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Show /. Oill. Nt'Ufl'-I,/,hth.llllh.l. 2: ~~7-~34. I')~:'.. The Marcus Gunn Pupil in Incomplete Optic Tract Hemianopias PATRICK tH.\)NNlW. M.P. CALVIN MEIN. M.ljM, LJSA, M.e. JANE HUCHES. M.l). Rl)BERT H. [)l)I\WART. M.ljllr. USAr, M. [):\ \'ID E. SHACKLETT. M.I1. Ahstract Three ralient~ with optic tract lesion<;. incomplele homon\'mou~ hemianopias. and good vi~ion in hoth eves ar~ presented. All three had a Marcus Gunn p'upil in the eye with temporal field lo<;s (eye contralateral to the tract lesion). This pupillary sign may serve to differentiate acule optic tract from acute geniculostriate lesion when the characteristic intrageniculate optic atrophy has nol had time to develop. Introduction The pr s('nl' l)f Ih(' Marcu. Gunn pupillMy ph n,)men,ln h.1S tr.lditil1n.llly Illc.llized th(' site of .m .1ffer('nt \'iSUJI d('f('ci Jntcrior to th(' hiolsm IOvl)l\,ing eith('r the ip i1.1ler.11 llptic nerve or retina. ' It has b('('n suggested. on Ihellreti oll grounds. Ihat such ol defect could .1150 occur in .10 eye conlralJter.1llll the sit(' of .1 IrJct lesion.~· I R('cently. Bell and Thompson I r('ported fou r p<lticnts with equ.1l vision bildler.1lly. convincing Iracl I('sions, and .1 complete homonymous hemi.100pi.l. All four had .1 rel.1tiv(' .1fferenl pupill.1ry defe t in lhe eye wilh lempor.11 field Ill" (the eye contr.ll.ller.11 II) the Iract le!>ion). Tht·y expecled Ilw, pupill.lry sign in all such .l es With .l cl'mp/et(' h('mi.lIlllpi.1. thll~ helping 10 differenti.lIe .lcule oplic trolct frllm gl'niculo tri'lte lesions. ·p<>riml'nt.ll1y. O'Cll/lIWr el al.·' confirml.'d Ihal ompl<'le i.ol.lled tr.Jrt lesions. dt least in th(' monkey, resulled in .1 M.HclI~ Clinn pupil c ntr.1l.lIer.ll to' the 1('.. ilIl1 (ip"il.lter.11 III the hemianopi.1). Wr rt'porl thrl'l' p.llit'nts wilh equ.11 vision biJatC'rJl/y. Ir.lcl I(·sitln ... dOl unwnled by CT scanning. incomplclt· hllmllnynllHI ... h(·ll1i.lnllpj.l~, and a Marcus Gunn pupil cllntr.II.lln.,1 1,1 thl' tr.ld lesi n (ipsil.lt<'r.11 to lhe temp"r.11 bell! defl'ct). From the I)(·p.>rtml·nt "I t1I'hth.,Ir",.I,,}:v (1'( 1(. II!. PI "l. Un,vcre-tlv of Te'j'" Hl".llth t..,lH.'I1\(' (t·nh-r. ",111 1\"11'1111'. fl·, ...... fllz~imml.n' Armv M"d".,1 (1'''11'' I( M). 11"11\"'0. I "1"r,HI,,. .nd Wilfurd H•• II 'USA~ M,'Ji,.,1 ( ",,!t., (I{11I1J. I.h kl.lI\d Air Force B",... TnJ'. Df?cember 191\2 Case] A 27-ye.H-llld whil(' femJI(' d('velop('d Ihl:' udden ons~t llf .1 right hemipJresis, right h('mihyprsIht'si. I, .1I1d .In in omplete righl honwnym us h 'mi.ll1l)pi.1 during .1 c1d i migrJine he.ldache. She h.ld ('xperienced migr.line head.lche .llmo I 1l1llnthly ..ince .1ge 10. Thesl:' W<'r(, then pr ded bv In .lurJ l)f fl.l hlllg lights Jnd I)Cc.J<,llln.ll1y .15~ l~ci.lt('d with ol signific.lI1l tr.lI1sient fi('ld defect. The he'ldJches lasted fr m b hour to 2 day. and were relil:'ved by rr. ting in .l dark. quiel nll)m. Her grJndmother .lnci .1lInt .11 l' h.ld migr.line he.ld. lches. Thrr(' W.1S no hi tl ry of Jcute unill ul.Jr vi_ u.ll loss llr perm.ment ViSU.ll Ill1p.lIrmrnt. LJbor.llorv eVJllI.Hilln. including CBC _MA-20. sedin)('nl.llil~n r.lle, pnlthnlmbin limr, p.Hti.11 thrombopl.lslin tlllle, unn.llysis, VORL. rh um.ltl, id f.Khlr, .1I1tinuclE'Jr .wtiblldy..lIld st'rum pr,Itrin rlrctwphorrsis. 