ry,J xx{ Innervation and Pain Patternsof the Cenrical Spine IVikoloiBogduk In manyrespectsthe cervicalspinehasbeenlike a "poor relation" of the lumbar spine. Thcre have beenfew cxperimenral and pathologicstudiesof servicalpain syndromes.lnstead,conceptsrelatingto thecervicalspinehave beenbasedmainly on e.rtrapolations of daraon the lumbarspine.Becauseit was believedthat root compression by herniated discswasthecardinatcause of low backpainondsciatica,it wasassumcd thatcervicalpainandarmpainmust be due to the sam€sause.Yet suchextrapolations havcbeenmade,andlargely accepted,without rccognizingthar srructurallyand functionallythe cervical spineis quite differenrfrom rhe lumbarspinc. The cervicalspineis designed for mobiliry,andit is not subjectto thesame magnitudeof weighr-bearing forcesand bendingmomentsas is the rumbar joints areorienredin a differentplaneand spine.The cervicalzygapophyscal af,emore involvedin weight-bearing andlessin the resistance of torsionthan joints.Th1cervicaldiscsaremorefibrousanddiffer the lumbarzygapophyseal biochemicallyfrom lumbardiscs,randdischcrniationis far lessfrequentin rhe cervical spine than in the fumbarspine.3', Spondylosis is the most common parhologicchangein the cervicclspine.andthecervicalnerverootsare most commonlyaffectedby disc bulgesor osreophyrcs of the uncovenebralregion joints thanby frankor acuredisi prolapse.se and the.zygapophyseal . Becouseof theseanatomic,funcrionaland pathologicdifferencesin the cervicalspine,cervicalpainsyndromes shouldbeanalyzed andinrerpreted asa s€paraleentity rarher than beingviewedas equivalentto lumbarsyndromcs locatedat a more rqstrallevel of the vertebralcolumn. Spine PhysicalTherapyof rhe Centicaland Thoracic CERVICAL PAIN SYNDROMES or it may9:tll in associaNeckpainmayo..u, in isolated lymptgm' limbitself'painin the tionwithpainin,n. upp.r",fitU giJf., p"inin theupper canbeclassified into combinaiions various Hii""vit, th-ese chest,or headache. puin radicular and two basicpattroptrysiJ;;iffit, somaticpainsyndromes syndromes. Somaticpainsyndromesarethoseinwhichthcsourceofpainliesinon sVno1111 of thecervicalspine..Thcse moreof the muscuto;lirl"idelemcnts nervcroot involve do not and abnormalities *iitr n"urotogic arenotassociated or are thosein which compression naOicuiarpain slnOtomes , compression. irri'tationofspinalncrvesornerverootsis-thecauselfPain.andobjectiv of thescsyndromes' signsarea cardinalcomponent neurologic SomaticPain spinethat receivesa Neck pain canarisefrom anystnrcturein thc cenrical the innervationof the ccrvical nervesupply.Conr.quiiiiv,.."'"ppreciation of differentialdiagnocisof spineforms a foundaiionfor the interpreurionof the clrvicat pain sYndromes. that lie bchindthe The posterio,.t"rint, of the neckare thos€structures all inacrvatcdby These arc intervencbralforaminaand cervicalnerYeroots. lateral branchesof the The ncrves.lo spinal the dorsal mmi of ,n. ctt"l*l posterior.neekmusclessushas cervicaldorsalrami supplythc moresuperficial and spleniuscervicisand cervicis iliocostaliscervicis,ffi;ilri;"; "no."pitit, the deeperand The meoiat[ra]i"rrii or tr,. ceryicaloorsd rami supply capiris.ro capitisand and cervlcis moremedialmusclesof th,enecksuch.assernisfinatis cervical the nirvis also innervate multifidus and the t";;t;il";i;i-ti-itisc by innervated are musclcs zygapophyseat.loinrs;i;iFrit-t). The suboccipital ttJCf and C2 dorsalrami.ro structures in front of the The anterior elemcntsof the neck are those intervertebraldiscs'the onte' cervicalspinaln"t"ui.nJ includerhc cervical prevertebralmuscles'and the rior and posterior