Bilambdoid and sagittal synostosis: Report of 39 cases

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1 SNI: Peditric Neurosurgery OPEN ACCESS For entire Editoril Bord visit : Editor: Sndi Lm, MD University of Chicgo Medicl Center, Chicgo, IL, USA Originl Article Bilmdoid nd sgittl synostosis: Report of 39 cses Nthlie Chivoret, Eric Arnud, Kim Girudt, Frzer O Brien, Leslie Pmphile, Philippe Meyer 1, Dominique Renier, C. Collet 2, Federico Di Rocco Crniofcil Unit, Deprtment of Peditric Neurosurgery, 1 Deprtment of Anesthesi, Hôpitl Necker Enfnts Mldes, 2 Service de Biochimie, Hôpitl Lrioisière, APHP, Pris, Frnce E mil: Nthlie Chivoret ntchivoret@gmil.com; Eric Arnud eric.rnud@php.fr; Kim Girudt kim.girudt@php.fr; Frzer O Brien frzerpmorien@gmil.com; Leslie Pmphile leslie.pmphile@php.fr; Philippe Meyer philippe.meyer@php.fr; Dominique Renier dominique.renier@gmil.com; C. Collet corinne.collet@php.fr; *Federico Di Rocco federicodirocco@gmil.com *Corresponding uthor Received: 01 Decemer 17 Accepted: 06 Decemer 17 Pulished: 11 Octoer 18 Astrct Bckground: Bilmdoid nd sgittl synostosis (BLSS), lso clled Mercedes Benz synostosis, is multisuturl crniosynostosis tht hs een descried s specific entity. However, this synostotic pttern cn lso e found in syndromic crniostenosis. To etter define this entity we reviewed our experience with ilmdoid nd sgittl synostosis. Methods: We serched our prospective dtse for cses of ilmdoid nd sgittl synostosis mong ll types of crniosynostosis. Two groups were distinguished ptients with isolted BLSS nd the group of syndromic crniostenosis for whom BLSS ws oserved t initil presenttion. We reviewed the clinicl findings, ssocited diseses, nd their mngement specificlly for isolted BLSS ptients. Results: Thirty nine ptients were dignosed with ilmdoid nd sgittl synostosis mong 4250 cses of crniosynostosis treted in our deprtment over period of 42 yers. Among them, 8 were finlly dignosed s Crouzon syndrome. Of the 31 ptients identified with isolted ilmdoid nd sgittl synostosis, 25 (81%) were mles nd 6 (19%) were femles. The verge ge t dignosis ws 17 months. At dignosis, 16% of the popultion presented with ppillry edem nd 58% posterior digitte impressions. Two types of crniofcil dysmorphy were oserved pttern with nrrow occiput (71% of cses) nd pttern with dolichocephly (29% of cses). Cereellr tonsillr hernition ws the most frequently ssocited mlformtion (61% of the isolted BLSS). Surgicl mngement evolved during the yers, nd severl surgicl techniques were used to tret ptients with BLSS, including isolted iprietl vult remodeling, posterior vult remodelling, nd posterior vult expnsion with internl or externl distrction. In some cses, crniocervicl junction decompression ws lso performed. The men follow up ws 82 months (7 yers). The overll mentl Access this rticle online Wesite: DOI: /sni.sni_454_17 Quick Response Code: This is n open ccess journl, nd rticles re distriuted under the terms of the Cretive Commons Attriution-NonCommercil-ShreAlike 4.0 License, which llows others to remix, twek, nd uild upon the work non-commercilly, s long s pproprite credit is given nd the new cretions re licensed under the identicl terms. For reprints contct: reprints@medknow.com How to cite this rticle: Chivoret N, Arnud E, Girudt K, O Brien F, Pmphile L, Meyer P, et l. Bilmdoid nd sgittl synostosis: Report of 39 cses. Surg Neurol Int 2018;9: Surgicl Neurology Interntionl Pulished y Wolters Kluwer - Medknow

2 development ws within norml limits in most children, ut mentl dely ws found in 25%. Conclusion: Bilmdoid nd sgittl synostosis constitute n isolted entity in lmost 80% of the cses, wheres in the remining 20% it is prt of fciocrniosynostosis syndrome. Two phenotypes my e found. Erly surgicl mngement is indicted, nd severl techniques cn e used in this heterogeneous popultion. A cereellr tonsillr prolpse is present in mjority of cses. Key Words: Bilmdoid nd sgittl synostosis, Chiri mlformtion, complex crniosynostosis, epidemiology, surgicl strtegies, outcome, ppilledem INTRODUCTION Crniosynostosis occurs in one out 2000 live irths. [8] In mjority of cses, the crniosynostosis is isolted, limited to single suture, nd without ssocited genetic nomly. In one fifth of the cses, it occurs s prt of genetic syndrome nd often ffects