Author s response to reviews Title: Argentine Tango in Parkinson Disease - A Systematic Review and Meta-Analysis Authors: Désirée Lötzke (desiree.loetzke@uni-wh.de) Thomas Ostermann (thomas.ostermann@uni-wh.de) Arndt Büssing (arndt.buessing@uni-wh.de) Version: 1 Date: 16 Sep 2015 Author s response to reviews: Dear reviewers and editor, please find enclosed our revised version of the manuscript, "Tango Argentino in Parkinson Disease A systematic review and meta-analysis" by Lötzke et al. we would like to submit for publication in BMC Neurology. We thank you and all reviewers for the helpful comments and suggestions for improvement. To improve the writing style and language and to reduce grammatical errors throughout the work, an English native speaker corrected the paper (changes indicated by using track changes). In the following I will respond point-by-point to the reviewer s comments. The numbers of pages, lines and paragraphs given in the comments refer to the first version of the paper. Reviewer 1: Page 1, Paragraph 1: At the end of the paragraph you appear to be suggesting that a reduced quality of life is an example of a non-motor symptom. Please clarify as quality of life can also be based upon feelings of physical health. I agree. I corrected the sentence to: Typical impairments of PD are bradykinesia, postural instability, rigidity, difficulty in dual tasking, and a resting tremor. Individuals with PD have thus a limited mobility and a higher risk for falls. Also non-motor symptoms like autonomic and depressive disorders, as well as cognitive impairments are among the symptoms of PD. Be affected by PD may also lead to a reduced quality of life [1, 2]. - Page 4, Paragraph 1:
Throughout the text there are some confusing sentences, such as the following: "Besides approaches of mind-body medicine to exercise like Qi Gong or Tai Chi, but also diet and nutritional supplements, also dance is discussed as an appropriate intervention" I would suggest rewording or changing the sentence structure to clarify what you mean here. Done. I changed it to: Besides approaches of mind-body medicine to exercise like Qi Gong or Tai Chi, also dance is discussed as an appropriate intervention [4].- In this same paragraph you begin by talking about the necessity to understand what is interesting to the group (of people with PD) and what will encourage long term participation. However, you then make note of and summarize findings from Heiberger et al. (2011) who looked at changes to motor impairments directly after class (among other things). There ap-pears to be a disconnect here between what you were arguing for at the beginning of the par-agraph and then what you discuss in this example. However, at the end of the paragraph you note work by Dreu et al. (2012) that does demonstrate the enjoyment that patients felt when moving to music. This last example makes more sense in relation to your initial arguments. However, please watch out for a spelling issue here - "enjoyment of moving to music" instead of "enjoyment of moving on music" which it currently says. -I delete the sentences by Heiberger et al. and also restructured the whole paragraph. Concerning the spelling issue: it is a mistake in the quoted paper. I corrected it and marked the change with a square bracket. Please read the whole new paragraphs of the background, because of major changes in the structure and argumentation of this section.- End of Page 4 Again, I would look at changing the structure of this sentence or rewording: "in recent years it came more and more in the focus of researchers and dance artists " -Done and changed to: In recent years an increasing discussion about Argentine Tango (AT) as a music-based movement therapy with beneficial effects for individuals with PD was ob-served among researchers and dance artists [12, 13].- Page 5, End of Paragraph 2: "could be also a reason for treating physicians to prescribe it to their patients". I understand what you are trying to say here but we don't necessarily "treat" physicians to prescribe something to patients. Maybe "encourage" would be a better word here. Page 5, Paragraph 3:
"When patients experience their abilities to perform dance movements, and that their partner responds positively to their dance impulses, they may feel psychologically better, as a process of self-efficacy and self-esteem" Please clarify your thoughts here. Perhaps say, "When patients experience a sense of achievement from mastering certain dance movements and when their dancing partner re-sponds positively to their dance impulses, participants may feel psychologically better due to a boost in self-efficacy and self-esteem" -Corrected to: When patients experience a sense of achievement from mastering certain dance movements and when their dancing partner responds positively to their dance impulses (in terms of successful dance interactions and positive emotions), participants may feel psycho-logically better due to a boost in self-efficacy and self-esteem, and joy.- "Yet, most of the existing rehabilitation programs do not place or just little importance on this aspect" Instead possibly say "Yet, most of the existing rehabilitation programs do not place, or place very little importance on this aspect" Page 6, Paragraph 1: "A dance partner spent balance aid to individuals with PD who feel insecure because of instability" Please clarify what you mean here -Corrected to: In AT, all movements are carried out slowly, and in close proximity to the dance partner, who provides security and stability as he or she gives balance aid with his/her body to individuals with PD who feel insecure because of their instability and motor affec-tions.- Page 8, Paragraph 2: Please explain why fmri studies excluded. -Done and corrected to: Further, eight studies were excluded because they were reviews, a study protocol, a recommendation paper, or a fmri study (which was not tango specific and reported an increased network connectivity between the basal ganglia and premotor corti-ces ). - Page 12, Paragraph 1: Is it necessary to describe what happens to the motor severity results if you removed 2 of out of 6 (or over 30%) of the relevant studies? It seems that these too are important even though they are showing the more negative result. I can possibly see why you would sometimes remove Hackney
and Earhart's (2010) study that compared partnered and non-partnered tango given that both are dance interventions. However, some of the other exclusions I would question if they are only being removed simply because they are showing a positive effect. -Paragraph corrected to: Motor severity (i.e., rigidity, tremor, gait, postural instability, bradykinesia) was measured mostly with the Unified Parkinson s Disease Rating Scale 3 (UPDRS-3). For the meta-analysis (figure 2) we were able to include six studies with 178 patients, and found a significant overall effect of -0.62 [CI: -1.04, -0.21] in favor of tango with a significant heterogeneity (I2=59%, p=0.03). If one would exclude the small study of Duncan & Earthart [9] which showed a strong effect with large variance, one would see a reduction of heteroge-neity (I2=55%, p=0.06) with a still considerable overall effect of -0.55 [CI: -0.93, -0.16].- Page 13: Interesting findings and really good to see some critical engagement with findings in the 6- minute walk test. -No changes required.- Page 19, Paragraph 3: Interesting points made here about the need for regular participation in activity to reduce symptoms. It may be worth elaborating on this point slightly in light of many studies stopping dance interventions after a period of 10-12 weeks. Could you possibly discuss the FITT principle of training and the need for overload to continue to elicit positive change? -There were major changes in the structure of the discussion section and should be read as a whole. The paragraph was changed to: Just three of the 13 included studies had follow-up assessments one month or 10 to 12 weeks after the end of intervention. Each of these publications reported that the assessed gains maintained [14, 15, 21]. This result is in so far interesting as regular participation is necessary to reduce symptoms and to delay mobility impairments in individuals with PD [36]. Further studies should continue to examine this issue on long-term effects of AT in PD. This is particular important against the background that just three studies considered interventions with a duration of one or two years [9, 30, 31]. I did not discuss the FITT principle of training due to the fact that we focus on Tango as a form of rehabilitative intervention or adjunctive therapy. I think these principles are not suita-ble in this context. - Page 20, Paragraph 2: Interesting points made here about the present studies not fully meeting the WHO recommendations for a physical activity frequency of 3 times per week but also how this may be difficult for the person with PD. Again, it would be great to elaborate more or debate these ideas fur-ther to try to come to a resolution as this appears to be a very big problem within the research.