foisituOinalligaments,the prevcrtebrol anJaiianioaxi*loints and ttrcir liggments'The atlanro-occipitaf by thc ventral tfong"t .ttuiti' -unOcapiris)arJ inn"rvatcd also inner' musclesof thc i.tusr-E.rr other musclesin the neck . ii';;l"J rami of the cl "a"f and th€ slernoUV*ruicat ueniratrami are the scalenus'the trapezius' innervadon motor iheir receive ""i.0 Althoughrhelattertwo muscles cleidomastoid. two or three nJrve,.rheirsensorysupplyis-fromlhe.upper joints are accessory from the latcral atlantoaxial cervicalvenrral r"tiLi ttt. oGn,o...ipi6f anO ramirr(Fig' l'2)' ventral innervated,..p..,iuity lV ,[. Cf ond C3 the Cl anttC3 innervatedby r.gion ott The ligamen,t'oi'itr;'",frntoaxiat materof the dura the andthese,ot. n.*ir.also innervare sinuvcrtebral.nerves Innentation and Pain Patterns oJ'the Ceruical Spine Fig. 1-1. An illustrarion of a deep dissection of the cervical dorsal rarni. The superficialposterior neck muscles have been resecred. The lateral branches (lb) of rhe dorsal rarni and the nerves to the intertransversarii (ni) have been lrirrsected, leaving only the medial branches (m) inracr. The C I dorsal rarnus supplies the obliquus superior (os), obliquus inferior (oi) and the rectlry capiris (rc) muscles. The medial branches of rhe C: and C3 dgrfal rami respecrively form rhe greater occipinl (gon) and third occipinl (toh) nerves.Communicaring loops (c) connecr rhe C I , 3. and l dorsal rami. Branches (nnS) of the C2, 3 medial branchesinnervareihe semispinaliscapiris. while rhe C3-8 medial branches send articular branches (a) to rhe zygapophyseal joinrs before innervaring mulrifidus (M) and semispinalis cervicis (SSCe), and those ar C+ and C.5 form superficial cutaneousbranches (s). TP: tnmsverseprocess of artas: SP: spinousprocessof Tl. (Bogduk N: The clinical anaromyof rhe cervical dorsal rami. Spine 7:319, lgg2.) upper spinalcordand the'prrsterior cranialfossarr(Fig. l-l). .{,tlowercervical levels (C3 to C8). the sinuvenebralnervesinnervatethe dura materof the spinal cord. and supplythe posteriorlongiludinal ligameirtand the posterior aspectsof thecervicalintervenebraldiscsls-17 (Fig,l-i). Larerally.thecervical intervertebraldiscsare innervatedby branches the of rhe venebralnervers-r7' plexusaccompanying transversaria.16 the venebralarterythroughtheforamina The innervationof the anteriortongitudinaltigamentin the neckhasnotbeen deterrnined.but presumablyit is similarto that of the prevenebral muscles which cover and tlank rhe ligamenr. The structureswhich receivean innervationand theretbre,whichare joints. the potential sourcesof cervicalpain are the cervicalzygapophyseal posterior,prevenebraland anterolateralneck muscles.the atlantooccipital joints and their ligaments,the cen,icalduia mater,and the and adantoa.rial cervicalintervenebraldiscsandrheir ligamenrs. physicalrherapyof the centicaland rhoracrcsp ine, c1 C2 Fig.L.2.Anillustrationofthedistri. Uuiion of the uPPer three cervical sinuvenebralnerves and the inner' vadon of the atlanto'occiPial and atlanto-uial joints' Anicular branch., (*owed) io the arlanto-oc' cipiml and atlanto-axialjoints ytt from the Cl and C2 vcntralratni' rs' spectively.The C t to C3 sinuvcFto' bral nelTcs (svn) Pass through the forarncn magnlrm to innervate the dura matgrover the clivus' En route' theycrossandsupplytherransverse ligamentof the atlas (TL)' The dura *l"rrr of the rnorelatcral partsof the posreriorcranialfossais innervated Lv meningealbranchesof the hYPo' glossal(xii) and vagus(x) nerves' Fig. tr.3. A sketch of the cervical sinuvenebralneryes its seen m a rpt.imen in