FerreiraandLuizChineseMedicine2013,8:24 http://www.cmjournal.org/content/8/1/24 RESEARCH Open Access Role of dermatomes in the determination of therapeutic characteristics of channel acupoints: a similarity-based analysis of data compiled from literature Arthur S Ferreira1* and Alexandre B Luiz2 Abstract Background: Analysis of therelationshipbetween thenervous system anatomy and thetherapeutic characteristics ofall acupuncturepoints inthe channel network may provide new insights onthephysiological mechanisms underlying acupuncturestimulation for prevention, treatment, and rehabilitationpurposes.This study investigates theassociation between the similarity ofacupoints’ dermatomes,traditional actions, and contemporary indications. Methods: Channel acupoints had their characteristics annotated from a literature review offour topographic atlases ofChinese medicine and one atlas of human anatomy: initialsof thechannel’sname (n=14),sequential number in thechannel(n=67), acupoint’sname (n=361), dermatomes related to perpendicular needle insertion (n=31), traditional actions (n=848), and contemporary indications (n=1143). Jaccard’ssimilarity coefficient quantified the similarities between dual acupoints. All dual acupoints were evaluated to generate similarity matrices for each nominal variable. Cross-tables were generated bysimultaneous classification of variables into levels of similarity withrespect to:dermatomes versus traditional actions,dermatomesversus contemporary indications, and traditional actions versus contemporary indications. Goodman-Kruskal γ and Rousson γ*2were calculated based oncross-tables, bootstrap and permutated samples to evaluate theassociation and determinationcoefficient between variables, respectively. Results: Significant associations were observed between levels ofsimilarities of dermatomes and traditional actions (γ=0.542; P<0.001), dermatomes and contemporary indications (γ=0.657; P<0.001), and traditional actions and contemporary indications (γ=0.716; P<0.001). Similarities ofdermatomes explained 16% of the variance of traditional actions and 25% of contemporary indications. Traditional actions explained 30% of thevariance of contemporary indications. The association between traditional actions and contemporary indications was the highest one (γ=0.716, 95% confidence interval(95%CI)=[0.715; 0.719]), followed by the associationbetween dermatomes and contemporary indications (γ=0.622, 95% CI=[0.621; 0.623]), and between dermatomes and traditional actions (γ=0.446, 95% CI=[0.444; 0.447]), all withP<0.001. Conclusions: The similarityof dermatomes between dual acupointspartiallydetermined the similarity of traditional actions and contemporary indications, therefore dermatomes partially determine thetherapeutic efficacy ofacupuncture. *Correspondence:[email protected] 1LaboratoryofComputationalSimulationandModellinginRehabilitation, PostgraduateProgramofRehabilitationScience,CentroUniversitário AugustoMotta,PraçadasNações34,3ºandar,Bonsucesso,RiodeJaneiro, Brazil Fulllistofauthorinformationisavailableattheendofthearticle ©2013FerreiraandLuiz;licenseeBioMedCentralLtd.Thisisanopenaccessarticledistributedunderthetermsofthe CreativeCommonsAttributionLicense(http://creativecommons.org/licenses/by/2.0),whichpermitsunrestricteduse, distribution,andreproductioninanymedium,providedtheoriginalworkisproperlycited. FerreiraandLuizChineseMedicine2013,8:24 Page2of12 http://www.cmjournal.org/content/8/1/24 Background application of acupuncture might balance sympathetic Context and parasympathetic activities. Cheng [21] suggested that Chinese medicine is one of several traditional medical in ‘many cases’ the acupoints have a neuroanatomical systems practiced by physicians, physiotherapists, nurses, relationship to Western medicine. Sánchez-Araujo et al. nutritionists, and other healthcare professionals as a [22] proposed a distinction between a ‘meridian-derived’ coadjutant intervention or even as the single therapeutic anda‘neurobiology-derived’effectsdependingonwhether intervention [1] for disease prevention, treatment or the therapeutic effects of acupoints were related to the rehabilitation [2]. Despite of a large amount of research corresponding zangfu [internal organs] or dermatome, on acupuncture with specific applications such as acu- respectively. These authors performed a partial litera- puncture-induced analgesia [3], the biomedical mecha- ture compilation and found that acupoints effects for nismsrelatedtoitstherapeuticefficacyremainunclearfor any dermatome are remarkably similar regardless of manymorbidconditions[4]. their corresponding channel [22]. Recently, Silva [23] In Chinese medicine (CM) theory, acupoints are suggested minor corrections to the optimal derma- defined as skin loci where vital substances qi and xue tomes of shu acupoints to stimulate the internal can be manipulated [5]. A philosophy-guided, explora- organ function. tory analysis of the body surface area (BSA) with conse- Most of those studies were limited to one or few quent systematization of the jingmai [channel network] acupoints located in one or few body parts or chan- was proposed [5]. The number of acupoints rapidly nels, and extrapolation of the results to all channels’ increased from 160 on the Yellow Emperor’s Inner network might not be not accurate. Furthermore, the