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For people with Parkinson’s disease, deep brain stimulation can calm the tremors and tame the unwanted movements that come with the progressive neurodegenerative disease. Electrodes implanted in the brain, controlled by a device placed under the skin of the chest and equipped with an on-off switch, can ease troubling symptoms and synchronize complex motions.

A new paper reports a worrying development: Nine proficient swimmers lost their ability to swim after DBS surgery for Parkinson’s, even though the implant improved other movements — walking, for one — that require coordination of the limbs. Why swimming mastery disappeared remains a mystery, but the doctors who described the cases Wednesday in Neurology wanted to sound an alarm right away.

“Patients and neurologists should be aware of the potential loss of the ability to swim following subthalamic DBS,” Dr. Christian Baumann, study co-author and an associate professor of neurology and a neurologist at University Hospital Zurich, told STAT. “We warn all patients to be cautious when going into deep waters.”


One patient, a 69-year-old man who owned a lakeside house, found this out in dramatic fashion. “Feeling confident after DBS because of his good motor outcomes, he literally jumped into the lake, where he would have drowned if he had not been rescued by a family member,” the researchers wrote.

A 61-year-old woman complained that although she was a competitive swimmer who had regularly raced across Lake Zurich, when her DBS was activated, she could swim only a little over a tenth of a mile, and only with an awkward stroke.


When three other patients switched off their DBS devices, they could immediately swim again. But their other movements and neuropsychological symptoms deteriorated so rapidly that they turned the DBS back on.

Deep brain stimulation, approved to treat Parkinson’s in the U.S. in 1997, has become the standard of care for people whose tremors and motor fluctuations are no longer responding to medical treatment. After other Parkinson’s drugs stop working, patients typically take levodopa, a precursor to dopamine, to restore levels of the neurotransmitter that their bodies no longer make in sufficient quantities. But levodopa’s effects fade, too. Doses wear off, patients sometimes freeze while walking, and they have involuntary movements.

Instead of restoring dopamine, DBS sends electrical signals from surgically implanted electrodes directly to neurons thought to be responsible for movement. Why patients could still walk but not swim made the researchers wonder if DBS affects the brain in a different way than levodopa does. Patients with DBS, which they can turn on when needed to control tremors, continue to take levodopa.

“I think that imprinted synchronized activity in different brain structures, which have been learnt, may be changed by DBS, i.e. the change of activity in one network piece alters the whole network, which might explain this outcome,” Baumann said. “But this is hypothetical.”

Dr. Michael Okun, medical director of the Parkinson’s Foundation and executive director of the Norman Fixel Institute for Neurological Diseases at University of Florida Health, noted the preliminary nature of the case reports as well as changes in how much dopamine the patients were taking after DBS. He was not involved in the study.

“All of the patients in their series had dopaminergic reductions in medication greater than 50% post-surgery and it is possible that this factor may have played a large role in the decline in function,” he said. “Proper prospective testing of the device in the on- and off-medication condition, as well as in the pre- and post-operative testing conditions, will be required to sort out the root causes of this phenomenon. In the meantime, Parkinson’s patients with or without DBS should not swim without a buddy.”

Other complex motor behaviors, such as skiing, playing golf, or skating, might also be affected, Baumann said. But swimming is the most worrisome — not just for people with DBS, Okun warned.

“One important piece of advice for all Parkinson’s patients is to never swim alone,” Okun said. “The risk of medication wearing off and freezing has been known to be associated with drowning in Parkinson’s disease regardless of whether or not a deep brain stimulator has been implanted.”

  • Thank you for this. I am a pool manager in a regional area in Western Australia. I work alone. One of my patrons has Parkins. He does come with he wife. As an industry, we must be aware of this. Would you be willing to write an article or perhaps give a talk on this in Australia? Can I forward this article to LIWA Aquatics? Please keep me in the loop.

  • This is what happens when you interfere with natural systems. The brain is a very complex organ with billions of neurons and trillions of synapses that connect and interact in complex ways – we are not even close to understanding it. There can also be many factors that are beyond our logical thinking that can be involved with the workings of the brain. Therefore simply supplying an electric current (just because someone thinks that might work) is very naïve and dangerous in the long run. Also, natural methods such as yoga and mindfulness appear to work very well for Parkinson’s – see for example the following link:

    [Please also check out the following article published in JAMA Neurology.
    Kwok, J. Y., et al. (2019). Effects of mindfulness yoga vs stretching and resistance training exercises on anxiety and depression for people with parkinson disease: a randomized clinical trial. JAMA neurology.]

    • Hi Nate,
      I stand firmly by my comments because I am telling the truth. There is no theory whatsoever to support these ‘brain stimulations’ – they are trying hard however by using medical jargon to promote it so that it sounds ‘scientific.’ Throughout history all kinds of strange theories have been put forward by various psychiatrists, DBS is a typical example of another one.

      DBS is simply the ‘placebo effect’ at play as indicated by the following study published in Lancet Psychiatry:

      Paul Holtzheimer et al., “Subcallosal Cingulate Deep Brain Stimulation for Treatment-Resistant Depression: A Multisite, Randomised Sham-Contolled Trial,” Lancet Psychiatry October 4, 2017.

      According to the above study “at the end of the 6-month blinded, controlled phase, there was no statistically significant difference in the primary efficacy outcome between the stimulation group . . . .. and the control group, or in remission.”

      Also, there appears to be serious side effects arising from this stimulation – according to the following article, “among these 28 patients, the authors report 56 serious adverse events.”

      A. Crowell, et al. (2019), “Long-Term Outcomes of Subcallosal Cingulate Deep Brain Stimulation for Treatment-Resistant Depression,” American Journal of Psychiatry, AJP in Advance.