1V.1S Iwrn1.11. Oth<>r stud Irs IIlciuding x-r.lys of the sl-ull .lnd ehe. t. lumbar puncture. E'choCMdi grJphy.•1nd fl)ur-vessel .1ngiography were n<,g.ltive. A CT sc.ln (Fig. I) performed 48 hour. .1fter 1111set delllonstr.lted .1 lucen y in the left th.ll.lmie .He.1 cllnsistl'nt wilh .111 ischl:'ll1ic ('vrnl. A repe.lI 5C.1I1 4 wed,s 1.lter rlve. lled res"lution of thiS lucencv. T"'ll \\'l'eks .Ifler lInsel. the p.lliellt IV.IS retl'rred ill u~ tIl, 1'\'.1 Iu.lI I,111 llf .1 M.lrcus Cunn pupil c,1I1Ir.ll.ltel.11 III 1111' isch(' mil.' illLHdillll which \\'.IS un.lc'·llll1p.lllil'd by .1I1Y obvi,'us lesillll .1nll.'rill r III the chi.lsm ,In th.11 side. On e,.ll11in.ltilln. thl' besl cllrn'ctl'd \'Isilln "'.15 20/ IS lIn the right I'Yl~ .lnd 20/15 'Ill th l' left. A 2+ M.HCU5 CUlln pupil IV.IS pn·...'·nl llll till.' ri~ht .Ind Ihis pupil, .1 ... I mill I.Jr~l·r th.1I1 tlw kit. A \.vernickI"" hl·1l1l.1I11'pil" I'upd 11.'.1" .I!...,I 1,.I~ily del111lnstr. ltl'd l'll lhl' ri~hl. l)ptd..lI1l'lic nyst.lgI1HIS. ~undus 1',.Jnlin.llilHI, .Jnd Vi~u.ll-eVllkl.'d rl.'sponses weft' ''''l"m.11 bil.Jll.'r.llly. A right inCllllgnlllus h,II11, H1vnlllUS hl·mi.lllllpi,l dl.'nSI'r .Ibov(' \V.1S pres('nt (Fig. 2). fl,lknv-up .It J n1l1nth ... rev('.lled improvement in the ViSU.ll fields (Fig. J). but th pupils were uIJrh.lIlgl'd. Thl.' right disc nln·v _11l.1wed slIbtle 227 l )1'11\ rr.1<1 ,11\.1 I'upd Fi~ure I. (., ..." I <. T '"JI1 J,'nlpn .. tr.lfIJ\,:..l lul'..'''' \' In\·,.lvln~ the I•.ott th ... IJmn. .)rl',' '·'h·lh.iJn~ Inlll Ih(' p""'h'r1,tr "pIll tr.h.1 \11""'I .. tl'nt \\Ith ..1I"l ""ht:mu. IIlI.Hlt"ln 1\ htll\I\\'·Up "',.lIl ...J Wt'l'"'' I.llt·r \\.1" 111'rnl.11 LEFT RIGHT I i~un.· !. ( .1 .. ,' I \ ,,11,,1 Iwld.. \h·I1H'I1 .. lf.\lII1~ ,1 n~ht "h\·,,~ru\'u .. 1"'llll.\Ih'pl., ~\• ...I.ltll pr(''''t·nt.lth.ln~ l""lUld ~(' dc-lc\.-ted Within the hC'lIl1.lItt'pI.i l'H' 1\llhJt'l 11· ... I'IWltll"h'fh t l\ w.,.. ",,,t1,, dl'n"'n...ll.lh',,i h'.t .;··H 1\: ...1 \.'l'll"·' tl'I11l'llr.11 p.ll/l.r. Chllf\'II.ltlwllltll 1l1ll\'1'1lH'llt~ h.ld ,II~II Jevl'lopl'J In thl' p.ltil'nt·~ ri~ht .HI11. TWI' y('.Jr~ .Ifter on~(·t thl' vi~illl'. pllpil~. fil'ld~..1IlJ rhl,rc'II.llhl'lolil 1l1\l\'cllH'llh \VcrI' 1I11\·h,lIl~l'd. A bow til' p,ltt rn of I'ptil .lln'ph" IV.I~ prl'~l'llt I'll thl' right with I11lnim.,l tl'mp"r.11 optic di~I' p.llll)r I'" Ih(' 11·t. t hn 1111.11 I lill".11 Il11pn',,~i'\l' \V.l~ .111 i.dWlllil "lIMIl,,'" III tIll' di~trihlltlllll Ill' the left ,IIlII'n" .. , l1"r<>ld,11 .If"'''\,. IIlduJlIlg th\' Ilplir Ir.Kt, b.l~.11 ~.lI1gli.l.•llld intern.ll c.lpsule due to complir, lll'd Illi~r.line. Case 2 A 52-Yl',H-old bl.lck male developed the sudden Iln~et Ilf .1 glob.ll aphasia, dense right hemiparesis, .llld incomplete right homonymous hemianopia in M.1Y IQtH. A CAT scan (Fig. 4 and 5) demonstrated .1 IMgl', left basal ganglion hemorrhage which com- Journal of Clinical Neuro-ophthalmology ()'( ""ll1.r, '" .11. LEFT Figure 4. .1'(, 2. Intr.lV('nllu'" \'I,hJl1lt,J ...,1.11 L I ".In .H lIH' I(·v I f Ih<' lIptll tr.lll, d,·mu"'lr.,I,"); ,. f.S ,m 7""" "' .,v,,"rmJI IU<<'II'y w,lhlll Ih.· p"'Il'n,,r pllrl"'1\ "f II", I.·ft "pt" Ir.ll I (solid whlll' de"'w). Nu mJ" dfl'<l " ""lnt .•1Ihi' In'"I December 1982 RIGHT .\ "",'1 .11 •. 1111 ',· .....IIIIII.n ,., ,II" rl~hl h. IUl.IIl,'pl.1 f. I Ii· I 1'1,1" HAure 5.....1 ·~' 1,,1"'\"'lhIU" l'llh.lIh.l'd L I ..,.\I\.