Classic (Han dynasty, 206 BC-220 AD) to 349 on the applied methods only investigated the anatomical sub- Systematic Classic of Acupuncture and Moxibustion strate of acupoints but not the relationship between (Jin dynasty, 265–420) [5]. The 361 acupoints used in anatomical and therapeutic characteristics attributed clinical practice today [6] were already described on to acupoints. the Acupuncture and Moxibustion Feng-Yuan (Qing RecurrentutilizationofacupointsbymanyCMscholars dynasty, 1644–1911). As a consequence, an increase led to the discovery and establishment of acupoints’ trad- inthenumberofacupointsresultsina‘high-densitymesh’ itional actions, which were combined to their previous of acupoints for a given body surface area (BSA), charac- known ones. Likewise, clinical practice and scientific terized by a decreased inter-acupoint distance – not only research led to a new set of contemporary indications of onthesamechannelbutalsobetweenadjacentones. acupoints [5]. Scientific evidence suggested that channel- Both scientific definition and anatomical substrate of based therapies could treat several morbid conditions acupoint remains debatable [7-16]. The correspondence [1,4], but acupoints’ specificity regarding treatment have to a dermatome pattern [7], the presence of neurovascu- been questioned [24,25]. Clinical studies showed either a lar bundles [8,9], different types of terminal nerves large variability inacupoint selectionfor the same clinical [9-11],and areduced skinelectric impedance [12,13] are condition [26] or similar effectiveness between sham and amongst the most common characteristics attributed to verum acupuncture [1,27]. Additionally, a recent review acupoints [14,15]. The material basis of acupuncture is considered the specificity of acupoints as controversial the nerves since the nervous system is the common fac- despite some scientific evidence [28]. Although acupoints tor between many scientific evidence on acupuncture’s were commonly considered as small cutaneous region, it efficacy [16]. wasfoundalargevarianceontheskinsurfaceareaforthe A dermatome refers to a cutaneous area innervated by exactlocationofacupointsbyCMexperts[29].Thislarge one nerve element, specifically nerve root, dorsal variation may stimulate different skin loci – and possibly ganglion or spinal segment [17]. Either inconsistent or different dermatomes inducing unexpected or new thera- incomplete results were obtained by several studies. A peutic effects. On the contrary, the high-density mesh of study on the segmental innervation of acupoints acupointsinthechannelnetworkmayresultinthestimu- observed that the needle stimulation of ‘correct’skin loci lation of common dermatomes for acupoints lying ‘close for acupoints Yanglingquan GB34,Yinlingquan SP9, and enough’toeachother,inducingtherapeuticcharacteristics Xiangu S43 resulted in zones of hyposensitivity confirm- similartonearbyacupoints. ing to a dermatome pattern of L3 and L5 [7]. Mayor This study aims to investigate the association between [18] found no justification based on dermatomes for the similarity of acupoints with respect to their derma- selecting the shu [traditional transporting] and mu tomes, traditional actions, and contemporary indications [alarm]acupointsforanorganratherthansomeothershu by a similarity-based analysis of their literature content. or mu acupoints associated with another organ. Cabioglu It was hypothesized that the strength of similarity of et al. [19,20] investigated both shu and Huato-Jiaji dermatomes of dual acupoints determines the strength acupoints and mu acupoints and suggested that the of their similarity concerning either traditional actions FerreiraandLuizChineseMedicine2013,8:24 Page3of12 http://www.cmjournal.org/content/8/1/24 or contemporaryindications,suggesting arole ofderma- the state-of-the-art knowledge on acupoints; (2nd) the tomes for determination of the therapeutic characteris- contemporary indications of acupoints described in the ticsofchannelacupoints. literature reflected the state-of-the-art knowledge on acupoints; (3rd) the dermatome information in these Methods atlaseswasaccuratelydescribed. Studydesignandassumptions This literature review study was divided into dataset Computationalresources generation, processing, and analyses (Figure 1). Informa- Thecompletedatasetofacupointswasshown(Additional tion from acupoints was compiled from four topo- file 1, in Portuguese language). Algorithms for dataset graphic atlases of CM acupoints [30-33] and one atlas of processing, dataset analysis and statistical analysis were human anatomy [34]. Dermatomes related to acupoints implemented in Maple 15 (Waterloo Maple Inc., USA) were obtained from only one of those atlases [30] (Additional file 2). The corresponding worksheet in edit- because of its systematic description of the anatomy of ablemodewasavailable(Additional file3).All algorithms needle insertion. Traditional actions and contemporary were executed on a 2.26 GHz Intel® Core 2 Duo micro- indications of acupoints were firstly annotated from the processor with 2 GB RAM running Mac OS X 10.8.2 same atlas [30] and completed with information from (AppleInc.,USA). the other three atlases [31-33]. The anatomical des- criptions on those atlases were verified with a human Datasetgeneration anatomy