whichthespinalcordand tt . teft halvesof thc neuralarches havi beenremoved.Egchsinuverteroot bral ncrveis formedby a sonnaric sPinal a of ramus venral the from (arl ncwe (sn)andan autonomicroot ac' that nen/es from the sympathetic Within anery' venebral .o*p*y t-ttt inr u.niUruf canaleachsinuvenebrsl (o) nrtut dividesinto ascending and innetrthat descending(d) branches (ivd) antl discs varerheiniervenebral (pll)' ligament posreriorlongitudinail the [BosOukN: The innervationof venebrd column. Aust J PhY') t:E9,1985 siother:B InnervafionandPainPatrcrnsoftheCervicalspine5 Somatic Referred Pain ReferrcdpainispainperceivedinaregionsePantefrom'thelocarionofthe pain' the sourcelies primary sourceof piin. fn ih, .or. of viiceral ieferred part of the body wall which within a viscusUut tfre-p"inis perceinedin some in a somaticstructure itself is unaffectedUy Ois"ase.Paincausedby a lesion and the leftn somaticreferred may similarlybe perceiu.oin a distantlocation. pain and to distinpak isused to high1;h; ;. io**ir -originof this form.of neck pain arising region' guish it from visceJ-refened pain. ln ihe cervical fromthezygapophysealjoinrs.ligaments"rnuscles.andinreru"nebraldiscsof by pain.perceivedin the head' the the cervical ,pinu tl:, f" ".""itpanied 16eiosterior or anteriorchest wall' shouldergirdle,tt .',ip.ifitnU. "riAot iotoric ref.erredpain.has..notbeen demon' The mechanirrn-li ".*-i*t atpeamenrt.bur certainclinicatstudiesindi' stratedexplicitly uv'ptnvtioroeic afferentpathways.in the cate that the mechanisminvolvesconvergenceof more roslral levels' central nervoussystem.either in the spinlUcord or.at the antt physiotgic processin which neuronsin i, ;;;;i;*ii a;;;A;;;, separate two distinctly central nervous ,yr,.t receiveafferentfibersfrom by the-corhmonsecond-' relayed are rignalsfrom either.site pcripheratrit.r, an afferentsignalfrom "nJuiiin. Bicauscof rhisarrangement. order neuronto ttre botHperipheralsites' one site may be inte-tpr.-troas arisingfrom eitheror from the vertebral afferents pain. In the caseof c"rui.ot somaricrltened from peripheralregions column convergeon commonneuronswith afferens a nociceptivesignal Conseguently, like the head,chest wall. or upperlimbfrom the head' arising as perceived arising from the vertebralcolumnmay be chest wall, or uPPerlimb. particularspinallesion Whetheror not ret'erredpainoccursasa resultof a lesionrelay to conver' the from dependson whetheror not the afferenrfibers dependson the siteof referred gent neurons.In turn, the site to which pui" it neuronin the central .originOfanyorherafferentsthat.onuergl on the comlnon wiih afferents converge nervoussysrcm.If afferentsfrom fhe ueniUratcolumn the chest from atTerents with occurs.lfi theyconverge frorn the head,headache wall, chestpain occurs , L_-:- of ^, visceral referred convergencehas been demonsrratedas lhe basis tharanatomiial pain.tebur to dare.therehavebeenno ui,irnp,, to demonsrrare the resultsof convergenceis the basisof cervicalt.i.i!O gain. Howev€r. in' mechanism 'is the various clinicat experimenrsimply rhat convirgence volved. S t i m u l a d o n o f t h e c e r v i c a l i n t e r s p i n o u s l i g a m e n t spain a n d in m ungqol scleswithnox. ious injecrionsof hypenonicsotin. proluces iomatic retlrred pain in the volunrcers.Stimufaiionof upperceiuioatlevelsproducesretirred pain the chestwall' head.:rg Stimularionof lower ceruicJieuelspioduces stimulationof shouldergirdle.and upperlimb.:r-ll EG.,ti."f and mechanical posreriorchestwall and the'cervicalintervenebraldiscspro.iucespainin the ligamentproduces scapularregion.:{and