\t th,' h'\'d l,f th..· th.'1.1mll 'tlo.,' l r.\llI.HI 1\. II~ .. :\1\ II rt·~lIl.lrl\' f.,,"h.lIl\"ln~ h'''ltlll WltlHI\ th,·ll'It th.,l.unll". \\'Itl,,'ut IH.h'" dh',l h ,,,'l'1l Th...· I,·... i,'ll .... Ill"..t .. un...... h'nl wlth.l hl'nh.'rrh.l~l\. Illt.Hdhlll..1 r,,'p".ll .., .111 ~ llhltHh ... I.lter \V" ... nunll.,!. 229 f-i~ure Q. l ,m"l'l1lh,II1,ll hl'IllI,lnllrlt rr\,"lwl l'rJ m .1"- \J'f'd In .1 p.ltU.'l1t With .i tpt.ll I('tt h"IIHlllvmpU'" hl·IlIl.ln(lr'll.l P.lhl·nl ... h,,!Ju'Ig )odd ·... dnJ Ih(· J.O·Jlllptt·r Fr<·...n ·1 pn,m I~ bJstt kll "11 Idl I,'''''. mllde. t vi UJI improvement WdS noted in our p<ltient with thesc prisms, probJbly becJu e llf the integrity of the mono ulJr temporal crescenl in the lefl eye <lnd <11511 beCJuse of the Riddoch phenomenon. To llur knowledge, this is Ihc first CJ e in which ,1" heck rboJrd" field defe I hd been documented by "chcckerboJrd" CT findings, Jnd in which "checkerbodrd" Fresnel prisms have been prescribed. References I. roencluw, A.: UbN cloppel eitige hemi..l11llp. ie (en- Ir..llen ursprun~s. Arch. Psvch. en·en!"r. 23: 339-300. 18°1. . ., Weymann. M.P.: A C.lse of quadrisector..ll homonymous heml,lm1psi.l. Am. ,. OphthJlm"I. II: 28<1-2°3, ItN-I. 3. Felix, CH.: CClls~ed qU.ldr,mt hemi..lnl'psi.l. Br. , Ophth'llmlll 10: JO I-1 05, 1020. 4. Allyn, G. W.: A c,lse of bilalerJI h"n1ll11Vnlllu.; hemidnopsi,l. Arch. Ophthalmc>l. 25: 20Cl-212, 180Cl. 5. Scolt, .1.: Tr,lquJir'.; Clinic,11 Perimetry (7th I'd I. CV. Mll bye"., _I. loul., 1057, pp. 277-278. o W..llsh, F.B., .Ind H"yt. W.F.: ·linic.11 {'ur,l-,'phth. llnll,!t,/,p'. Vol. I (3rd ed.). Wi I11.1 illS .Ind \i tlkll1S ,1., B.lltimore, 10Clo, p. 03 7. '.m~ I'n", C ..md BNIhell'n, _.: QUJdr.lIlllpsll' hl'ml'nylllc cwisee. Bu/l Sl"·. Bel~e J'l)phth.ilnll'/' ICl5: 37Cl-381.1 073. 8. RidJ,,, h, C. n'~""Ci.ltillll ,If vbu.ll rf'rcepli"lb due III III 'lpit.,1 iniune~, With ('~peci,11 re('n'n"e t" ,I!,prl'd" ti,'n Il( m"vI'nwnt. Rr.lill 40: IS-57, 1'117 0. HI'nt"n, ~., I.I·vy. I..•lJ)l! ~\'\"'I.;h. M.: Vbi,'n in lhl' tl'mp"rJI ,1'('" ('nl in 1'''·lpit.,1 intHetinn. Rr.lIll 103: 83-°7, 1°80. 10. ~ym"nJ~, C, .lJ)d M.lCKenZIC, I.: Bil.ller,ll I"ss "f vi ..i"n (nllll I (,1'I·hr.11 inf.Hctil'n. Br.lin ~O: -115-0155, 1057. I J. K..lul, :--.;, DuBoulJY, G.H.. Kendall. B.E., and Ross Rus ell. R. .: Rel.Ili<ln~hlp between visual field defect dnd .lrlen..ll ,((IU~llln III Ihe po teri I' erebral cir UIJtllln , ,"(>un" ,'·C'ur,'surg. PsychIatry 37: 1022-1030, 1<:17-1. 12, H,'yt. \-V F.. ..lnJ \:e\\'ton. T.H.: Angiographic (h.ln~e. \\'Ith ,( lu I,'n l,f .Irtenes that supply the VISUJI c,'rte'\ . .\'. Z. II'J' 72: 310-317,1°70. 13. McAuley, D.l.. JnJ Rl'~_ Ru. ell. R.~ .: Correldtion of CAT. C.In .Ind VLu..l1 field defect in vascular leSIOns I f the pO~len,'r vi. UJI pathways. I- 'eurol. eurosur~. Psv hi.ltr\' -12: 208-311 1979. 1-1. Melenberg, 0:: Sp.Hl·n~ "f the lem~oral crescent in hom,lnvllll'u.; hellll.lnl'pi..l dnd its significance for VlsU.l1 onent..lltl n .\'eur"·I'phthJ/ml'l. 2: 120-13-t, 1°81 . IS V".1Ish. T I.. .lnd Smith. I.l . Hemi.lnl'pic spectacles. Am.'. phth.J/nll'l. t<1: 01-1-015. I<:Ic>o. ICl. Mintz, M.I.. A mirr,'r f,'r hemi..lnl1 pia. Am. I- OphthJlnhl/. 88: 7c>8. 1<:17<:1 17. Burns. T.A .. H.lIlley. \\'.1 .. Pietri. I.F.. and Welsh. E. .: SpE'ct.lCles fl'r heIllIJll,'pla. A cJinicJI evaluatll'n. Am , l)rhth.llnwl. 35: 1-18°-1-1°2. 