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Tabari F, Patron C, Cryer H, Johari K. HD-tDCS over left supplementary motor area differentially modulated neural correlates of motor planning for speech vs. limb movement. Int J Psychophysiol 2024; 201:112357. [PMID: 38701898 DOI: 10.1016/j.ijpsycho.2024.112357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 04/15/2024] [Accepted: 04/30/2024] [Indexed: 05/05/2024]
Abstract
The supplementary motor area (SMA) is implicated in planning, execution, and control of speech production and limb movement. The SMA is among putative generators of pre-movement EEG activity which is thought to be neural markers of motor planning. In neurological conditions such as Parkinson's disease, abnormal pre-movement neural activity within the SMA has been reported during speech production and limb movement. Therefore, this region can be a potential target for non-invasive brain stimulation for both speech and limb movement. The present study took an initial step in examining the application of high-definition transcranial direct current stimulation (HD-tDCS) over the left SMA in 24 neurologically intact adults. Subsequently, event-related potentials (ERPs) were recorded while participants performed speech and limb movement tasks. Participants' data were collected in three counterbalanced sessions: anodal, cathodal and sham HD-tDCS. Relative to sham stimulation, anodal, but not cathodal, HD-tDCS significantly attenuated ERPs prior to the onset of the speech production. In contrast, neither anodal nor cathodal HD-tDCS significantly modulated ERPs prior to the onset of limb movement compared to sham stimulation. These findings showed that neural correlates of motor planning can be modulated using HD-tDCS over the left SMA in neurotypical adults, with translational implications for neurological conditions that impair speech production. The absence of a stimulation effect on ERPs prior to the onset of limb movement was not expected in this study, and future studies are warranted to further explore this effect.
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Affiliation(s)
- Fatemeh Tabari
- Human Neurophysiology and Neuromodulation Lab, Communication Sciences and Disorders, Louisiana State University, Baton Rouge, LA, USA
| | - Celeste Patron
- Human Neurophysiology and Neuromodulation Lab, Communication Sciences and Disorders, Louisiana State University, Baton Rouge, LA, USA
| | - Hope Cryer
- Human Neurophysiology and Neuromodulation Lab, Communication Sciences and Disorders, Louisiana State University, Baton Rouge, LA, USA
| | - Karim Johari
- Human Neurophysiology and Neuromodulation Lab, Communication Sciences and Disorders, Louisiana State University, Baton Rouge, LA, USA.
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Gatto RG, Pham NTT, Duffy JR, Clark HM, Utianski RL, Botha H, Machulda MM, Lowe VJ, Schwarz CG, Jack CR, Josephs KA, Whitwell JL. Multimodal cross-examination of progressive apraxia of speech by diffusion tensor imaging-based tractography and Tau-PET scans. Hum Brain Mapp 2024; 45:e26704. [PMID: 38825988 PMCID: PMC11144950 DOI: 10.1002/hbm.26704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 03/27/2024] [Accepted: 04/17/2024] [Indexed: 06/04/2024] Open
Abstract
Progressive apraxia of speech (PAOS) is a 4R tauopathy characterized by difficulties with motor speech planning. Neurodegeneration in PAOS targets the premotor cortex, particularly the supplementary motor area (SMA), with degeneration of white matter (WM) tracts connecting premotor and motor cortices and Broca's area observed on diffusion tensor imaging (DTI). We aimed to assess flortaucipir uptake across speech-language-related WM tracts identified using DTI tractography in PAOS. Twenty-two patients with PAOS and 26 matched healthy controls were recruited by the Neurodegenerative Research Group (NRG) and underwent MRI and flortaucipir-PET. The patient population included patients with primary progressive apraxia of speech (PPAOS) and non-fluent variant/agrammatic primary progressive aphasia (agPPA). Flortaucipir PET scans and DTI were coregistered using rigid registration with a mutual information cost function in subject space. Alignments between DTI and flortaucipir PET were inspected in all cases. Whole-brain tractography was calculated using deterministic algorithms by a tractography reconstruction tool (DSI-studio) and specific tracts were identified using an automatic fiber tracking atlas-based method. Fractional anisotropy (FA) and flortaucipir standardized uptake value ratios (SUVRs) were averaged across the frontal aslant tract, arcuate fasciculi, inferior frontal-occipital fasciculus, inferior and middle longitudinal fasciculi, as well as the SMA commissural fibers. Reduced FA (p < .0001) and elevated flortaucipir SUVR (p = .0012) were observed in PAOS cases compared to controls across all combined WM tracts. For flortaucipir SUVR, the greatest differentiation of PAOS from controls was achieved with the SMA commissural fibers (area under the receiver operator characteristic curve [AUROC] = 0.83), followed by the left arcuate fasciculus (AUROC = 0.75) and left frontal aslant tract (AUROC = 0.71). Our findings demonstrate that flortaucipir uptake is increased across WM tracts related to speech/language difficulties in PAOS.