textbook [34], chosen due to its systematic Acupoints had the following characteristics annotated as description. nominal variables in the raw dataset: capitalized initials In this study, we assumed that (1st) the traditional of the channel’s name (n=14), sequential number in the actions of acupoints described in the literature reflected channel (n=67), acupoint’s name (n=361), dermatomes Figure1Flowchartofthestudy.Theflowchartofthestudywasdividedintostages:datasetgeneration,datasetqualitycontrol,computation ofdualacupoint’ssimilarity,andstatisticalanalysis. FerreiraandLuizChineseMedicine2013,8:24 Page4of12 http://www.cmjournal.org/content/8/1/24 related to perpendicular needle insertion (n=31), trad- Datasetanalysis:computationofdualacupoints’similarity itional actions (n=1180), and contemporary indications Skin loci of acupoints were usually supplied by two or (n=1567), and other information not used in this study moredermatomesbecauseofsuperimpositionofcutane- (circulation level, channel’s six-level theory, moxibustion ous innervation, and thus acupoints shared dermatomes duration, needle insertion depth, and myotome). The depending on whether or not they were close to each first three variables were concatenated to generate full other in the channel network. Likewise, both traditional and unique identification of acupoints, e.g. CV21 Xuanji. actions and contemporary indications were sets of terms Deviations from the anatomical norm on dermatomes as describing the expected therapeutic usefulness of acu- well as missing data regarding local innervation on the points, which might also be shared with other acupoints CM atlases were checked by the human anatomy atlas eithercloseenoughoraparteachotherduetotheirlocal [34]. Nominal variables that present with one or more orsystemiceffects,respectively[5].Therefore,ameasure values per acupoint (dermatomes, traditional actions, and of co-occurrence of terms was selected to quantify contemporaryindications)wereannotated as a single text similarities between dual acupoints based on these entryformattedwithcommaseparatedvalues(CSV). nominal variables. For each dual acupoints i and j, the Jaccard’s similarity coefficient J [35] was calculated i, j Datasetprocessing:qualitycontrolofthechannel asfollowing: acupoints’dataset The natural language in the consulted literature may eaxcthioibnits aanmdbciognutietimespoirnaryteinrmdiscatcioonnsceorfnaincugpotirnatdsi,tisouncahl Ji;j ¼NiþNNi;jj−Ni;j ð1Þ as plurals, synonyms, capitalized words, and use of different prepositions. Therefore, the raw dataset passed where N is the number of terms contained in both acu- ij atwo-steps procedure to produce alist with a controlled points,andN andN arethenumberoftermscontained i j vocabulary to ensure high-quality data before statistical in either acupoints i or j (i=1, 2, …, 361 and j=1, 2, …, analysis: 361) members of the dual acupoint. Coefficient J indi- i, j (1st) All typos due to manual annotation were cates the strength of similarity between acupoints i and j corrected by the worksheet text processor dictionary. and ranges from perfect dissimilarity (J =0) to perfect i, j Misspelled terms were corrected and additional spaces similarity (J =1). For instance, the lower boundary i, j before comma, between words, and after commas and condition for dermatomes was satisfied by dual words were removed. Capitalized words were converted acupoints that did not share any dermatomes (perfectly tolowercaseones. dissimilar dual acupoints), while the upper boundary (2nd) Each data column containing traditional actions condition is satisfied by dual acupoints that shared all and contemporary indications – from all acupoints was dermatomes (perfectly similar dual acupoints). The same firstly merged and then separated into individual terms reasoning applied to traditional actions and contempor- for generating two independent lists of unique terms. aryindicationsasseparatedvariables. Both lists were simultaneously inspected by two ob- The dataset defined 130,321 dual acupoints in a servers (ABL andASF)for repetition ofterms and ambi- symmetrical matrix, including the elements at the main guities were minimized as follows. Synonymous were diagonal. Similarity matrices were calculated for the replaced by the same exact term because they represent following variables considering all dual acupoints: thesametherapeuticaction(e.g.“strengthensthelumbo- dermatomes (D ), traditional actions (T ), and 361,361 361,361 sacral region” and “strengthens the lumbar region” were contemporary indications (C ). Acupoints in all 361,361 replaced by the latter term). Composite terms were split similarity matrices were arranged with the rostral-caudal into individual terms because they comprised different sequenceofdermatomeslevel: C2,C3,…,S4,S5.Within therapeutic actions that co-occur (e.g. “tonifies qi and the same dermatomes the acupoints were arranged in xue” was replaced by “tonifies qi, tonifies xue”). This the sequence of qi circulation among channels: du mai second step was repeated until both observers did not [Governing vessel], ren mai [Conception vessel], fei change either lists, counting up four rounds of dataset [Lung], dachang [Large Intestine], wei [Stomach], pi processing. [Spleen], xin [Heart], xiaochang [Small Intestine], pang- All changes per round