Stina Sundstedt

Division of speech and language pathology, department of clinical sciences, Umea University, Umea, Sweden.

Victoria Murphy:

My guest today is Stina Sundstedt from the division of speech and language pathology, department of clinical sciences, Umea University, Umea, Sweden. Stina, a very warm welcome to you and thank you for joining us.

Stina:

Thank you for inviting me.

Victoria:

Today we are here to discuss a paper you authored in Acta Neurologica Scandinavia in November 2012. The title of your paper was ‘Deep brain stimulation – effects on swallowing function in Parkinson’s disease’.

Stina, what were the objectives of your study?

Stina:

Since dysphagia is common in Parkinson’s disease and affects both mortality and morbidity we think it is important to evaluate swallowing function when new treatment alternatives arise. Deep brain Stimulation is now becoming an established treatment alternative for patients with Parkinson disease.

The aim of our study was to evaluate the effect of deep brain stimulation (DBS) in the Subthalamic nucleus on pharyngeal swallowing function in patients with Parkinson disease.

Victoria:

How was it designed?

Stina:

Well, patients were evaluated preoperatively and at 6 and 12 months after surgery. Preoperative examinations were done with medication on and medication off. Postoperative examinations were done with DBS stimulation either turned on or off. During the postoperative examinations patients used L-dopa medication.

The swallowing evaluations were self-estimation on a visual analogue scale, and a fiberoptic endoscopic examination. The fiberoptic examination was done according to a predefined protocol and the protocol included Rosenbek’s Penetration-Aspiration Scale, Secretion Severity Scale, pre-swallow spillage, pharyngeal residue, and pharyngeal clearance.

Victoria:

What types of patients were included?

Stina:

The study included 11 patients with idiopathic Parkinson. Six of the patients had bilateral DBS and five had unilateral DBS. All patients had DBS in the Subthalmic nucleus. All patients performed self-estimations and eight of them underwent the fiberoptic endoscopic examination.

Victoria:

What were the study endpoints?

Stina:

We wanted to compare the results from the self-estimation as well as the parameters from the fiberoptic endoscopic examination before and after the operation and at 6 and 12 months with and without stimulation.

Victoria:

What were the results?

Stina:

The self-assessments of swallowing function revealed a subjective improvement with DBS stimulationturned on but the data from the swallowing protocol did not show any significant positive or negative effect of the DBS treatment itself. The prevalence of aspiration was not affected by the surgery or the stimulation. Overall the swallowing function was mildly impaired in the sample.

Victoria:

Are there any limitations to the study?

Stina:

When interpreting the results it is important to consider that the sample was small and that the swallowing problems were mild to moderate. It is also important to remember that the study focused on the pharyngeal stage of swallowing and did not examine the oral or esophageal stage.

Victoria:

What conclusions can be drawn from these results?

Stina:

The results show that the swallowing function was not negatively affected by DBS in these eight patients who had mild swallowing problems. The risk of aspiration did not increase. Self-estimation of swallowing function showed a subjective improvement due to stimulation. The patients felt they had better swallowing function with the stimulation on compared to off.

Victoria:

Can these results be considered conclusive?

Stina:

The results need to be confirmed in larger samples and the oral and esophageal stage of deglutition needs to be examined as well.

Victoria:

Stina, thank you for joining us today, it has been a pleasure.

Stina:

Thank you very much to you too.