pre"sureon the iot,itto, tongitudinal pain in the anteriorchest.I 6 PhysicalTherapyof the Centicaland ThoracicSpine joints have not beenstimulatedin Althoughthe cervicalzygapophyseal painreferredfrom thesestructures. patterns of normalvolunteersto determine pain is demonstratedby a different line of their capacityto prodUcerefened joint disorders,anes' evidencl.In parientsaffiictedby cervicalzygapophyseal joint or its nerye supply temporarilyrelicvps neck thetizationof the affected pain and any referredpain.:o-lt All these expcrimentaland clinicat obscrvationsindicate that noxious stimulifrom rhe cervicalspineare capable"ofcausingpainin the head,upper limb, or chestwall. None of the experimentsin normalvolunteersor anesthetiTherefore,nerve iations'inpatientsinvolvedthe spinalnervesor ncrvO'roOts. pain. in the central Convergence root irritadon cannothave bbenthe causcof postulated,to date,that explaimthesc newoussystemis the only mechanism phenomena ' The capacityof cervicalpain to be referredto lhe head.upper limb, or difficulties.For instance,paticntswith referred chesrrvallcan posediagnosric pain to the headma], presentcomptainingof headacheratherthan neck pain. and rhis headachemay be misinterpretedas tensionheadachiif the cervical Referredpainto theanteriorchcstwall maymimic causeis not recognized.le.]o and methods phenomenon of cerviCalangina,or pseudoangina, angina,and the pubticarecent in rcviewed been have angina, foidistinguishingit from cardiac tiOnS.ttJ!' Patternsof ReferredPain The carly experimentson somaticreferredpainwereundertakento establish chans of refened pain patterns.a It had been noted that refcrred pain tendedto foltow a segmentalpsttern in that stimuli to lower levels in the verrebralcolumn resulfedin the referralof painto morecaudalareasin the upperlimb or chestwall. The apparentPattemsof referredpaindiffcredfrom rhisdifferentpatternthecon'ieptof andto-disringuish thoseof thedermatomes, sclerotomes was introduced.l{ It was assumed,thatdeep structuresin the body wall and limbs wcre innervated.but in a differentpatternto theoverlyingskin. All thc segmentally the sclero' nerveconstituted deip tissuesinnervaredby a panicularsegmental pain w4l tOoccur tomeof that nerYe,and4twasftrnher assumedthat if refcrred within or as the result of a leiion in the venebral columnit would occur of thenervewhichinneryated throughouttheperipheralpartsof thesclerotome the lesion. Consequently,it was expectedthat by chartingthe Patternsof referred Thesc couldbc constructed. painin normaluoiunteersmapsof the sclerotomes pain on spinal of origin segmental the deduce used clinicrlly'to tould thenbe patients ' pain by suffered referred of my peripheral disribution rhebasisof the was thwarred. This ambition.howcvcr. revealswide' Analysisotl rhe Variouspublishedchartsof sclerotomes ot distribudons difrerent report individuals Differenr spreadinconsistencies. Innervationand.Pain Parrerns of the Ceruieal Spine 7 referredpain,evenwhcnexactlythe samestructuresandsegmental levelsare stimulatcd.Morcover,the distributionsof referredpain reponedin differenr studiesdiffer markedly(Fig. l-1). Thereis roo ri,ruchvariationand overlap in thc pattcrnsofreferredpainfor the siteofreferredpainro be usedur u pre.is. clue in the diagnosisof its segmentalvenebralorigin.The rangeof enor is at leastone segmenthigheror lower. Thus,for example,while stimulationof the c5 segm€nrof the verrebralcolumncan causepain in the s'houlder.referted painin thisregionalsocanbecausedby srimularion of rhec4 or c6 seg1196j.!l-ll Notwithstanding this lack of