Parkinson’s rarely deadly
medwireNews: Patients with Parkinson’s disease (PD) are no more likely to die than people in the general populace, and they rarely die as a direct result of their condition, research shows.
“Together, these findings support the message commonly given to patients in clinical practice that people die ‘with’ rather than ‘of’ PD,” say lead researcher Caroline Williams-Gray (University of Cambridge, UK) and team.
The findings emerge from the 10-year analysis of the CamPaIGN study, which is tracking 142 patients from diagnosis onward and supplies “true-to-life natural history data over 10?years of PD for the first time in the post-[levodopa] period,” says the team.
The patients were aged an average of 70.2 years at diagnosis. Although 55% died during follow up, the standardized mortality ratio relative to the UK population was a nonsignificant 1.29. The researchers note this is lower than in some previous studies, accounted for by the fact that the cohort was population- rather than hospital-based, and was monitored from diagnosis rather than from later in the disease course when death is more likely.
On the death certificates of the 63 patients who died, PD was stated as the primary cause of death for just 10%, although 33% of the patients died of pneumonia, to which PD could have contributed. PD was stated as a substantial contributor to death in a further 10% of patients and as a comorbid condition in 40%, but was not mentioned for the remaining 40%.
The team also monitored patients for another two key outcomes: dementia, which had a cumulative 10-year probability of 46%; and postural instability (Hoehn & Yahr stage 3), which had a probability of 68%.
The researchers note that the probability of postural instability is no less than that reported before the introduction of levodopa.
“These data suggest that dopaminergic treatment has had little impact on development of this key milestone, in keeping with the hypothesis that the underlying basis of postural instability in PD is non-dopaminergic dysfunction of brainstem regions such as the pedunculopontine nucleus,” they comment in the Journal of Neurology, Neurosurgery, and Psychiatry.
The median time to death, dementia, or postural instability was 3.8 years; however, 23% of patients remained free of all these outcomes.
“Further biological investigation of this latter subgroup may prove informative in identifying protective factors in PD which can be exploited in the search for disease-modifying therapies,” says the team.
medwireNews (www.medwirenews.com) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2013
By Eleanor McDermid, Senior medwireNews Reporter