Beware of deep water after subthalamic deep brain stimulation

We thank Ferreira et al. for their interest in our publication.¹ As highlighted in their comment, swimming can be a difficult task for patients with Parkinson disease. In our publication, we, therefore, cited their important contribution for raising the awareness of this serious issue.

The novelty of our paper was the observation that our patients remained good swimmers after developing Parkinson disease while on dopaminergic treatment and only lost their ability to swim after initiation of deep brain stimulation (DBS) treatment. Thus, this potentially life-threatening side effect of DBS should be recognized and communicated to patients.

We most certainly agree with Dr. Ferreira and his team that we all need to pay attention and to continue studying this important safety issue.

Disclosure

The authors report no relevant disclosures. Contact [email protected] for full disclosures.

References

1. Waldvogel D, Baumann-Vogel H, Stieglitz L, Hänggi-Schickli R, Baumann CR. Beware of deep water after subthalamic deep brain stimulation. Neurology 2020;94:39–41.
2. Neves MA, Bouça-Machado R, Guerreiro D, Caniça V, Ferreira JJ. Risk of drowning in people with Parkinson’s disease. Mov Disord 2018;33:1507–1508.

We most appreciate the comments of Dr. Sidiropoulos on our article.¹ First, the notion of a deep brain stimulation- (DBS) induced task specific dystonia is interesting; however, observing our patients, inter-limb coordination seemed to be the prominent problem, not dystonia. Whether different modes of stimulation make a difference is a very valid question. According to our experience so far, the observed side effect could not be ameliorated through reprogramming. We did not mention the brand of the stimulator because we hypothesize that the observed side effect is related to the procedure, not the brand. We use one of the most commonly used systems.

Three of the 9 reported patients were tremor-dominant.

Dr. Sidiropoulos wonders rightly whether the overall reduction in dopaminergic medication may have played a role in the patients’ lost ability to swim. In this case, we would have expected other motor tasks to deteriorate as well. On the contrary, the good effect of DBS—partially also on axial UPDRS values—allowed for the substantial reduction in Levodopa, suggesting that DBS affects inter-limb coordination differently than Levodopa therapy does. Certainly, the pathophysiology of the observed problem deserves further studies.

Disclosure

The authors report no relevant disclosures. Contact [email protected] for full disclosures.

References

1. Waldvogel D, Baumann-Vogel H, Stieglitz L, Hänggi-Schickli R, Baumann CR. Beware of deep water after subthalamic deep brain stimulation. Neurology 2020;94:39–41.

We read with great interest the report by Waldvogel et al.¹ alerting neurologists to the risk of drowning in patients with Parkinson disease (PD) after implantation of Deep Brain Stimulation (DBS) devices. Their findings follow an earlier report by Bangash et al.² on the drowning hazard post DBS. In the latter case, the patient had received a DBS lead in the zona incerta, rather than the subthalamic nucleus (STN). Anecdotally, other stimulation targets may entail a similar risk.

The underlying mechanisms of this phenomenon are unclear but merit further evaluation, and clinicians need to alert their patients of this possibility.

Bangash et al. suggested that the worsening of swimming abilities could be due to a form of task specific dystonia. I was also wondering whether Waldvogel et al. considered reprogramming strategies like changing the active contact, switching to bipolar stimulation, or using segmented stimulation. Furthermore, they did not mention the stimulation parameters, nor the DBS system brand they used. It would also be noteworthy to report the axial UPDRS subscores, to further support their claim that gait did not worsen after DBS, and to comment on the PD subtype of their patients–tremor dominant vs other–and the fact that many of their patients had a robust reduction in their levodopa daily doses post-surgery, as a possible factor for worsening of their swimming performance.

Disclosure

The authors report no relevant disclosures. Contact [email protected] for full disclosures.

References

1. Waldvogel D, Baumann-Vogel H, Stieglitz L, Hänggi-Schickli R, Baumann CR. Beware of deep water after subthalamic deep brain stimulation. Neurology 2020;94:39–41.
2. Bangash OK, Thorburn M, Garcia-Vega J, et al. Drowning hazard with deep brain stimulation: case report. J Neurosurg 2016;124:1513–1516.

We read with great interest the article by Waldvogel et al.¹ The researchers report the cases of nine patients who underwent deep brain stimulation (DBS) who found their swimming ability deteriorated after DBS.

We recently found similar results in two studies focusing on PD patients’ swimming ability.² According to our survey, 87.7% (n=243) of the patients noticed a change in swimming performance after disease onset and 49.1% (n=136) reported to have had a drowning or near-drowning episode.² The mean disease duration of the participants was 6 years and all were able to swim before PD onset. In a subsequent study³ evaluating different styles of swimming, only 27% of patients (n = 3) were able to swim according to our definition. The majority of patients presented slower and smaller movements, coordination and breathing difficulties, and an inability to maintain a horizontal position.

We want to highlight that swimming difficulties are not a problem exclusively encountered by DBS patients. They can potentially affect any PD patient from the early stages of the disease. We also would like to reinforce the need to pay attention and to continue studying this important safety issue.

Disclosure

The authors report no relevant disclosures. Contact [email protected] for full disclosures.

References

1. Waldvogel D, Baumann-Vogel H, Stieglitz L, Hänggi-Schickli R, Baumann CR. Beware of deep water after subthalamic deep brain stimulation. Neurology 2019 Epub Nov 27.
2. Neves MA, Bouça-Machado R, Guerreiro D, Caniça V, Ferreira JJ. Risk of drowning in people with Parkinson’s disease. Mov Disord. 2018. p. 1507–1508.
3. Neves MA, Bouça-Machado R, Guerreiro D, Caniça V, Pona-Ferreira F, Ferreira JJ. Swimming Is Compromised in Parkinson’s Disease Patients. Mov Disord 2019 Epub Dec 4.