Chiari III malformation: a comprehensive review of this enigmatic anomaly

Neonatal Ventricular Reservoir Implantation for Hydrocephalus Management in Chiari III Malformations: A Case Report

Chiari III malformation, a rare and severe subtype of Chiari malformations, is frequently associated with hydrocephalus. The conventional treatment approaches for hydrocephalus in Chiari III malformations have mainly focused on ventriculoperitoneal (VP) shunting, but optimal methods and timing remain uncertain. We report a case of a newborn girl with Chiari III malformation who underwent surgical closure of an occipitocervical encephalocele and ventricular reservoir implantation on her third day of life. This procedure successfully managed her hydrocephalus without significant short-term complications. Three months post-surgery, she developed secondary external hydrocephalus, which was managed through subdural-peritoneal shunting, allowing her to thrive until at least five years of age. This case demonstrates the potential of ventricular reservoir implantation in treating hydrocephalus associated with Chiari III malformation and brings to light secondary external hydrocephalus, subsequently managed by VP shunting.

Chiari type III malformation associated with Klippel-Feil syndrome, a case report with a narrative review of the literature

BACKGROUND

Chiari malformation type III (CM III), a rare hindbrain anomaly, often presents with various concurrent anomalies. This paper reports a unique case of CM III associated with Klippel-Feil syndrome (KFS), a condition previously unreported in Saudi Arabia and documented in only one other case globally in Turkey. This study aims to share insights into the unusual association between CM III and KFS, considering their close embryological development and involvement in the craniocervical junction.

METHODOLOGY

The study presents a case of a 2.5-year-old female diagnosed with CM III and KFS. Diagnostic tools such as ultrasound, CT scans, MRI, and physical examinations were used to confirm the patient's condition. Surgical interventions, including decompression and encephalocele repair, were performed.

RESULTS

Successful surgical interventions, including encephalocele repair and duraplasty, were carried out. Follow-up visits indicated a stable condition, marked improvement in lower limb strength, and the patient's ability to walk with assistance. CT follow-up affirmed a satisfactory surgical outcome.

CONCLUSION

This case study illustrates the potential for an optimistic prognosis in CM III, even when accompanied by complex conditions such as KFS, through early diagnosis and intervention. It underscores the significance of antenatal screening for effective care planning and calls for further research and publications due to the rarity of this association. These findings contribute to our understanding of CM III and its related conditions, emphasizing the need for open-minded consideration of potential embryological associations.

Chiari III malformation in a neonate

Chiari malformation (CM) is a group of complex deformities of the posterior fossa and hindbrain, of which CMIII is the rarest. We report a term neonate, with an antenatal diagnosis of occipital encephalocele, who underwent resection of the encephalocele and ligation of vessels, with repair of a large scalp defect and dural reconstruction on day 4 of life. The parents of the child had been counselled for a guarded and poor prognosis on initial diagnosis. The child has had a good postoperative course without complications but suffers from cortical visual impairment and global developmental delay.

Treatment of Chiari III Malformation in Infant with 4K 3D ORBEYE Exoscope

Chiari malformation (CM)-III is the rarest anomaly among CMs.¹ Treatment of choice is surgical repair,² although poor outcome and postoperative mortality has been reported.³ Surgical timing is still debated.^4,5 We present the case of a male infant with a prenatal diagnosis of encephalocele. Presentation was characterized by hemodynamic instability, horizontal nystagmus, and left shoulder dystocia due to caesarean section, with a 64 mm × 49 mm × 76 mm soft, fluctuant, and translucent suboccipital-cervical sac. Magnetic resonance imaging revealed a median occipital bone defect with the meningoencephalic sac communicating with the vermian cistern and the fourth ventricle, moderate hydrocephalus, reduction of the posterior cranial fossa volume, hypoplasia of cerebellar hemispheric, vermian structures, and corpus callosum hypoplasia. The patient underwent surgery on day 4 with the use of a 4K 3D ORBEYE exoscope (Video 1). Surgery consisted of disengagement of nervous structures and repair of the neurocutaneous defect, followed on day 12 by a ventriculoperitoneal shunt with a programmable valve. The procedures were well tolerated. At the 14-month follow-up visit he was in range with growth charts (weight, height, and cranic circumference) and gained the physiologic stages of growth. He had no motor impairment but still present were convergent strabismus and mild left C5-C6 radiculopathy, secondary to shoulder dystocia. This is the first case reported in the literature of CM-III treated with the 4K 3D ORBEYE exoscope. Advantages of the exoscope were ergonomic positions for operative staff, possibility for the team to assist in the 4K 3D view, especially in cases with a narrow operative field, with a clear and detailed vision, although a learning curve is required⁶ to become a valid alternative in pediatric neurosurgery.

