consolidation and recognition performance scores of the VLMT as well as between right hippocampal subfield volumes and visual memory performance. Results: The volume of the left subicular complex was highly correlated to learning performance (ß = 0.284; p = 0.042) and free recall performance in the VLMT (ß = 0.434; p = 0.001). The volume of the left CA3 subfield showed a significant correlation to the consolidation performance in the VLMT (ß = 0.378; p = 0.006) and recognition performance in the VLMT (ß = 0.290; p = 0.037). There was no significant correlation identified between the right hippocampal subfields and the visual memory performance. Conclusion: The results of this study show verbal memory correlates with hippocampal subfields and support the role of left subiculum and left CA2/CA3 in verbal memory performance.

11.
Headache ; 52(2): 274-82, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22082475

RESUMO

BACKGROUND: Cluster headache (CH) is a rare headache disorder with severe unilateral headache bouts and autonomic symptoms. The pathophysiology of CH is not completely understood. Using a voxel-based morphometric paradigm or functional imaging, a key role of the hypothalamus and the pain matrix could be demonstrated during CH episodes. However, there are no diffusion tensor imaging (DTI) data investigating the white matter microstructure of the brain in patients with CH. Therefore, we used DTI to delineate microstructural changes in patients with CH in a headache-free state. METHODS: Seven male patients with episodic CH and 7 healthy subjects were included and examined with a routine 1.5 T magnetic resonance imaging scanner. Whole-head DTI scans measuring fractional anisotropy were analyzed without a priori hypotheses using track-based spatial statistics. RESULTS: We found significant microstructural brain tissue changes bilaterally in the white matter of the brainstem, the frontal lobe, the temporal lobe, the occipital lobe, the internal capsule, and on the right side of thalamus and cerebellum. There were further lesions in the basal frontal lobe that were part of the olfactory system. Alterations of fractional anisotropy in the brainstem might indicate changes of the medial lemniscus and central sympathetic pathways. CONCLUSIONS: Patients with episodic CH have microstructural brain changes in regions that belong to the pain matrix. Furthermore, we were able to detect structural changes suggesting an involvement of the olfactory system as well as lesions in the brainstem indicating an involvement of trigeminal and sympathetic systems.


Assuntos
Mapeamento Encefálico , Encéfalo/patologia , Cefaleia Histamínica/patologia , Imagem de Tensor de Difusão , Adulto , Idoso , Anisotropia , Lateralidade Funcional , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade
12.
Epilepsia Open ; 7(3): 518-524, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35766437

RESUMO

We report detailed functional MRI (fMRI) analyses in a patient with reflex seizures elicited by driving along a specific rural crossroad or by watching a video thereof. Semiology consisted of epigastric aura, followed by a sensory seizure of the left hand and sporadic automotor seizures. The right amygdala-region (rh-amygdala) was surgically and electroclinically confirmed as the epileptogenic zone. Presurgical task-fMRI was performed, during which videos of the driving along that specific crossroad (IC), of another crossroad (NC) or noise were presented. Independent component analysis was conducted, and one component was used to aid in selection of a seed region within the rh-amygdala for subsequent psychophysiological interaction analysis (PPI). Here, the following regions showed stronger connectivity with the rh-amygdala seed during the IC condition compared to NC: right > left visual cortex, bilateral insulae, and right secondary somatosensory cortex (S2), potentially explaining epigastric aura and left somatosensory seizure semiology. Contralateral analyses did not reproduce these results. Overall, the ictogenic stimulus elicited enhanced connectivity of the epileptogenic rh-amygdala with visual cortex and further regions of potential seizure spread (S2, insula) as a putative mechanism of ictogenesis. Our results highlight the potential of PPI in the analysis of stimulus-dependent networks in patients with reflex epilepsies to gain insight into seizure generation.