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Affiliation(s)
| | | | | | | | | | - Hugo Botha
- Department of NeurologyMayo ClinicRochesterMinnesotaUSA
| | - Mary M. Machulda
- Department of Psychiatry and PsychologyMayo ClinicRochesterMinnesotaUSA
| | - Val J. Lowe
- Department of RadiologyMayo ClinicRochesterMinnesotaUSA
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Gatto RG, Martin PR, Utianski RL, Duffy JR, Clark HM, Botha H, Machulda MM, Josephs KA, Whitwell JL. Diffusion tensor imaging-based multi-fiber tracking reconstructions can regionally differentiate phonetic versus prosodic subtypes of progressive apraxia of speech. Cortex 2024; 171:272-286. [PMID: 38061209 PMCID: PMC10922200 DOI: 10.1016/j.cortex.2023.08.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 06/30/2023] [Accepted: 08/09/2023] [Indexed: 02/12/2024]
Abstract
Two subtypes of progressive apraxia of speech (PAOS) have been recognized: phonetic PAOS (PAOS_ph) where speech output is dominated by distorted sound substitutions and prosodic PAOS (PAOS_pr) which is dominated by segmented speech. We investigate whether these PAOS subtypes have different white matter microstructural abnormalities measured by diffusion tensor tractography. Thirty-three patients with PAOS (21 PAOS_ph and 12 PAOS_pr) and 19 healthy controls were recruited by the Neurodegenerative Research Group (NRG) and underwent diffusion MRI. Using a whole-brain tractography approach, fractional anisotropy (FA) and mean diffusivity (MD) were extracted for cortico-cortical, cortico-subcortical, cortical-projection, and cerebello-cortical white matter tracts. A hierarchical linear model was applied to assess tract-level FA and MD across groups. Both PAOS_ph and PAOS_pr showed degeneration of cortico-cortical, cortico-subcortical, cortical-projection, and cerebello-cortical white matter tracts compared to controls. However, degeneration of the body of corpus callosum, superior thalamic radiation, and superior cerebellar peduncle was greater in PAOS_pr compared to PAOS_ph, and degeneration of the inferior segment of the superior longitudinal fasciculus (SLF) was greater in PAOS_ph compared to PAOS_pr. Worse parkinsonism correlated with greater degeneration of cortico-cortical and cortico-subcortical tracts in PAOS_ph. Apraxia of speech articulatory error score correlated with degeneration of the superior cerebellar peduncle tracts in PAOS_pr. Phonetic and prosodic PAOS involve the compromise of a similar network of tracts, although there are connectivity differences between types. Whereas clinical parameters are the current gold standard to distinguish PAOS subtypes, our results allege the use of DTI-based tractography as a supplementary method to investigate such variants.