were indicated in the guang [Bladder], shen [Kidney], xinbao [Pericardium], Additional file 1, as well as the final list of terms. After sanjiao [Triple Burner], dan [Gallbladder], and gan this quality control procedure, the quantities of unique [Liver] [5]. This ‘dermatome/channel’ arrangement terms describing the traditional actions and contempor- allowed the selection of corresponding pairs of dual ary indications in the processed dataset were reduced by acupoints’ similarity in two different matrices by the 28%(n=848) and27%(n=1143), respectively. same indexing. FerreiraandLuizChineseMedicine2013,8:24 Page5of12 http://www.cmjournal.org/content/8/1/24 Statisticalanalysis pairs of variables classified by their levels of similar- Literature compilation was characterized by descriptive ity. P values were calculated as the proportion of the analysis using absolute and relative frequencies. The Goodman-Kruskal γ values generated in the permuta- top-five most frequent traditional actions and con- tion test that was larger than the Goodman-Kruskal γ temporary indications were identified. Also, top-five co- calculated from the original cross-tables [39]. occurrence of terms in dataset were described for the following pairs: (1) traditional versus traditional actions; Results (2) traditional actions versus contemporary indications; Exampleacupoints and(3)contemporaryversuscontemporaryindications. In the following examples, the texts in italic format Similarity maps were generated from matrices D, T, representedtermssharedbetweenacupoints.Considered and C in dermatome/channel arrangement and after the CV21 Xuanji (i = 49) and CV22 Tiantu (j = 50) as a shuffling to visualize the effect of sequence on the simi- first dual acupoint, they were described in dataset by larity map. Grey-scaled mapping was used to indicate dermatomes: CV21 = {C3, C4} and CV22 = {C2, C3}. low (=blackish)and high (=whitish)values of similarity, Their respective traditional indications were: CV21 = respectively. {regulates the qi, alleviates the asthma, alleviates the Cross-tables were generated from similarity matrices cough, harmonizes the thoracic qi, harmonizes the qi with respect to: (a) dermatomes versus traditional ac- inversion} and CV22 = {tonifies fei-qi, dominates qi tions (D x T ); (b) dermatomes versus contemporary inversion, promotes fei-qi circulation, alleviates the i, j i, j indications(D xC );and(c)traditional actions versus asthma, eliminates heat, remove humidity, befits the i,j i,j contemporary indications (T x C ). Each cross-table throat, refreshes the throat, clear the voice, stops the i, j i, j was established by simultaneous classification of all J cough}. Also, their contemporary indications were: i, j values from the two matrices into the following categor- CV21 = {asthma, chronic bronchitis, tonsillitis, pulmon- iesrepresenting thestrength ofsimilarity: ary emphysema, pleurisy, spasm of the oesophagus, (1st) 0.000|—0.167:Null ornegligible; spasm of the stomach, difficult deglutition, phlegm, aph- (2nd) 0.167|—0.333:Veryweak; ony} and CV22 = {asthma, chronic bronchitis, acute (3rd)0.333|—0.500:Weak; bronchitis, pharyngitis, hiccup, acute cough, chronic (4th) 0.555|—0.667:Moderate; cough, aphony, phlegm, sudden dysphonia, difficult (5th) 0.667|—0.833:Strong; deglutition, goitre, pertussis, reflux, vocal cord dis- (6th) 0.833|—1.000:Verystrong. eases, sudden snoring}. Therefore, the calculated Perfect similarity was not included in the last class Jaccard’s similarities were D = 0.33, T = 0.07, 49,50 49,50 because acupoints with J =1 were found only in the and C = 0.24. i, j 49,50 main diagonal of matrices. Goodman-Kruskal γ [36] was Considered another dual acupoint with the same calculated from the cross-tables to evaluate the mono- acupoint CV21 Xuanji (i = 49) but with LU6 Kongzui tonic linear-to-linear association between the strength of (j = 58). Acupoint LU6 was described by dermatomes dual acupoint similarities. The squared value of the LU6 = {C5, C6}, its traditional indications were LU6 = Rousson γ* (a variant of Goodman-Kruskal γ [37]) was {reducesfever,descendsfei-qi,regulatesfei-qi,stopshaem- calculated to represent the coefficient of determination orrhage,alleviatesthecough,alleviatesthedyspnoea},and between the ordinal variables, i.e. the percentage of its contemporary indications were LU6 = {headache, dys- variation in one variable that was explained by the phonia,cough,throatpain,elbowpain,fever,tuberculosis, other variable. acuteasthmaticcrisis,epistaxis}.Therefore,the calculated Statistical significance of Goodman-Kruskal γ were Jaccard’s similarities were D = 0.00,T = 0.10, and 49,58 49,58 obtained based on the analysis of 95% confidence inter- C =0.00. 