A new MRI rating scale for progressive supranuclear palsy and multiple system atrophy: validity and reliability

Rolland, Yan; Vérin, Marc; Payan, Christine A; Duchesne, Simon; Kraft, Eduard; Hauser, Till K; Jarosz, Josef; Deasy, Neil; Defevbre, Luc; Delmaire, Christine; Dormont, Didier; Ludolph, Albert C; Bensimon, Gilbert; Leigh, P Nigel

doi:10.1136/jnnp.2010.214890

A new MRI rating scale for progressive supranuclear palsy and multiple system atrophy: validity and reliability

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¹Medical Imaging Department, Eugène Marquis Centre, Rennes, France
²Department of Neurology, Pontchaillou University Hospital, Rennes, France
³Département de Pharmacologie Clinique, Centre Hospitalo-Universitaire de la Pitié-Salpétrière, Assistance publique hôpitaux de Paris and UPMC Univ, Paris, France
⁴Department of Radiology and Robert Giffard Laval University Research Centre, Laval University, Quebec City, Canada
⁵Department of Neurology, University of Ulm, Baden-Wuerttemberg, Germany
⁶Department of Neuroradiology, University of Tübingen, Tübingen, Germany
⁷Department of Neurology, Brighton and Sussex Medical School, Trafford Centre for Biomedical Research, University of Sussex Falmer, East Sussex, UK
⁸MRC Centre for Neurodegeneration Research, King's College London, Institute of Psychiatry, Department of Clinical Neuroscience, London, UK
⁹Department of Neurology Movement Disorders, Lille University, Salengro Hospital, Cedex Lille, France
¹⁰Department of Neuroradiology, Lille University, Salengro Hospital, Cedex Lille, France
¹¹Département de Neuroradiologie, Hôpital de la Pitié-Salpétrière, Assistance Publique Hôpitaux de Paris and UPMC Univ, Paris, France

Correspondence to Professor P N Leigh, Professor of Neurology, Brighton and Sussex Medical School, Trafford Centre for Biomedical Research University of Sussex, Falmer, East Sussex BN1 9RY; bsms2899{at}bsms.ac.ukor Dr Gilbert Bensimon, Département de Pharmacologie Clinique, Hôpital Pitié-Salpêtrière, 47 Bd de L'Hôpital, 75651 Paris Cedex 13, France; gilbert.bensimon{at}psl.aphp.fr

Received 15 April 2010
Accepted 6 January 2011
Published Online First 8 March 2011

Abstract

Aim To evaluate a standardised MRI acquisition protocol and a new image rating scale for disease severity in patients with progressive supranuclear palsy (PSP) and multiple systems atrophy (MSA) in a large multicentre study.

Methods The MRI protocol consisted of two-dimensional sagittal and axial T1, axial PD, and axial and coronal T2 weighted acquisitions. The 32 item ordinal scale evaluated abnormalities within the basal ganglia and posterior fossa, blind to diagnosis. Among 760 patients in the study population (PSP=362, MSA=398), 627 had per protocol images (PSP=297, MSA=330). Intra-rater (n=60) and inter-rater (n=555) reliability were assessed through Cohen's statistic, and scale structure through principal component analysis (PCA) (n=441). Internal consistency and reliability were checked. Discriminant and predictive validity of extracted factors and total scores were tested for disease severity as per clinical diagnosis.

Results Intra-rater and inter-rater reliability were acceptable for 25 (78%) of the items scored (≥0.41). PCA revealed four meaningful clusters of covarying parameters (factor (F) F1: brainstem and cerebellum; F2: midbrain; F3: putamen; F4: other basal ganglia) with good to excellent internal consistency (Cronbach α 0.75–0.93) and moderate to excellent reliability (intraclass coefficient: F1: 0.92; F2: 0.79; F3: 0.71; F4: 0.49). The total score significantly discriminated for disease severity or diagnosis; factorial scores differentially discriminated for disease severity according to diagnosis (PSP: F1–F2; MSA: F2–F3). The total score was significantly related to survival in PSP (p<0.0007) or MSA (p<0.0005), indicating good predictive validity.

Conclusions The scale is suitable for use in the context of multicentre studies and can reliably and consistently measure MRI abnormalities in PSP and MSA.

Clinical Trial Registration Number The study protocol was filed in the open clinical trial registry (http://www.clinicaltrials.gov) with ID No NCT00211224.

Footnotes

GB and PNL contributed equally to this paper.
Funding NNIPPS was an academic led study with core funding from the European Union 5th Framework programme (QLG1-CT-2000-01262); support from the French Health Ministry, Programme Hospitalier de Recherche Clinique (AOM97073, AOM01125) and from Sanofi-Aventis affiliates in the UK, France and Germany, providing an unconditional research grant and drug supply throughout the study. Three academic institutions (Institute of Psychiatry, King's College London; Assistance Publique-Hôpitaux de Paris; and University of Ulm) were sponsors of the study in each country, and jointly own the data. The authors did not receive any financial contribution from these funding sources. The funding sources had no involvement in the study design or data collection, subsequent analysis and interpretation of data, writing of the report or in the decision to submit the paper for publication. SD received support from the Fonds pour la Recherche en Santé du Québec.
Competing interests None.
Ethics approval The protocol and amendments were reviewed and approved by the Comité de Protection des Personnes of Pitié-Salpêtrière Hospital (France), the UK Multicentre Research Ethics Committee (MREC) (UK), Ethikkommission of the University of Ulm (Germany) and by local institutional review boards (ethics committees) where appropriate (UK, Germany).
Provenance and peer review Not commissioned; externally peer reviewed.

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