Parkinson’s disease and sex-related differences in electromyography during daily life

Are the digit ratio (2D:4D) and hand grip strength related to Parkinson disease in elderly males?

BACKGROUND

Sex hormones affect the pathogenesis of Parkinson patients and it has been suggested that gender is the most important factor in the development and progression of Parkinson's disease. Studies have shown that the second to fourth digit ratio (2D:4D) is affected by the prenatal testosterone and estrogen levels and can predict predisposition to disease. In addition, decreased muscle strength in people with Parkinson's has been repeatedly reported. Hand grip strength (HGS) is a suitable measure to evaluate the musculoskeletal system among the elderly and it is considered as an indicator of the overall strength of the body. This study aimed at investigating the relationship between Parkinson's disease and HGS and 2D:4D ratio.

METHODS

In this study 117 elderly men with Parkinson disease (mean age of 61.66 ± 11.28 years) and 156 healthy control subjects (mean age of 61.86 ± 6.29 years) participated. After determining the level of disability of Parkinson patients by a neurologist (level of disability in the range of 1-4), anthropometric indices (height, weight, length of the second and fourth fingers) and maximum HGS were measured.

RESULTS

Although 2D:4D ratios (right and left hand) of male patients with Parkinson's disease were higher than those of healthy males, this difference was not statistically significant (P = 0.12, P = 0.40; respectively). Conversely, HGS for the right and left hands of Parkinson patients were significantly lower than those of healthy males (P = 0.02, P = 0.03; respectively). The results showed a significant negative relationship between Parkinson disease and the right and left HGS (R = -0.16, P = 0.005; R = -0.17, P = 0.003; respectively). Parkinson disease had no significant relationship with 2D:4D of the right hand, left hand, mean finger ratio and DR-L 2D:4D (P > 0.05). The regression results showed that the right and left HGS were not able to predict Parkinson disease (P = 0.25, P = 0.16; respectively).

CONCLUSION

We concluded that HGS was negatively associated with the Parkinson disease, but conversely, 2D:4D may not be a valuable biomarker of elevated risk of Parkinson in elderly males.

People with mild Parkinson's disease have impaired force production in upper limb muscles: A cross-sectional study

BACKGROUND

There has been little examination of force production of the upper limb in people with Parkinson's disease (PD), despite its impact on activities of daily living and clear evidence that force production is significantly reduced in lower limb muscle groups. The aim of this study was to determine the force production of the major muscle groups of the upper limb in people with PD during the "on" phase after medication, compared with aged-matched neurologically-normal controls.

METHOD

A cross-sectional study was carried out.

PARTICIPANTS

Thirty people with mild PD (Hoehn Yahr mean 1.1) and 24 age-matched neurologically-normal controls.

OUTCOME MEASURES

Maximum isometric force production of the shoulder flexors, extensors, abductors, adductors, internal rotators and external rotators, elbow flexors and extensors, wrist flexors and extensors and hand grip using dynamometry.

RESULTS

There was a significant impairment in force production in all upper limb muscle groups, compared with control participants, except in the wrist flexors. On average the deficit in force production was 22%, despite people with PD having mild disease, being physically active and being measured during the "on" phase of medication. The most severely affected muscle groups were the upper limb extensors.

CONCLUSION

People with PD have a significant deficit in force production of the upper limb muscle groups compared with age-matched neurologically normal controls.

CLINICAL IMPLICATIONS

Regular assessment of strength of the upper limb should be considered by clinicians and strengthening interventions could be implemented if a deficit is identified.

The Impact of Parkinson's Disease on Postural Control in Older People and How Sex can Mediate These Results: A Systematic Review

INTRODUCTION

Parkinson's disease is most prevalent among elderly people, 65 years and over, and leads to an alteration in motor control associated with postural instability. Current evidence shows that postural control decreases with the aging process. In addition, postural control is more altered in healthy aged men than in women. Until today, few studies have evaluated the combined impact of Parkinson's disease and sex on postural control. This review has allowed to evaluate the impact of Parkinson's disease and sex on postural control measurements in elderly people.

METHODOLOGY

Studies have been selected from two main databases: PubMed and EBSCO using the keywords "Parkinson", "postural control OR balance" and "sex". Articles related to the evaluation of postural control, including men and women with Parkinson's aged over 65 years old, regardless of stage, were included (n = 179). Articles were excluded if not written in French or English or not presenting original content.

RESULTS

Ten (10) studies out of 179 that fulfilled inclusion and exclusion criteria were reported in the final analysis, which cumulates a total of 944 individuals with Parkinson's (410 women). In general, results show greater postural instability among people with Parkinson's compared to healthy subjects, and this according to different objective measurements using stabilographic parameters from force platforms. Only two studies out of ten evaluated postural control while briefly considering distinctions between sex, but without showing a significant difference between men and women with Parkinson's. Parkinson's severity, length of time of Parkinson's disease and cognitive state of the person are the three variables with a negative impact on postural control.

CONCLUSION

Older people with Parkinson's disease have greater postural instability. Sex does not seem to influence the postural control of elderly people with Parkinson's, although more studies are necessary.

How Wearable Sensors Can Support Parkinson's Disease Diagnosis and Treatment: A Systematic Review

Background: Parkinson's disease (PD) is a common and disabling pathology that is characterized by both motor and non-motor symptoms and affects millions of people worldwide. The disease significantly affects quality of life of those affected. Many works in literature discuss the effects of the disease. The most promising trends involve sensor devices, which are low cost, low power, unobtrusive, and accurate in the measurements, for monitoring and managing the pathology.