49,58 vals (95% CI) estimated by bootstrap resampling with B=1000 replications of dual acupoints on the similar- Descriptiveanalysisofliteraturecompilation ity matrices D x T , D x C , and T x C . Both frequencies and co-occurrences of terms were i, j i, j i, j i, j i, j i, j Median and confidence intervals for the Goodman- presented in Table 1. The most frequent traditional Kruskal γ and Rousson γ*2 were estimated based on action was “dispels wind” (n=140, 38.8%) and the most the percentile method (2.5th and 97.5th) of the boot- frequent contemporary indication was “headache” strap samples [38,39]. Permutation test was also per- (n=100, 27.7%). Co-occurrences of traditional versus formed by bootstrap resampling with B=1000 traditional actions, traditional actions versus contem- replications of different pairs of acupoints in the simi- porary indications, and contemporary versus contem- larity matrices D x T , D x C , and T x porary indications represented n=11579, n=42928, i, j k, q i, j k, q i, j C to test the null hypothesis that there was no lin- and n=39039 unique dual terms, respectively. Dual k, q ear association (γ=0; P≥0.05) between each tested terms “dispels wind–dispelsheat” (n=77, 21.3%), “dispels FerreiraandLuizChineseMedicine2013,8:24 Page6of12 http://www.cmjournal.org/content/8/1/24 Table1Descriptiveanalysisoftermsfromtheliteraturecompilation Category Terms N % Traditionalactions (1)Dispelswind 140 38.8 N=848terms(norepetition) (2)Dispelsheat 136 37.7 (3)Reducesfever 90 24.9 (4)Calmsthemind 81 22.4 (5)Eliminatespain 68 18.8 Contemporaryindications (1)Headache 100 27.7 N=1143terms(norepetition) (2)Lowbackpain 95 26.3 (3)Asthma 78 21.6 (4)Vomiting 73 20.2 (5)Convulsion 71 19.7 Traditionalvs.traditional (1)Dispelswind–dispelsheat 77 21.3 N=11579pairsofterms(norepetition) (2)Dispelswind–eliminatespain 48 13.3 (3)Dispelswind–reducesfever 47 13.0 (4)Dispelsdamp–dispelsheat 40 11.1 (5)Calmsthemind–dispelsheat 36 10.0 Traditionalvs.contemporary (1)Dispelswind–headache 69 19.1 N=42928pairsofterms(norepetitions) (2)Dispelsheat–headache 60 16.6 (3)Dispelswind–vertigo 45 12.5 (4)Calmsthemind–epilepsy 43 11.9 (5)Dispelswind–convulsion 42 11.6 Contemporaryvs.contemporary (1)Asthma–cough 49 13.6 N=39039pairsofterms(norepetition) (2)Convulsion–epilepsy 45 12.5 (3)Headache–vertigo 44 12.2 (4)Asthma–bronchitis 42 11.6 (5)Convulsion–schizophrenia 38 10.5 wind–headache” (n=69, 19.1%), and “asthma–cough” variables (top-left cell in each cross-table). A decrease in (n=49,13.6%)werethemostfrequentones,respectively. the frequency of acupoints as a function of decreasing levels of similarity calculated from dermatomes versus Similaritymapsofdermatomes,traditionalactions,and traditional actions, dermatomes versus contemporary contemporaryindications indications, and traditional actions versus contemporary Similarity maps for matrices D, T, and C (left, middle, indications. Only a minority of dual acupoint was right, respectively) in dermatome/channel arrangement labelledasverystrongsimilarity. and after permutation (top and bottom row, respect- As compared to the permutation test, the Goodman- ively) wereexhibitedin Figure 2.Thewhite diagonal line Kruskal γ (Table 2) revealed a significant association evidences the perfect similarity between dual acupoints betweenacupointssimultaneouslygroupedbythestrength where i=j. The similarity maps arranged in dermatome of similarity of dermatomes and traditional actions sequence showed several high-similarity small clusters (γ=0.542; P<0.001), as well as by the strength of (whitishregions) ofdualacupointsspread inalargelow- similarity of dermatomes and contemporary indica- similarity background area (blackish regions). Such tions (γ=0.657; P<0.001). A significant association clustering was not evident on the similarity maps after between acupoints simultaneously grouped by the permutation oflinesandcolumns,ifexistent. strength of similarities of traditional actions and contem- poraryindications(γ=0.716;P<0.001)wasalsoobserved. Associationbetweendermatomesandtherapeutic Similarities of dermatomes explained approximately 16% characteristicsofchannelacupoints (bootstrapγ*2=10.5%[10.4;10.6])ofthevarianceoftrad- Cross-tables from simultaneous classifications of all dual itionalactionsand25%(bootstrapγ*2=21.7%[21.6;21.8]) acupoints into levels of similarity were presented in ofcontemporaryindications.Traditionalactionsexplained Table 2. Most of dual acupoints presented null to negli- 30% (bootstrap γ*2=30.2% [30.1; 30.5]) of the variance of gible level of similarity in all tested combinations of contemporaryindications. FerreiraandLuizChineseMedicine2013,8:24 Page7of12 http://www.cmjournal.org/content/8/1/24 Figure2Similaritymapsofchannelacupointscalculatedbasedondermatomeinformation,traditionalactions,andcontemporary indications.Toprow:Similaritymapsofdermatomes(left),traditionalactions(middle),andcontemporaryindications(right)arrangedin top-downsequenceofdermatomesandchannels.Bottomrow:Similaritymapsofdermatomes(left),traditionalactions(middle),andcontemporary indications(right)arrangedaftershuffling.Grey-scalecoloursindicatevariationsfromlow(blackish)tohigh(whitish)valuesofsimilarity. The bootstrap resamples also showed significant acupoints’ anatomical and therapeutic characteristics for differences (all P<0.001) between all pairs of variables elucidating the role of the nervous system in the acu- in cross-tables (Table 2). The association between the puncture stimulation. We found that the dermatomes strength of similarity of traditional actions and contem- played a role in the determination of both traditional porary indications was the highest (bootstrap γ=0.716, actions and contemporary indications of channel acu- CI 95%=[0.715; 0.719]), followed by the association of points,basedonthefollowingthreemainresultsfromthis thestrengthofsimilarityofdermatomesandcontempor- study. ary indications (bootstrap γ=0.622, 95% CI=[0.621; 