-Changed to: The present studies not fully met the global recommendations of the World Health Organization (WHO) for 65 year olds and above with poor mobility which state an optimal frequency of 3 or more days per week to be physically active to enhance balance [38]. Yet, one has to take into account that the participants are not merely old, but old and handi-capped by their PD symptoms. Three times of more might be optimal but this is not easily feasible for most PD patients. AT courses are social meetings which require transportation to a specific location, while private physical activities can be practiced at any time by persons with PD. To comply with these recommendations, a combination of AT intervention with organizationally less complex physical activity e.g. self-directed home-based physical activity might be a possibility.- End of page 21 to top of page 22 When quoting McGill, Houston, and Lee (2014), remove the plural from the word "individuals" Reviewer 2: Abstract Page 2, line 29: You should consider removing the word "predominantly" from this sentence as it implies you are not disclosing all databases searched. In the results section, you do not mention the name of the scale used to assess motor severity while you do mention the others. Consider adding this in for consistency. Main text Background In general, this section needs review and editing. Currently, the text is very truncated and does not display a clear flow of information to arrive at the main research focus and aim. On reading, there appears to be some repetition and paragraphs do not always link together. The introduction of a paper must, in a way, tell a storey, ie. begin with a brief introduction of the boarder topic area that ultimately links into the main focus and thus, the need for this research piece. A more succinct and concise introduction can often achieve this very well. -Done. I tried to restructure the section to display a clear flow of information, delete repeti-tions, and to reformulate the section for a more succinct and concise introduction.-
Page 4, line 77: Please rephrase this sentence as it is unclear. -Changed to: Besides approaches of mind-body medicine to exercise like Qi Gong or Tai Chi, also dance is discussed as an appropriate intervention [4].- Page 4, line 84: Typo. Should this be "to music" instead of "on music". -It is a mistake in the quoted paper. I corrected it and marked the change with a square brack-et.- Page 4, line 92: Typo. Replace "researches" with "researchers". Page 6, line 121: Typo. "Spend balance" needs to be corrected. -Corrected to: In AT, all movements are carried out slowly, and in close proximity to the dance partner, who provides security and stability as he or she gives balance aid with his/her body to individuals with PD who feel insecure because of their instability and motor affec-tions. Please review the journal recommendations for in-text citations when referring to authors names in sentences. Currently, you use name followed by year and name followed by citation number. Please correct. Methods You do not mention anything about stage of disease in your inclusion criteria. Consider adding it as it is mentioned in your results ie. all stages of disease were included. -Done. Changed to: For a comprehensive summary of existing literature on the effectiveness of AT for patients with PD, there were no limitations for study design, year of publication, stage of disease, considered outcome and age of participants.- Results Page 8, lines 175-180: Please rewrite this paragraph. Currently, it reads like you excluded 11 of your 13 included articles. -Done and corrected to: Based on the described search strategy 24 hits (figure 1) were found. Among the primary hits three were excluded because they either do not address PD, or the search term tango was not used for the dance, or it was a commentary. Further, eight studies were excluded because they were reviews, a study protocol, a recommendation paper, or a fmri study (which was not tango specific and reported an increased network connectivity between the basal
