<%server.execute "isdev.asp"%> Outcomes of Chiari malformation III: A review of literature Elbaroody M, Mostafa HE, Alsawy MF, Elhawary ME, Atallah A, Gabr M - J Pediatr Neurosci
home : about us : ahead of print : current issue : archives search instructions : subscriptionLogin 
Users online: 824      Small font sizeDefault font sizeIncrease font size Print this page Email this page

  Table of Contents    
Year : 2020  |  Volume : 15  |  Issue : 4  |  Page : 358-364

Outcomes of Chiari malformation III: A review of literature

1 Department of Neurosurgery, Cairo University, Giza, Egypt
2 Department of Neurosurgery, Benha University, Benha, Egypt

Date of Submission19-Oct-2019
Date of Decision15-Jan-2020
Date of Acceptance24-May-2020
Date of Web Publication19-Jan-2021

Correspondence Address:
Dr. Mohammad Elbaroody
Al-Saray Street, El Manial, Cairo 11956.
Login to access the Email id

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/JPN.JPN_135_19

Rights and Permissions



Purpose: Chiari malformation type III (CM III) is the rarest type compared to other types of CMs. CM III usually reported as sporadic case reports which reflect the rarity of this anomaly. We report two cases of operated CM III at our institute with a reasonable outcome and reviewed the literature to illustrate the variability of prognosis and related hydrocephalus. Materials and Methods: We operated two cases of CM III in our hospital followed by ventriculoperitoneal shunt (VPS) placement with an accepted neurological outcome at 10 and 6 months follow-up. We reviewed the literature for other cases of CM III with focusing on prognosis to illustrate the real image of reported prognosis and related hydrocephalus. Results: After follow-up for 10 and 6 months, respectively, both cases had mild developmental delays. In this review, we report 51 cases of CM III over the last 30 years since 1989, there was slight male predilection, hydrocephalus was evident in 27 cases which was almost managed with VPSs and was evident in seven deaths. Conclusion: CM III is a rare anomaly which usually carries a bad prognosis, but death is not ultimate, and there may be a minority who carry good prognosis. This bad prognosis pushes some parents to refuse surgery otherwise repair should be done. With good pre- and postoperative care, physical therapy, and follow-up, the outcome is reasonable.

Keywords: Chiari 3 malformation, Chiari III, encephalocoele, hindbrain, prognosis

How to cite this article:
Elbaroody M, Mostafa HE, Alsawy MF, Elhawary ME, Atallah A, Gabr M. Outcomes of Chiari malformation III: A review of literature. J Pediatr Neurosci 2020;15:358-64

How to cite this URL:
Elbaroody M, Mostafa HE, Alsawy MF, Elhawary ME, Atallah A, Gabr M. Outcomes of Chiari malformation III: A review of literature. J Pediatr Neurosci [serial online] 2020 [cited 2023 May 27];15:358-64. Available from: https://www.pediatricneurosciences.com/text.asp?2020/15/4/358/307360

   Introduction Top

Hans Chiari reported three types of hindbrain dysplasia according to the degree of descent of cerebellum after dissection of children’s autopsies.[1]  Chiari malformation More Details (CM) type III reported as low occipital and/or high cervical encephalocoele and herniated posterior fossa dysplastic contents.[2] CM type III is an extremely rare anomaly with much more poor neurological outcome, developmental delay, and mortality compared to other types to CMs.[3] We report surgical repair of two cases of CM III with a reasonable prognosis and review of the literature for cases of CM III with focusing on prognosis and related hydrocephalus.

   Methods Top

Review of literature

PubMed search was done using terms “Chiari III,” “Chiari 3,” “malformation,” and “encephalocele” in a single and combination manner. Only articles written in English are included and articles mentioning other types of Chiari malformation other than type III are excluded.