Assuntos
Epilepsias Parciais , Epilepsia Reflexa , Tonsila do Cerebelo/diagnóstico por imagem , Epilepsia Reflexa/diagnóstico , Humanos , Imageamento por Ressonância Magnética , Convulsões
13.
Brain Commun ; 4(3): fcac137, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35702729

RESUMO

Bimanual coordination is impaired in Parkinson's disease affecting patients' ability to perform activities of daily living and to maintain independence. Conveyance of information between cortical and subcortical areas is essential for bimanual coordination and relies on the integrity of cerebral microstructure. As pathological deposition of alpha-synuclein compromises microstructure in Parkinson's disease, we investigated the relationship between microstructural integrity and bimanual coordination using diffusion-weighted MRI in 23 patients with Parkinson's disease (mean age ± standard deviation: 56.0 ± 6.45 years; 8 female) and 26 older adults (mean age ± standard deviation: 58.5 ± 5.52 years). Whole-brain analysis revealed specific microstructural alterations between patients and healthy controls matched for age, sex, handedness, and cognitive status congruent with the literature and known Parkinson's disease pathology. A general linear model revealed distinct microstructural alterations associated with poor bimanual coordination in Parkinson's disease, corrected for multiple comparisons using a permutation-based approach. Integrating known functional topography, we conclude that distinct changes in microstructure cause an impediment of structures involved in attention, working memory, executive function, motor planning, motor control, and visual processing contributing to impaired bimanual coordination in Parkinson's disease.

14.
Seizure ; 87: 94-102, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33752160

RESUMO

OBJECTIVE: The present study validates the results of automated hippocampal subfield segmentation with histopathology in epilepsy patients undergoing epilepsy surgery. METHODS: We performed an automated hippocampal subfield segmentation on presurgical three-dimensional, T1-weighted magnetization Prepared Rapid Acquisition of Gradient Echoes Magnetic Resonance Imaging (MRI) data of 25 patients with unilateral mesial temporal lobe epilepsy due to hippocampal sclerosis (HS), using Freesurfer Version 6.0. The resulting volumes of cornu ammonis (CA) subfields CA1, CA2/3, CA4 and the dentate gyrus (DG) were compared to the histopathological cell count. RESULTS: We found a significant correlation between histopathology in subregion CA2 and automated segmentation of subregion CA1 (p = 0.0062), CA2/3 (p = 0.004), CA4 (p = 0.0062) and the DG (p = 0.0054), between histopathology in CA3 and automated segmentation of CA1 (p = 0.0132), CA2/3 (p = 0.0004), CA4 (p = 0.0032) and the DG (p = 0.0037), as well as between histopathology in the DG and automated segmentation of CA1 (p = 0.0115), CA2/3 (p < 0.0001), CA4 (p < 0.0001) and the DG (p = 0.0001). The histopathological finding of HS type 1 could correctly be classified in all cases on MRI. SIGNIFICANCE: The present study shows significant correlations between histopathological evaluation and results of the automated segmentation of the hippocampus, thereby validating the automated segmentation method. As the differential involvement of different hippocampal subfields may be associated with clinical parameters and the outcome after epilepsy surgery, the automated segmentation is also promising for prognostic purposes.


Assuntos
Epilepsia do Lobo Temporal , Contagem de Células , Epilepsia do Lobo Temporal/diagnóstico por imagem , Epilepsia do Lobo Temporal/cirurgia , Hipocampo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética
15.
Sleep ; 33(6): 767-73, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20550017

