(I thought someone else had posted this here back in late July but I couldn't find it tonight when I searched. Apologies if this is a duplicate.)

This Mayo Rochester research concludes that RBD (REM sleep behavior disorder) can precede other symptoms of PD, MSA, or DLB by up to 50 years! Interestingly, the article indicates that RBD symptoms are first noticed on a wedding honeymoon! (This was true for one local support group member.)

Twenty-seven patients "experienced isolated RBD for at least 15 years before evolving into PD, PD dementia (PDD), DLB, or MSA." The "median length of RBD symptoms to neurodegenerative syndrome symptom onset was 25 years (range 15–50 years), and the median age at onset of RBD symptomatology was 49 years."

Of the 27, "63% [had] progressed to develop dementia (PDD or DLB)." The authors note that the "disproportionate association of RBD with cognitive impairment has previously been noted... Why the clinical presence of RBD portends a propensity toward dementia/cognitive impairment is not entirely clear, but might relate to more pervasive Lewy body disease." (Two Lewy body diseases are discussed in this article -- PD and DLB. MSA is *not* a Lewy body disease but it is an alpha-synucleinopathy.)

Of the 27 patients, 24 were men. "There were 14 patients who met criteria for definite RBD, and 13 for probable RBD." "The diagnosis of probable RBD was based on history and evaluation by a specialist in sleep medicine while definite RBD was based on polysomnographic confirmation."

"These findings suggest that PD, DLB, and MSA have very long durations of activity, often with long latencies when the pathogenic process is active, but inapparent or marginally apparent. Thus, the median onset of RBD in this series was age 47.5 years, but as early as age 21 in these syndromes that did not fully present with neurodegenerative syndromes until middle age or beyond."

The article points out that another symptom that can precede the development of PD with a mean latency of 10 years is "the dysautonomic symptom of constipation." And a third symptom: "Preexisting anxiety was associated with later development of PD including extension of the analysis to 20 years before parkinsonism onset."

I've copied the abstract below. (The full article was available online just for a few days only. I guess the journal realized it had made a mistake and took the link down.)

Robin


Here's the abstract:

REM sleep behavior disorder preceding other aspects of synucleinopathies by up to half a century

D.O. Claassen, MD; K.A. Josephs, MD, MST; J.E. Ahlskog, MD, PhD; M.H. Silber, MB, ChB; M. Tippmann-Peikert, MD; B.F. Boeve, MD
Mayo Clinic, Rochester, MN

ABSTRACT
Background: Idiopathic REM sleep behavior disorder (RBD) may be the initial manifestation of synucleinopathies (Parkinson disease [PD], multiple system atrophy [MSA], or dementia with Lewy bodies [DLB]).

Methods: We used the Mayo medical records linkage system to identify cases presenting from 2002 to 2006 meeting the criteria of idiopathic RBD at onset, plus at least 15 years between RBD and development of other neurodegenerative symptoms. All patients underwent evaluations by specialists in sleep medicine to confirm RBD, and behavioral neurology or movement disorders to confirm the subsequent neurodegenerative syndrome.

Results: Clinical criteria were met by 27 patients who experienced isolated RBD for at least 15 years before evolving into PD, PD dementia (PDD), DLB, or MSA.

The interval between RBD and subsequent neurologic syndrome ranged up to 50 years, with the median interval 25 years.

At initial presentation, primary motor symptoms occurred in 13 patients: 9 with PD, 3 with PD and mild cognitive impairment (MCI), and 1 with PDD.

Primary cognitive symptoms occurred in 13 patients: 10 with probable DLB and 3 with MCI.

One patient presented with primary autonomic symptoms, diagnosed as MSA.

At most recent follow-up, 63% of patients progressed to develop dementia (PDD or DLB).

Concomitant autonomic dysfunction was confirmed in 74% of all patients.

Conclusions: These cases illustrate that the alpha-synuclein pathogenic process may start decades before the first symptoms of PD, DLB, or MSA. A long-duration preclinical phase has important implications for epidemiologic studies and future interventions designed to slow or halt the neurodegenerative process.

That's right, Leone, but you'd have to sleep with them to find out, wouldn't you, creating another, moral, dilemma [for some].