Case Reports

Four- and 6-month-old female infants presented to our neurosurgery department in Cairo university hospitals in December 2018 and April 2019 subsequently with occipital swelling after birth that was expanding with their growth. Both infants had non-consanguineous parents and the mothers of both cases did not receive antenatal care as they live in rural areas, so they were not diagnosed until birth. No relevant history from both mothers during pregnancy. By examination, both had a normal tone in four limbs as well as reflexes, lax Anterior fontanel, and soft swelling in the occipital region covered by normal intact skin [Figure 1]A and [Figure 2]A, respectively], no spells of apnea reported and the infants had a normal cry. Mild developmental delay in milestones was evident in both of them. Cranial computed tomography (CT) showed a small defect in the posterior fossa region. Magnetic resonance imaging (MRI) showed small posterior fossa, herniation of cerebellum surrounded by cerebrospinal fluid (CSF), no apparent hydrocephalus nor syringomyelia [[Figures 1B] and [2B], respectively], and herniation of part of brain stem down to the cervical canal detected in the second case [[Figure 2B]. Magnetic resonance venography (MRV) confirmed the patency of venous sinuses in both of them. In both cases, we performed primary repair through dissection in anatomical layers till reaching the bony edge of posterior fossa then removal and excision of herniated cerebellum till the bony edges because it is mostly contused and nonfunctioning [Figure 3], then untethering of the cerebellum from the bony edge to avoid the growth and recurrence of herniation again because this potential space that the cerebellum allowed easily to grow and finally closure of the dura with fascial graft completely to minimize CSF leak. Both cases were extubated postoperatively and on the second and the fourth day, respectively, the infants developed symptoms suggestive of increased intracranial tension in the form of repeated vomiting with bulging Anterior fontanels, CT brain showed hydrocephalus, and a ventriculoperitoneal shunt was placed for both of them and both were discharged 1 week later in good status and no deterioration. Follow-up for both cases 10 months and 6 months, respectively, showed both of them caught the supposed milestones with mild delay. The literature included all cases of CM III; i.e., the classic occipitocervical defect with herniation of posterior fossa contents and the cervical or occipital that are included in the expanded classification by many authors.[4] We found 30 case reports and two case series[5],[6] with 51 as a total number of reported cases over 30 years from 1989 till 2019 as shown in [Table 1].
Figure 1: (A) Occipital mass in first 4-month-old child. (B) MRI T2 sagittal view for the child showing herniation of cerebellum surrounded by CSF through low occipital defect

Click here to view
Figure 2: (A) Occipital mass in second 6-month-old child. (B) MRI T2 sagittal view showing herniation of cerebellum surrounded by CSF through low occipital defect and downward displacement of brain stem

Click here to view
Figure 3: Describe the cranial part of surgery. * indicates the cranial part, # indicates the caudal part toward the cervical spine, (1) points to normal cerebellum, (2) points to the bone of posterior fossa from inside, the red arrow points to the bony edges of posterior fossa after coagulation and removal of herniated cerebellum, which is the cut off point for our removal

Click here to view
Table 1: The results of literature review for cases of CM III

Click here to view

Most of the cases reported radiological diagnosis with MRI study, exact structures included in the encephalocoele, local examination of the encephalocoele, and the neurological status of the child. There was no privilege for a specific gender; there were 23 males, 21 females, 6 cases in which gender was not mentioned, and a single stillbirth case. Both of our cases were female infants. Hydrocephalus was evident in 27 cases (56%); in 19 cases, hydrocephalus was diagnosed preoperative, in eight cases it was postoperative, and hydrocephalus was not evident in 19 cases (40%) neither preoperative nor postoperative with follow up ranging from 12 months up to 2 years.[4],[24] The status of ventricles was not mentioned in three cases[7],[10] and dilated ventricles was a description in two cases.[10],[28] In our two cases, VPS was done postoperative due to hydrocephalic changes. The prognosis of CM III is not so dismal as predicted or reported by some authors. There was a single stillbirth case.[28] Seven cases died, in which two of them died 8 months[21] and 4 months,[23] respectively, postoperatively due to chest infection. Thirty-three cases had various degrees of motor and mental developmental delays, seizures, weakness, and nasogastric feeding, and the parents refused surgery in two kids. Although partial improvement or good development is not the main outcome, it was reported in minor cases. Both our cases have mild developmental delays and are doing well till 10 and 6 months postoperatively.