RESUMO

STUDY OBJECTIVES: Idiopathic rapid eye movement sleep behavior disorder (iRBD)--a parasomnia characterized by dream enactments--is a risk marker for the development of Parkinson disease (PD) and other alpha-synucleinopathies. The pathophysiology of iRBD is likely due to dysfunction of brainstem nuclei that regulate REM sleep. Diffusion tensor imaging (DTI) is a method for studying microstructural brain tissue integrity in vivo. We investigated whether DTI detects microstructural abnormalities in the brain of patients with iRBD--compared with age-matched control subjects--as an in vivo potential indicator for changes related to "preclinical (premotor)" neuropathology in PD. DESIGN: N/A. PATIENTS: Patients with iRBD (n = 12) and age-matched healthy control subjects (n = 12) were studied. INTERVENTIONS: At a 1.5T MRI maschine, whole-head DTI scans of fractional anisotropy, axial diffusivity (a potential marker of neuronal loss), and radial diffusivity (a potential marker of glial pathology) were analyzed using track-based spatial statistics, and 2 types of group analysis tools (FreeSurfer and FSL). MEASUREMENTS AND RESULTS: We found significant microstructural changes in the white matter of the brainstem (P < 0.0001), the right substantia nigra, the olfactory region, the left temporal lobe, the fornix, the internal capsule, the corona radiata, and the right visual stream of the patients with iRBD. CONCLUSIONS: Changes were identified in regions known to be involved in REM-sleep regulation and/or to exhibit neurodegenerative pathology in iRBD and/or early PD. The study findings suggest that iRBD-related microstructural abnormalities can be detected in vivo with DTI, a widely available MRI technique.


Assuntos
Encéfalo/patologia , Imagem de Difusão por Ressonância Magnética/métodos , Doença de Parkinson/diagnóstico , Transtorno do Comportamento do Sono REM/diagnóstico , Adulto , Idoso , Anisotropia , Mapeamento Encefálico/métodos , Tronco Encefálico/patologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Substância Negra/patologia
16.
Mov Disord ; 25(9): 1232-8, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20222139

RESUMO

We investigated DTI changes, potentially indicating alterations of microstructure and brain tissue integrity in 13 patients with probable progressive supranuclear palsy (PSP, Richardson syndrome) at stage III or less and 10 age-matched controls using a whole brain analysis of diffusion tensor imaging (DTI) data. DTI images were analyzed using tract-based spatial statistics, a hypothesis-free technique. Fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD) were determined. In patients with PSP, significant increases in FA (P < 0.0001), an unspecific measure of microstructural tissue integrity, were found in the cerebellum and in the superior cerebellar peduncle bilaterally, in the fornix, the body of the corpus callosum and the olfactory region, when compared with age-matched healthy controls. Further, regional reductions in AD (P < 0.0001), an indicator of altered axonal integrity, were observed in the pons, the right substantia nigra and the cerebellar white matter bilaterally. Significant increases in RD (P < 0.0001), a potential measure of altered myelin integrity, occurred bilaterally in the superior cerebellar peduncle, the cerebellar white matter, the vermis of the cerebellum, the fornix, the body of the corpus callosum, and the olfactory region. RD values in the superior cerebellar peduncle discriminated patients with PSP and controls with high sensitivity (0.92) and specificity (1.0). The findings are supported by neuropathological studies. Our data suggest the usefulness of this clinically available new technique as a possible tool for differential diagnosis.


Assuntos
Mapeamento Encefálico , Encéfalo/patologia , Imagem de Difusão por Ressonância Magnética , Paralisia Supranuclear Progressiva/patologia , Idoso , Anisotropia , Estudos de Casos e Controles , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Dinâmica não Linear
17.
Brain Behav ; 5(9): e00327, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26442748

RESUMO

BACKGROUND AND PURPOSE: We evaluated cerebral white and gray matter changes in patients with iRLS in order to shed light on the pathophysiology of this disease. METHODS: Twelve patients with iRLS were compared to 12 age- and sex-matched controls using whole-head diffusion tensor imaging (DTI) and voxel-based morphometry (VBM) techniques. Evaluation of the DTI scans included the voxelwise analysis of the fractional anisotropy (FA), radial diffusivity (RD), and axial diffusivity (AD). RESULTS: Diffusion tensor imaging revealed areas of altered FA in subcortical white matter bilaterally, mainly in temporal regions as well as in the right internal capsule, the pons, and the right cerebellum. These changes overlapped with changes in RD. Voxel-based morphometry did not reveal any gray matter alterations. CONCLUSIONS: We showed altered diffusion properties in several white matter regions in patients with iRLS. White matter changes could mainly be attributed to changes in RD, a parameter thought to reflect altered myelination. Areas with altered white matter microstructure included areas in the internal capsule which include the corticospinal tract to the lower limbs, thereby supporting studies that suggest changes in sensorimotor pathways associated with RLS.


