Survival in Parkinson Disease Dependent on Parkinsonian Type, Characteristics
In early PD, a mild cognitive impairment diagnosis, freezing of gait, and hyposmia were significantly associated with shorter survival.
In patients with Parkinson disease (PD), the presence of multiple system atrophy or progressive supranuclear palsy is associated with higher mortality compared with mortality rates in people with idiopathic parkinsonism, according to a study in Neurology. Study researchers also found that cognitive status, gait characteristics, and the presence of hyposmia are associated with shorter survival in people with PD.
A total of 182 patients from Sweden who were diagnosed with new-onset idiopathic parkinsonism between 2004 and 2009 were enrolled. Patients were followed for up to 13.5 years to identify associations between disease presentation and survival. The Unified Parkinson's Disease Rating Scale, the modified Hoehn and Yahr scale, the Mini-Mental State Examination, and the 39-item Parkinson's Disease Questionnaire were administered ≥1 time per year. In addition to calculating the standardized mortality ratio and expected survival using mortality rates from the general Swedish population, the researchers also sought to identify independent mortality predictors.
In the overall cohort, the standardized mortality ratio was 1.84 (95% CI, 1.50-2.22; P <.001). The initial analysis revealed age at first visit to be a significant predictor for survival (hazard ratio for death, 3.03 for each decade older; 95% CI, 2.30-3.98; P <.001). Atypical parkinsonism was associated with the highest mortality, whereas patients with atypical parkinsonism and higher concentrations of amyloid beta 42 in cerebrospinal fluid (CSF) had a moderately increased survival (0.97 per pg/mL; 95% CI, 0.95-1.00; P =.036).
Independent biomarker predictors for reduced survival among those with PD included having a mild cognitive impairment diagnosis, hyposmia, reduced dopamine transporter activity in the caudate, freezing of gait, and increased CSF leukocytes.
The collection of neuropathologic diagnosis at autopsy in only 5 of 109 deaths as well as the potential uncontrolled confounders cited by the researchers represent possible limitations of the study.
The researchers added that the study's “finding of a low-grade immune reaction in the CSF of patients with PD who have short survival may have important clinical implications and therefore merits further investigation.”
Disclosure: Multiple authors disclosed affiliations with pharmaceutical companies. See the reference for complete disclosure information.
Bäckström D, Granåsen G, Domellöf ME, et al. Early predictors of mortality in parkinsonism and Parkinson disease: a population-based study. Neurology. 2018;91(22):e2045-e2056.