Mild Parkinsonian Signs in a Community Population

One question that many of the PREDICT-PD participants ask me is “I am slower than I used to be, does it mean that I am getting Parkinson’s?”

I am interested in the early motor phases of Parkinson’s disease. They are subtle in appearance and usually start before the classical symptoms of Parkinson’s arise, which are slowness of movement, stiffness and tremor. 

When studying subtle abnormalities it is important to know the full range of normal amongst older people. It can be difficult to establish the boundaries between what is normal and abnormal, especially at very early stages of Parkinson’s and in older people.

What it is known is that mild parkinsonian signs or subtle motor symptoms are quite common in the elderly population (ranging from 15% to 50%). The question of whether their presence occurs as part of normal aging or as the result of neurodegeneration has not been clearly answered. 

Here I share a paper that tries to address the issue mentioned above. 

https://www.ncbi.nlm.nih.gov/pubmed/32310187?dopt=Abstract

Abstract.

Background: Mild parkinsonian signs (MPS) are common in the older adult and associated with a wide range of adverse health outcomes. There is limited data on the prevalence of MPS and its significance.

Objective: To determine the prevalence of MPS in the community ambulant population and to evaluate the relationship of MPS with prodromal features of Parkinson’s disease (PD) and cognition.

Methods: This cross-sectional community-based study involved participants aged ≥50 years. Parkinsonian signs were assessed using the modified Unified Parkinson’s Disease Rating Scale (mUPDRS) and cognition using the Montreal Cognitive Assessment (MoCA). Premotor symptoms of PD were screened using a self-reported questionnaire. Linear regression was used to assess the association of MPS with premotor symptoms of PD and cognitive impairment.

Results: Of 392 eligible participants, MPS was present in 105 (26.8%). Mean age of participants with MPS was 68.8 +/- 6.9 years and without MPS was 66.1 +/- 5.9 years (p < 0.001). Multivariate analysis revealed that MoCA scores were significantly lower in the MPS group (b= –0.152, 95% CI = –0.009, –0.138, p < 0.05). A significant correlation between the presence of REM sleep behavior disorder (RBD) and total MPS scores (b= 0.107, 95% CI = 0.053, 1.490, p < 0.05) was also found. Neither vascular risk factors nor other premotor symptoms were significantly associated with MPS.

Conclusion: MPS is common and closely related to cognitive impairment and increasing age. Presence of RBD is predictive of higher MPS scores. This study highlights the necessity of other investigations or sensitive risk markers to identify subjects at future risk of PD.

The main purpose was to know how frequent subtle motor symptoms were in an elderly community without Parkinson´s and evaluate if these features were associated with a loss of cognitive abilities or other features known to be part of the early phase of Parkinson’s including reduced sense of smell, constipation, depression and sleep disturbances. 

To do that, participants were evaluated with motor and memory tasks as well as answering a self-reported questionnaire about the other symptoms mentioned. 

The authors found that one quarter of the group had subtle movement symptoms and this proportion increased with age, with 3 out of 10 people older than 75 having some kind of movement abnormalities. It is important to note that none of these symptoms were strong enough to make the diagnosis of Parkinson’s. They also found that cognitive and motor symptoms were highly associated.

We can extract several conclusions from these results. It is undeniable that once we get older our movement becomes slower and clumsier. The point here is when these motor symptoms occur together with mild memory problems it could mean that some neurodegenerative condition apart from simple aging is occurring.  

In order to these findings be more convincing, we would need to know how many of these people ended up having Parkinson’s or other conditions like Alzheimer’s over time. This was not reported in the study and so further studies are needed.

Cristina Simonet