Assuntos
Substância Cinzenta/patologia , Síndrome das Pernas Inquietas/patologia , Substância Branca/patologia , Estudos de Casos e Controles , Imagem de Tensor de Difusão/métodos , Feminino , Substância Cinzenta/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Neuroimagem/métodos , Síndrome das Pernas Inquietas/fisiopatologia , Substância Branca/fisiopatologia
18.
Cortex ; 65: 219-31, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25754503

RESUMO

Emotional instability, difficulties in social adjustment, and disinhibited behavior are the most common symptoms of the psychiatric comorbidities in juvenile myoclonic epilepsy (JME). This psychopathology has been associated with dysfunctions of mesial-frontal brain circuits. The present work is a first direct test of this link and adapted a paradigm for probing frontal circuits during empathy for pain. Neural and psychophysiological parameters of pain empathy were assessed by combining functional magnetic resonance imaging (fMRI) with simultaneous pupillometry in 15 JME patients and 15 matched healthy controls. In JME patients, we observed reduced neural activation of the anterior cingulate cortex (ACC), the anterior insula (AI), and the ventrolateral prefrontal cortex (VLPFC). This modulation was paralleled by reduced pupil dilation during empathy for pain in patients. At the same time, pupil dilation was positively related to neural activity of the ACC, AI, and VLPFC. In JME patients, the ACC additionally showed reduced functional connectivity with the primary and secondary somatosensory cortex, areas fundamentally implicated in processing the somatic cause of another's pain. Our results provide first evidence that alterations of mesial-frontal circuits directly affect psychosocial functioning in JME patients and draw a link of pupil dynamics with brain activity during emotional processing. The findings of reduced pain empathy related activation of the ACC and AI and aberrant functional integration of the ACC with somatosensory cortex areas provide further evidence for this network's role in social behavior and helps explaining the JME psychopathology and patients' difficulties in social adjustment.


Assuntos
Mapeamento Encefálico , Córtex Cerebral/fisiopatologia , Imageamento por Ressonância Magnética , Epilepsia Mioclônica Juvenil/psicologia , Adolescente , Adulto , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Masculino , Epilepsia Mioclônica Juvenil/patologia , Testes Neuropsicológicos , Adulto Jovem
19.
Epilepsy Behav Case Rep ; 1: 118-21, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-25667843

RESUMO

AIM: The aim of this report is to provide initial evidence that add-on treatment with perampanel might be highly effective in progressive myoclonic epilepsy such as Lafora disease. CASE REPORT: We report on a 21-year-old woman suffering from persistent myoclonus and generalized tonic-clonic seizures for more than seven years. Additionally, ataxia, a disturbance in speech and gait, as well as a cognitive decline were rapidly progressing. Subsequently, the diagnosis of Lafora disease was confirmed by the identification of a novel homozygous missense mutation in exon 3 of the EPM2A gene (c.538C>G; p.L180V). Adjunctive therapy with perampanel was started in this patient with advanced Lafora disease and was titrated up to 8 mg/day. A sustained and reproducible remission of myoclonus and GTCS could be achieved for a follow-up of three months. After dosage reduction to 6 mg/day, seizures recurred; however, on increasing the daily dose to 10 mg, seizures stopped for another three months. The patient also regained her ability to walk with help and the aid of a walker. CONCLUSIONS: Perampanel is a selective, noncompetitive antagonist of AMPA-type glutamate receptors and recently licensed as adjunctive therapy for the treatment of refractory focal onset seizures. There is evidence for its effectiveness in generalized epilepsies, and phase III studies for this indication are on the way. Our case illustrates the possibility that perampanel might be a valuable option for treatment in PME. Considering its impressive efficacy in this case, we suggest a prospective, multicenter study evaluating perampanel in PME.

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