1
|
Improving sensitivity, specificity, and reproducibility of individual brainstem activation. Brain Struct Funct 2019; 224:2823-2838. [PMID: 31435738 PMCID: PMC6778541 DOI: 10.1007/s00429-019-01936-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 08/07/2019] [Indexed: 12/20/2022]
Abstract
Functional imaging of the brainstem may open new avenues for clinical diagnostics. However, for reliable assessments of brainstem activation, further efforts improving signal quality are needed. Six healthy subjects performed four repeated functional magnetic resonance imaging (fMRI) sessions on different days with jaw clenching as a motor task to elicit activation in the trigeminal motor nucleus. Functional images were acquired with a 7 T MR scanner using an optimized multiband EPI sequence. Activation measures in the trigeminal nucleus and a control region were assessed using different physiological noise correction methods (aCompCor and RETROICOR-based approaches with variable numbers of regressors) combined with cerebrospinal fluid or brainstem masking. Receiver-operating characteristic analyses accounting for sensitivity and specificity, activation overlap analyses to estimate the reproducibility between sessions, and intraclass correlation analyses (ICC) for testing reliability between subjects and sessions were used to systematically compare the physiological noise correction approaches. Masking the brainstem led to increased activation in the target ROI and resulted in higher values for the area under the curve (AUC) as a combined measure for sensitivity and specificity. With the highest values for AUC, activation overlap, and ICC, the most favorable physiological noise correction method was to control for the cerebrospinal fluid time series (aCompCor with one regressor). Brainstem motor nuclei activation can be reliably identified using high-field fMRI with optimized acquisition and processing strategies—even on single-subject level. Applying specific physiological noise correction methods improves reproducibility and reliability of brainstem activation encouraging future clinical applications.
Collapse
|
2
|
Beisteiner R, Pernet C, Stippich C. Can We Standardize Clinical Functional Neuroimaging Procedures? Front Neurol 2019; 9:1153. [PMID: 30671017 PMCID: PMC6331467 DOI: 10.3389/fneur.2018.01153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 12/13/2018] [Indexed: 12/01/2022] Open
Abstract
In recent years, the interest in clinical applications of functional neuroimaging techniques like functional Magnetic Resonance Imaging (fMRI) or modern Magneto- or Electro- Encephalography (MEG-EEG) has steadily grown as have discussions about possible standardizations of these methodologies. The modern techniques allow non-invasive localization of essential brain functions with the potential to extend or even replace invasive clinical technologies (1–4). The focus of this article is to discuss standardization options in using functional MRI for clinical cases, mostly in the context of medical decision aid for planning treatment (radiotherapy and surgery).
Collapse
Affiliation(s)
- Roland Beisteiner
- Department of Neurology, High Field MR Center, Medical University of Vienna, Vienna, Austria
| | - Cyril Pernet
- Center for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Christoph Stippich
- Department of Neuroradiology, University Hospital Zürich, Zurich, Switzerland
| |
Collapse
|
3
|
Amini A, Fischmeister FPS, Matt E, Schmidhammer R, Rattay F, Beisteiner R. Peripheral Nervous System Reconstruction Reroutes Cortical Motor Output-Brain Reorganization Uncovered by Effective Connectivity. Front Neurol 2019; 9:1116. [PMID: 30619069 PMCID: PMC6305497 DOI: 10.3389/fneur.2018.01116] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 12/05/2018] [Indexed: 01/30/2023] Open
Abstract
Cortical reorganization in response to peripheral nervous system damage is only poorly understood. In patients with complete brachial plexus avulsion and subsequent reconnection of the end of the musculocutaneous nerve to the side of a phrenic nerve, reorganization leads to a doubled arm representation in the primary motor cortex. Despite, homuncular organization being one of the most fundamental principles of the human brain, movements of the affected arm now activate 2 loci: the completely denervated arm representation and the diaphragm representation. Here, we investigate the details behind this peripherally triggered reorganization, which happens in healthy brains. fMRI effective connectivity changes within the motor network were compared between a group of patients and age matched healthy controls at 7 Tesla (6 patients and 12 healthy controls). Results show the establishment of a driving input of the denervated arm area to the diaphragm area which is now responsible for arm movements. The findings extend current knowledge about neuroplasticity in primary motor cortex: a denervated motor area may drive an auxilliary area to reroute its motor output.