ganglia and premotor cortices ). Thirteen hits correspond to the aim of the review to summarize the current evidence on the effectiveness of AT in individuals with PD and were included in the review. You use the term "most studies" when describing results throughout this section. Please be more specific and consider stating the exact number of studies that reported the particular result in question. Page 9, line 204: This sentence is very long and unclear. Please rephrase to shorten. -Done and changed to: Seven studies described one hour AT interventions twice a week for ten [15, 21], 12 [29], or 13 [20, 22, 32, 33] weeks. Two studies had an intervention period of 12 months [30, 31]. Tango interventions with a duration of 1.5 hours were described in the uncontrolled pre-post study by Hackney et al. (ten lessons within two weeks) [35] and in the N- RCT by McKee & Hackney (20 lessons within 12 weeks) [14].- Page 10, line 210: The dosage of dance reported here is unclear. Please clarify by editing language used. -Done and changed to: In contrast, the shortest intervention period is described in the case study by Kaski et al., i.e., the 79 year old male patient performed in total four dances. The participant performed two dances (each with a duration of 3.45 minutes) in one session. There was one week between session one and two one week [34]. - Page 14, line 306: Explain what "x five patients" means or is it a typo? -Corrected to: Only the small study of Duncan & Earthart [9] with five patients in each group reported a high effect size in favor of tango (ES = -1.18 [CI: -2.43, 0.07]), while all other studies reported small or moderate effects between -0.37 [CI: -0.94, 0.20] and 0.23 [CI: -0.48, 0.94].- Page 15, line 329: Replace "of" with "on". You report on the control interventions in studies in two different places, page 9, lines 196-200 and page 10, lines 212-216. Please report all results together for each aspect of studies. Discussion (Confidential comment) While this section identifies some interesting weaknesses in the current literature, major revisions and editing are needed to the layout, sentence structure and paragraph formatting. Cur-
rently, this section is very difficult to follow and leaves the reader unsure of the main findings. This section requires major editing and would benefit from review by an expert of medical English writing Your institution may have these services. The discussion section must discuss the findings and the implications of these findings. Information needs to be presented with a concise flow to language and paragraph layout. Also be careful not to repeat. -The discussion as a whole was restructured.- Page 17, line 372-373: This sentence does not seem to link with the information provided in this paragraph. It maybe better placed at the start of the next paragraph. -The discussion as a whole was restructured. Therefore the sentence is now placed in the sec-ond paragraph of the discussion.- Page 17-18, lines 379-389: This paragraph is unclear. It needs re-phrasing. Currently, you compare the conflicting results of two 12-13 week interventions and a 12 month trial in one sentence. However, this is an inaccurate comparison due to differences in intervention dura-tion. Generally, this paragraph needs re-phrasing as it does not make sense to read. -Done and changed to: Of interest are the conflicting results of Romenets et al. [29] and Hackney et al. [33] who did not find significant benefit of AT classes on the motor severity after 12 and 13 weeks tango intervention (2x/week), while Duncan and Earhart did find sig-nificantly better scores in the AT group than in the control group as well as significantly im-proved scores in the AT group compared to baseline after 12 weeks of intervention [30]. These results are interesting because of the fact that the intervention characteristics i.e. intervention period, frequency and duration of therapy were similar. However, it is to consider that the assessment after 12 weeks was one of three follow-up assessments and that the intervention period in the study of Duncan & Earhart lasted in total 12 months. Future research will be necessary to discover the reasons for the conflicting findings. One possible cause to consider might be the fact that study participants in the study of Romenets et al. [29] and Hackney et al. [33] were on their regular medication while individuals with PD in the study by Duncan & Earhart [30] were not. The influence of regular medication intake in individuals with PD dur-ing exercise interventions on study results should be investigated in future research activities.- Page 18, lines 390-409: This paragraph is not clear. There are a number of different points made but their is no link or flow to them. They all appear as separate sentences, with no mes-sage. Please re-write to make clearer. What outcome are you referring to at the start (line 390)? -I agree. The discussion as a whole was restructured to make is clearer and to link different points. The different points were assigned to the new subtitles: Health related effects of AT; Intervention Characteristics, and Social and Partner Relationships.- Page 19, line 410: Please include a reference for this sentence and mention the strength of literature supporting this.
