Cognitive impairment in MSA and PSP
05 July 2010
A study by Professor Richard Brown from the Institute of Psychiatry (IOP), Kings College London (KCL) describes cognitive impairment in two rare progressive and life shortening neurological disorders, Progressive Supranuclear Palsy (PSP) and Multiple System Atrophy (MSA), recently published in the journal Brain.
This is the largest study to date describing the prevalence and pattern of cognitive impairment in these two disorders. Despite sharing some features with Parkinson’s disease they involve different brain changes and do to respond so well to available treatments. Early and accurate diagnosis is essential for both effective clinical management and research.
372 patients with MSA and 311 with PSP received a detailed assessment which was repeated annually for 3 years. Cognitive impairment and dementia have been reported previously in PSP. In contrast, MSA has been thought to present with little in the way of significant cognitive impairment. Indeed, it has been felt that significant impairment rules out a diagnosis of MSA. In this study a clinical diagnosis of MSA was permitted even when some impairment was evidence. It was found clinically significant cognitive problems in 20% of the MSA sample and 57% of the PSP group, with the diagnosis confirmed in the large majority of patients who died during the course of the study and who brains were studied in detail. Furthermore, when the two patients groups were matched for overall severity of impairment, they showed almost identical profiles of impairment, despite differences in the underlying brain disease.
Professor Brown said: 'The findings provide the best estimates to date of the prevalence of cognitive impairment in MSA and PSP and demonstrate crucially that previous beliefs about lack of impairment in MSA were incorrect. In the absence of biomarkers, distinguishing between parkinsonian syndromes remains a largely clinical judgement. The evidence from the present study demonstrates that the presence or absence of significant cognitive impairment should not be given significance in the process of diagnosis.'
Further analysis of the follow-up data is planned in addition combining the cognitive findings from brain imaging to further understand the causes of cognitive impairment in these two diseases.
These data were collected as part of the large scale international study Natural History and Neuroprotection in Parkinson Plus Syndromes (NNIPPS) (Leigh et al 2009), led by Professor P Nigel Leigh recently retired head of the Department of Clinical Neuroscience. NNIPPS was a ground breaking study, not only because it was the first full-scale trial of a drug that was hoped to change of the course of disease in MSA and PSP rather than just treat the symptoms but also because it allowed the most detailed study ever of these two rare disease.
Cognitive impairment in patients with multiple system atrophy and progressive supranuclear palsy
Brown RG, Lacomblez L, Landwehrmeyer BG, Bak T, Uttner I, Dubois B, Agid Y, Ludolph A, Bensimon G, Payan C, Leigh NP; for the NNIPPS Study Group. Brain. 2010 Jun 24. [Epub ahead of print] PMID: 20576697
Riluzole treatment, survival and diagnostic criteria in Parkinson plus disorders: the NNIPPS study
Bensimon G, Ludolph A, Agid Y, Vidailhet M, Payan C, Leigh PN; NNIPPS Study Group. Brain. 2009 Jan;132(Pt 1):156-71. Epub 2008 Nov 23.PMID: 19029129 Free PMC Articl