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Floeter MK, Danielian LE, Braun LE, Wu T. Longitudinal diffusion imaging across the C9orf72 clinical spectrum. J Neurol Neurosurg Psychiatry 2018; 89:53-60. [PMID: 29054917 PMCID: PMC6454927 DOI: 10.1136/jnnp-2017-316799] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 09/26/2017] [Accepted: 10/04/2017] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Discrepancies between diffusion tensor imaging (DTI) findings and functional rating scales in amyotrophic lateral sclerosis (ALS) may be due to symptom heterogeneity, particularly coexisting cognitive-behavioural dysfunction affecting non-motor regions of the brain. Carriers of expansion mutations in the C9orf72 gene, whose motor and cognitive-behavioural symptoms span a range from ALS to frontotemporal dementia, present an opportunity to evaluate the relationship between symptom heterogeneity and DTI changes. METHODS Twenty-eight C9orf72 mutation carriers with varied cognitive and motor symptoms underwent clinical evaluation and DTI imaging. Twenty returned for two or more follow-up evaluations. Each evaluation included motor, executive and behavioural scales and disease staging using the King's college staging system. RESULTS Widespread reduction of white matter integrity occurred in C9orf72 mutation carriers compared with 28 controls. The ALS Functional Rating Scale (ALSFRS-R) and King's stage correlated with DTI measures of the corticospinal tract and mid-callosum. Cognitive and behavioural scores correlated with diffusion measures of frontal white matter. King's stage, but not ALSFRS-R, correlated with anterior callosum DTI measures. Over a 6-month follow-up, DTI changes spread from anterior to posterior, and from deep to superficial subcortical white matter. In C9orf72 carriers with ALS or ALS-FTD, changes in corticospinal tractography measures correlated with changes in ALSFRS-R. CONCLUSION Discrepancies between DTI findings and clinical measures of disease severity in ALS may partly be accounted for by cognitive-behavioural deficits affecting extramotor white matter tracts. Both ALSFRS-R and King's stage correlated with corticospinal DTI measures. Group-level DTI changes could be detected over 6 months.
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Affiliation(s)
- Mary Kay Floeter
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Laura E Danielian
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Laura E Braun
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Tianxia Wu
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
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Floeter MK, Traynor BJ, Farren J, Braun LE, Tierney M, Wiggs EA, Wu T. Disease progression in C9orf72 mutation carriers. Neurology 2017; 89:234-241. [PMID: 28615433 DOI: 10.1212/wnl.0000000000004115] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 04/28/2017] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE To assess changes in 3 clinical measures, the Revised ALS Functional Rating Scale (ALSFRS-R), letter fluency, and Frontal Behavioral Inventory (FBI), over time in C9orf72 mutation carriers (C9+) with varied clinical phenotypes. METHODS Thirty-four unrelated participants with mutations in C9orf72 were enrolled in a prospective natural history study. Participants were classified as asymptomatic, amyotrophic lateral sclerosis (ALS), ALS-familial frontotemporal dementia (FTD), or behavioral-variant FTD by clinical diagnostic criteria. Diagnostic cognitive and motor tests were repeated at 6 and 18 months. The ALSFRS-R, letter fluency, and FBI were administered at baseline and follow-up visits at 6, 12, and 18 months. RESULTS The clinical diagnosis of most patients did not change over the follow-up. ALSFRS-R scores correlated with measures of motor function. Letter fluency correlated with FBI and cognitive tests. ALSFRS-R, letter fluency, and FBI differed among the C9+ diagnostic subgroups at enrollment and worsened over follow-up in symptomatic patients, with different slopes among the subgroups. Most patients survived to the 6-month time point after enrollment. Survival of C9+ patients with ALS and C9+ patients with ALS-FTD declined over the 12- and 18-month follow-up. CONCLUSIONS The pattern of scores of the ALSFRS-R, letter fluency, and FBI distinguished between ALS, ALS-FTD, and FTD presentations of C9orf72 mutation carriers and asymptomatic carriers. Longitudinal changes in these measures occurred with disease progression in a manner consistent with presenting phenotype.
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Affiliation(s)
- Mary K Floeter
- From the National Institute of Neurological Disorders and Stroke (M.K.F., J.F., L.E.B., M.T., E.A.W., T.W.) and National Institute of Aging (B.J.T.), NIH, Bethesda, MD.