0.623]), and finally between the strength of associ- Similarityofdermatomespartiallydeterminesthesimilarity ation of dermatomes and traditional actions (bootstrap oftherapeuticcharacteristicsofchannelacupoints γ=0.446,CI95%=[0.444;0.447]). The results suggested that two acupoints shared derma- tomes, traditional actions, and contemporary indications Discussion in a directly proportional variation that the explained In this study, we investigated the association between variation was higher for contemporary indications than the similarity of all channel acupoints with their derma- for traditional actions. Those associations, besides being tomes,traditional actions,andcontemporaryindications. moderate-to-strong and accompanied by moderate coef- To our knowledge, this is the first study to simul- ficients of determination, were clinically relevant since it taneously explore the relationship between all channel represented the analysis of all acupoints on the channel FerreiraandLuizChineseMedicine2013,8:24 Page8of12 http://www.cmjournal.org/content/8/1/24 Table2Cross-tablesofdualacupointsclassifiedbysimilarity Dualacupointsimilarityon: Traditionalaction Category Nulltonegligible Veryweak Weak Moderate Strong Verystrong Dermatome Nulltonegligible 118872 5763 440 23 12 0 Calculated:γ=0.542;γ*2≈16% Veryweak 223 14 5 0 0 0 Bootstrapestimation:γ=0.446[0.444;0.447] Weak 1460 187 27 2 2 0 Moderate 2166 372 58 3 0 0 Permutationtest:γ=0.002[0.001;0.006] Strong 259 64 8 0 0 0 Verystrong 0 0 0 0 0 0 Contemporaryindication Dermatome Nulltonegligible 120799 4083 206 22 0 0 Calculated:γ=0.657;γ*2≈25% Veryweak 215 27 0 0 0 0 Bootstrapestimation:γ=0.622[0.621;0.623] Weak 1447 212 17 2 0 0 Moderate 2197 379 17 2 2 2 Permutationtest:γ=−0.001[−0.006;0.002] Strong 254 75 2 0 0 0 Verystrong 0 0 0 0 0 0 Contemporaryindication Traditionalaction Nulltonegligible 119094 3706 172 6 0 2 Calculated:γ=0.716;γ*2≈30% Veryweak 5444 898 48 8 2 0 Bootstrapestimation:γ=0.716[0.715;0.719] Weak 360 160 16 2 0 0 Moderate 12 8 6 2 0 0 Permutationtest:γ=0.000[−0.001;0.005] Strong 2 4 0 8 0 0 Verystrong 0 0 0 0 0 0 network. These results were explained by the spatial [7,18-23]. Discrepancies in the observed relationship arrangement of dermatomes and channels on the body between dermatomes and therapeutic characteristics of surface,andthe strength ofdualacupointssimilarity. acupoints were due to the applied methods for inves- The observed association might be attributed to the tigation of the relationship and the coverage of channel differences in the organization of the channel network acupoints, while most previous studies [18-23] investi- and dermatomes over the body surface. On the one gated acupoints located in the trunk (i.e. shu, mu and hand, the channel network is predominantly organized Huatuo-Jiaji acupoints), where a major spatial relation- along the vertical axis of the body [5]. On the other ship between the acupoint skin loci and the visceral hand, the dermatomes system predominantly follows a efferentinnervation wasexpected. rostral-caudal distribution of the nervous system with The relationship between the high-density mesh of horizontal body segments [34,40]. Hence, there was no acupoints and the therapeutic characteristics of acu- theoretical link between the organizational systems of points should be focus of further in-deep investigation. channels and dermatomes to generate expectations on For instance, considered a BSA=1.79 m2 of a subject high similarities between dermatomes and traditional with height=1.70 m and weight=70.0 kg [41]. Consid- actions of dual acupoints. The small number of dual ered also the total of acupoints spread over the BSA as acupoints that actually present some degree of similarity 295 (25 midline+2 × 135 bilateral) in the Yellow basedonthese variablescouldbeaconsequenceofthese Emperor’s Inner Classic and as 670 (52 midline+2 × 309 systematic differences, and supported the partial role of bilateral)intheGoldenMirrorofMedicine[5].Therefore, the dermatomes in the determination of traditional the average skin area of a subject for finding an acupoint actions of acupoints. Nevertheless, the observation that wasreducedfromapproximately61cm2(7.8×7.8cm)to the association between dermatomes and contemporary 27 cm2 (5.2 × 5.2 cm) in the referred classic books. This actions were stronger than between dermatomes and average area would be much lesser, around 12 cm2 (3.5 × traditionalactions requiredfurtherclarification. 3.5 cm), if 386 ‘new’ and ‘off-channel’ bilateral acupoints The partial role of dermatomes observed in this study were also summed [5]. Although these values were not consideringallchannelacupointsresolvedthe contradic- representative for all acupoints because of the actual tion of studies regarding a subset of acupoints showing channel paths along the body surface and the variable negligible, partial, or strong relationship between der- inter-acupoint distance along channels, they provided matomes and therapeutic characteristics of acupoints estimations on how close the acupoints wereon the body FerreiraandLuizChineseMedicine2013,8:24 Page9of12 http://www.cmjournal.org/content/8/1/24 surface – as a matter of fact, some acupoints are indeed the needle and connective tissue [47,48], and a significant located closer than this distance. In combination