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Affiliation(s)
| | - Peter R Martin
- Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN, USA
| | | | - Joseph R Duffy
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | | | - Hugo Botha
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Mary M Machulda
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, USA
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Gatto RG, Meade G, Duffy JR, Clark HM, Utianski RL, Botha H, Machulda MM, Josephs KA, Whitwell JL. Combined assessment of progressive apraxia of speech brain microstructure by diffusion tensor imaging tractography and multishell neurite orientation dispersion and density imaging. Brain Behav 2024; 14:e3346. [PMID: 38376044 PMCID: PMC10761330 DOI: 10.1002/brb3.3346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/13/2023] [Accepted: 11/18/2023] [Indexed: 02/21/2024] Open
Abstract
BACKGROUND Progressive apraxia of speech (PAOS) is characterized by difficulties with motor speech programming and planning. PAOS targets gray matter (GM) and white matter (WM) microstructure that can be assessed using diffusion tensor imaging (DTI) and multishell applications, such as neurite orientation dispersion and density imaging (NODDI). In this study, we aimed to apply DTI and NODDI to add further insight into PAOS tissue microstructure. METHODS Twenty-two PAOS patients and 26 age- and sex-matched controls, recruited by the Neurodegenerative Research Group (NRG) at Mayo Clinic, underwent diffusion MRI on 3T MRI. Brain maps of fractional anisotropy (FA) and mean diffusivity (MD) from DTI and intracellular volume fraction (ICVF) and isotropic volume fraction (IsoVF) from NODDI were generated. Global WM and GM, and specific WM tracts were identified using tractography and lobar GM regions. RESULTS Global WM differences between PAOS and controls were greatest for ICVF, and global GM differences were greatest for MD and IsoVF. Abnormalities in key WM tracts involved in PAOS, including the body of the corpus callosum and frontal aslant tract, were identified with FA, MD, and ICVF, with excellent differentiation of PAOS from controls (area under the receiver operating characteristic curves >.90). MD and ICVF identified abnormalities in arcuate fasciculus, thalamic radiations, and corticostriatal tracts. Significant correlations were identified between an index of articulatory errors and DTI and NODDI metrics from the arcuate fasciculus, frontal aslant tract, and inferior longitudinal fasciculus. CONCLUSIONS DTI and NODDI represent different aspects of brain tissue microstructure, increasing the number of potential biomarkers for PAOS.
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Affiliation(s)
| | | | | | | | | | - Hugo Botha
- Department of NeurologyMayo ClinicRochesterMinnesotaUSA
| | - Mary M. Machulda
- Department of Psychiatry and PsychologyMayo ClinicRochesterMinnesotaUSA
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Wei Y, Ye S, Jiang H, Chen Y, Qiu Y, Zhang L, Ma R, Gao Q. Effects of non-invasive brain stimulation over supplementary motor area in people with Parkinson's disease: a protocol for a systematic review and meta-analysis of randomised controlled trials. BMJ Open 2023; 13:e076948. [PMID: 38070907 PMCID: PMC10729189 DOI: 10.1136/bmjopen-2023-076948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 11/19/2023] [Indexed: 12/18/2023] Open
Abstract
INTRODUCTION Individuals with Parkinson's disease (PD) often experience initial hesitation, slowness of movements, decreased balance and impaired standing ability, which can significantly impact their independence. Transcranial magnetic stimulation and transcranial direct current stimulation are two widely used and promising non-invasive brain stimulation (NIBS) modalities for treating PD. The supplementary motor area (SMA), associated with motor behaviour and processing, has received increasing attention as a potential stimulation target to alleviate PD-related symptoms. However, the data on NIBS over SMA in PD individuals are inconsistent and has not been synthesised. In this article, we will review the evidence for NIBS over SMA in PD individuals and evaluate its efficacy in improving PD function. METHOD AND ANALYSIS Randomised controlled clinical trials comparing the effects of NIBS and sham stimulation on motor function, activities of daily living and participation for people with PD will be included. A detailed computer-aided search of the literature will be performed from inception to February 2023 in the following databases: PubMed, EMBASE, Physiotherapy Evidence Database (PEDro), Web of Science (WOS) and The Chinese National Knowledge Infrastructure (CNKI). Two independent reviewers will screen articles for relevance and methodological validity. The PEDro scale will be used to evaluate the risk of bias of selected studies. Data from included studies will be extracted by two independent reviewers through a customised, preset data extraction sheet. ETHICS AND DISSEMINATION Ethical approval is not required for this systematic review. The study's findings will be presented at scientific meetings and published in peer-reviewed journals. PROSPERO REGISTRATION NUMBER CRD42023399945.
