OBJECTIVE: To date, very few studies have focused on structural changes and their association with cognitive performance in isolated REM sleep behaviour disorder (iRBD). Moreover, the results of these studies are inconclusive. This study aims to evaluate differences in the associations between brain morphology and cognitive tests in iRBD and healthy controls. METHODS: Sixty-three patients with iRBD and thirty-six controls underwent MRI with a 3 T scanner. The cognitive performance was assessed by a comprehensive neuropsychological battery. Based on performance, the iRBD group was divided into two subgroups with (iRBD-MCI) and without mild cognitive impairment (iRBD-NC). The high-resolution T1-weighted images were analysed using an automated atlas segmentation tool, voxel-based (VBM) and deformation-based (DBM) morphometry to identify between-group differences and correlations with cognitive performance. RESULTS: VBM, DBM and the comparison of ROI volumes yielded no significant differences between iRBD and controls. In the iRBD group, significant correlations in VBM were found between several cortical and subcortical structures primarily located in the temporal, parietal, occipital lobe, cerebellum, and basal ganglia and three cognitive tests assessing psychomotor speed and one memory test. Between-group analysis of cognition revealed a significant difference between iRBD-MCI and iRBD-NC in tests including a processing speed component. CONCLUSIONS: iRBD shows deficits in several cognitive tests that correlate with morphological changes, the most prominent of which is in psychomotor speed and visual attention as measured by the TMT-A and associated with the volume of striatum, insula, cerebellum, temporal lobe, pallidum and amygdala.
Isolated REM sleep behavior disorder (iRBD) is an early stage of synucleinopathy with most patients progressing to Parkinson's disease (PD) or related conditions. Quantitative susceptibility mapping (QSM) in PD has identified pathological iron accumulation in the substantia nigra (SN) and variably also in basal ganglia and cortex. Analyzing whole-brain QSM across iRBD, PD, and healthy controls (HC) may help to ascertain the extent of neurodegeneration in prodromal synucleinopathy. 70 de novo PD patients, 70 iRBD patients, and 60 HCs underwent 3 T MRI. T1 and susceptibility-weighted images were acquired and processed to space standardized QSM. Voxel-based analyses of grey matter magnetic susceptibility differences comparing all groups were performed on the whole brain and upper brainstem levels with the statistical threshold set at family-wise error-corrected p-values <.05. Whole-brain analysis showed increased susceptibility in the bilateral fronto-parietal cortex of iRBD patients compared to both PD and HC. This was not associated with cortical thinning according to the cortical thickness analysis. Compared to iRBD, PD patients had increased susceptibility in the left amygdala and hippocampal region. Upper brainstem analysis revealed increased susceptibility within the bilateral SN for both PD and iRBD compared to HC; changes were located predominantly in nigrosome 1 in the former and nigrosome 2 in the latter group. In the iRBD group, abnormal dopamine transporter SPECT was associated with increased susceptibility in nigrosome 1. iRBD patients display greater fronto-parietal cortex involvement than incidental early-stage PD cohort indicating more widespread subclinical neuropathology. Dopaminergic degeneration in the substantia nigra is paralleled by susceptibility increase, mainly in nigrosome 1.
- MeSH
- lidé MeSH
- mozek diagnostické zobrazování patologie MeSH
- Parkinsonova nemoc * komplikace MeSH
- porucha chování v REM spánku * diagnostické zobrazování MeSH
- substantia nigra diagnostické zobrazování patologie MeSH
- synukleinopatie * komplikace patologie MeSH
- železo MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND AND OBJECTIVES: The intricate relationship between deep brain stimulation (DBS) in Parkinson's disease (PD) and cognitive impairment has lately garnered substantial attention. The presented study evaluated pre-DBS structural and microstructural cerebral patterns as possible predictors of future cognitive decline in PD DBS patients. METHODS: Pre-DBS MRI data in 72 PD patients were combined with neuropsychological examinations and follow-up for an average of 2.3 years after DBS implantation procedure using a screening cognitive test validated for diagnosis of mild cognitive impairment in PD in a Czech population - Dementia Rating Scale 2. RESULTS: PD patients who would exhibit post-DBS cognitive decline were found to have, already at the pre-DBS stage, significantly lower cortical thickness and lower microstructural complexity than cognitively stable PD patients. Differences in the regions directly related to cognition as bilateral parietal, insular and cingulate cortices, but also occipital and sensorimotor cortex were detected. Furthermore, hippocampi, putamina, cerebellum and upper brainstem were implicated as well, all despite the absence of pre-DBS differences in cognitive performance and in the position of DBS leads or stimulation parameters between the two groups. CONCLUSIONS: Our findings indicate that the cognitive decline in the presented PD cohort was not attributable primarily to DBS of the subthalamic nucleus but was associated with a clinically silent structural and microstructural predisposition to future cognitive deterioration present already before the DBS system implantation.