Surgical outcomes of calvaria reconstruction in cranial pansynostosis associated with Arnold-Chiari type 1.5 malformation, a case report

A 6-year-old girl with persistent headaches and the visual problem was diagnosed as a delayed onset cranial pansynostosis with concurrent type 1.5 Arnold-Chiari malformation. She underwent multi-sutural reconstructive surgery and followed. The headache was greatly decreased and tonsillar-brain stem herniation and syrinx were resolved.

Chiari III malformation with defect in Liliequist membrane on MR imaging

The Liliequist membrane is a radiologically neglected structure, with routine evaluation only carried out in pre-operative and post-operative cases of third ventriculostomy. We report two cases of Chiari III malformation in two unrelated females with similar findings on magnetic resonance imaging study including occipital and low cervical encephalocele, hydrocephalus, and segmentation anomalies in cervical spine. Along with these findings, we report a flow void on T2-weighted images observed in both cases across the site of Liliequist membrane between interpeduncular and chiasmatic cistern. Our findings of CSF flow across the Liliequist membrane may represent spontaneous third ventriculostomy or another congenital defect in the myriad of anomalies seen in cases of Chiari III malformation.

Chiari type III malformation: Case report and review of literature

Chiari III (CM III) is the rarest of the Chiari malformations, characterized by high cervical or occipital encephalocele and osseous defects, associated with herniation of the posterior cerebral fossa contents through the foramen magnum.

We report the case of a female newborn, with a cervico-occipital mass, hypotonia and sharp osteotendinous reflexes in the lower limbs. An MRI was performed showing a low occipital encephalocele with caudal displacement of cerebellar tonsils.

Because of its high contrast resolution, MRI is more useful than CT, preoperatively, to assess the content of the encephalocele. MRI can identify the position of the brain stem and spinal cord, so that they are preserved during the surgical procedure.

Hydrocephalus and occipital encephaloceles: presentation of a series and review of the literature

INTRODUCTION

Encephaloceles are rare congenital malformations of the central nervous system in which brain tissue is extruded from a defect in the skull. Hydrocephalus can occur in 60 to 90% of patients with posterior encephaloceles when compared to other types of this malformation. This article aims to present a series of posterior encephaloceles and its association with hydrocephalus as well as promote a review of the pertinent literature.

MATERIAL AND METHODS

A retrospective study of our series based on hospital charts of 50 patients with posterior encephaloceles was performed. Data on sex, location of encephalocele, presence of associated malformations, presence of neural tissue within the malformation, presence of hydrocephalus and microcephaly were recorded.

RESULTS

There were 29 females and 21 males. There were 25 (50%) supratorcular, 8 (16%) torcular, and 17 (34%) infratorcular lesions. Mean age of encephalocele primary repair was 8 days (range 2-120 days). Hydrocephalus was diagnosed in 25 (50%) of the cases. Ventriculoperitoneal shunt was inserted in 24 patients. The mean age at VP shunt insertion was 1.3 months (range 0.3-9 months). Endoscopic third ventriculostomy was successfully performed in one patient. Dandy-Walker malformation and ventriculomegaly prior to encephalocele surgical correction were positively associated with hydrocephalus (p values 0.05 and 0.01, respectively). Chiari III malformation was found in 2 cases, both requiring CSF shunt for treatment of hydrocephalus and are stable in follow-up. Microcephaly was present in 9 cases. The known mortality rate was 8%.