   Discussion Top

CM type III was first reported by Hans Chiari as herniated cerebellar tissue through bony defect associated with bifid cervical spine.[19],[35] Cakirer[17] reported that up to 70% of cases of CM III have incomplete fusion at the posterior arch of C1. The presence of occipital and/or cervical defect and neural tissue herniation are essential for diagnosis that may be associated with other anomalies.[4] Many authors have considered occipital and/or cervical encephalocoele with cerebellar tissue within the sac and displaced brain stem downward in the cervical canal as the criteria for CM III diagnosis.[1],[10],[26],[36] Young et al.[4] cleared that cervical myelomeningocele or occipital encephalocoele are different entities and misdiagnosed as CM III while the classic picture is occipitocervical defect with herniated posterior fossa dysplastic contents inside the encephalocoele or CSF sac.

The pathogenesis behind CM III is not clear and may be related to improper neutralization during the extension of ventricles giving the chance for cerebellum and brain stem prolapse.[32],[37] Other theory that could explain the resultant occipitocervical defect is the persistent leakage of CSF with subsequent failure of closure of neural tube and ossification centers.[16] Although the dark reported prognosis of CM had been changed from being incompatible with life[38] to be dismal even after repair,[12],[13],[14],[15] other authors considered occipitocervical encephalocoele is not a must for bad prognosis. There are some factors that can predict the prognosis such as neurological signs at birth like difficulty in breathing and swallowing, hypotonia, and muscle weakness;[4] in our cases, there is only mild delay in developmental milestones.

MRI brain is the standard method for accurate anatomical diagnosis for CMs and for the detection of associated anomalies like kinking of the medulla, beaking of the quadrigeminal plate of the tectum, syrinx of the spinal cord, and shallow posterior fossa,[9],[10] and some neurological symptoms like cranial nerves palsy, hypotonia, and respiratory compromise may be owed to those abnormalities.[14] MRV has additional preoperative importance for localization of venous sinuses and detection of their patency; double and triple division of superior sagittal sinus has been reported.[16],[19] This information could prevent massive bleeding.

The main aim of treatment is the closure of the dura in a water-tight manner as possible and CSF diversion if hydrocephalus is present that could be done before or after the repair.[12],[16],[20] In case of a large bone defect, Furtado et al.[22] reported the use of methyl-methacrylate cranioplasty flap and occipital scalp rotational flap based on occipital artery to close the defect. Amputation of herniated neural tissue may be obligatory for proper closure of the defect.[4] We used the bony edges of the posterior fossa as a cut-off point for excision.

Reported pathological examination of these tissues notified that those tissues were not functional gliotic and fibrotic tissues and were evidence of heterotopias.[8],[13],[28] Zolal et al.[23] could identify the corticospinal tract with the herniated sac using Diffusion Tensor imaging which added information about the functionality of the tissues.

Factor that could affect the outcome of surgical repair: timing of repair, neurological status, size of encephalocele and its covering, closed or ruptured sac, and respiratory distress.[5],[20],[26] In cases of large encephalocele that were accompanied by severe respiratory distress due to compressed brain stem, it is possible to relieve the compression gradually through drainage of CSF from the sac through external drain along 10 days, this will avoid rapid decompression then surgical repair came later on.[15] Although surgical repair can improve the prognosis, postoperative complications like thrombosis of the sagittal sinus were reported.[10],[17]