absoluteprecision.someclinicallyuseful conclusionscan be drawn from the experimentson cervicalreferrid pain. Referredpain to rhe headhas been producedonl;r by stimuli deliverid to structuresinnervated by thecl, C2. or C3 spinalnerves.riStimulito srrucrures innervatedby Ca can producepain in rhe occipiralregion.bur stimuli at this Ievel or lower havenot beenrcponedas causingpainin the forehead.similarly, relief of headache hasbeenreporredfoltowinganesrherizarion of srructures innervatedby cl, c2, un693.:c.31.3e-!r but not by lowercervicatnenyes. convelsely, paill il the upperlimb hasbeenreported foltowingstimuli ro rhe -higher c5 to Tl levels,rJ burnorfollowingsrimuliro levels.Referredpain to the shoulderexhibirsa widespread retadonship, andcanbecausedby stimuliat any level from Ct to C8.1r'x Thus,an approximate patternemerges. Referredpainto rheheadcanarise from upperccrvicallevets(cr to c3). Rifcned painto rheupperlimb can arise from lowercervicallevels(Ci to Tl), andshoulderpaincanarisefrom virtualty anV 99rvi9{ level (Cl to C8). Thcsc relationships providethe besr index oi suspicionif thedistributionof referredpainis ro be usedar all asa guidero the segmentalorigin of irs primarysource,and the publisheddatado nor permit endorsementof a more preciseguide.At best. the complaintof headache invitesa searchfor a possibleprimarysourcein theuppercirvical spine,while pain in the upperlimb suggesis a searchin the lowei cervicalspine.shoulder pain indicatesassessment of the entireneck. The deniled investigation and examination of the neckin rheiearch for possiblesourcesof somaticpainis beyondthe scopeof rhischaprer,bur contemporarymedicaldiagnostic techniques aredescribed elsewherej6 andmanual techniquesare describedin manychaprersin rhisbook. Radicular Pain Syndromes Vinually all of the previouslirerarureon cervicalpan syndromeshas focusedon cervicalsponrlyrosis and nerre roor compresiion.ano rhereis no doubt that discbulgesandosteophytes of eirhertheuncovenebral regionor rhe cctryicalzygapophyseal jointscanaffecrthecervicalnerveroors.r?-rr-However. the emphasison nerveroor compression hasresultedin an inappropriatepro. clivity to interpretall cervicalpainsyndromes as dueto nerverool compresSIOO. ffimffim d }F cs ulfl ffi\$ ffi iv d A \gt t# A (18{ /F 4il T1 Flg. 1{. Pottcrnsof rcfertcdpoin induccrlin normalvoluntccrsby rdmularionof rhc intcnpinousstructuresot the levcls indicatcd.Thc left.handfigurcsare bascdon rhc studiccof Kcllgren.$The right-handfiguresarc bascdon thc studic: of Feinsteiner al.:: Comparisonof thc two sctsof figuresrcvealsthc variationin' parrcrnsof rcferrcd pain from thc samcccrvicll structurcsand segmentallcvcls. Innentationand Pain Patternsof the CentiealSpine ' Nerve root comprcssiontheorieswerc developedto explainthe association betweenlow backpain and sciatica,{..7andthesewercextrapolatedto the ceryical region to expliin the concunenceof ncck pain and upperlimb pain. Howevcr, thesetheorieswere formulatedurd thc cxtrapolations madewithout regnrd to the contemporaryexperimentson somaticrcferrcd pain. Consequently, somatic mechanismshave remaincdlargely ovirlooked as explanations for cervical pain syndromes,and nerveroot compressionhasremained acceptcdas the principal(if nor the only) mechanism for gcrvicalpain. Howwit\ the clinical cver, as a mcchanism,nerlreroot compression is inconsistent features of the majority of cervical pain syndromes,and in fact accountsfor o.nlyggvc,#-specificproponion of cases. ,,.rNpwe rbdt compression producessymptomsin two ways.First,objective ncurologic signs can be produced if root compicssionblocks