CONCLUSIONS

Hydrocephalus is common in patients with posterior encephaloceles, being more frequent in the supratorcular type, especially when associated to Dandy-Walker, Chiari III malformation, and pre-existing ventriculomegaly. The severity of giant encephaloceles, when associated to torcular types and microcephaly, is a limiting factor for development of hydrocephalus, due both to the rapid evolution of natural history and the structural changes in microcephaly.

Chiari III Malformation on Prenatal and Postnatal Imaging Complicated by Syndrome of Inappropriate Secretion of Anti-diuretic Hormone (SIADH) and Serratia marcescens Meningitis

Among various types of Chiari malformations (CMs), CM III is the most infrequently encountered. In this article, we present a case of CM III with occipital cephalocele appreciated on both prenatal imaging and postnatal follow-up MRI. This case illustrates not only the evolution of this malformation from the in-utero images of fetal MRI to the newborn MRI but also highlights the complications that may accompany this diagnosis such as hydrocephalus and infection. The patient also developed syndrome of inappropriate secretion of anti-diuretic hormone (SIADH). The most current thoughts on the pathophysiology of this entity are also reviewed along with an approach to the differential diagnosis and treatment.

Chiari Malformation Type III: A Case Report and Review of Literature

Chiari malformations (CMs) are a group of disorders involving deformities of the posterior fossa and hindbrain. There are seven types of CMs: 0, I, 1.5, II, III, IV, and V. CMIII is a very infrequent disorder characterized by low occipital or superior cervical encephalocele and inferior displacement of the brainstem. Here we present a unique case of CMIII associated with cleft palate, abnormal midbrain, and abnormal corpus callosum. CMIII is a very rare condition, which needs to be reported. This study primarily aims to compare our case to other cases of CMIII. We did not find another case with cleft palate and CMIII. There are only a few cases reported of CMIII. That is why it is vital to report each of these cases. Among reported CMIII cases, our case is unique regarding the co-occurrence of cleft palate. There seems to be an embryological link between these two conditions. However, cleft palate is a relatively common congenital defect, which means that the co-occurrence could be just a coincidence as well. Further research is warranted to broaden the information of this extremely rare syndrome.

Outcomes of Chiari Malformation III: A Review of Literature

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.

The Perplexity Surrounding Chiari Malformations - Are We Any Wiser Now?

Chiari malformations are a diverse group of abnormalities of the brain, craniovertebral junction, and the spine. Chiari 0, I, and 1.5 malformations, likely a spectrum of the same malformation with increasing severity, are due to the inadequacy of the para-axial mesoderm, which leads to insufficient development of occipital somites. Chiari II malformation is possibly due to nonclosure of the caudal end of the neuropore, with similar pathogenesis in the rostral end, which causes a Chiari III malformation. There have been significant developments in the understanding of this complex entity owing to insights into the pathogenesis and advancements in imaging modalities and neurosurgical techniques. This article aims to review the different types and pathophysiology of the Chiari malformations, along with a description of the various associated abnormalities. We also highlight the role of ante- and postnatal imaging, with a focus on the newer techniques in the presurgical evaluation, with a brief mention of the surgical procedures and the associated postsurgical complications.

An unusual presentation of bobble-head doll syndrome in a patient with hydranencephaly and Chiari 3 malformation

Bobble-head doll syndrome is a rare movement disorder that is usually associated with lesions involving the third ventricle. It is characterised by stereotypical rhythmic up-and-down or side-to-side head movements. The pathophysiology and anatomical basis for this unusual manifestation is still a subject of intense scrutiny. The syndrome has never been described in a patient with both hydranencephaly and Chiari type 3 malformation. We describe a 2-year-old female patient who presented with congenital hydrocephalus, an occipital encephalocele and rhythmic bobbling of the head. Imaging investigation revealed a Chiari type 3 malformation and hydranencephaly. The patient was taken to theatre for a ventriculoperitoneal shunt insertion, and at day 3 post operatively, the patient had a markedly decreased head circumference and a decrease in the frequency of the bobbling of the head. A further review at 2 weeks showed that the bobbling of the head had ceased. Although the pathophysiology of bobble-head doll syndrome is yet to be fully understood, there has been postulation of either a third ventricular enlargement or a cerebellar dysfunction to explain bobble-head doll syndrome. Our case illustrates that the pathophysiology is most likely multifactorial as illustrated by the fact that by just addressing the high intracranial pressure with a shunt was sufficient to treat the condition.