with a higher pull-out force for needle extraction [49]. previousstudy[29]showingthatthelocationofacupoints Altogether, these sensory stimuli excite several afferent by CM experts demonstrated variances in range 2.7 cm2 nerve types [50] as evidenced by the variety of subjective to 41.4 cm2 for their location, many ‘newly discovered’ reportofthedeqisensation[51].Althoughitwasshowna acupoints after the Yellow Emperor’s Inner Classic could somatotopic representation of some acupoints in the be mainly due to anatomical variations on the exact humanprimarysomatosensorycortex[52],theautonomic locationofacupointslyinginsidethesamedermatome.In responses to a nociceptive stimulus is characterized by view of this, the investigation of the actual distance patterns of cardiovascular and motor changes [53]. Thus, between dual acupoints over the BSA and its relationship future experimental studies should investigate if stimula- withtherapeuticcharacteristicsofacupointsisnecessary. tion of acupoints with similar dermatomes may actually Much effort was directed into research on pattern evoke proportionally similar physiological responses in differentiation for improvement of the efficacy of CM internal organs, and concentrate on how it is possible to intervention [42], including many automated methods stimulate the same dermatomes to obtain different for diagnosing a patient [43]. Based on the results of this therapeutic actions with applications to contemporary study, researchers should also consider the significant indications. relationship between dermatome and therapeutic char- acteristics ofacupointswhen planning controlled clinical Analysisofliteraturecompilationcontent:co-occurrence trials on the efficacy of acupuncture stimulation – and ofterms probably other channel-based therapies. The high “Dispels wind” was the most frequent traditional action density-mesh of acupoints on the BSA and the variation among all acupoints. Wind is the common source for on the exact location of acupoints suggested a larger many diseases [54] and is characterized by manifes- distance between verum and sham acupoints for testing tations with sudden arousal and quick changes, such as theirtherapeutic effects. muscle spams, vertigo and pain that often changes its location [5]. Wind is not only the external cause of a Associationbetweentraditionalactionsand pattern itself, but also may help other climatic factors contemporaryindicationsofacupoints such as heat (huo) to penetrate the exterior body [5] – The level of similarity between dual acupoints based on notice that “dispels heat” occupies the 2nd position as traditional actions partially determined the level of the top-cited unique term. Likewise, the co-occurrence similarity based on the contemporary indications, being of “dispels wind–dispels heat” as the most frequent dual this association the stronger one. The pattern differenti- traditional actions was neither surprising. These results ation process in CM was used to guide the treatment of reflected either the relevance of the traditional concepts many diseases from all body systems [42,44]. For of Six Excess to characterize patterns and the prescrip- instance, target-organ damage in patients with systemic tion of acupuncture intervention based on pattern arterial hypertension was strongly associated to specific differentiation. patterns in CM [45] and might aid the selection of the Headachewasthemostfrequentcontemporaryindica- best therapeutic intervention with respect to the Inte- tion, while “asthma–cough” was the most frequent dual grative Medicine. Also, it was shown that post-stroke term. Three of the top-five terms – headache, low back patients exhibited frequency distribution of specific pat- pain, and vomiting – were amongst the symptoms for terns as compared to healthy subjects [46]. Therefore, which acupuncture was proved through controlled trials the either empirical or systematic methods used in the to be an effective treatment [4], whereas the 3rd top- consulted literature [30-33] for derivation of the con- ranked term asthma was listed a conditions for which temporary indications of acupoints suggested a more the therapeutic effect of acupuncture has been shown consistent relationship between these two therapeutic but for which further proof was required. The 5th top- characteristics than between each one and the derma- ranked term convulsion was listed under the conditions tomes – a relationship that is dependent of the biologic for which acupuncture may be tried provided the practi- phenomenon itself. Thisresult callsfor acareful revision tioner has special modern medical knowledge and and urgent update of contemporary CM literature that adequate monitoring equipment [4]. These findings describes therapeutic intervention for diseases without a reinforced the need for retaining only evidence-based clear evidence-basedscientificbackground. contemporary indications for education of health profes- The acupuncture stimulation comprises a nociceptive sionals onCM. stimulus from the combination of needle insertion The co-occurrence of “dispels wind–headache” might through the dermis and subcutaneous muscles, needle be explained by several factors. Firstly, headache and manipulationpromotingthemechanicalcouplingbetween many related disorders are among the most frequent