Uncovering clinical and radiological asymmetry in progressive supranuclear palsy—Richardson’s syndrome

Marina Picillo,Sofia Cuoco,Francesco Di Salle,Sara Ponticorvo,Nevra Oksuz,Roberto Erro,Gianfranco Di Salle,Fabrizio Esposito,Filomena Abate,Maria Teresa Pellecchia,Paolo Barone,Maria Francesca Tepedino,Renzo Manara

doi:10.1007/s10072-022-05919-x

Abstract

BackgroundRichardson’s syndrome (RS) is considered the most symmetric phenotype of progressive supranuclear palsy (PSP) as opposed to PSP with predominant corticobasal syndrome (PSP-CBS) or parkinsonism (PSP-P).ObjectivesEvaluate asymmetrical motor and higher cortical features in probable PSP-RS and compare the degree of asymmetry of cortical lobes and hemispheres between PSP-RS, PSP-CBS, PSP-P, and age-matched healthy controls (HC).MethodsAsymmetry of motor and higher cortical features evaluated with an extensive videotaped neurologic examination was investigated in 28 PSP-RS, 8 PSP-CBS, and 14 PSP-P. Brain MRI to compute the laterality index (LI) was performed in 36 patients as well as in 56 HC.ResultsIn PSP-RS, parkinsonism was the most common asymmetric motor feature (53.6%), followed by dystonia and myoclonus (21.4% and 17.9%, respectively). Among higher cortical features, limb apraxia was found asymmetric in about one-third of patients. PSP-RS disclosed higher LI for hemispheres compared to HC, indicating a greater degree of asymmetry (p = 0.003). The degree of asymmetry of clinical features was not different between PSP-RS and those qualifying for PSP-CBS or PSP-P. As for imaging, LI was not different between PSP-RS, PSP-CBS, and PSP-P in any cortical region.ConclusionsMotor and higher cortical features are asymmetric in up to 50% of PSP-RS who also present a greater degree of asymmetry in hemispheres compared to age-matched HC. Lateralization of clinical features should be annotated in PSP.

Highlights

Richardson’s syndrome (RS) is the most common phenotype of progressive supranuclear palsy (PSP) and is characterized by the early onset of postural instability and falls and vertical supranuclear gaze palsy [1]
On a clinical ground and given the lack of biomarkers, the correct identification of the latter phenotypes often represents a clinical challenge and, despite the rigorous application of clinical diagnostic criteria, the final diagnosis is often based on clinical judgment [1, 5]
Twenty-eight patients with probable PSP-RS, 8 with possible PSP with predominant corticobasal syndrome (PSP-CBS), and 14 with probable PSP-P according to the Movement Disorder Society (MDS) criteria were included in the present analysis [1]

Summary

Introduction

RS is the most common phenotype of PSP and is characterized by the early onset of postural instability and falls and vertical supranuclear gaze palsy [1]. Richardson’s syndrome (RS) is considered the most symmetric phenotype of progressive supranuclear palsy (PSP) as opposed to PSP with predominant corticobasal syndrome (PSP-CBS) or parkinsonism (PSP-P). Objectives Evaluate asymmetrical motor and higher cortical features in probable PSP-RS and compare the degree of asymmetry of cortical lobes and hemispheres between PSP-RS, PSP-CBS, PSP-P, and age-matched healthy controls (HC). PSP-RS disclosed higher LI for hemispheres compared to HC, indicating a greater degree of asymmetry (p = 0.003). The degree of asymmetry of clinical features was not different between PSP-RS and those qualifying for PSP-CBS or PSP-P. Conclusions Motor and higher cortical features are asymmetric in up to 50% of PSP-RS who present a greater degree of asymmetry in hemispheres compared to age-matched HC.

Methods

Results

Conclusion