1952. I~. \Veiss. N.I.: An .lppllc,lti,'n "f cemented prisms wilh severe field Il,.;s. Am. ,. Ort1'm. ~9: 201-20-1. 1972. 1<:1. Smith. J.l.. Weiner. I.G.. .lnd lucero, A.J.: Hemi,1Il,' P" Fresnel pnsms. ,. elin. , 'eu((l-ophthalmol. (In pres. ) Acknowledgments . Gr.lteful ,lCklll1wledgement is given to Drs. John l.Hks" II , .1nd. Slllgh P,lnnu for referring the patient repNted III thiS r.1per. The .1uthors Jre also indebted to Mis.; BMb.H.,.French h'r photographic help, and to Mrs. Rev,l Hurtf's h'r libr,try help. WritE' f,'r reprints to: I. lawton Smith, M.D., P. O. Bo'\ o1Cl880, Mi,lmi. Floridd 33101. Journdl of Clinical Neuro-ophthalmology a l.lrge, right th.ll.llnk 1n.1SS with ench.mcin~ b~lrdeL The white C~lunt W,l:-. 17,QOO with .1 m,lrl..ed kfl hift. Innl'.lsing Il'lh.ngy W.l:-' .KClllllp,mil'd bv f.lil· ure ~)f b~lth up- .md d~\JVllg,IZt', but lhe pupil:-. Wl'r~' Figure 8. C.l~e 3. Ir'lrdven,'u, em'h.1nll'd CT >l.1n obt.1lIll'd :! months fL,lk>lvln~ ~ur~":.11 dr.1"'.1~(' .1nJ ."'l,blll!'l ther.lpv f~" the th.ll.lmll .lbsle". A 'e"du.11 Zl,ne lit Jlml'rm.,1 IUlenlY in the regil'n l,f the n~hl th.1I.,mlJ~ " d'mlln_!,.•! d, but th~' "ze dnd mdSS efff:,! Jre nur"edly ,e-Ju(('d. A (l'"l'w-up ~l-.1[' in April lQ82 IVd ol'rmdl n'pllrh'd Iv IHlnn.11. 011 [)l'cl'mber IQ, IQ8 I, (1 right Ull ipit.ll ~ r.lIlilltomy W,l~ rcrformt'd with drain.ilge III ,1 right th,ll,llllit .lb~n'...<; du(' tll strepto eeu virid.IIl'. A th"rough ~t·.lrch for the' sour e of inh'~ I i~11l W.l' lIonrr"ductive' ,lnd the p.lti('nt W.l ,t.trh'd 1111 IV pl'lli~ illin (, ro~t()Pt·r,ltively. Prior to di'lh.lrgt', tl1(' r.lli~·"t', llIotility .11'1'(',1< d full, with diplopi,t ollly (Ill right 1.ltn,11 .lnd down g.JZl'. The Idl puril W.l' .11 .." notpd to be' 2 mm IJrg<.'r than thl' right .1t thi, tlml' but r('porll'dly r('Jcted norm, llly t~1 light. We fir,t '.IW the p,lti('nt on F('bru.Jry Ib, IQ 2, hlr ('v.llu,lliun of her pcr..i"tt·nt diplopi.J whICh by hi ..tory h,ld improved. On eX,lmin<1tion th" pdti nt h'ld ,1 r('sidu.ll I('ft hcmipart'sis .Jnd heml.Jnesthesi.il. Her best eMr' -tcd vi i 1I1 W,l!> 20/20+ in th ' right eyc ,md 20/20+ on the Idt. The' right pupil WJ 3.5 mm .lnd rc.Kted 4+ to light whilt' the left pupil was 5.5 mm .1Ild rea ted 3+ to light. A 2+ Marcus Cunn pupil WdS present on the left. Motility testing r ve.lled .1 left uperior oblique palsy with a -1diopter left hypertropia in primary, an 8-diopter left hypertropia on right gaze, and a IS-dIOpter left hypertropia on the left head tilt. No other extraocular weakne 5 or restriction was noted. Fundus e ami nation revealed normal appearing discs bilaterally. Color plates, brightne ,and c lor comparisons were normdl in b th eves. VisUJI fields dem n tr.lted an incomplete i~congruous left uperi r quadr.lntopid (Fig, 8). Repeat CT scanning revealed marked resolution of the right tha( dmic mdSS (Fig. 9). A third CT SC,ln perf rmed in April was normal. The patient was fitted with prism glasses Jnd scheduled to return for foll<w.'up in 6 months. LEFT RIGHT Fig-ure 9. CJ~(" 3: V,">u.ll fJcld .. J(·mun... tr.)lIn~ II ... nl.l11. Inulillplt'tl', 111t:l\n~rll'\1l'" kit ~UIll'n\\r (llI.llh.ll1t.\nl~pl.