severl sutures. [2,3] In such syndromic cses, most often oth coronl sutures re involved. Aprt from these two forms, nother group cn e descried multisuturl synostosis without n identified genetic syndrome tht is usully referred to s multisuturl crniostenosis or complex crniostenosis. This complex form of crniostenosis hs een oserved in one of every 20 cses of crniostenosis, nd my occur in multiple comintions. [9] Becuse of the difficulty in defining identifile sutypes in this complex group, little hs een reported on multisuturl crniostenosis. [18] However, it hs een shown tht these forms re ssocited with different rin nomlies, tht they my require multiple surgicl procedures, nd tht they re ssocited with developmentl dely more frequently thn the isolted forms. [4,5,7] For these resons, complex cses my require multidisciplinry tem with crniofcil expertise. However, with the improvement of genetic techniques, this group is progressively reducing. In fct, new genes hve een recently found to e involved in some cses such s TCF12 nd ERF, [10,20] llowing proper nosologicl identifiction. It should e noted tht, in newly identified syndromes, regrding the clssicl crniofcil syndromes, the coronl sutures re most often involved. In the present report, we retrospectively reviewed the complex synostosis not involving the coronl sutures, nd in prticulr, the trisuturl pttern of complex crniostenosis which presents with sgittl nd ilmdoid involvement (BLSS). Neuhuser et l. reported in 1976 [17] the first series of 7 cses of crniostenosis with fusion of oth lmdoid sutures nd the sgittl suture ssocited with short stture nd developmentl dely; [1,2,16] they employed the term crniofcil dysynostosis. In 1998, Moore et l. introduced the term Mercedes Benz to define BLSS due to the chrcteristic ppernce of the fused sutures on three dimensionl CT imging. [15] The uthors did not find n ssocition with short stture. Little is known out BLSS. It seems to e heterogeneous disese. To etter define this entity, we retrospectively serched in our prospective dtse cses of ilmdoid nd sgittl synostosis mong ll types of crniosynostosis. This study represents, to the est of our knowledge, the lrgest pulished series of ptients with BLSS. We reviewed the clinicl findings, epidemiologicl dt, ssocited diseses, nd mngement for these ptients nd discuss the surgicl strtegy. PATIENTS AND METHODS Popultion The study ws conducted mong consecutive ptients with confirmed BLSS dignosed etween 1972 nd 2014 t Necker Enfnts Mldes. We reviewed the clinicl records, rdiologicl findings, nd their mngement. The clinicl dignosis of ilmdoid nd sgittl synostosis ws confirmed on X ry, skull computed tomogrphy (CT), nd for the most recent cses three dimensionl CT imges, showing ilmdoid nd sgittl synostosis with open coronl sutures. RESULTS Among 4250 cses of crniosynostosis treted in our deprtment, 39 ptients were dignosed with ilmdoid nd sgittl synostosis (0.9% of the glol popultion) over period of 42 yers. The men ge t presenttion ws 23 months (3 dys to 8 yers). Eighty percent of this popultion ws mle. The trisuturl pttern of crniostenosis ws isolted in 31 cses (lmost 80% of the cses), wheres syndromic crniostenosis ws identified in 8 cses (8 ptients demonstrting during follow up clinicl Crouzon syndrome which ws geneticlly confirmed in recent ptients). Ppillry oedem ws present in 6 cses t dignosis (15% of the cses). Isolted BLSS (n = 31) Of these 31 ptients identified with isolted ilmdoid nd sgittl synostosis, 25 (81%) were mles nd

3 6 (19%) were femles. The men ge t dignosis ws 17 months (4 dys to 88 months). The ge t dignosis ws less thn or equl to 6 months in 52% of the cses. However, the men ge t dignosis decresed over the yers due to etter recognition of crniofcil nomlies y peditricins nd improvement in rdiologicl investigtions. This trend ws lso shown y the increse in the numer of ptients dignosed with BLSS during time [Figure 1]. The men pternl ge ws 36 nd the men mternl ge ws 30. Among them, 23 ptients originted from Europe, 4 from Mghre, nd 1 from Su Shrn Afric. For 3 ptients, dt were unknown. One cse of consnguinity ws found ut no dditionl fmily memers with crniosynostosis were reported. Two ptterns of crnil fetures could e distinguished: A pttern with nrrow occiput in lmost 