- MeSH
- hluboká mozková stimulace * škodlivé účinky MeSH
- kognitivní dysfunkce * etiologie diagnostické zobrazování patofyziologie patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- magnetická rezonanční tomografie * metody MeSH
- neuropsychologické testy MeSH
- nucleus subthalamicus * diagnostické zobrazování MeSH
- Parkinsonova nemoc * terapie diagnostické zobrazování patologie MeSH
- senioři MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Parkinson's disease (PD), even though generally perceived as a dominantly motor disorder, is associated with a wide range of non-motor symptoms, including mixed anxiety-depressive disorder (MADD). OBJECTIVES: The aim of the presented study was to determine whether deep brain stimulation (DBS) of the subthalamic nucleus (STN) brings the functional characteristics of non-motor networks closer to the condition detected in healthy population and whether pre-DBS presence of MADD in PD patients was associated with different reaction to this therapeutic modality. METHODS: Resting-state fMRI signature elicited by STN DBS activation and deactivation in 81 PD patients was compared against healthy controls, with the focus on measures of efficiency of information processing and localised subnetwork differences. RESULTS: While all the MRI metrics showed statistically significant differences between PD patients in DBS OFF condition and healthy controls, none were detected in such a comparison against DBS ON condition. Furthermore, in the post-DBS evaluation, PD patients with MADD in the pre-DBS stage showed no differences in depression scales compared to pre-DBS psychiatrically intact PD patients, but still exhibited lower DBS-related connectivity in a subnetwork encompassing anterior and posterior cingulate, dorsolateral prefrontal and medial temporal cortices. CONCLUSIONS: STN DBS improved all the metrics of interest towards the healthy state, normalising the resting-state MRI signature of PD. Furthermore, pre-DBS presence of MADD, even though clinically silent at post-DBS MRI acquisition, was associated with lower DBS effect in areas highly relevant for depression. This finding points to a possibly latent nature of post-DBS MADD, calling for caution in further follow-up of these patients.
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Multiple hippocampal transection (MHT) is a surgical technique used for the treatment of drug-resistant mesial temporal lobe epilepsy in situations where standard procedures would pose a high risk for memory deterioration. During MHT, the longitudinal fibers of the hippocampus, implicated in epilepsy spreading, are interrupted, while the transverse memory circuits are spared. The extent of MHT is governed by intraoperative electrocorticography; abolition of epileptic discharges serves as an end point to terminate the transection. In other words, the aim of MHT is not the anatomical completeness of hippocampal transection. In contrast, we hypothesize that only the complete transection of hippocampal cross-section is needed to durably terminate epilepsy, avoiding possible postoperative reorganization of longitudinal pathways. Here, we report an anatomical study designed to evaluate the feasibility of complete transection of hippocampus with the aid of ultrasound neuronavigation and we propose new instruments to reach this goal. METHODS: Five cadaveric brains were analyzed in this study. MHT was performed on both sides of each brain either with or without ultrasound neuronavigation. The percentage of transected cross-section of the hippocampus was measured using magnetic resonance imaging (MRI) and both sides were compared. RESULTS: The ultrasound-guided MHTs were more likely to achieve complete hippocampal transection compared with the nonnavigated MHT transection (73 vs 58%; p < 0.01). Our study also allowed us to propose specialized transectors to minimize invasivity of this procedure. CONCLUSION: Completeness of MHT can be better reached with the aid of an ultrasound neuronavigation system; modified instruments for this procedure were also designed.