\ prl~~l'nt 21110nth Jfter tredtment for d ril:ht th.1l.1rnll .11:>".,,, December 1982 23] l )1'11< Tr.ll"l .111<1 I'upil Discussion TIll' pn'sence of .1 M.lrcus Cunn pupill.lry re~ PllllSl' Cllntr.ll.lter.11 tll .Hloptic tr.lct lesic n .1ppeoHS III cllntr.Hlil't tr.Hlitilll1.11 te.Khing. In f.let, S.lVino et ,11." in .1 review llf 21 p.llil'nts with Ic'sion~ of the' llptk tr,lct st.lted th.lt .Ilthllugh In .lffcrent pupill.lry ddc'd W.IS fn'lJlIl'ntly encountered, rlll p.1tient with rlllrm.11 ViSU.11 .ll'uity bil,ltrr.llly hJd thifo finding dc'spite tIl(' prrsenn' llf grossly .lsymmrtric fidd IlIss. They rll~tul.ltl'd th.ll ,11 Ir.lst in the'ir c.l~es, ~uch .1 pupill,lry .1bnorm.llity W.1S due to ~imult<llll'llllS invllivement of more Jnterior tructures (l'hi.lsm .md optic nerve) by the optic trd t lesion. While llur (Jses do involve structures surrounding the tr.let, they .He foc<ll enough in 10 <ltion to rule llut simult.mellll involvement of the chid m or .1I1terillr vi. u.ll pathwJys. ThJt such Ie ions still produce .1 M.ucu Gunn pupil in the contrJlateral eye c.m. in fdct, be re<lson<lbly understood in terms of certain Jnatomical and physiological facts. For years perimetrists have recognized thdt the nasal field i nsiderably smaller than a temporal field, even when te ting with small isopter. Thi w.1S origin'lily ..lllributed to interference by the nose restricting the ..lbsolute limit of the n,ls.11 field.: GlaserM demonstrated th.1I the nose had no signific, mt effect on the extent of the nasal field. and that .l more rational e pJdnation is found in the asymmetry of retinal cell topogrdphy which demonstrates the ganglion cell layer redching nearly twice as far on the medial as on the lateral side of the 180~"f'--'-l"-'-' LEFT fovea.~' Other studies'" also have demonstrated that both rod and cone densities are somewhat greater in the superior nasal quadrants than inferiotemporal portions of the retina. Furthermore, when the .He,l within each isopter is measured with a planimeter the temporal field is 61% to 71% larger than the nasal field.~ This difference can easily be .lppreciated if the nasal field is folded on the temporal field (Fig. 10). It would then be reasonable to expect J Ma rcus Gunn (relative afferent defect) pupil in a complete tract hemianopia in the eye with the temporal field loss. In addition to the Jnatomic difference between nasal and temporal retina, more fibers cross than remain uncrossed in the chiasm. 'I , 1-' These data suggest that stimulation of the nasal retina (or temporal field) will yield a stronger response than stimulation of the temporal retina (nasal field). Our finding of a Marcus Gunn pupil on the side of the temporal defect would certainly support this concept. The two best known pupillary signs associated with tract lesion are those of Wernicke'" and Behr, II both of which have fallen into clinical disrepute, Wernicke's pupillary hemiakinesia is difficult to demonstrate c1inicallv because of intraocular light scatter. I:, Its value is ;'so marred by reports of its presence In suprageniculate as well as infrageniculate lesions."; Interestingly. our cases (l and 2) had an easily demonstrated Wernicke's pupil ipsilateral to the hemianopia (contralateral to the lesion). This response was difficult to appreciate in the eye ipsilatNdl to the lesion. This phenomenon. RIGHT Fi~ur" 10. I,·" "rol,.,1 ",,".•II,,·ld h', till' I ·1·""I',,·r w.th tl\l' 11.".,1 fil'lJ f"IJ"J '-'nl,' th" t"mn,.-llrJ I f',eId . PI.ln.lmeter mc.)surements """'.• 1...1 Ih.