71% of the cses [Figure 2]: short BLSS with coup de serpe. A frontl ossing ws lso ssocited in hlf of the cses A pttern with dolichocephly nd occipitl ossing in 29% of the cses [Figure 3]: long BLSS. The clinicl findings oserved in BLSS re descried in Tle 1. Associted nomlies At dignosis, 16% of this popultion of BLSS presented ppillry edem nd 58% posterior digitte impressions. Multiple centrl nervous system (CNS) mlformtions were found in ptients with BLSS. The most commonly reported were cereellr tonsillr hernition, (19 ptients; 61% of isolted BLSS popultion), enlrged ifrontl surchnoid spces (12 ptients; 39% of the cses), venous nomlies (11 ptients; 35% of the cses), enlrgement of the cererl ventricles (10 ptients; 32% of the cses), syringomyeli (1 ptient; 3% of the cses), microcephly with ilterl defness (1 ptient; 3% of the cses), nd gyrtion nomlies (1 ptient; 3% of the cses) [Tle 2]. Tle 1: Phenotype in ptients with isolted ilterl lmdoid nd sgittl synostosis or Mercedes syndrome Physicl chrcteristics Numer of ptients Percentge of ptients Flt occiput Frontl ossing Dolichocephly 9 29 Biprietl nrrowing 6 19 Prominent occiput 5 16 Sgittl ossing 4 13 Retrocoronl nrrowing 3 10 Hypertelorism 3 10 Turricephly 3 10 Though tonsillr hernition concerned lmost two third of the popultion, only 2 symptomtic cses were reported. Similrly, though 32% of the ptients presented with n enlrgement of the cererl ventricles, no cses of ctive hydrocephlus were found nd no tretment ws required. Interestingly, the popultion of BLSS with cereellr tonsillr hernition presented more commonly other nomlies such s ventriculr dilttion compred to those without cereellr tonsillr hernition. Over hlf of these ptients with the ssocition of ventriculr diltion nd cereellr tonsillr hernition presented with symptoms tht prompted surgicl decompression of the formen mgnum. Extr CNS mlformtions were lso present in this popultion of isolted BLSS. One ptient presented syndctyly of digit IV nd V nd low set ers nd Figure 1: Evolution of the numer of cses in time Figure 2: Three dimensionl CT showing ilterl lmdoid nd sgittl synostosis with nrrow occiput ( short BLSS ) in posterior view () nd lterl view (). We cn notice concve occipitl one, severe posterior digitte impressions of the skull ( nd ), nd the descent of the cereellr tonsils on sgittl CT scn reconstructions (c) Figure 3: Three dimensionl CT scn showing pttern of ilterl lmdoid nd sgittl synostosis with dolichocephly nd occipitl ossing ( long BLSS ) in posterior view () nd lterl view () nd T1 sgittl MRI exm showing long BLSS pttern with moderte ventricles dilttion nd smll posterior foss (c) c c

4 nother rchydctyly. One ptient presented multiple mlformtions with costl, verterl, nd urogenitl mlformtions. Another ptient presented isolted congenitl urogenitl mlformtion. No genetic syndrome ws identified in these cses. Surgicl results Of the 31 ptients, 25 hd reconstructive surgery (81%). The men ge t surgery ws 21 months (3 months to 8 yers). For 6 ptients, no surgery ws performed. Five ptients were not operted ecuse prents refused the tretment or ecuse the child ws considered too old due to delyed dignosis. In one child, due to severe hemorrhgic compliction t the eginning of the procedure, the originlly plnned crnil remodelling ws not performed nd no second surgery ws performed. Two min types of crnil vult reconstruction were used in our experience (1) posterior decompression nd (2) prietl remodelling. Posterior decompression ws pplied in 17 ptients. All ptients presented short BLSS, i.e., the phenotype with occipitl nrrowing. In 11 ptients, prieto occipitl decompression without internl or externl distrction ws performed nd sgittl crniectomy ws comined in 4 cses. Formen mgnum decompression ws ssocited if tonsillr prolpse ws oserved (in 5 cses). For the most recent cses with occipitl nrrowing (6 cses), prieto occipitl decompression with externl distrction ws performed without formen mgnum decompression [Figure 4]. Tle 2: Centrl nervous system ssocited nomlies found in our popultion of isolted BLSS Associted nomlies Numer of cses Cereellr tonsils hernition 19 Enlrged surchnoid spces 12 Venous nomlies 11 Ventricles dilttion 10 Syndctylie 3 Syringomyeli 1 Microcephly 1 Gyrtion nomlies 1 Another type of crnil vult