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Affiliation(s)
- Yixin Wei
- Department of Rehabilitation Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Saiqing Ye
- Department of Rehabilitation Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Hanhong Jiang
- Department of Rehabilitation Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Yawen Chen
- Department of Rehabilitation Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Department of Rehabilitation Sciences, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hong Kong, People's Republic of China
| | - Yitong Qiu
- Department of Rehabilitation Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Li Zhang
- Department of Rehabilitation Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Runting Ma
- Department of Rehabilitation Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, West China Hospital of Sichuan University, Chengdu, Sichuan, China
| | - Qiang Gao
- Department of Rehabilitation Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China
- Key Laboratory of Rehabilitation Medicine in Sichuan Province, West China Hospital of Sichuan University, Chengdu, Sichuan, China
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Pracar AL, Ivanova MV, Richardson A, Dronkers NF. A case of pure apraxia of speech after left hemisphere stroke: behavioral findings and neural correlates. Front Neurol 2023; 14:1187399. [PMID: 37576017 PMCID: PMC10421996 DOI: 10.3389/fneur.2023.1187399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 06/29/2023] [Indexed: 08/15/2023] Open
Abstract
Introduction Apraxia of speech (AOS) is a motor speech disorder impairing the coordination of complex articulatory movements needed to produce speech. AOS typically co-occurs with a non-fluent aphasia, or language disorder, making it challenging to determine the specific brain structures that cause AOS. Cases of pure AOS without aphasia are rare but offer the best window into the neural correlates that support articulatory planning. The goal of the current study was to explore patterns of apraxic speech errors and their underlying neural correlates in a case of pure AOS. Methods A 67-year-old right-handed man presented with severe AOS resulting from a fronto-insular lesion caused by an ischemic stroke. The participant's speech and language were evaluated at 1-, 3- and 12-months post-onset. High resolution structural MRI, including diffusion weighted imaging, was acquired at 12 months post-onset. Results At the first assessment, the participant made minor errors on the Comprehensive Aphasia Test, demonstrating mild deficits in writing, auditory comprehension, and repetition. By the second assessment, he no longer had aphasia. On the Motor Speech Evaluation, the severity of his AOS was initially rated as 5 (out of 7) and improved to a score of 4 by the second visit, likely due to training by his SLP at the time to slow his speech. Structural MRI data showed a fronto-insular lesion encompassing the superior precentral gyrus of the insula and portions of the inferior and middle frontal gyri and precentral gyrus. Tractography derived from diffusion MRI showed partial damage to the frontal aslant tract and arcuate fasciculus along the white matter projections to the insula. Discussion This pure case of severe AOS without aphasia affords a unique window into the behavioral and neural mechanisms of this motor speech disorder. The current findings support previous observations that AOS and aphasia are dissociable and confirm a role for the precentral gyrus of the insula and BA44, as well as underlying white matter in supporting the coordination of complex articulatory movements. Additionally, other regions including the precentral gyrus, Broca's area, and Area 55b are discussed regarding their potential role in successful speech production.
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Affiliation(s)
- Alexis L. Pracar
- Department of Psychology, University of California, Berkeley, Berkeley, CA, United States
| | - Maria V. Ivanova
- Department of Psychology, University of California, Berkeley, Berkeley, CA, United States
| | - Amber Richardson
- VA Northern California Health Care System, Martinez, CA, United States
| | - Nina F. Dronkers
- Department of Psychology, University of California, Berkeley, Berkeley, CA, United States
- Department of Neurology, University of California, Davis, Davis, CA, United States
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Utianski RL, Josephs KA. An Update on Apraxia of Speech. Curr Neurol Neurosci Rep 2023; 23:353-359. [PMID: 37269450 PMCID: PMC10629164 DOI: 10.1007/s11910-023-01275-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/08/2023] [Indexed: 06/05/2023]
Abstract
PURPOSE OF REVIEW Apraxia of speech (AOS) is a motor speech disorder that has long been recognized to occur secondary to acute neurologic insults and, more recently, to neurodegenerative diseases as a harbinger for progressive supranuclear palsy and corticobasal syndrome. This article reviews recent findings regarding the clinic phenotypes of AOS, neuroimaging correlates, and the underlying disease processes. RECENT FINDINGS Two clinical subtypes of AOS map onto two underlying 4-repeat tauopathies. New imaging techniques have recently been applied to the study of progressive AOS. There is no data on the impact of behavioral intervention, although studies of nonfluent/agrammatic primary progressive aphasia that include patients with AOS suggest some benefit in speech intelligibility and maintenance. While recent findings suggest subtypes of AOS exist that are linked to molecular pathology and have important implications for disease progression, further research is needed to assess outcome of behavioral and other types of intervention.