conductionin axons.Thc symptomsor signsthat occurdependsori exactlywhichaxonsare '...afrected.If sensoryfibers,arecompressed, then sensorylosswill be experiweakness will occur,andthedepthof any cnced. If motor fibersare affected proponional sensoryloss or motor weaknesswill bc to thc numberof axons affected by the compression. Parcsthesiamay be a featureof nerveroot compnession, but the mechanism is not compressionof axons. Experimcntson peripheralncrveshave dcmonstratcdthat par€sthesia occursas a resultof ischemiaof nerves.Therefotc, it canbe deducedthat paresthesia of neryerootcompresin the presence sion is likely to be due to compression causingnef?eroot of radicularvessels, ischemiaratherthan frank compressionof the root itself. Thc secondmanifestation maybe pain,but the of nerveroot compression urcchanism,quality, and distribution of.this pain are differcntfrom those of somatic pain. Root pain. or radicular pain, is causcdby the generationof ectopic impulsesin nociceptiveafferentsin the affectedroot.Theseimpulses can be generatcdby mechanicalstimulationof thc dorsalroot ganglion.or by mechanicalsdmulationof previouslydamaged dorsalnerueroots.&$ Notwithstandingthe capaciryof nerveroot compression to generateboth objectiveneurologicsignsand radicularpain. thcreare severalanatomicand physiologicfactors that limit neraeroot compression as fie cxplanationfor most gervicalpain syndro.mes, l. A cardinalfeatureof nerve root cbmpression is that any symptomor sign'mustbe in the terriroryinnervaredby theaffecredroot.Thus.for example. compressionof the C6 root shouldbe associated with sensorysymptomsin the C6 dermatome.and/ormotor weaknessin the C6 myotome.Clinicalfeatures not in the appropriatedistribution cannotlegitimatelybeascribedto root compression. 2. There is no known mechanismwherebylesionscausingroot compression can sclcctively affecr only those axons thar innervotethe venebral column.while sparingthe other axonsin the rootthat supplytheupperlimb or other non-venebralstructures.Root compression mustinvolvea combination of local'and referredsymptomsrorsigns.Therefore,nerveroot compression l0 nerYe ischemiaof the largediameterfibersin rhc affdctod.rpon:Citnscquenlly, be the mcch4oisrnof rymp' root compressiohcannotlegitimatelybc dcemed..to ip.prcscnt;' weakness, or paresthcsia toms unlessnumbness. can be thc mechanismof symptomsonly at 4. Nerve root compression segment4llevelswhererootsaresusceptibletq'egmprcalbn .Becausethcy run in the intervenebralforamina.the mid and lowct cera-icaltpott sre susceptible to compressionby disor.dcrsof thc intervertebraldircs. .uncinaleprocpsses. and zygapophysealjoints that form the boundarics of tbc intcrvertebral toramina.'Hot"e"er,itreCt andC2 roots do not run in intcrvertebralforamina There' and haveno structuralrelatlonsthat renderthcm liabla to cornPJcssion. of rnechanism be a to be held of thc.Cl or C2 rootscannot fore, compression uppercervicalpain. 5. Ths quality and behaviorof radicular pain is distinctive. Experimenrs on lumbarncrrc rootshavcdcmonstrstcdthat meehanicalor clcctricalstirnula' tion of ncrve roots producespain that is quite distincr from som$ic pafu.tt-'r Lumbarradicularpainrendsto be shootingor lanclnatingin qualityandtravels inro the lower limb alongnanow bands.It is not dull, achingin qualityand spreadover diffuseareaswhereit is hardto localize,which are lhe characteristics of somaticpainandsomaricrefenedPain.tr'ss Becauseof theseseveralanatomicand physiologicfactors' nerv€root thatmustbe restrictedto levelsC3 andbelow,lnd compression is a mechanism with objectivcncurologicsigns.or