remodelling, prietl remodelling with sgittl crniectomy, ws used in 8 ptients [Figure 5]. Six ptients presented long BLSS, i.e. the phenotypicl pttern with dolichocephly. This technique ws lso pplied in two ptients who presented short BLSS with occipitl nrrowing, ut t follow up they showed n unstisfctory outcome from cosmetic viewpoint. In one of these two ptients, there ws limittion of crnil vult remodelling ecuse of hemorrhgic complictions; hence, second procedure ws required with posterior decompression. In the other cse, second procedure ws needed ecuse of recurrence of signs of intrcrnil hypertension during the follow up period. In ssocition with these two techniques of remodelling, surgicl decompression of the crniocervicl junction ws performed in 8 ptients. In 6 cses, this decompression ws performed during the sme nesthesi for the crnil vult remodelling. In 2 cses, it ws performed during seprte procedure (2 cses of symptomtic tonsillr hernition). One of these two symptomtic ptients required second procedure of crniocervicl junction decompression ecuse of development t follow up of motor deficit nd increse in the size of syrinx cvity. This ws cse of pttern of short BLSS with nrrow occiput. Surgicl complictions were oserved in few ptients. Dur mter ters were oserved in 5 ptients nd locl infection in one cse. Mjor complictions s venous sinus injury occurred in one cse. Overll, of the 25 ptients operted on, 3 required more thn one surgery 1 ptient ecuse of infection, 1 required 2 surgeries ecuse of d functionl result fter formen mgnum decompression, nd finlly third ptient required 3 opertions due to hemorrhgic complictions during the first procedure with limittion of crnil vult remodelling nd ecuse of d esthetic result fter the second procedure. Follow up The men follow up ws 82 months (7 yers). No dditionl synostosis ws oserved during the follow up Figure 4: A schemtic view of short pttern of BLSS () nd representtion of the optiml surgicl strtegy in this type of BLSS, posterior crniectomy with externl distrction () Figure 5: A schemtic view of long BLSS () nd the optiml surgicl strtegy for this type of BLSS, sgittl crniectomy with prieto occipitl remodelling ()

5 period. At the lst follow up, 8 ptients (25% of ptients) presented moderte to severe developmentl dely. In this popultion, 4 ptients presented with dely in dignosis (ge t dignosis etween 20 nd 51 months) nd one surgicl compliction with notle limittion of crnil vult remodelling. Of the 4 ptients with delyed dignosis, 3 demonstrted severe signs of intrcrnil hypertension t dignosis nd the other microcephly with no crniofcil surgery eing performed. Aesthetic result ws considered good or excellent in 75% of the cses nd insufficient in the rest of the cses. Insufficient esthetic result required second procedure in only one cse. Crouzon syndrome (n = 8) Among the overll popultion of BLSS, Crouzon syndrome ws identified nd geneticlly confirmed in 8 ptients. Six ptients were mles nd 2 were femles. The men ge t dignosis ws 44 months (4 102). The men pternl ge ws 37 yers nd the men mternl ge ws 33 yers. DISCUSSION BLSS is rre pttern of complex crniostenosis. Only 39 cses were found mong the popultion of 4250 crniosynostosis mnged t Necker hospitl etween 1972 nd 2014 (0.9%). Only 44 cses were reported in the literture. [1 3,12 17,19] The clinicl fetures nd surgicl mngement of the pulished cses re summrized in Tle 3. Interestingly, in our series, though 79% of the cses (31 ptients) hd n isolted BLSS, 8 children ctully hd Crouzon syndrome (21%). In cses of Crouzon syndrome, no involvement of the coronl sutures ws found t dignosis or during follow up. Becuse of the high incidence of this type of syndrome, genetic testing should e considered in cse of n infnt with BLSS to rule out FGFR2 muttion, llowing proper mngement nd prentl counseling. Phenotypes Two types of deformtion cn e distinguished in BLSS. The most frequent phenotype in our series ws chrcterized y reltive rchycephly with occipitl nrrowing the short BLSS. A similr phenotype ws oserved y Neuhuser et l. [17] The second sutype ws scphocephly like deformtion with dolichocephly nd occipitl ossing with little or no impct of the closure of the lmdoid sutures on the deformtion ( long BLSS ). This sutype vrition could e due to