The Incidence of Chiari Malformations in Patients with Isolated Sagittal Synostosis

Background:

We report the incidence of Chiari malformation I (CMI) in a cohort of 377 patients with isolated sagittal synostosis (ISS), which is to the best of our knowledge the largest such series reported to date.

Methods:

A retrospective review of patients seen at a single institution from 2007 to 2017 was completed. ISS, Chiari malformations (CMI and CMII) and hydrocephalus were diagnosed by a senior neuroradiologist (G.Z.). Patients who met the inclusion criteria were divided into early (group A) and late (group B) presenting groups, as well as operated (group I) and unoperated (group II) groups. The patients were further subdivided into group AI (early operated), group AII (early unoperated), group BI (late operated), and group BII (late unoperated). Once identified, patient notes were examined for the following data sets: date of birth, age of presentation, age at last follow-up, other systemic conditions as well as molecular testing results. Surgical interventions, ophthalmological, and other relevant data were recorded. Statistical analysis was run in the form of a chi-square test to identify a significant difference between each subgroup. A literature review of the incidence of Chiari malformations in patients with ISS was conducted.

Results:

Three hundred seventy-seven patients constitute the study’s total cohort (272 were males and 105 females). This cohort was divided into patients who underwent surgical repair of ISS (group 1: n = 200), and patients who did not (group 2: n = 177). The entire cohort was also divided into early (group A: n = 161) and late (group B: n = 216) presenting craniosynostosis. In the total cohort, 22/377 (5.8%) patients with CMI were identified. CMI was found in 14/200 (7.0%) patients in group I, and 8/177 (4.5%) patients in group II. CMI was found in 2/161 (1%) patients in group A, and 20/216 (9.2%) patients in group B. The incidence of CMI in group AI (early operated) was 2/151 (1.3%), in group AII (early unoperated) was 0/10, in group BI (late operated) was 11/49 (21%), and in group BII (late unoperated) was 9/167 (5.4%). Chi-square analysis revealed a significant difference between the incidence of CMI in the early-presenting (group A) and late-presenting (group B) groups (P = 0.001) and between the late-presenting operated (BI) and late-presenting unoperated (BII) groups (P = 0.001). The incidence of hydrocephalus was 1.6% (6/377) in the total cohort. However, all patients diagnosed with hydrocephalus came from group II (no surgical ISS correction). The incidence of hydrocephalus in group II was 3.3% (6/177). The incidence of hydrocephalus in group BII (late unoperated ISS) was 3.0% (5/167). The incidence of hydrocephalus in group AII (early unoperated ISS) was 9.0% (1/11).

Conclusions:

We noted the highest incidence of CMI—21%—in group BI (late-presenting operated). We noted hydrocephalus in group II (nonoperated), with the highest incidence of hydrocephalus found in the group BII (late-presenting unoperated) subgroup. We therefore recommend patients with ISS receive funduscopic examination to screen for raised intracranial pressure (ICP) associated with CMI and hydrocephalus, especially patients with late-presenting ISS.

Overview on neural tube defects: From development to physical characteristics

Neural tube defects (NTDs) are the second most common congenital malformations in humans affecting the development of the central nervous system. Although NTD pathogenesis has not yet been fully elucidated, many risk factors, both genetic and environmental, have been extensively reported. Classically divided in two main sub-groups (open and closed defects) NTDs present extremely variable prognosis mainly depending on the site of the lesion. Herein, we review the literature on the histological and pathological features, epidemiology, prenatal diagnosis, and prognosis, based on the type of defect, with the aim of providing important information based on NTDs classification for clinicians and scientists.