•1 Ill\' .11".1 \\,.111l1I Ill\' h·IllI','r.,IIIl·IJ " 7'";.I.lr",·r th,1I1 till' 1\ ,,,1 fidd R,·..ht· Norm I' If' Id f hi' . ~ , • • <" .1 V'SUJ If? or t €' :!.-,soptl'r With ,I", 11 •• ,.,1 1",1.1 ,..1.1",1 """. IIII' "·I1'p,'r.,1 hdJ l'l.mlll\l'tl'r "ll'.,'un'lll""'_ rl'v"JI thp HPJ with,'n th n tft . • , .mporaI f'.€'Id t0 bf? IMgcr'han I Ill' .• n'" wltlHI1 1111' 11.... ,,1 tll'ld It\' l~PJ" (I\lh'ph'lt In.IIl' l'h·lI.lIhJ Th'\fllr:"~lnl) Journal of Clinical Neuro-ophthalmology for which we h.lVe Illl cleM expl.lI,.ltilln, W.l~ .11~11 observed in .m .1Oilll.,1 modeLl' Behr" suggested: I) th.lt tr.lft (esillns .1Iw.1Y~ produce .In <lnisl)C\lri.l (with till' 1.lr~l'r pupil 1'1111tral. lter.ll tI) the tr.l\t lesion), .lnd 2.) Ihis pupil re,lCted tess IVI'II til light. Bl'lI .md TllIll1ll'Slln 17 point llut th.lt Behr's 1',pJ.m.ltilln fllr till' .1nislln'ri,1 is b.,sed 1)(1 the f.lulty .,sslllnptiI111 th.lt till' midbr.lin decuss.ltilll1 l,f the light rdlc' p.lIh i~ llllt .1 50/50 decuss.llilll1 but is prl'lhmlin.,tdy 'f\ISSl'd, It i~ trlll', however, th.lt tht' plll'rer re.l\tilln II) light in Illl' 1.lr~er pupil i~ b.lsed ,In Behr'~ lIther .Is~umptil)n th.lt the d,i.lsm.ll denls~.ltil'n is more nossed th.ln uncrllssed. This. in r",.llity, is IVh.lt lVe ,He Ilbserving ,15 .1 M,HCUS (,unn pupil in thl' I've 1'llnlr.ll.lt",r.,1 Il' the trKt It-silln. While It m.1Y be true th.ll Behr's .InisucI'ri. l is Ill)t prt-senl in J pure tr.let lesion, it is .1151) true th.lt lesions In this .He.l invJriJbly invllive more th.lO just the tr.Kt. All three Ilf I'ur c<lses h.,d .l IJrger pupil contrJl. lter.ll to the trJct lesion, .lses I .1Od 3 h.ld J history (If equJI pupils in the p.,st. Noting that Simple aniSllcori.l C.lO eJsily be overlooked, it is difficult for us to stJte unequivocJlly th.lt the ,IniSOCOria we observed represents Behr's ign, but its presence in all three CJse is at least suggestive. Hoyt l " has described the typical pattern of optic atrophy to be expected following omplete infrageniculate lesions consisting of a temporal pallor (more prominent superiorly and inferiorly) on the side of the trolet lesion with J bowtie p<lttern of atrophy involving a horizontal sector through the disc contralateral to the I sion, This ha. been documented experimentally as well.'~ Kestenbaum,~" although agreeing in principle with this observation, stressed that in reality such bowtie pallor is visible only In some cases. In fact, the pallor may be unifonn over the whole disc or be even more marked temporally in the eye on the ide of the hl:'mianopla. He further stressl:'d that this <ltrophy may take months to develop, as was demonstrated in our case 1, who originally had only light temporal pallor which developed Into a bowtie pattern of atrophy over a I-year period, Similarly, case :2 had only an early sector temporal pallor ipsilater,,1 to the hemianopia at 4 months, possibly reldted to a greater preexisting cup/disc asymmetry on tholl side. Finally, case 3 had no uggestiun of atrophy 2 months postinsult. In dddition, due to the p.lrli.ll nature of the tract lesions, e peci<llly in C,I. (' 3, it is not unreasonable to assume that long-term followup will not reveal the striking pattern described by Hoyt but some subtler variant of thi u h as those cases described by Frisen,~l where (lnly nerve fibN layer changes could be identified, The visual fields in our ca es W('fe llf some interest. None had a complete homonymous hemianopia. Case I had an incongruous right homonymous hemianopia (denser <lbove) with Rid- December 1982 'Connor, et al. doeh's ph('nlJml'n(ln~~ d('monstrated to a V-4E in thc' inferior tfu.ldrJnh bil.,terally (no static present. Hion .. wc'rl' identified in the'e areas; however, 1ll\lVl'nll'nt W.I" c,.l ..ily recognized), Pr('s('nce of this plwnofllc'nllll involving infrdg('ni ulatl:' pathways h.l~ pn'violl~ly b('('n r('porled by Cay ('t al.