the time of onset of the lmdoid closure, locliztion of the lmd, nd progression of the closure of the lmdoid nd sgittl sutures. The possile scphocephly like phenotype of BLSS rises the question of the proper nosologicl identifiction sed purely on the clinicl ppernce. This is n rgument for the role of preopertive CT or Tle 3: Description of the 44 pulished cses of ilmdoid nd sgittl crniostenosis Neuhuser et l. 1976: 7 ptient AL Torki et l. 1998: 1 ptient Moore et l. 1998: 3 ptients Grosso et l. [11] 2004: 1 ptient Shiihr et l. 2004: 1 ptient ND: Not determined Gender: M/F Ethnicity 3/4 4 ptients: Hispnic/ Ltino Developmentl dely Phenotypic pttern Other nomlies Genetic syndrome 3 ptients 2: Mcrocephly 1: Hypertelorism 1: Dolichocephly 3: ND M Ar Yes Dolichocephly Prominent occiput Frontl ossing Hypertelorsim Low set ers Midfcil hypoplsi 6: Short stture 2: Seizures 2: Hydrocephlus 1: Agenesis corpus cllosum Fcil nomlies Agenesis of corpus cllosum Seizures Cereellr Numer/type hernition of surgicl procedures ND ND ND Norml ND ND 2/1 Austrlin No ND ND No ND Yes (3 Ptients) M ND Yes Scphocephly, Inguinl herni, nd No No ND prominent occiput, frontl cryptorchidism, prtil consnguinity ossing, low frontl genesis of the corpus hirline, deep set eyes, cllosum hypertelorism, ulous nose, nd low set ers F Jpnese No Oxycephly, hypertelorism, low set, mlformed ers Crniofcil normlities, crdic mlformtions, trunk nd lim mlformtions Trisomy for 5q34 qter/extr copy of MSX2 ND Suoccipitl crniectomy t 13 months

6 X ry in the preopertive evlution of crniostenosis with dolichocephlic presenttion, though such exmintion crries potentil rdition relted risks. The use of nonirrditing methodologies to ssess the ptency of the lmdoid sutures, especilly ultrsounds, should e promoted to llow proper identifiction of the long BLSS. Associted nomlies MRI remins the optiml imging modlity in the ssessment of CNS ssocited nomlies in this popultion. The ptients in this study hd evidence of cereellr tonsil s hernition, venous nomlies, nd ventriculr enlrgement, which re perhps relted to the significnt ony normlity ssocited to the fusion of the lmdoid sutures. The most frequent ssocited CNS nomly reported in our series ws the tonsillr hernition presenting in 61% of isolted BLSS. Such n ssocition etween tonsillr hernition nd crniofcil synostosis, first descried in 1972 y Sldino et l. [21] is frequent in multisuturl syndromic crniosynostosis, [4] though less common t dignosis thn initilly reported in recent studies sed on genetic confirmtion of FGFR2 muttions (38.1% of the cses with Crouzon syndrome). [5,6] The physiopthology of such hernition could e explined y the premture fusion of the posterior crnil vult which would result in disproportion etween smll posterior foss nd hindrin growth. However, it could lso e explined y congenitl nomlies of the cereellum nd rin stem. [4] As expected, syrinx (1 cse) nd centrl pne (2 cses) were oserved in the group of ptients with cereellr tonsillr hernition. MRI is lso useful during the follow up period to evlute the evolution of the tonsil hernition. Becuse rdiologicl ltertions my pper efore the child ecomes symptomtic, we dded routine MRI control in our follow up exmintions. Oviously, the follow up ssessments will e more frequent if symptoms of Chiri occur. One third of the ptients presented ventriculr dilttion in our series. However, no ctive hydrocephlus ws oserved nd no ptient required tretment for cererospinl fluid (CSF) disorders. Enlrged ventricles re frequent in complex crniostenosis. Two min pthogenic fctors my explin the ventriculr enlrgement mechniclly incresed CSF outflow resistnce due to compression of posterior foss nd rised pressure secondry to venous outflow ostruction. These pthogenic mechnisms my coexist in BLSS. [23] As for syndromic cses, ventriculr size is ssocited with the presence of tonsil s hernition. [6,22] In fct, enlrged ventricles were found in 8% of the cses without tonsillr hernition, ut in 44% of cses with tonsillr hernition in our series. No difference ws found etween ptients with or without cereellr tonsillr hernition concerning the venous nomlies (present in 33% of ech sugroup), lthough hernition of the cereellr tonsils is ssocited in the literture with venous nomlies nd venous hypertension. [12] Venous