Clinical Notes on Chiari Malformation

Chiari malformations (CMs) are variant structural setup of cerebellum and brain stem at the craniovertebral junction. Normally the cerebellum and parts of the brain stem lie above the foramen magnum. When the part of the cerebellum and/or brainstem protrudes into the upper spinal canal through foramen magnum, it is defined as CM. Chiari malformations may develop when part of the skull is smaller than normal or misshapen, due to which the cerebellum herniates into spinal canal through foramen magnum. This compresses the cerebellum and brainstem affecting functions controlled by these parts and blocks the flow of cerebrospinal fluid that surrounds and cushions the brain and spinal cord. Chiari malformation may cause sensory loss, ataxia, weakness, nystagmus, spastic limbs to name a few. Thus, various morbid and mortal neurologic disorders result from CM. Therefore, sound and thorough knowledge of CM and its variant anatomy are essential for diagnosis and management of neurologic disorders. Therefore, review study has been carried out for updating and consolidating the knowledge of all the variations of CMs. Literature search was carried out using databases, SciELO, ScopeMed, MEDLINE, PubMed, and Wiley Online Library. Papers containing original data were selected and secondary references retrieved from bibliographies. Various terms related to CMs were used for net surfing. The knowledge will be of immense importance to neurologists and neurosurgeons to diagnose and treat the CMs and decrease the mortality associated with CM and to radiologists for correctly interpreting the magnetic resonance imaging.

The newer classifications of the chiari malformations with clarifications: An anatomical review

In 1891, Hans Chiari described a group of congenital hindbrain anomalies, which were eventually named after him. He classified these malformations into three types (Chiari malformations I, II, and III), and four years later added the Chiari IV malformation. However, numerous reports across the literature do not seem to fit Chiari's original descriptions of these malformations, so researchers have been encouraged to propose new classifications to encompass these variants (e.g., Chiari 0, Chiari1.5, and Chiari 3.5 malformations). Moreover, there is a continued misunderstanding and misuse of the term "Chiari IV malformation." Therefore, the current review intended to describe anatomical, pathophysiological, and clinical aspects of the newer classifications with clarifications of the Chiari malformations. We reviewed available literature about Chiari malformations and their variants using "PubMed" and "Google Scholar." We also looked into the term Chiari IV, clarifying its original description and citing examples where the term has been used erroneously. References in the reviewed articles were searched manually. Variants of the originally described Chiari malformations are termed Chiari 0, Chiari 1.5, and Chiari 3.5. Each has distinct anatomical characteristics and some of these are extremely rare and incompatible with life (e.g. Chiari 3.5). Chiari IV malformation has been further clarified. Some physicians might be unfamiliar with the newer classifications of Chiari malformations because these conditions are rare or even unique. Furthermore, care is needed in using the term "Chiari IV malformation", which must be consistent with Chiari's original description, i.e. an occipital encephalocele containing supratentorial contents. Clin. Anat. 31:314-322, 2018. © 2018 Wiley Periodicals, Inc.

Post-mortem magnetic resonance (PMMR) imaging of the brain in fetuses and children with histopathological correlation

Post-mortem magnetic resonance (PMMR) imaging is rapidly emerging as an alternative, "less invasive", and more widely accepted investigative approach for perinatal deaths in the UK. PMMR has a high diagnostic accuracy for congenital and acquired fetal neuropathological anomalies compared to conventional autopsy, and is particularly useful when autopsy is non-diagnostic. The main objectives of this review are to describe and illustrate the range of common normal and abnormal central nervous system (CNS) findings encountered during PMMR investigation. This article covers the standard PMMR sequences used at our institution, normal physiological post-mortem findings, and a range of abnormal developmental and acquired conditions. The abnormal findings include diseases ranging from neural tube defects, posterior fossa malformations, those of forebrain and commissural development as well as neoplastic, haemorrhagic, and infectious aetiologies. Neuropathological findings at conventional autopsy accompany many of the conditions we describe, allowing readers to better understand the underlying disease processes and imaging appearances.

The Chiari 3.5 malformation: a review of the only reported case

INTRODUCTION

In 1894, Giuseppe Muscatello described what we believe to be the only case of an occipitocervical encephalocele with a communication to the stomach. This case and its history and context compared to the Chiari 3 malformation as described 3 years earlier by Hans Chiari are presented.

CONCLUSIONS

Based on the uniqueness of this case, we propose the term Chiari 3.5 malformation be used to describe its anatomical derailment.