~:l There W.IS.l .. ignifil'.1111 n'..o!ution of th is hemianopia over time, wilh I1P eh.lngl' in th(' pupillary rca tion , Cl~I' :2 .d~ll h.ld .In incongruous right homonymous Ill'mi.lIl1lpi.l. Fin.llly, C,I!>C' 3 h"d an incomplete innlOgruous l('ft homonymous superior quadranl. mopi.l invplving only th(' mallest i opters. The diff('renC\' in rel.ltive field lo!>s between the two ('yes in ,IS(' 3 .It firsl glanc doe not appear suHid('nl to generate a MMCUS Cunn pupil based on field "symmetry. It is pos ibll:' that surrounding edem.l and the urgical trauma illv Ived in draining her absce re ulled in greater involvement of the pupillary fibers with relative sparing of the visual fibers. What ver the explanation, it appears clear thai a omplete homonymous hemianopia is not a prerequisite for the development of an afferent defect in tract lesions, Furthermore, because most tract lesions also involve surrounding structures, it is not unreasonable to suggest that involvement of the ,matomically separate pupillary fibers may be out of proportion to Involvement of the visual pathway synapsing in the lateral gl:'niculate body, The presence of the M.HCUS Cunn pupil is and should continue to be considered the hallmark of lesions anterior to the chi<lsm ip ilateral to the abnormal pupil. In th rare patient with a tract Il:'sion, equal vi ion bilaterally, and a homonymous hemian pia, the presence of a M.HCUS Cunn pupil ipsilateral to the hemianopid (contralateral to the lesion) localizes the pathology to the optiC tract rather than the suprageniculate pathways even before the typical infrageniculate atrophy develops. Knowledge of this fact can be of practical value in this rare patient in whom the presence of tW,l dpparently sep.HJle Ie ions (i.e.. one c.:lusing the hemiolnopia .lnd the other lesi(ln .lnterillr t(l the chi.lsm c.lUsing .1 M.HCLIS .unn pupil contr.ll.1ter.ll 10 the first) m.1Y le.ld the uniniti.lted tCI further investig.ltion of wh.lI IS in re.llily .1 single Ie. il)n. References I. M,·Cr.lry, LA., III: Li~hl reflC'" .In.HI,mv .md thl? ,,((('r('111 pupill.lrv dde"1. Tr,II1'. AIll, A;'.Ili. 01'11Ih, I/IlI,.I, OI,'/,lrvl1.~"I. 113: ~20-~2co, 1"77. 2, Bunk, R,M.: Th(' pupil. Ill/ lll'hth.tltlll,l. Olll, 7: 1\4", 1"co7. 3. W.,bh, F,B., .111<1 H" ...!, W.F,: Clil1ic.tI l'unl-Oph. Ih.)/nlllhl~Y. V"I, I (Jrd ('d.), Willi.lnlS .wd Will..ins ('"m 1'.1 Ily, F1.1ItimlH''. 1"1''', p. S03. 4. Bell, R.A" .1I1d Tlwmpslll1, H.5.: Rel.lllve .,Herent rupill.lry ddC'(1 III "ptj( Ir.lll hl'mi.lllopsi.I, Am. ]. 0l'hlh.lln101. 85: 53~-540, 1"71\. 5. D'CllllllOr, 1'.5" K.lsd,'n, D., Trl:'dici, T.)., .md Ivan, 233 t )1'11, rr." I .'Ild I'lipil 1).1.· i'lli' M,lr,'lI' 1.1Inn I'llI'd III '·\I"·rIlI"'I1I.,1 11'.1<1 "'""n, ()/,hlh.,/Ill"I,.gv 89: 1,,0-11,,1. 1<)I\Z. .' ~.'Vllh', 1'.1.. I',m,. M.. ~,h.,I/, N I.. d ,II. 1)1'11< tr.ld 'vl1d,,,,,1I'. A I'l'VI<'W ", 21 1'.111t'"e-. 