OBJECTIVES

This review focuses on wearable devices for PD applications and identifies five main fields: early diagnosis, tremor, body motion analysis, motor fluctuations (ON-OFF phases), and home and long-term monitoring. The concept is to obtain an overview of the pathology at each stage of development, from the beginning of the disease to consider early symptoms, during disease progression with analysis of the most common disorders, and including management of the most complicated situations (i.e., motor fluctuations and long-term remote monitoring).

DATA SOURCES

The research was conducted within three databases: IEEE Xplore®, Science Direct®, and PubMed Central®, between January 2006 and December 2016.

STUDY ELIGIBILITY CRITERIA

Since 1,429 articles were found, accurate definition of the exclusion criteria and selection strategy allowed identification of the most relevant papers.

RESULTS

Finally, 136 papers were fully evaluated and included in this review, allowing a wide overview of wearable devices for the management of Parkinson's disease.

The Association of Grip Strength With Severity and Duration of Parkinson’s

Background. Weakness is reported in Parkinson’s but always unadjusted for recognized factors that influence muscle strength such as participants’ age, gender, and body size. This may obscure the true association of Parkinson’s with muscle strength. Objective. To evaluate the relationship between grip strength, Parkinson’s severity, and duration adjusting for these factors. Methods. Age, gender, height, weight, grip strength, Unified Parkinson’s Disease Rating Score (UPDRS) motor score, Hoehn and Yahr (H&Y) stage, disease duration, number of comorbidities and medications, Barthel score, Mini Mental State Examination (MMSE) score, and Malnutrition Universal Screening Tool (MUST) score were recorded. Results. Fifty-seven of 79 (72%) people with Parkinson’s resident in one town were recruited. Age, gender, height, and Parkinson’s severity were the most significant determinants of grip strength. Each unit increase in UPDRS motor score and H&Y stage was associated with lower grip strength in univariate linear regression analyses adjusted for gender: −0.3 kg strength (95% confidence interval = −0.51, −0.09), P = .006 for each additional UPDRS point, and −3.87 kg strength (95% confidence interval = −6.54, −1.21), P = .005 for each additional H&Y stage. Disease duration was not associated with grip strength. In multivariate regression, Parkinson’s severity remained strongly associated with grip strength (UPDRS score P = .09; H&Y stage P = .04). Conclusions. This is the first demonstration that increasing severity of Parkinson’s was associated with weaker grip after adjustment for known influences on muscle strength. Participants’ age, gender, and body size also had a significant impact on strength. Adjustment of reported values for all these factors is essential to allow accurate reporting of grip strength values in intervention trials and comparison between different groups.

Identification of Changing Lower Limb Neuromuscular Activation in Parkinson's Disease during Treadmill Gait with and without Levodopa Using a Nonlinear Analysis Index

Analysis of electromyographic (EMG) data is a cornerstone of research related to motor control in Parkinson's disease. Nonlinear EMG analysis tools have shown to be valuable, but analysis is often complex and interpretation of the data may be difficult. A previously introduced algorithm (SYNERGOS) that provides a single index value based on simultaneous multiple muscle activations (MMA) has been shown to be effective in detecting changes in EMG activation due to modifications of walking speeds in healthy adults. In this study, we investigated if SYNERGOS detects MMA changes associated with both different walking speeds and levodopa intake. Nine male Parkinsonian patients walked on a treadmill with increasing speed while on or off medication. We collected EMG data and computed SYNERGOS indices and employed a restricted maximum likelihood linear mixed model to the values. SYNERGOS was sensitive to neuromuscular modifications due to both alterations of gait speed and intake of levodopa. We believe that the current experiment provides evidence for the potential value of SYNERGOS as a nonlinear tool in clinical settings, by providing a single value index of MMA. This could help clinicians to evaluate the efficacy of interventions and treatments in Parkinson's disease in a simple manner.

Daily electromyography in females with Parkinson's disease: a potential indicator of frailty

Females with Parkinson's disease (PD) are at increased risk for frailty, yet are often excluded from frailty studies. Daily electromyography (EMG) recordings of muscle activity can dissociate stages of frailty and indicate functional decline in non-neurological conditions. The purpose of this investigation was to determine whether muscle activity can be used to identify frailty phenotypes in females with PD. EMG during a typical 6.5-h day was examined in biceps brachii, triceps brachii, vastus lateralis and biceps femoris on less-affected PD side. Muscle activity was quantified through burst (>2% maximum exertion, >0.1s) and gap characteristics (<1% maximum exertion, >0.1s). Differences across frailty phenotype (nonfrail, prefrail, frail) and muscle (biceps brachii, BB; triceps brachii, TB; vastus lateralis, VL; biceps femoris, BF) were evaluated with a 2-way repeated measure ANOVA for each burst/gap characteristic. Thirteen right-handed females (mean=67 ± 8 years) were classified as nonfrail (n = 4), prefrail (n = 6), and frail (n = 3) according to the Cardiovascular Health Study frailty index (CHSfi). Frail females had 73% decreased gaps and 48% increased burst duration compared with nonfrail. Decreased gaps may be interpreted as reduced muscle recovery time, which may result in earlier onset fatigue and eventually culminating in frailty. Longer burst durations suggest more muscle activity is required to initiate movement leading to slower movement time in frail females with PD. This is the first study to use EMG to dissociate frailty phenotypes in females with PD during routine daily activities and provides insight into how PD-associated motor declines contributes to frailty and functional decline.