FerreiraandLuizChineseMedicine2013,8:24 Page10of12 http://www.cmjournal.org/content/8/1/24 disorders estimated to occur in 47 % of the adult popu- books to acquire knowledge on acupoints’ anatomic and lation at least once a year [52], and any disturbance in qi therapeutic characteristics regardless of the source of circulation may result in headache [55], but in particular this knowledge. Despite the lack of a clear distinction the excess from external Wind and Heat, among others between real and noisy information, the results reflected [5]. Therefore, CM scholars might find acupoints that the current knowledge on the role of the dermatomes resulted in the promotion of a healthy flow of qi for for determining the therapeutic characteristics of amelioration of headaches as related to Wind and Heat acupoints. Future studies should test whether or not the as individual or combined factors. The underlying selection of a subset of therapeutic characteristics mechanisms of the therapeutic action of headache by (both traditional and contemporary ones) affected the acupuncture stimulation were still unclear and required similarity-based association between therapeutic char- furtherresearch. acteristics of acupoints and their respective derma- tomes, in special those subsets that were selected Implicationsforclinicalpractice based on high-quality scientific evidence. From the clinical point-of-view, the observed role of The assumption that the dermatomes were correct, dermatomes in the determination of therapeutic charac- constant, and the same in every subject must be teristics of acupoints reinforced the strategy of simultan- discussed as well. Such assumption might not be true eously selecting local, distant, and specific acupoints because of the variations among atlases of human anat- along with painful, ashi points [5]. The use of one or omy, mainly due to known differences in the methods more local acupoints over the same dermatomes might for assessment of their dermatome maps [17,41]. Like- evoke the ‘spatial summation’ phenomenon as observed wise, there were departures from the anatomical norm for pain perception [56]. The acupuncture stimulation of of dermatomes on individual subjects and variations one or more distant acupoints located in different throughout the subject’s life spam. Altogether, these dermatomes might cause the ‘whole system’ therapeutic criticisms might affect the association. Nevertheless, effect in which multiple targets at both visceral and cen- most health professionals probably disregardthese issues tral nervous systems were activated to promote homeo- during their acupuncture intervention. As the anatomy stasis. The use of one or more specific acupoints was science was also evolving into an evidence-based encouraged that the therapeutic characteristics were approach and new dermatome maps were being gene- effectiveinhigh-qualitycontrolledtrials. rated [40], the impact of dermatome variety should be consideredinfuturestudies. Studylimitations The natural language permitting ambiguities within Conclusions medical terms makes the development of an acupoints Thesimilarityofdermatomesbetweendualacupointspar- dataset challenging. The manual annotation used in this tially determined the similarity of traditional actions and workmightintroduceerrorsinthedescriptionsofthera- contemporaryindications,dermatomespartiallydetermine peutic characteristics of acupoints. Nevertheless, it is inthetherapeuticefficacyofacupuncturestimulation. believed that all typos were resolved and most of the ambiguities minimized after the revisions for quality control procedure. Additional files All traditional actions and contemporary indications were assumed to reflect the current knowledge and Additionalfile1:CompletedatasetofacupointsinPortuguese therapeutically effective. This assumption might not be (Brazil)language. true because many of the contemporary indications have Additionalfile2:Computationalroutinesforstatisticalanalysisof not been tested in double-blinded, controlled ran- acupointsdataset. domized clinical trials to be included as an actual Additionalfile3:Computationalroutinesineditablemodefor statisticalanalysisofacupointsdataset. contemporary indication to acupuncture [4]. Indeed, no explanations were provided in the consulted atlases concerning the source of the descriptions of therapeutic Abbreviations characteristics, i.e. consulted classic books, research AD:Annodomini;B:Numberofreplicationsinresampling;BC:BeforeChrist; studies, clinical experience, among others. Some of the BSA:Bodysurfacearea;C361,361:Similaritymatrixofvariablecontemporary indications;CI95%:95%confidenceinterval;CSV:Commaseparatedvalue; therapeutic characteristics were noise originated from D :Similaritymatrixofvariabledermatomes;J :Jaccardcoefficientof 361,361 i,j personal experience of the authors, placebo effect, trans- similaritybetweenacupointsiandj;N:Numberoftermscontainedin i lation errors, transcription errors, and typos. However, acupointi;Nij:Numberoftermscontainedinbothacupoints;Nj:Numberof termscontainedinacupointj;T :Similaritymatrixofvariabletraditional this assumption was valid since it simulated how health actions;γ:Goodman-Kruskalgam36m1,3a6;1γ*2:Squaredvalueofthevariantofthe practitioners used these atlases: they consulted such Goodman-Kruskalgamma.