      Further, DBS research appears to be deeply biased due to extensive funding from industry sources – it appears that most don’t even declare conflicts of interest. According to the following article (on medical devices; published in JAMA surgery), conflicts of interest were declared in only 84 of 225 relevant publications:

      Ziai, K., et al. (2018). Association of compensation from the surgical and medical device industry to physicians and self-declared conflict of interest. JAMA surgery, 153(11), 997-1002.

      By the way, FYI – vaccinations are firmly rooted in good science (with evidence coming from well conducted medical experiments spanning decades of research) – so, I am not at all against them!

    • Nate, I can only speak anecdotally. I have had the DBS for deafferentation pain in the face 2ndary to trigeminal neuralgia for only about 2 months. I have an area in my eyelid that was exquisiteky painful to stimuli that since the turning on of the implant has been painfree. I have hopes that this will not only ocntinue but as we tweak the variables will result in more lessening, if not even better, of my pain.
      You seem to want to deal with DBS for depression as opposed to parkinsons tremor, chronic pain.
      I have had other implants, a dorsal column stimulator that took away 85% of my trigeminal neuralgia pain. Unfortunately I lost it to an unrelated infection. That was not placebo. It did nto work for 3 months my neurosurg and I agreed it was a failure and I would have it removed when ready to have another surgery. For some reason, probably because it necver occurred to me, I kept it on and at 3 months, the night before I could not tolerate any touch to the affected area, had constant pain as well as spontaneous. (In fact pain so bad I could not wash the area of the face involved (V1, V2 (L) that because of the dirt build up causding eye infections I was having my face washed under general anaesthesia every few months.) The next morning I go0t into the shower and by mistake allowed a droplet of water to touch my face and I had no pain. That wa snot placebo. It was by all accounts a failure. I had no cause to think or expect to see any kind of benefit. I also had a sensory cortical stimulator implant, 100% experiemntal and I had only a minimal benefit but enough that I was able to do more then I had been able to do and less once, after about 15 years, it failed.
      You seem to have a biads against implants. I am not sure why. I dont know about parkinsons/depression but for chronic pain it is not mereely an issue of electrical current.l It does interfere with the pain mechanism. Just because the benefit may not be well understood does not ipso facto mean it is placebo.

  • The specificity of this reaction to device implantation suggests we may be just a little naive about our human physiology. We revere our body’s anatomic material model, rejecting that it, and the brain, may possess an unseen , but inferred holographic organization.

    Dr. Baumann, the author of the research paper, remarked that “the change of activity in one network piece alters the whole network, which might explain this outcome. But this is hypothetical.”

    Personally, I think our acceptance of our holographic selves is a long way off. Ironically, we can’t easily fathom this with our apparently holographic minds. We cling to our parts and compartments because we love labels. Labels can create an illusion of deeper understanding than we have. Just ask me, I’m a psychiatrist.

    Meanwhile, we reject the scientific evidence to support the body’s energetic/ magnetic/electrical attractions and pathways. We also give stingy recognition and credit to the 3000-5000 years of acupuncture from China, South East Asia, Japan, Korea, and please forgive if I leave anyone out. These Medicines are based on a holographic model of the body.
    Unfortunately, our scientific communities demand proof for these Medicines’ effectiveness using our material-based, gold standard, double blind studies. Some significant acceptance may eventually happen by dumbing them down into “protocols.” But to “accomplish” that, we will lose the holographic model and what it could teach us.

    Among those who believe in energy fields and our body’s magnificent ability to “right” itself, it is known that swimming optimizes re-balancing our energy fields, short of what’s created by anatomic pathology. The immersion in water allows the (holographic body) to more effectively complete its circuits. In the cases described here, the water apparently neutralized the deep brain device’s readjustments. Impressive progress that the device was so effective, as measured by the reversal from the water submersion.

    About 15 years ago, I treated a woman with fluctuating, migrating chronic pain and skin temperature change. These symptoms began following a cerebral shunt implantation for Arnold Chiari Syndrome. The shunt’s magnetic polarity was set by the neurosurgeon, checked every month. The patient first contacted me during the first few months, after she made about 10 ER visits, Weather change, especially with Monsoon season, set off these symptoms. We learned, and she was definitely a partner, how to move her energy and equalize the temperature differences so she could be reasonably comfortable and decrease her pain meds. In the next 6 months, she succeeded in convincing her neurosurgeon to remove the pump. When he did, her symptoms stopped.

    Congratulations to Dr. Baumann for reporting medical outcomes that don’t fit into our “Box.” I can’t imagine a more impressive proof that illnesses, even neurological ones, are solely caused by anatomical, irreversible pathology. We are fortunate, indeed, that our Creator has an imagination beyond what we conceive. How long would the human race have lasted if it was just up to us?
    Peggy Finston MD

    • Addendum:
      Sorry, last paragraph should read:Congratulations to Dr. Baumann for reporting medical outcomes that don’t fit into our “Box.” I can’t imagine a more impressive proof that illnesses, even neurological ones, are NOT solely caused by anatomical, irreversible pathology. We are fortunate, indeed, that our Creator has an imagination beyond what we conceive. How long would the human race lasted if we were just up to us?
      Peggy Finston MD


  • That the ability (or loss thereof) to perform a certain activity is so uniquely precisely defined or related to a certain treatment might / ought to open doors for research and solution from that angle. Hopefully this happens and will assist those afflicted with PD. And of course it is just logical not to swim alone when challenged by inconsistent motor skills.

  • This is wild, thank you for spreading the word. It is important to keeping looking for various triggers of PD, and mitigating them. For example, a 2016 large scale analysis of a national health database in Taiwan found people over 55 with dental amalgams were more than 1.5 times as likely to have PD than those without mercury containing fillings. Other heavy metals and toxins may play a similar role.

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