CSF shunting is not mandatory in all cases and CSF diversion first policy may be the convenient decision if posterior fossa is crowded with eventual obstructive hydrocephalus or if the encephalocoele is not covered with full skin.[2],[17] Some authors reported that hydrocephalus is a constant finding in all cases,[39] whereas Işik et al.[5] reported that the incidence of hydrocephalus is 88% in CM III. Maybe the presence of wide defect will give the chance for CSF to circulate through foramen of Magendi and Luschka without obstruction and this could explain why hydrocephalus is not present in all cases.[26],[29]

In our review of 51 cases, hydrocephalus was evident in 27 cases (56%); in 19 cases, hydrocephalus was diagnosed preoperative and ventriculoperitoneal shunt (VPS) was done in 18 cases and in one case endoscopic third ventriculostomy (ETV) was done,[18] the ETV was functioning with follow up 3 months later. In eight cases, the hydrocephalus was postoperative and VPS was done. In our two cases, VPS was done postoperative due to early hydrocephalic changes. The prognosis of CM III is not so dark as predicted or reported by some authors; there was a single stillbirth case,[28] only seven cases died, and in 33 cases the prognosis varied from good development of the children to severe mental and motor retardation and in between those there were a lot of reported neurological deficits like weakness, seizures, walking with support, abnormal movement, and NG tube feeding. Signs of brain stem compression could predict worst prognosis, developmental delay was evident in most cases but there were cases that still near normal or asymptomatic till 11 years.[11],[24],[27] So, if a bad prognosis or severe delay in milestones was evident from the start, this means the dismal prognosis as expected and those children that had few symptoms or asymptomatic could continue their lives as well. The parents could not accept the anomaly from the start and refuse surgery.

   Conclusion Top

CM type III is a hindbrain malformation anomaly that does not carry dismal prognosis in all cases as mentioned in old articles. Based on our two cases and as mentioned in most published articles; there are variations in the outcome and not all cases of CM III will die and severe developmental delay is not a must. Proper operative planning and technique followed by postoperative care and physiotherapy could lead to a reasonable outcome and decreased mortality.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