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Affiliation(s)
- Rene L Utianski
- Department of Neurology, Mayo Clinic College of Medicine and Science, 200 1St Street S.W., Rochester, MN, 55905, USA
| | - Keith A Josephs
- Department of Neurology, Mayo Clinic College of Medicine and Science, 200 1St Street S.W., Rochester, MN, 55905, USA.
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Robinson CG, Duffy JR, Clark HA, Utianski RL, Machulda MM, Botha H, Singh NA, Thu NT, Ertekin-Taner N, Dickson DW, Lowe VJ, Whitwell JL, Josephs KA. Clinicopathological associations of hemispheric dominance in primary progressive apraxia of speech. Eur J Neurol 2023; 30:1209-1219. [PMID: 36869612 PMCID: PMC10410644 DOI: 10.1111/ene.15764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/24/2023] [Accepted: 02/27/2023] [Indexed: 03/05/2023]
Abstract
OBJECTIVE Primary progressive apraxia of speech (PPAOS) is associated with imaging abnormalities in the lateral premotor cortex (LPC) and supplementary motor area (SMA). It is not known whether greater involvement of these regions in either hemisphere is associated with demographics, presenting, and/or longitudinal features. METHODS In 51 prospectively recruited PPAOS patients who completed [18 F]-fluorodeoxyglucose (FDG) positron emission tomography (PET), we classified patients as left-dominant, right-dominant, or symmetric, based on visual assessment of the LPC and SMA on FDG-PET. SPM and statistical analyses of regional metabolic values were performed. Diagnosis of PPAOS was made if apraxia of speech was present and aphasia absent. Thirteen patients completed ioflupane-123I (dopamine transporter [DAT]) scans. We compared cross-sectional and longitudinal clinicopathological, genetic, and neuroimaging characteristics across the three groups, with area under the receiver-operating curve (AUROC) determined as a measure of effect size. RESULTS In all, 49% of the PPAOS patients were classified as left-dominant, 31% as right-dominant, and 20% as symmetric, which was supported by results from the SPM and regional analyses. There were no differences in baseline characteristics. Longitudinally, right-dominant PPAOS showed faster rates of progression of ideomotor apraxia (AUROC 0.79), behavioral disturbances (AUROC 0.84), including disinhibition symptoms (AUROC 0.82) and negative behaviors (AUROC 0.82), and parkinsonism (AUROC 0.75) compared to left-dominant PPAOS. Symmetric PPAOS showed faster rates of dysarthria progression compared to left-dominant (AUROC 0.89) and right-dominant PPAOS (AUROC 0.79). Five patients showed abnormal DAT uptake. Braak neurofibrillary tangle stage differed across groups (p = 0.01). CONCLUSIONS Patients with PPAOS and a right-dominant pattern of hypometabolism on FDG-PET have the fastest rates of decline of behavioral and motor features.