nomlies such s jugulr stenosis or thromosis, lterl sinus compression, sgittl sinus compression, or hypoplsi of lterl sinus were found in 35% of isolted BLSS in our study. Like other multisuturl crniostenosis, BLSS cn e ssocited with intrcrnil hypertension. In our series, 16% of the ptients presented t the time of dignosis ppillry edem nd 58% posterior digitte impressions. This is nother rgument to etter identify this pttern of crniostenosis for n erly surgicl mngement to prevent ophthlmologic nd neurologic deteriortion. Surgicl mngement Severl surgicl techniques cn e used in BLSS. The surgicl mngement my differ ccording to the two phenotypic ptterns. Indeed in long BLSS, i.e. dolichocephly like, the gol ws shortening the nteroposterior length y opening the premturely fused suture ssocited with iprietl remodelling. Conversely, in short BLSS, i.e. rchycephly with occipitl nrrowing, the gol ws skull elongtion y posterior decompression with or without distrction. For ll recent cses, technique of externl distrction osteogenesis ws used. The use of externl distrction (two or three) for clvri vult expnsion is sfe nd efficient method offering the importnt dvntge of controlling the vectors of distrction, nd llowing grdul expnsion. Furthermore, the distrctors llow the child to rest supine in the postopertive period. This technique seems to e effective to tret the group of short BLSS with occipitl nrrowing. The question whether to open the formen mgnum or not in symptomtic ptients is still deted. Despite preventive erly opening, there is risk of secondry stenosis nd symptom ppernce during follow up. Therefore, some uthors hve recommend to perform surgery fter 12 months of life to reduce the risk of needing new surgicl procedure for secondry stenosis of the formen mgnum with the rgument tht the likelihood of durl regenertion of one would e lower t this lter ge. [8] However, delying the crnil decompression crries the risk of incresing the crnioencephlic disproportion, thus ggrvting the tonsillr hernition nd, more importntly, incresing the risk of prolonged rised intrcrnil pressure nd its consequences. For this reson, surgicl tretment ws indicted in our recent cses efore 12 months of ge in ll ptients with BLSS independent of the tonsillr hernition. Our study crries some limittions; ecuse of the rrity of such complex sutype, the period of the study ws extremely long. Surgicl nd nesthetic procedures

7 evolved during the lst decdes nd s such reson; different techniques were pplied in this popultion. Moreover, the rrity nd heterogeneity of this complex crniostenosis hinder the possiility of rndomized trils on lrge series to compre the different techniques. CONCLUSION We presented 39 cses of ilmdoid nd sgittl synostosis (BLSS). This lrge series llow us to descrie this entity nd chrcterize the clinicl fetures, evolution, nd surgicl mngement of this rre multisuturl crniostenosis. BLSS could e found in syndromic forms, i.e. Crouzon syndrome, underlying the importnce of genetic testing. Nevertheless, in most cses in this series (31 cses), BLSS remined n isolted entity with no dditionl synostosis oserved t follow up nlysis. Two min phenotypes cn e found ssocited with trisuturl synostosis the short BLSS nd the long BLSS. Becuse these children, especilly when presenting with the ltter phenotype, my e misdignosed, cre must e tken to nlyze the ptency of the lmdoid sutures during clinicl exmintion nd on eventul rdiologicl exmintions (ultrsounds, CT, or MRI). MRI evlution is recommended in the mngement of these ptients to identify ssocited nomlies nd pln the surgicl procedure. The most frequent ssocited nomly is cereellr tonsillr hernition. Venous nomlies nd ventricles enlrgement were lso oserved. Such high incidence of tonsillr hernition in BLSS compred to other crniostenoses cn e explined y the erly involvement of lmdoid sutures nd smll posterior foss. Erly surgicl correction seems to e required in this popultion of BLSS to try to reduce the risk of developmentl dely. Finncil support nd sponsorship Nil. Conflicts of interest There re no conflicts of interest. REFERENCES 1. Al Torki NA, Sry MA, Al Twri A, Al Kndri NH, Al Awdi SA. Crniofcil dyssynostosis with cryptorchidism nd norml stture. 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