1\1'1/1. Uphlh.l/1111.1. <)0: "~"-l'l'.I, 1"711 7. ",·'klll-.It'll'. 1\.: (111.1<.11 M.·/Ir ..t! "' "ur,,- t )/,III/,.,',""I.'1:le I \.II1,".I/le'" (Zlld ",1.). ( ,1'11111' .'Ild ~I r.lt!III'. It". "w \ "r~. I I)" I, I' 7.\: 7., ~ I.I.h,·r·. I ~ .. Thl' ".I,.d v,,".11 'It'ld 1\1'111. ()/,/IIII.,/. Ill"/. 77: .I~II-JN1. 1",,7 ,). V.m HilI'''''. I M I'h,' 1~1'I1I1.,1 ( .. 111,>:1'''11 ( ,./1 I..IVI·/. (h,lrI,·, l Th,"".I'. ~I'rll,):f... ld, 1'1".\. p. I.'O-I.'Z IL' 1),1('1'[>,"'):. ( •. : r"l'"gr.ll'hv ,,, IIll" I.'vn "I rlld, .111.1 ""ll" 1./ 11ll' hlllll.1I1 1'1'1111.,. ;\,1.1 ()/,hlh.I"""I. (~ul'pl "1 11l3~. I I. I\.up"'r. C. l humbll'V. l. .11,,1 J),'wIH'r. JJ.·l : VUJI1llt, ll,,,,' h"I"I,,).\y ,,1 ,'ptt, IWrV(', IIpli, Ir.ld. ,111.1 1.11<'1'.11 g'·I1I<'UI.I!<' Ilud,'u, ,.1 m,\l1 J AII,II. 101: 3<).' ·101, ").,7 IZ. I{,·,'J, 1-1 .. ,HId 1)1',111",. ~.M: Th.. /."('1111,1/, III I'.,· nnw/rr. ~t •• I" .11It! J(1I1dl< (2".1 ",1.). t) (,,1'.1 CI1'vl'I', ily 1'1'("" L".ld"I1, IOn, p. I.l 13. Wprnid,(', '.: U.'b('r hpmi"pi,.-h" l'upill"l1r(',KllOn. F,.rt,,'hr M('d, I: 411-S3. 11\1\.1. J.1. (:khr. C: Il,.' l"hr(' vI'n d"11 l'urilll·l1b(,wc·).\un~(,11 I" H.'I1t!budl del' ,>:('.,.11I1/('11 IIU.>:(,l1h('II.Ul1d(', (;r"dc ~,ICIllI.'lh V"I ~ (31'.1 •..1./. Du' '''I('I',ulhu,,~,nl('lh. , •.110'11. W. Ll1g('!m,ll1l1, L"lpz,~. 1<l24. rp, .'-1-05 IS. l,'rbl'lt. 1.1.. ,lV 111". 1'1 . ~,hJtz. N,! .. ,111.1 Orr. L. : l'upill,lry ,ij-\'" ill "I'll<' Ir,lll I..,i"n,. In T"rll~ 111 Neu,,'·Oph/ll.I/nlll/",>:I'. H l,lllley Th,lmps,'n. Ed Willi,lm ,lIld Wil~ln~. BJIt,mt>r(', I<l7<l, PI' 1",,-1(\7 10. Clbi,. .W" Clmpl". E C . ,md Alh,'rn. E.. rupdl'lr\' hemi,lkincSl,l in suprJgeniculale Ie ion~, 1\1'< h Oph/ h.l/n10/.93: 1322-/327. 1975. 17. B('II. R.A.. Jnd Thomp on. H.S.: Optic trJet lesions ,lnd pupilJ.Jry .afferent defect. In Topic~ in NeuroOf'h/ I1"lnlll/,,~.v. H, Stanley Thompson. Ed, Wil· II,lm~ .lnd Wilkins, BJJt,more. 1979. pp. 104-100. 11\. Huyl. W,F.. R,us-Montencgro. E.N.• Behrens. M.M.. .,nJ [.I.e!h"fr. R.'.: Homunymous hemi.Jnopie hyp" rIJ~i.1. Fundu'( lIpi, (e,ltures in sl.Jndard red-free IIlum,n"ti'"1 In 3 pJllCl1ts with congenital hemiple) 4,.1 Hr J ()phth,llml'/. 56: 537-535. 1972. J<) Tn·JIlI. T I, (hmidl. R E.. Jnd O·Connor. r.s.: The H"t"p,llh.oI"l!:Y ,,( 1".I,lled Optl Tra t Hemiilllopia. )', "I('r pr('~('nl,llllln, Annudl Mceting of American A',IJ"my"( phlhalmoJogy. All.anl.a. Georgia. 1981, 20 K(,~tc'l1bJum, A,' Clime,,1 Melh"d of euro- I..lphrh.t/rnt>}uXIl [\Jmlll,llll.n (2nd ed.). Grune and "lrJlt"n, In, .. i':('1V Y,.rk, lObI, pp. 187-188. 21 r1'I,('n, L. Hulml'gJJrd. L.. Jnd Rosencrantz. M.: ~'" t<lr uplil Jtr<lphy Jnd h monymou horizontal '(',lur,lnl1p'J 1\ IJI('rJI ehllro,dJ! artery syndrome? J ,"cur,,1 ."('ur,,'ur~ r$~1 hiatry. 41: 37-1-380. 1978. R,dd<l,h. G.G . DIssl'lIJtton of VI ual perceplion due h. IpitJllIliune~with espp lal referen(f,' 10 appre( 1,1I'0n "i m,wement 8r,IIn 40: PI'. 15-57. 1917. Z3 l,'ppl,l. R I . En"lh. R.. tJmp('T, I.B" Wtnkelman. 1.8. ,)nd L,ly, A.I.· The 1{ldd,'ch ph('nomen.>n re\' e,lleJ In neon-"~l< Ip,tJI I,lbc' Ir~I,'n, 81' J Uphtha/1111> 1 55: -Ill'--I20. Ill,1 \ \'rite I,', ,eprtnt~ t,l; f'JIl'll ~ O'C, nn,,,.. .D.. De-pJrtmenl ,,( OrhthJlm"I,'g\'. L'ni\'ersity of Te'\a Health 5"cn,' ('nIN...In Ant,'n;,' Te\J. ;i2~-I loum.J1 of Clinical Neuro-ophlhalmology ,.......------ |