| | - Bryan J Traynor
- From the National Institute of Neurological Disorders and Stroke (M.K.F., J.F., L.E.B., M.T., E.A.W., T.W.) and National Institute of Aging (B.J.T.), NIH, Bethesda, MD
| | - Jennifer Farren
- From the National Institute of Neurological Disorders and Stroke (M.K.F., J.F., L.E.B., M.T., E.A.W., T.W.) and National Institute of Aging (B.J.T.), NIH, Bethesda, MD
| | - Laura E Braun
- From the National Institute of Neurological Disorders and Stroke (M.K.F., J.F., L.E.B., M.T., E.A.W., T.W.) and National Institute of Aging (B.J.T.), NIH, Bethesda, MD
| | - Michael Tierney
- From the National Institute of Neurological Disorders and Stroke (M.K.F., J.F., L.E.B., M.T., E.A.W., T.W.) and National Institute of Aging (B.J.T.), NIH, Bethesda, MD
| | - Edythe A Wiggs
- From the National Institute of Neurological Disorders and Stroke (M.K.F., J.F., L.E.B., M.T., E.A.W., T.W.) and National Institute of Aging (B.J.T.), NIH, Bethesda, MD
| | - Tianxia Wu
- From the National Institute of Neurological Disorders and Stroke (M.K.F., J.F., L.E.B., M.T., E.A.W., T.W.) and National Institute of Aging (B.J.T.), NIH, Bethesda, MD
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Floeter MK, Bageac D, Danielian LE, Braun LE, Traynor BJ, Kwan JY. Longitudinal imaging in C9orf72 mutation carriers: Relationship to phenotype. Neuroimage Clin 2016; 12:1035-1043. [PMID: 27995069 PMCID: PMC5153604 DOI: 10.1016/j.nicl.2016.10.014] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/17/2016] [Accepted: 10/19/2016] [Indexed: 11/24/2022]
Abstract
Expansion mutations in the C9orf72 gene may cause amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), or mixtures of the two clinical phenotypes. Different imaging findings have been described for C9orf72-associated diseases in comparison with sporadic patients with the same phenotypes, but it is uncertain whether different phenotypes have a common genotype-associated imaging signature. To address this question, 27 unrelated C9orf72 expansion mutation carriers (C9 +) with varied phenotypes, 28 age-matched healthy controls and 22 patients with sporadic ALS (sALS) underwent 3T MRI scanning and clinical phenotyping. Measures of brain volumes and cortical thickness were extracted from T1 images. Compared to healthy controls and sALS patients, symptomatic C9 + subjects had greater ventricular volume loss and thalamic atrophy for age, with diffuse, patchy cortical thinning. Asymptomatic carriers did not differ from controls. C9 + ALS and ALS-FTD patients had less thinning of the motor cortex than sALS patients, but more thinning in extramotor regions, particularly in frontal and temporal lobes. C9 + ALS patients differed from sporadic ALS patients in the thickness of the superior frontal gyrus and lateral orbitofrontal cortex. Thickness of the precentral gyrus was weakly correlated with the revised ALS functional rating scale. Thickness of many cortical regions, including several frontal and temporal regions, was moderately correlated with letter fluency scores. Letter fluency scores were weakly correlated with ventricular and thalamic volume. To better understand how imaging findings are related to disease progression, nineteen C9 + subjects and 23 healthy controls were scanned approximately 6 months later. Ventricular volume increased in C9 + patients with FTD and ALS-FTD phenotypes and remained stable in asymptomatic C9 + subjects. We conclude that diffuse atrophy is a common underlying feature of disease associated with C9orf72 mutations across its clinical phenotypes. Ventricular enlargement can be measured over a 6-month time frame, and appears to be faster in patients with cognitive impairment. Patchy cortical thinning and diffuse atrophy are a hallmark of symptomatic ALS and FTD C9orf72 mutation carriers. Symptomatic C9orf72 carriers have more atrophy and diffuse thinning than sporadic ALS patients and healthy controls. Ventricular enlargement can be detected over a 6-month interval in symptomatic C9orf72 carriers. Impaired letter fluency is associated with diffuse cortical thinning. Changes in letter fluency, but not ALSFRS-R are correlated with 6-month ventricular enlargement.
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Key Words
- ALS, amyotrophic lateral sclerosis
- ALSFRS-R, ALS functional rating scale — revised
- ANCOVA, analysis of covariance
- ANOVA, analysis of variance
- Amyotrophic lateral sclerosis
- C9orf72
- C9 +, subjects with C9orf72 expansion mutations
- CSF, cerebrospinal fluid
- Cortical thickness
- DRS-2, Mattis dementia rating scale
- DTI, diffusion tensor imaging
- Diffusion tensor imaging
- FBI, frontobehavioral inventory
- FDR, false discovery rate correction
- FTD, frontotemporal dementia
- Frontotemporal dementia
- MRI, magnetic resonance imaging
- SD, standard deviation
- TIV, total intracranial volume
- Ventricular volume
- bvFTD, behavioral variant frontotemporal dementia
- sALS, sporadic ALS
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Affiliation(s)
- Mary Kay Floeter
- Motor Neuron Disorders Unit, OCD, NINDS, NIH 10 Center Drive Room 7-5680 Bethesda, MD 20892-1404, United States
| | - Devin Bageac
- Motor Neuron Disorders Unit, OCD, NINDS, NIH 10 Center Drive Room 7-5680 Bethesda, MD 20892-1404, United States
| | - Laura E Danielian
- Motor Neuron Disorders Unit, OCD, NINDS, NIH 10 Center Drive Room 7-5680 Bethesda, MD 20892-1404, United States
| | - Laura E Braun
- Motor Neuron Disorders Unit, OCD, NINDS, NIH 10 Center Drive Room 7-5680 Bethesda, MD 20892-1404, United States
| | - Bryan J Traynor
- Neuromuscular Disease Research Section LNG, NIA, NIH 35 Convent Drive Room 1A213 Bethesda, MD 20892-3707, United States
| | - Justin Y Kwan
- Department of Neurology, University of Maryland, 110 S. Paca Street, Baltimore, MD 21201, United States
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