-Done. Corrected to: Furthermore, study results showed significant improvements after AT intervention with regard to total current activity participation, low-demand leisure activity as well as new social activities [31]. Because of the fact that just one study investigated those outcome parameters, the findings should be interpreted as a hint and require further scientific research.- Page 19, line 412: The sentence discussing quality of life appears to be missing an "a" before "patient-relevant outcome. Page 20, line 431: It may be best to say "In Tango" as opposed to "In dance here. You should not assume all dance types have a "leading role". Page 20, line 443-448: This first sentence in relation to WHO is missing a word. Please cor-rect. Page 21, line 456: "there impairments and needs" should be replaced with "their impairments and needs." To assess the quality of included studies, you developed a checklist. While it is a very comprehensive list, it's psychometric properties have not be tested. You shoulder consider acknowledging this in your limitations section. -Done: As a limitation for this review we have to acknowledge the fact that the psychometric properties of the developed checklist to assess the quality of included studies is not tested.- Table 2: Consider adding authors name as well as citation numbers to match layout of Table 1. Reviewer 3: Background In general the degree of focus in the background section could be improved. For example, it would be beneficial to clearly convey the rationale and need for conducting this meta-analysis. -I agree. There are major changes in the structure and argumentation of this section to improve the degree of focus. I also added the need for conducting this meta-analysis: A number of studies
investigated the effectiveness of AT for individuals with PD on a scientific basis. Analyzing results across studies is important for understanding whether AT is an effective adjunctive treatment for the multitude of symptoms in PD. This review/ meta-analysis aimed to summarize the current research results on this topic and to identify research gaps and key areas requiring future research. - There are quite a few direct quotes that could be paraphrased and cited to convey these ideas. -I agree. After rewriting the background section with major changes, there is just one direct quote left.- Page 4, lines 73-74: Please hyphenate "disease-specific". Page 4, lines 76-78: This sentence is confusing. Consider rephrasing. ("Besides approaches [ ] appropriate intervention.") -Corrected to: Besides approaches of mind-body medicine to exercise like Qi Gong or Tai Chi, also dance is discussed as an appropriate intervention [4].- Page 4, lines 78-80: Facial expression was measured using just one item of the UPDRS motor subscale for the uncontrolled, unblinded study cited. Though the UPDRS motor subscale as a whole is the gold-standard for assessing motor signs in PD, the validity of this item (or the sum of the few fine motor/rigidity items) as a stand-alone measure is not established. The point conveyed in this sentence is not critical to the flow of the introduction. This sentence could be removed, qualifiers could be added, or a single-session intervention with a stronger study design/different outcome measures could be substituted to demonstrate the immediate effects of dance. -I agree. I removed the sentence.- Page 4, lines 88-90: Please indicate whether there were increases or decreases in activity levels in the specified brain regions during these tasks. -After rewriting and restructuring the background section this sentence was removed.- Page 4, line 92: "reasearches" should be "researchers". Page 5, line 114: It is unclear what the authors mean by "[ ] their partner responds positively to their dance impulses [ ]". -I corrected the sentence to: When patients experience a sense of achievement from mastering certain dance movements and when their dancing partner responds positively to their dance
impulses (in terms of successful dance interactions and positive emotions), participants may feel psychologically better due to a boost in self-efficacy and self-esteem, and joy.- Page 5, line 117-118: "[ ] programs do not place or just little importance on this aspect." This sentence should be reworded to something like "[ ] programs do not emphasize the importance of these factors." -I corrected it as suggested by reviewer 1 to: Yet, most of the existing rehabilitation programs do not place, or place very little importance on this aspect [19].- Page 6, line 121: "A dance partner spent balance aid to individuals with PD [ ]." I'm not sure what this sentence is trying to convey. -I corrected it to: In AT, all movements are carried out slowly, and in close proximity to the dance partner, who provides security and stability as he or she gives balance aid with his/her body to individuals with PD who feel insecure because of their instability and motor affec-tions. It might accelerate the learning of motor-skills [21, 22].- Methods The methods are reasonable and well-described. -No changes required.- Results Page 11, lines237-238: In follow-up section, the authors mention that the Foster 2013 RCT measured data at 4 time points. This was also true for the Duncan 2012 study included in this review, and this reference should be added. -I agree. I corrected the paragraph to: While six studies assessed the outcome parameters in the week before and after the intervention [20, 22, 29, 32, 33, 35], one publication describes three assessment points with a further assessment in the middle of intervention period [9]. Further, some studies measured before and after intervention, and had a follow-up one month later [15, 21], or 10 to 12 weeks after the end of intervention [14]. The RCTs by Foster et al. and Duncan & Earhart measured at four time points (0, 3, 6, 12 months; intervention: 12 months) [30, 31]. In contrast, in the case study by Kaski et al., the outcomes were measured across the intervention in addition to a questionnaire which was completed by the dance part-ner before and after the dances [34].- Gait has also been reported using spatiotemporal parameters (velocity, stride length) during backward, single task forward, and dual task forward, in some of these studies (for example, Duncan 2012, Hackney 2010, Duncan 2014), but this was not commented on. Please add a sentence or two to summarize those findings across studies.