- MeSH
- epilepsie temporálního laloku * chirurgie diagnostické zobrazování MeSH
- hipokampus * diagnostické zobrazování chirurgie MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- mrtvola MeSH
- neurochirurgické výkony metody MeSH
- neuronavigace * metody MeSH
- refrakterní epilepsie chirurgie diagnostické zobrazování MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Corpus callosum (CC) je největší mozková komisura spojující levou a pravou mozkovou hemisféru. Obsahuje axony, které propojují především homotopické kortikální oblasti obou hemisfér. Konvenčním MR zobrazením je CC velmi dobře přehledné a hodnotitelné. Postižení corpus callosum lze rozdělit do tří kategorií - vrozené vady, signálové změny a atrofie. První dvě zmíněné jsou na MR většinou správně rozpoznány a zhodnoceny v popisech. Atrofie CC je naproti tomu často přehlížena a připisována pouze pokročilému věku. Může však být podmíněna celou řadou patologických stavů a reflektovat postižení jak bílé, tak šedé hmoty mozkové. K primárnímu postižení bílé hmoty a atrofii CC vedou patologické stavy podmiňující demyelinizaci a následný úbytek axonů. Atrofie CC může být také sekundárním důsledkem postižení šedé hmoty mozkové, konkrétně neuronů III. korové vrstvy, jejichž zánik je následován walleriánskou degenerací axonů projikujících skrze CC. Jelikož jsou vlákna v CC topograficky uspořádána, zánik neuronů určité korové oblasti koresponduje s úbytkem vláken v příslušném segmentu CC a výsledným obrazem je regionální atrofie CC. Článek si klade za úkol nabídnout širší pohled na problematiku atrofie CC, ukázat její pestrou diferenciální diagnostiku.
Corpus callosum (CC) is the largest brain commissure interconnecting the left and right cerebral hemisphere. It consists of fibers projecting mainly to homotopical cortical regions and is well visualized on the conventional MR scans. The main types of callosal abnormalities are congenital defects, signal changes and atrophy, where the first two are rarely unnoticed and unreported - contrary to atrophy, which is frequently attributed to the old age only. Aside from age-related involution, callosal atrophy may be caused by a broad spectrum of pathological conditions damaging either white or gray matter. Demyelinating conditions lead to CC atrophy by primary damage of white matter. Loss of cortical neurons and subsequent wallerian degeneration lead to loss of axons projecting through CC and its secondary atrophy. Because fibers in CC are topographically arranged, loss of neurons in certain cortical regions corresponds to loss of fibers (and thus loss of volume) in certain segments of CC, resulting in regional callosal atrophy. The aim of this article is to provide a broader view on the atrophy of corpus callosum, present its differential diagnosis and potential practical use.
- MeSH
- atrofie diagnostické zobrazování etiologie patologie MeSH
- corpus callosum * diagnostické zobrazování patologie MeSH
- diferenciální diagnóza MeSH
- difuzní axonální poranění diagnostické zobrazování klasifikace patologie MeSH
- lidé MeSH
- magnetická rezonanční tomografie MeSH
- nemoci nervového systému * diagnostické zobrazování klasifikace patologie MeSH
- neurodegenerativní nemoci diagnostické zobrazování patologie MeSH
- roztroušená skleróza diagnostické zobrazování patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Závěrečná zpráva o řešení grantu Agentury pro zdravotnický výzkum MZ ČR
nestr.
Neurodegenerative diseases are serious fatal disorders caused by progressive loss of specific neuronal populations.Correct recognition of neurodegenerative dementias during the patients’ life is still very difficult.Combinations of two or more neurodegenerative diseases are far more common than previously admitted, even though more precise epidemiological data is still missing.Overlap of neurodegenerative diseases may be involved into a more rapid progression or very atypical presentation in many patients.Moreover,newly described neuropathological entities related to the aging-Aging-related tau astrogliopathy(ARTAG) or Primary age-related tauopathy(PART)-are more frequent than previously expected and till this time a precise definition of the clinical picture of these impairments is missing.The principal objective is to estimate the proportion of comorbid neurodegenerative dementias in a single centre and in a neuropathological reference laboratory based on retrospective and prospective clinic-pathological correlations in order to improve the clinical diagnosis of different diseases.
Neurodegenerace jsou důsledkem postupného zániku specifických skupin neuronů. Patofyziologickou podstatou je ukládání určitého specifického – pro dané onemocnění charakteristického proteinu (např. beta-amyloidu, tau proteinu nebo alfa-synukleinu) v mozkové tkáni v kombinaci s obecnými mechanismy apoptózy a autofagie (řízené smrti buňky). Správné rozpoznání neurodegenerací během života pacientů je i v současné době velmi obtížné. Kombinace dvou i více neurodegenerativních onemocnění jsou častější, než se dříve soudilo, i když zatím nejsou dostupná přesnější epidemiologická data. Překrývání neudegenerací může být příčinou rychlejšího průběhu i někdy velmi atypických klinických obrazů u řady pacientů. Je proto nutné zdůraznit nutnost provádění detailního neuropatologického vyšetření mozku pacientů a následnou retrospektivní klinicko-patologickou korelací analyzovat vliv a případně též podíl jednotlivých komorbidit na průběh onemocnění. Výsledná analýza totiž může mít u budoucích pacientů potenciální terapeutické konsekvence a být přínosná pro zpřesnění prognostických aspektů onemocnění.
