In Some PD Cases, Pathogenesis “May Span Most of the Lifetime”

Subject: In Some PD Cases, Pathogenesis “May Span Most of the Lifetime”

Date: 11/24/2010

REM sleep behavior disorder (RBD) may precede Parkinson’s disease or other forms of alpha-synucleinopathy by up to 50 years, according to a new study.

The Mayo Clinic Medical Records Linkage System was used to identify patients with PD (including PD dementia), dementia with Lewy bodies, or multiple system atrophy, who also had a diagnosis of RBD with symptoms of at least 15 years’ duration before diagnosis with the synucleinopathy. Of 550 patients with PD, DLB, or MSA within a 5-year period who also had a diagnosis of RBD, 27 (4.9%) met the 15-year criterion (13 PD, 13 DLB, 1 MSA).

Within this cohort, the median interval from RBD symptom onset to synucleinopathy symptom onset was 25 years (range 15-50 years). At last follow-up, 64% of patients had developed dementia. Dysautonomia occurred in 74% of patients, predominantly postural hypotension.

“These cases illustrate that PD, DLB, and MSA may have extremely long courses, with preclinical periods extending back decades in at least some cases. Thus, in some cases, the pathogenic process may span most of the lifetime,” the authors conclude. “[T]he current series documenting very long latencies raises a question whether all patients with RBD would later develop such neurodegenerative syndromes if they lived long enough.”

REM sleep behavior disorder preceding other aspects of synucleinopathies by up to half a century
DO Claassen, KA Josephs, JE Ahlskog, MH Silber, M Tippmann-Peikert, BF Boeve
Neurology 2010;75:494-499