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Affiliation(s)
| | | | | | | | - Mary M. Machulda
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN
| | - Hugo Botha
- Department of Neurology, Mayo Clinic, Rochester, MN
| | | | | | | | - Dennis W. Dickson
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL, United States
| | - Val J. Lowe
- Department of Radiology, Mayo Clinic, Rochester, MN
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Catena Baudo M, Villamil F, Paolinelli PS, Domenech NC, Cervio A, Ferrara LA, Bendersky M. Frontal Aslant Tract and Its Role in Language: A Journey Through Tractographies and Dissections. World Neurosurg 2023; 173:e738-e747. [PMID: 36889642 DOI: 10.1016/j.wneu.2023.02.145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/25/2023] [Accepted: 02/27/2023] [Indexed: 03/09/2023]
Abstract
BACKGROUND The frontal aslant tract (FAT) is a bilateral tract located within each frontal lobe. It connects the supplementary motor area in the superior frontal gyrus with the pars opercularis in the inferior frontal gyrus. There is a new and broader conceptualization of this tract called the extended FAT (eFAT). The eFAT tract role is believed to be related to several brain functions, including verbal fluency as one of its main domains. METHODS Tractographies were performed by using DSI Studio software on a template of 1065 healthy human brains. The tract was observed in a three-dimensional plane. The Laterality Index was calculated based on the length, volume, and diameter of fibers. A t test was performed to verify the statistical significance of global asymmetry. The results were compared with cadaveric dissections performed according to the Klingler technique. An illustrative case enlightens the neurosurgical application of this anatomic knowledge. RESULTS The eFAT communicates the superior frontal gyrus with the Broca area (within the left hemisphere) or its contralateral homotopic area within the nondominant hemisphere. We measured the commisural fibers, traced cingulate, striatal, and insular connections and showed the existence of new frontal projections as part of the main structure. The tract did not show a significant asymmetry between the hemispheres. CONCLUSIONS The tract was successfully reconstructed, focusing on its morphology and anatomic characteristics.
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Affiliation(s)
- Melanie Catena Baudo
- Living Anatomy Laboratory, Anatomy Department, School of Medicine, University of Buenos Aires (UBA), Buenos Aires, Argentina.
| | - Facundo Villamil
- Laboratory of Neuroanatomy, Anatomy Department, School of Medicine, University of Buenos Aires (UBA), Buenos Aires, Argentina; Department of Neurosurgery, Microsurgical Neuroanatomy Laboratory, FLENI, Buenos Aires, Argentina
| | - Pablo Sebastían Paolinelli
- Laboratory of Neuroanatomy, Anatomy Department, School of Medicine, University of Buenos Aires (UBA), Buenos Aires, Argentina
| | - Nicolás Cristian Domenech
- Living Anatomy Laboratory, Anatomy Department, School of Medicine, University of Buenos Aires (UBA), Buenos Aires, Argentina
| | - Andres Cervio
- Department of Neurosurgery, FLENI, Buenos Aires, Argentina
| | - Lucía Alba Ferrara
- ENyS (Studies in Neurosciences and Complex Systems), National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina; Psicology Department, School of Medicine, Austral University, Buenos Aires, Argentina
| | - Mariana Bendersky
- Living Anatomy Laboratory, Anatomy Department, School of Medicine, University of Buenos Aires (UBA), Buenos Aires, Argentina; ENyS (Studies in Neurosciences and Complex Systems), National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina; National University A. Jauretche (UNAJ), El Cruce Hospital Néstor Kirchner, Buenos Aires, Argentina
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Josephs KA, Duffy JR, Martin PR, Stephens YC, Singh NA, Clark HM, Botha H, Lowe VJ, Whitwell JL, Utianski RL. Acoustic Analysis and Neuroimaging Correlates of Diadochokinetic Rates in Mild-Moderate Primary Progressive Apraxia of Speech. BRAIN AND LANGUAGE 2023; 240:105254. [PMID: 37584042 PMCID: PMC10424909 DOI: 10.1016/j.bandl.2023.105254] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/17/2023]
Abstract
Speech rate can be judged clinically using diadochokinetic (DDK) tasks, such as alternating motion rates (AMR) and sequential motion rates (SMR). We evaluated whether acoustic AMR/SMR speech rates would differentiate primary progressive apraxia of speech (PPAOS) from healthy controls, and determined how DDK rates relate to phonetic and prosodic speech characteristics and brain metabolism on FDG-PET. Rate was calculated for each of three AMRs (repetitions of 'puh', 'tuh', and 'kuh') and for SMRs (repetitions of 'puhtuhkuh') for 27 PPAOS patients and 52 controls who underwent FDG-PET. PPAOS patients were slower than controls on all DDK tasks. All DDK rates correlated with apraxia of speech severity, with strongest associations with prosodic speech features. Slower DDK rates were associated with hypometabolism in the right cerebellar dentate and left supplementary motor area. Performance on AMR rate, not just SMR rate, may be impaired in mild PPAOS, but sensitivity and specificity require further study.