- Klíčová slova
- biomarkery, biomarkers, demence, dementia, neurodegeneration, neurodegenerace, neuropatologie, neuropathology, překrývání, overlap,
- NLK Publikační typ
- závěrečné zprávy o řešení grantu AZV MZ ČR
REM sleep without atonia (RWA) is the hallmark of isolated REM sleep behavior disorder (iRBD) and is caused by neurodegeneration of brainstem structures. Previously, quantitative susceptibility mapping (QSM) was shown to detect microstructural tissue changes in neurodegenerative diseases. The goal of the study was to compare brainstem magnetic susceptibility (MS) in iRBD and controls using the voxel-based QSM approach and to examine the association between brainstem MS and severity of RWA in iRBD. Sixty iRBD patients and 41 healthy controls were included in the study. Phasic, tonic, mixed RWA and SINBAR score was quantified. QSM maps were reconstructed with QSMbox software from a multi-gradient-echo sequence acquired at 3T MRI system and normalized using a custom T1 template. Voxel-based analysis with age and gender as covariates was performed using a two-sample t-test model for between-group comparison and using a linear regression model for association with the RWA parameters. Statistical maps were generated using threshold free cluster enhancement with p-value p < 0.05, corrected for family wise error. Compared to controls, the iRBD group had higher MS in bilateral substantia nigra (SN), red nucleus and the ventral tegmental area. MS positively correlated with iRBD duration in the right pedunculotegmental nucleus and white matter of caudal mesencephalic and pontine tegmentum and with phasic RWA in bilateral SN. QSM was able to detect MS abnormalities in several brainstem structures in iRBD. Association of MS levels in the brainstem with the intensity of RWA suggests that increased iron content in SN is related to RWA severity.
- Publikační typ
- časopisecké články MeSH
BACKGROUND AND PURPOSE: Globular glial tauopathies (GGTs) have heterogeneous presentations; little evidence regarding typical clinical and magnetic resonance imaging (MRI) presentations are available. METHODS: We retrospectively assessed MRIs from three postmortem-confirmed GGT cases, in two patients with atypical progressive aphasia and one with corticobasal syndrome. RESULTS: We suggest that four principal concomitant MRI findings characterize GGT type I: a sagittal callosal hyperintense band, marked focal callosal atrophy suggesting white matter degeneration originating in cortical areas responsible for symptoms (anterior atrophy in predominantly language manifestations and posterior atrophy in predominantly apraxia), periventricular white matter lesions, and mild-to-moderate brain stem atrophy. CONCLUSIONS: We observed four concomitant MRI abnormalities in patients with atypical dementia, parkinsonism, and late incomplete supranuclear gaze palsy. Two patients had atypical progressive aphasia and one had corticobasal syndrome.
Introduction: Primary progressive aphasia (PPA) is a clinically variable syndrome manifesting as slow progressive loss of speech and language with multiple underlying neurodegenerative pathologies. Materials and Methods: We included data from nine PPA patients with available autopsies. We then retrospectively reviewed all available medical records, neuropsychology, and MRI results to confirm the corresponding subtypes of PPA and compared them with postmortem neuropathological results. Results: Clinical presentations corresponded to the nonfluent/agrammatic variant in six cases, the semantic variant in one case, the logopenic variant in one case, and the mixed variant (concomitant nonfluent/agrammatic plus semantic variant) in one case. Patients with a broader clinical presentation, i.e., combining manifestations of one PPA subtype and symptoms of another PPA variant, had autopsy comorbidities showing multiple neurodegenerative disorders. Of the nine subjects enrolled in the study, Alzheimer's disease (AD) was found in eight cases; however, in only one case, AD was detected as an isolated neuropathological substrate of PPA. In eight brain samples, different comorbid neuropathologies were detected: three cases with comorbid AD and dementia with Lewy bodies, two cases with comorbid AD and TDP-43 pathology, one case with comorbid AD and complex tauopathies, and one case with comorbid AD with both tau and TDP-43 deposits. Finally, one case had comorbid tau and TDP-43 pathology but without comorbid AD pathology. Conclusions: Our observation suggests that PPA cases could be more heterogeneous in their etiology than previously thought and underlying neurodegenerative comorbidities should be considered in routine practice, especially if the clinical presentation of PPA is atypical.
- MeSH
- Alzheimerova nemoc * komplikace MeSH
- DNA vazebné proteiny metabolismus MeSH
- lidé MeSH
- mozek patologie MeSH
- primární progresivní afázie * MeSH
- retrospektivní studie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
