Neurology. 2013 Jan 29;80(5):496-503.

Criteria for the diagnosis of corticobasal degeneration.

Armstrong MJ, Litvan I, Lang AE, Bak TH, Bhatia KP, Borroni B, Boxer AL, Dickson DW, Grossman M, Hallett M, Josephs KA, Kertesz A, Lee SE, Miller BL, Reich SG, Riley DE, Tolosa E, Tröster AI, Vidailhet M, Weiner WJ.


From the University of Maryland (M.J.A., S.G.R., W.J.W.), Baltimore; University of California San Diego (I.L.), San Diego; Morton and Gloria Shulman Movement Disorders Center and the Edmond J. Safra Program in Parkinson's Disease (A.E.L.), Toronto Western Hospital, Toronto, Canada; Edinburgh University (T.H.B.), Edinburgh, UK; Sobell Department of Movement Neuroscience (K.P.B.), Institute of Neurology, University College London, Queen Square, London, UK; University of Brescia (B.B.), Brescia, Italy; University of California San Francisco (A.L.B., S.E.L., B.L.M.), San Francisco; Mayo Clinic (D.W.D.), Jacksonville, FL; University of Pennsylvania (M.G.), Philadelphia; National Institute of Neurological Disorders and Stroke (M.H.), National Institutes of Health, Bethesda, MD; Mayo Clinic (K.A.J.), Rochester, MN; University of Western Ontario (A.K.), London, Canada; Case Western Reserve University (D.E.R.), Cleveland, OH; Neurology Service (E.T.), Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Hospital Clínic, IDIBAPS, Universitat de Barcelona, Spain; Barrow Neurological Institute (A.I.T.), Phoenix, AZ; and Hôpital de la Salpetrière (M.V.), Pierre Marie Curie Paris-6 University and CRICM UPMC/INSERM UMR_S975 CNRS UMR7225, Paris, France.

Abstract
Current criteria for the clinical diagnosis of pathologically confirmed corticobasal degeneration (CBD) no longer reflect the expanding understanding of this disease and its clinicopathologic correlations. An international consortium of behavioral neurology, neuropsychology, and movement disorders specialists developed new criteria based on consensus and a systematic literature review. Clinical diagnoses (early or late) were identified for 267 nonoverlapping pathologically confirmed CBD cases from published reports and brain banks. Combined with consensus, 4 CBD phenotypes emerged: corticobasal syndrome (CBS), frontal behavioral-spatial syndrome (FBS), nonfluent/agrammatic variant of primary progressive aphasia (naPPA), and progressive supranuclear palsy syndrome (PSPS). Clinical features of CBD cases were extracted from descriptions of 209 brain bank and published patients, providing a comprehensive description of CBD and correcting common misconceptions. Clinical CBD phenotypes and features were combined to create 2 sets of criteria: more specific clinical research criteria for probable CBD and broader criteria for possible CBD that are more inclusive but have a higher chance to detect other tau-based pathologies. Probable CBD criteria require insidious onset and gradual progression for at least 1 year, age at onset ≥50 years, no similar family history or known tau mutations, and a clinical phenotype of probable CBS or either FBS or naPPA with at least 1 CBS feature. The possible CBD category uses similar criteria but has no restrictions on age or family history, allows tau mutations, permits less rigorous phenotype fulfillment, and includes a PSPS phenotype. Future validation and refinement of the proposed criteria are needed.