   References Top

Chiari H Ueber Veränderungen des Kleinhirns infolge von Hydrocephalie des Grosshirns1. Dtsch med Wochenschr 1891;17:1172-5.  Back to cited text no. 1
Garg K, Malik N, Jaiswal AK, Behari S Chiari III malformation with hypertelorism and microcephaly in a neonate: case report and a review of the literature. J Pediatr Neurosci 2008;3:169.  Back to cited text no. 2
Ivashchuk G, Loukas M, Blount JP, Tubbs RS, Oakes WJ Chiari III malformation: a comprehensive review of this enigmatic anomaly. Childs Nerv Syst 2015;31:2035-40.  Back to cited text no. 3
Young RM, Shafa JS, Myseros JS The Chiari 3 malformation and a systemic review of the literature. Pediatr Neurosurg 2015;50:235-42.  Back to cited text no. 4
Işik N, Elmaci I, Silav G, Çelik M, Kalelioğlu M Chiari malformation type III and results of surgery: a clinical study. PNE 2009;45:19-28.  Back to cited text no. 5
Castillo M, Quencer RM, Dominguez R Chiari III malformation: imaging features. AJNR Am J Neuroradiol 1992;13:107-13.  Back to cited text no. 6
Dyste GN, Menezes AH, VanGilder JC Symptomatic Chiari malformations. An analysis of presentation, management, and long-term outcome. J Neurosurg 1989;71:159-68.  Back to cited text no. 7
Kannegieter LS, Dietrich RB, Pais MJ, Goldenberg TM Pediatric case of the day. Chiari III malformation. Radiographics 1994;14:452-4.  Back to cited text no. 8
Cama A, Tortori-Donati P, Piatelli GL, Fondelli MP, Andreussi L Chiari complex in children—neuroradiological diagnosis, neurosurgical treatment and proposal of a new classification (312 cases). Eur J Pediatr Surg 1995;5(S1):35-8.  Back to cited text no. 9
Aribal ME, Gürcan F, Aslan B Chiari III malformation: MRI. Neuroradiology 1996;38 Suppl 1:S184-6.  Back to cited text no. 10
Kernan JC, Horgan MA, Piatt JH Tethered hindbrain. Case report. J Neurosurg 1996;85:713-5.  Back to cited text no. 11
Snyder WE Jr, Luerssen TG, Boaz JC, Kalsbeck JE Chiari III malformation treated with CSF diversion and delayed surgical closure. Pediatr Neurosurg 1998;29:117-20.  Back to cited text no. 12
Sirikci A, Bayazit YA, Bayram M The Chiari III malformation: an unusual and asymptomatic variant in an 11-year old child. Eur J Radiol 2001;39:147-50.  Back to cited text no. 13
Häberle J, Hülskamp G, Harms E, Krasemann T Cervical encephalocele in a newborn—Chiari III malformation. Child’s Nerv Syst 2001;17:373-5.  Back to cited text no. 14
Caldarelli M, Rea G, Cincu R, Di Rocco C Chiari type III malformation. Childs Nerv Syst 2002;18:207-10.  Back to cited text no. 15
Lee R, Tai KS, Cheng PW, Lui WM, Chan FL Chiari III malformation: antenatal MRI diagnosis. Clin Radiol 2002;57:759-61.  Back to cited text no. 16
Cakirer S Chiari III malformation: varieties of MRI appearances in two patients. Clin Imaging 2003;27:1-4.  Back to cited text no. 17
Cho EY, Lee JJ, Lim JW, Choen EJ, Ko KO, Lee YH A case of Chiari III malformation. J Korean Child Neurol Soc 2005;13:282.  Back to cited text no. 18
Smith AB, Gupta N, Otto C, Glenn OA Diagnosis of Chiari III malformation by second trimester fetal MRI with postnatal MRI and CT correlation. Pediatr Radiol 2007;37:1035-8.  Back to cited text no. 19
Jaggi RS, Premsagar IC Chiari malformation type III treated with primary closure. Pediatr Neurosurg 2007;43:424-7.  Back to cited text no. 20
Muzumdar D, Gandhi S, Fattepurkar S, Goel A Type III Chiari malformation presenting as intermittent respiratory stridor: a neurological image. Pediatr Neurosurg 2007;43:446-8.  Back to cited text no. 21
Furtado SV, Anantharam BA, Reddy K, Hegde AS Repair of Chiari III malformation using cranioplasty and an occipital rotation flap: technical note and review of literature. Surg Neurol 2009;72:414-7; discussion 417.  Back to cited text no. 22
Zolal A, Vachata P, Hejcl A, Malucelli A, Bartos R, Sames M Identification of the large descending tracts using diffusion tensor imaging in Chiari III malformation. Childs Nerv Syst 2010;26:867-70.  Back to cited text no. 23
ile Birlikteliği TIM The association of Chiari type III malformation and Klippel–Feil syndrome with mirror movement: a case report. Turkish Neurosurg 2011;21:655-8.  Back to cited text no. 24
Agrawal A, Mittal A, Kohali GB, Sampley S, Gupta A Chiari III malformation. Pediatr Neurosurg 2011;47:309-10.  Back to cited text no. 25
Garg K, Tandon V, Mahapatra AK Chiari III malformation with proatlas abnormality. Pediatr Neurosurg 2011;47:295-8.  Back to cited text no. 26
Ambekar S, Devi BI, Shukla D Large occipito-cervical encephalocele with Chiari III malformation. J Pediatr Neurosci 2011;6:116-7.  Back to cited text no. 27
Rani H, Kulkarni AV, Rao RV, Patil P Chiari III malformation: a rare case with review of literature. Fetal Pediatr Pathol 2013;32:169-74.  Back to cited text no. 28
Andica C, Soetikno RD Chiari malformation type III: case report and review of the literature. Radiol Case Rep 2013;8:831.  Back to cited text no. 29
Ramdurg SR, Solpure S, Dubey S, Gubbi S Asymptomatic Chiari III malformation with tectal beaking and holocord syrinx. J Pediatr Neurosci 2013;8:254-6.  Back to cited text no. 30
Bulut MD, Yavuz A, Bora A, Gülşen I, Özkaçmaz S, Sösüncü E Chiari III malformation with a giant encephalocele sac: case report and a review of the literature. Pediatr Neurosurg 2013;49:316-9.  Back to cited text no. 31
Jeong DH, Kim CH, Kim MO, Chung H, Kim TH, Jung HY Arnold-Chiari malformation type III with meningoencephalocele: a case report. Ann Rehabil Med 2014;38:401-4.  Back to cited text no. 32
Tan GI, Low DC, Ng LP, Seow WT, Low SY Synchronous Chiari III malformation and polydactyly. World Neurosurg 2018;118:301-3.  Back to cited text no. 33
Ganeriwal V, Dey P, Bawage R, Gore B Giant meningoencephalocele with Arnold-Chiari type III malformation and anaesthetic challenges: a rare case report. Saudi J Anaesth 2019;13:136-9.  Back to cited text no. 34
Schijman E History, anatomic forms, and pathogenesis of Chiari I malformations. Childs Nerv Syst 2004;20: 323-8.  Back to cited text no. 35
Maroun FB Syringomyelia and the Chiari malformations. 1997. Edited by John A. Anson, Edward C. Benzel, Issam A. Awad. Published by The American Association of Neurological Surgeons. 193 pages. $C124.00 approx. Can J Neurol Sci. 1998;25:175-5.  Back to cited text no. 36
McLone DG, Knepper PA The cause of Chiari II malformation: a unified theory. Pediatr Neurosci 1989;15:1-12.  Back to cited text no. 37
Pittman HW The Chiari crisis. BNI Quart 1990;6:10-6.  Back to cited text no. 38
Aleksic S, Budzilovich G, Greco MA, Reuben R, Feigin I, Pearson J, et al. Cerebellocele and associated central nervous system anomalies in the Meckel syndrome. Childs Brain 1984;11:99-111.  Back to cited text no. 39