to caseswhereradicularpainis assosiated distribution.In the absenseof thcse paresrhesia in the appropriate.segmenral associatedneurologicfecures, any poin is more likely to be someform of somaticpain andsomalicrefenedpain stemmingfrom one or ano$er of the of the cervicalspine. elements musculoskeletal COMBINEDSTATES While it is imponanlto highlighrthe differencesbetweensomaticpain statesand root compression syndromes.and'to redressthe relativeneglectof . il somadcretbrrcdpainin rhedifferen(ialdiagnosisof cervicalpainsyndromes. Lesions may co-exist. is equallyimponaqtto recogniZe tharthe two conditions ,:I ..r;'.;-i..f/.\'rili"l? Inneruationancl Pain Patternsof the CervicalSpine 1l cause that causesomaticpainand somaticreferredpainalsomaysecondarily syndromemay nerverOOtcompression, and the featuresof root cOmpresSion on thoseof a somaricpain syndrome. be superimposed For example,disc diseasemay be.inrrinsicallypairu'ul,causinglocal and develop,the referredsomaticpain, but if the disc bulges,or if osteophytes Similarly,arthroticzygapophy' adjacentnerveroot may becomecomprbssed. may osteophytes sealjoints may be intrinsicallypainful, but zygapophyseal joint. the concomitantlyaffectthe nerveroot in front of such as these,patientsmay pr€sentwith a As a resultof combinations combinafionof neck pain, somaticret'erreclpain, objectiveneurologicsigns, andthemultiplicity and radicularpain.It is imperariverharsuchcombinations and consequent Of mechanismsinvolvedbe recognized.lest the assessment to assume.in treatmcntbe incompleteor inappropriate.It wouldbeerroneous is the only s patient with objectiveneurologicsigns,that root compression theobjective wouldcenainlyaccount'for pnocess operating.Rootcompression couldbe somalic neurologicsigns,but the painof whichthe patientcomplains to be causingthe root pain due to the lesionthat only secondarilyhappens Decompression compression. of the root mightreversethe objectiveneuro' logic signsandrelievean;rassociatedradicularpain.but it will notnecessarily relieve the somaticpain and any sornaticreferredpain.unlessthe'causative lesion is inadvcrtentlytreatedin the courseof the dqcomprgssion. andsigns symptoms In the assessment of patients,eachof the presenting be deter' each should of should be individuallyanalyzedand the mechanisrn in a prescribed each complaint for mined.Subsequently, treatmentshouldbe the mechanisms production. with its mechanism Because rnanneiconsistent of and sourcesof somaticreferredpain and radicularpainareso different.these for radicularpainmay shouldbe distinguished. Moreover,srandardtreatments not be appropriatefor somaticpain and vice versa.Failureto distinguishthe being componentsof a patient'scomplaintin this way runstheriskof treatrnenr anddisillusion' directedat onlypartof theproblem.wirh patientdissatisfaction ment with the therapistbeingthe consequence. REFERENCES disc.p' 3?7.In of thcintervenebral l. BaileyAJ. HerbenCM. JaysonItlV: Collagen (ed): OrlandoFL. & Stratton. Grune and Eackpain. JaysonI1IV TheLumbarSpinc r975 Z, Naylor A: Brachial neuriris. wirh panicular ret'erence(o lesionsof the cervical intervenebraldiscs.Ann R Coll Surg Engl 9:155,[95I 3, Hunt WE: Cervical spond!-losis:natuml history and rare intlicationstor surgical dccompression. Clin Neurosurg17:a66.l9E0 London.1980 4. JeffreysE: Disordersof rheCervicalSpinc.BirttenvonhP.rblishcrs. London.l97l Ed. Heinemann. 5. WilkinsonM (ed):CervicaiSpondt'losis.2nd RH. Si' p. 387.In Rothman 6. SimeoncFA. RothmanRH: CcrvicalDisc Disease. 197-( (eds): Philadelphia' mconeF.{ The Spine.Vol l, WB Suunders,