-I agree. I add a paragraph for Gait velocity in the results section: While five studies which assessed gait velocity did not found significant improvements, changes, and/or differences [9, 22, 32, 33, 35], the study by Duncan & Earhart (2012) found significant improvements in pre-ferred forward walking velocity (not for fast-as-possible walking) and dual task walking ve-locities within the AT group [30]. Significant improvements on gait velocity were also report-ed for comfortable walking velocity and fast -as-possible walking velocity after 10 weeks of AT intervention with partnered tango as well as non-partnered tango in the RCT by Hackney & Earhart (2010) [21].- In the results section, the authors state that "Two studies reported of cognitive functioning [31, 16], but did not find significant differences between the groups." However, earlier in the manuscript (p4, line93), they state "AT may lead to an improvement of spatial cognition [ ]". Both sentences refer to the same reference ([16]). In that study, spatial working memory improved with tango only. Please update to reflect this. -I agree. I corrected it in the results section (cognitive measures) to: Two studies reported on cognitive functioning [14, 29]. Romenets et al. found a non-significant trend towards improvements in individuals participating in the tango group in comparison to individuals in the self-directed exercise group [29]. McKee reported a significant improvement on spatial cognition in the tango group compared to the control group [14].- Discussion Page 17, lines 369-370: "[ ] AT as an optional intervention". Re-word this since all interventions are optional. Perhaps a "potential intervention" or "adjunct intervention" is more appropriate. -I agree. I corrected it to potential intervention.- Page 18, lines 387-391: The sentence at the end of the top paragraph and the start of the next paragraph are essentially the same. Page 18, lines 400-401: Use of the Fullerton Advanced Balance Scale was not mentioned previously for this included study and should be moved up to the results section. -I agree. I added the paragraph balance (subjective) in the results section.- Page 19, lines 406-408: "[ ] summarized that the greatest effects with new therapeutic concepts (included dance therapy) can be inter alia expected on postural instability." I'm not sure what this sentence is indicating. -After restructuring and major changes in the discussion section the sentence was removed.-
Page 21, lines 454-455: "[ ] AT has a high potential in the therapy of PD also with regard to long-term participation of patients to worsening of symptoms." The link the authors are drawing between continuing participation and worsening symptoms over time is unclear. -I agree. After restructuring and major changes in the discussion section the sentences were removed.- Page 21, lines 474-475: "[ ] this might be due to the fact that PD is a progressive disease, and thus strong treatment effects are rather unlikely." I disagree. People with Parkinson dis-ease and other progressive disorders can demonstrate substantial treatment effects with a wide variety of different kind of interventions (pharmacological, surgical, physical/exercise). I do not think the progressive nature of a disease precludes the ability to improve substantially with intervention, particularly within acute time frames like the ones studied (e.g. approximately 12 weeks). -The sentence was removed.- Page 22, line 478: There is a typo within the direct quote from a reference. "individuals" should be "individual". Please note, as proposed by the reviewers, there are major changes in the structure of the background and discussion section. All changes are highlighted in the text. For better clarity I did not highlight the changes with regard to the structure in the background and the discussion section. The two sections should be read as a whole, because of major changes. In hope that you will assess this revised paper suitable for publication in BMC Neurology. We look forward to hearing from you at your earliest convenience. I remain with best wishes (on behalf of all authors) Sincerely, Désirée Lötzke, MSc. Please address all correspondence to: Désirée Lötzke, desiree.loetzke@uni-wh.de