Motor, cognitive and behavioral differences in MDS PSP phenotypes

• Published in: Journal of neurology Vol. 266; no. 7; pp. 1727 - 1735
• Main Authors: Picillo, Marina, Cuoco, Sofia, Tepedino, Maria Francesca, Cappiello, Arianna, Volpe, Giampiero, Erro, Roberto, Santangelo, Gabriella, Pellecchia, Maria Teresa, Barone, Paolo
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-07-2019; Springer Nature B.V
• Subjects: Aged; Aged, 80 and over; Apraxia; Basal ganglia; Brain diseases; Central nervous system diseases; Cognition & reasoning; Cognitive ability; Cognitive Dysfunction - diagnosis; Cognitive Dysfunction - psychology; Cohort Studies; Dementia; Dementia disorders; Diagnosis, Differential; Female; Genotype & phenotype; Humans; Male; Medicine; Medicine & Public Health; Mental Disorders - diagnosis; Mental Disorders - psychology; Middle Aged; Movement disorders; Movement Disorders - diagnosis; Movement Disorders - psychology; Neurology; Neuroradiology; Neurosciences; Original Communication; Paralysis; Phenotype; Phenotypes; Progressive supranuclear palsy; Retrospective Studies; Semantics; Supranuclear Palsy, Progressive - diagnosis; Supranuclear Palsy, Progressive - psychology; Progressive supranuclear palsy; Diagnostic criteria; MDS; Subtype
• ISSN: 0340-5354; 1432-1459
• DOI: 10.1007/s00415-019-09324-x

Introduction
Movement Disorder Society (MDS) new diagnostic criteria for Progressive Supranuclear palsy (PSP) identifying different disease phenotypes were recently released. The aim of the present study is to report on the cognitive and behavioral features of the different phenotypes diagnosed according to the MDS criteria.
Methods
Forty-nine PSP patients underwent an extensive battery of clinical assessments. Differences between PSP subtypes were computed with
χ
2
or ANOVA tests. Using the z scores, subjects were classified as having normal cognition, mild cognitive impairment, single or multiple domain, and dementia. A logistic regression model was implemented to investigate the major determinants of PSP non-Richardson’s syndrome phenotype.
Results
Half of the cohort presented Richardson’s syndrome (46.9%), followed by PSP with parkinsonism and corticobasal syndrome (22.4% and 14.2%, respectively). Richardson’s syndrome and PSP with corticobasal syndrome presented a similar burden of disease. The only cognitive testing differentiating the phenotypes were semantic fluency and ideomotor apraxia. The majority of our cohort was either affected by dementia or presented normal cognition. Richardson’s syndrome presented the highest rate of dementia. The only marker of PSP non-Richardson’s syndrome phenotype was better performance in visuo-spatial testing, implying worse visuo-spatial abilities in PSP Richardson’s syndrome.
Conclusion
Available clinical assessments hardly capture differences between PSP phenotypes. The cognitive testing differentiating the PSP phenotypes were semantic fluency and ideomotor apraxia. In PSP, mild cognitive impairment likely represents an intermediate step from normal cognition to dementia. The only marker of PSP non-Richardson’s syndrome phenotype was better performance in visuo-spatial testing.