Collapse
Affiliation(s)
- Ahmad Amini
- Study Group Clinical fMRI, Department of Neurology, Medical University of Vienna, Vienna, Austria.,Highfield MR Centre, Medical University of Vienna, Vienna, Austria.,TU-BioMed Association for Biomedical Engineering, Vienna University of Technology, Vienna, Austria
| | - Florian Ph S Fischmeister
- Study Group Clinical fMRI, Department of Neurology, Medical University of Vienna, Vienna, Austria.,Highfield MR Centre, Medical University of Vienna, Vienna, Austria.,Institute of Psychology, University of Graz, Graz, Austria
| | - Eva Matt
- Study Group Clinical fMRI, Department of Neurology, Medical University of Vienna, Vienna, Austria.,Highfield MR Centre, Medical University of Vienna, Vienna, Austria
| | - Robert Schmidhammer
- Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Vienna, Austria
| | - Frank Rattay
- TU-BioMed Association for Biomedical Engineering, Vienna University of Technology, Vienna, Austria
| | - Roland Beisteiner
- Study Group Clinical fMRI, Department of Neurology, Medical University of Vienna, Vienna, Austria.,Highfield MR Centre, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
4
|
Giorgio A, Zhang J, Stromillo ML, Rossi F, Battaglini M, Nichelli L, Mortilla M, Portaccio E, Hakiki B, Amato MP, De Stefano N. Pronounced Structural and Functional Damage in Early Adult Pediatric-Onset Multiple Sclerosis with No or Minimal Clinical Disability. Front Neurol 2017; 8:608. [PMID: 29184534 PMCID: PMC5694464 DOI: 10.3389/fneur.2017.00608] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 10/31/2017] [Indexed: 12/29/2022] Open
Abstract
Pediatric-onset multiple sclerosis (POMS) may represent a model of vulnerability to damage occurring during a period of active maturation of the human brain. Whereas adaptive mechanisms seem to take place in the POMS brain in the short-medium term, natural history studies have shown that these patients reach irreversible disability, despite slower progression, at a significantly younger age than adult-onset MS (AOMS) patients. We tested for the first time whether significant brain alterations already occurred in POMS patients in their early adulthood and with no or minimal disability (n = 15) in comparison with age- and disability-matched AOMS patients (n = 14) and to normal controls (NC, n = 20). We used a multimodal MRI approach by modeling, using FSL, voxelwise measures of microstructural integrity of white matter tracts and gray matter volumes with those of intra- and internetwork functional connectivity (FC) (analysis of variance, p ≤ 0.01, corrected for multiple comparisons across space). POMS patients showed, when compared with both NC and AOMS patients, altered measures of diffusion tensor imaging (reduced fractional anisotropy and/or increased diffusivities) and higher probability of lesion occurrence in a clinically eloquent region for physical disability such as the posterior corona radiata. In addition, POMS patients showed, compared with the other two groups, reduced long-range FC, assessed from resting functional MRI, between default mode network and secondary visual network, whose interaction subserves important cognitive functions such as spatial attention and visual learning. Overall, this pattern of structural damage and brain connectivity disruption in early adult POMS patients with no or minimal clinical disability might explain their unfavorable clinical outcome in the long term.
Collapse
Affiliation(s)
- Antonio Giorgio
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Jian Zhang
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | | | - Francesca Rossi
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Marco Battaglini
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Lucia Nichelli
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | | | | | - Bahia Hakiki
- Department of Neurology, University of Florence, Florence, Italy
| | - Maria Pia Amato
- Department of Neurology, University of Florence, Florence, Italy
| | - Nicola De Stefano
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| |
Collapse
|