Loud, Startling Sounds Can Decrease Parkinson’s Muscle Stiffness, Study Suggests

loud sounds, muscle stiffness

Loud and alarming sounds can reduce muscle stiffness in Parkinson’s disease patients treated with subthalamic nucleus deep brain stimulation (STN-DBS), a study suggests.

The study, “Influence of alarming auditory cues on viscoelastic stiffness of skeletal muscles in patients with Parkinson’s disease,” was published in Clinical Biomechanics.

Almost 100 years ago, a French neurologist described a phenomenon called paradoxical kinesis (meaning “difficult to understand movement”) consisting of a dramatic but temporary reversal of Parkinson’s motor symptoms in the face of startling situations such as an oncoming car or loud sounds.

“The phenomenon of [paradoxical kinesis] suggests the existence of neural systems that can override parkinsonian impairment in certain conditions,” the researchers wrote in this study.

The association between paradoxical kinesis and muscular rigidity has never been described, probably due to the subjective, observer-dependent scoring methodology while performing clinical assessments of “rigidity during the transitory motor alterations” and also due to the “subjective nature of the examinations according to the Unified Parkinson’s Disease Rating Scale (UPDRS),” according to the researchers.

Increased rigidity has been linked to more viscoelastic stiffness of skeletal muscles. Muscles behave like springs, and while something that is elastic immediately returns to its original shape once a stress has been removed, a tissue that is viscous will deform permanently. Therefore, viscoelasticity refers to the muscle having properties of both, allowing it to slowly recover from being stretched or deformed.

Measurement of muscle tone using a myotonometer — a device that measures viscoelastic characteristics of soft tissues — has proved useful in quantifying the effect of therapeutic interventions on rigidity in Parkinson’s patients.

“Thus, evaluation of viscoelastic stiffness could potentially enable quick and reliable measurements of muscular rigidity during the enhancement of motor performance due to external cues in patients with [Parkinson’s disease],” the researchers wrote.

The team from the University of Tartu in Estonia assessed the effect of alarming auditory signals on viscoelastic stiffness of skeletal muscles in patients treated with STN-DBS — a surgical treatment for Parkinson’s disease that involves implanting a device to stimulate targeted regions of the brain with electrical impulses generated by a battery-operated neurostimulator. Patients can use a handheld controller to turn the DBS system on and off.

The team recruited 10 advanced stage Parkinson’s disease patients (three women and seven men) who had been treated with STN-DBS for approximately 4.5 years prior to the study.

Eight subjects had akinetic-rigid (i.e., slowness of movement accompanied by muscle stiffness), and two had the tremor-dominant subtype of Parkinson’s disease. Ten age- and gender-matched healthy individuals were also recruited to use as controls.

Using a myotonometer, the investigators measured the viscoelastic stiffness of the participants’ wrist skeletal muscles, or in other words, the muscle’s resistance to the force that changes its shape, after one night of Parkinson’s medication withdrawal.

Wrist examinations were performed by two different examiners, 10 times each. Measurements were repeated and compared during the DBS-on and DBS-off periods, with and without auditory alarming signals.

Compared with the DBS-off period, muscular stiffness was significantly reduced in the DBS-on phase, supporting the the effectiveness of the stimulation treatment in lessening one of Parkinson’s motor features.

In addition, wrist stiffness was also significantly decreased during the DBS-off period in the presence of alarming auditory signals.

“The mean values of stiffness during the DBS-on phase were lower than during the DBS-off with [alarming auditory] signals phase but the difference was not significant,” the researchers wrote.

Exposure to loud sounds did not change muscle stiffness in the control sample, suggesting that the paradoxical kinesis phenomenon is more pronounced in Parkinson’s patients.

“According to our data, the changes in muscular rigidity due to [alarming auditory] signals are an exclusive characteristic of the patients with [Parkinson’s disease],” the researchers said.

Further larger-scale research is necessary to confirm this study’s findings and assess the efficacy of auditory cueing in Parkinson’s disease.

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Welcome to Dr. C’s Journey with Rigid Parkinson’s Disease

Journey, Different approach to Parkinson's

Before I delve into the diverse range of topics I plan to write about, let me introduce myself.

I was diagnosed with a type of rigid Parkinson’s disease (PD) in my early 60s. It is an idiopathic form, and hard for others to see. I experience the symptoms of rigidity, inaccurate muscle aiming, and slowing of movement, along with some non-motor symptoms and quite a bit of pain.

I have a good response to Sinemet (carbidopa-levodopa), but still see a slow progression in my symptoms. I see the effects every day of my life. I have been on a journey to make sense of what is happening and to attain a high quality of life in the face of PD symptoms. This column will share my journey and the insights I’ve gained along the way.

I am also a researcher and writer (see:

After years of hearing, “You look fine, I don’t see the PD in you,” while having the worst of the symptoms under medication control, I thought it was time to put pen to paper. I have a unique background that combines clinical experience helping people with the ability to reframe things so that they may be viewed in a new light.

In this column, I will discuss new ideas and things you haven’t heard before. But mostly they will be ideas that are reframed. This is the result of my struggle to make meaning out of rigid Parkinson’s disease and what it is doing to my life. Hopefully, the information will help you to make sense of some experiences you might have in connection with PD.

The unique perspective that this column will bring to the topic of attaining quality of life with rigid Parkinson’s disease is one I believe will be of interest to the reader. I have a Ph.D. in rehabilitation counseling and I specialized in the treatment of cerebral-neurological disorders. I have helped people attain a higher quality of life after terrible things happened to their brains.

I am also a scientist, and during the past five years, I have conducted extensive research on the ideal rehabilitation plan for a person like me, with early signs of PD. I have put such a plan in place for my own life, although it’s not as perfect as I would like, and I am struggling with things like cutting back on ice cream.

I think that tackling the disease head-on with a vigorous rehabilitation plan makes as much of a difference in the quality of my life as medication does. (I’m not saying to replace the medication, but rather to enhance it.) My plan includes the following:

  • Five to 10 hours of light and hard exercise per week.
  • Fifteen to 20 hours of mental-stimulation activities per week.
  • An ADA house (one that meets standards set by the Americans with Disabilities Act) close enough to receive support from family.
  • Decreased stress, a healthy diet, and doing fun things.

Those are the basics of the plan, which is quite flexible. A lot of fine-tuning happens when the basic plan is applied specifically to the needs of a person, like you, the reader.

Any rehabilitation plan needs to consider where a person falls within the spectrum of Parkinson’s symptoms. In a treatise on PD by Stewart Factor and William Weiner, the authors speak to the importance of understanding the non-motor symptoms associated with PD and the necessity of early intervention.

“Dr. C’s Journey with PD” is personal, but it also will address these two points and various aspects of the PD spectrum. In each column, I will try to leave readers with something that might improve their quality of life with Parkinson’s.

Next week: Parkinson’s disease as a spectrum.


Note: Parkinson’s News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website. The opinions expressed in this column are not those of Parkinson’s News Today or its parent company, BioNews Services, and are intended to spark discussion about issues pertaining to Parkinson’s disease.

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Source: Parkinson's News Today