  [Figure 1], [Figure 2], [Figure 3]

  [Table 1]

This article has been cited by
1 Adult Chiari Malformation Type I
Alisa Arnautovic, Mirza Pojskic, Kenan I. Arnautovic
Neurosurgery Clinics of North America. 2023; 34(1): 91
[Pubmed] | [DOI]
2 Treatment of Chiari III Malformation in Infant with 4K 3D ORBEYE Exoscope
Maria Luisa Gorgoglione, Roberta Laera, Antonello Curcio, Gerardo Caruso, Gabriele Delia, Antonino F. Germano
World Neurosurgery. 2023;
[Pubmed] | [DOI]
3 The Nomenclature of Chiari Malformations
Michael J. Cools, John C. Wellons, Bermans J. Iskandar
Neurosurgery Clinics of North America. 2022;
[Pubmed] | [DOI]
4 Chiari III Malformation on Prenatal and Postnatal Imaging Complicated by Syndrome of Inappropriate Secretion of Anti-diuretic Hormone (SIADH) and Serratia marcescens Meningitis
Ryan McGeary, Chetan Shah
Cureus. 2021;
[Pubmed] | [DOI]


Print this article  Email this article
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Article in PDF (2,044 KB)
    Citation Manager
    Access Statistics
    Reader Comments
    Email Alert *
    Add to My List *
* Registration required (free)  

    Article Figures
    Article Tables

 Article Access Statistics
    PDF Downloaded116    
    Comments [Add]    
    Cited by others 4    

Recommend this journal