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Affiliation(s)
| | | | - Peter R. Martin
- Department of Quantitative Health Research, Mayo Clinic, Rochester, MN, USA
| | | | | | | | - Hugo Botha
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Val J. Lowe
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
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Satoh R, Arani A, Senjem ML, Duffy JR, Clark HM, Utianski RL, Botha H, Machulda MM, Jack CR, Whitwell JL, Josephs KA. Spatial patterns of elevated magnetic susceptibility in progressive apraxia of speech. Neuroimage Clin 2023; 38:103394. [PMID: 37003130 PMCID: PMC10102559 DOI: 10.1016/j.nicl.2023.103394] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/23/2023] [Accepted: 03/27/2023] [Indexed: 03/30/2023]
Abstract
PURPOSE Progressive apraxia of speech (PAOS) is a neurodegenerative disorder affecting the planning or programming of speech. Little is known about its magnetic susceptibility profiles indicative of biological processes such as iron deposition and demyelination. This study aims to clarify (1) the pattern of susceptibility in PAOS patients, (2) the susceptibility differences between the phonetic (characterized by predominance of distorted sound substitutions and additions) and prosodic (characterized by predominance of slow speech rate and segmentation) subtypes of PAOS, and (3) the relationships between susceptibility and symptom severity. METHODS Twenty patients with PAOS (nine phonetic and eleven prosodic subtypes) were prospectively recruited and underwent a 3 Tesla MRI scan. They also underwent detailed speech, language, and neurological evaluations. Quantitative susceptibility maps (QSM) were reconstructed from multi-echo gradient echo MRI images. Region of interest analysis was conducted to estimate susceptibility coefficients in several subcortical and frontal regions. We compared susceptibility values between PAOS and an age-matched control group and performed a correlation analysis between susceptibilities and an apraxia of speech rating scale (ASRS) phonetic and prosodic feature ratings. RESULTS The magnetic susceptibility of PAOS was statistically greater than that of controls in subcortical regions (left putamen, left red nucleus, and right dentate nucleus) (p < 0.01, also survived FDR correction) and in the left white-matter precentral gyrus (p < 0.05, but not survived FDR correction). The prosodic patients showed greater susceptibilities than controls in these subcortical and precentral regions. The susceptibility in the left red nucleus and in the left precentral gyrus correlated with the prosodic sub-score of the ASRS. CONCLUSION Magnetic susceptibility in PAOS patients was greater than controls mainly in the subcortical regions. While larger samples are needed before QSM is considered ready for clinical differential diagnosis, the present study contributes to our understanding of magnetic susceptibility changes and the pathophysiology of PAOS.
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Affiliation(s)
- Ryota Satoh
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Arvin Arani
- Department of Radiology, Mayo Clinic, Rochester, MN, USA
| | - Matthew L Senjem
- Department of Radiology, Mayo Clinic, Rochester, MN, USA; Department of Information Technology, Mayo Clinic, Rochester, MN, USA
| | - Joseph R Duffy
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | | | | | - Hugo Botha
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Mary M Machulda
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, USA
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Sintini I, Duffy JR, Clark HM, Utianski RL, Botha H, Machulda MM, Senjem ML, Strand EA, Schwarz CG, Lowe VJ, Jack CR, Josephs KA, Whitwell JL. Functional connectivity to the premotor cortex maps onto longitudinal brain neurodegeneration in progressive apraxia of speech. Neurobiol Aging 2022; 120:105-116. [DOI: 10.1016/j.neurobiolaging.2022.08.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 08/27/2022] [Accepted: 08/30/2022] [Indexed: 11/26/2022]
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