Primary Cerebellar Tuberculoma in Arnold-Chiari Malformation Mimicking Posterior Cranial Fossa Tumor: the First Report

Type I Chiari malformation (CM) is a complex disorder of the craniospinal system characterized by underdevelopment of the posterior cranial fossa and overcrowding of the normally developed hindbrain [1], and may be a precursor to more severe secondary disorders such as syringomyelia and hydrocephalus. Diagnosis of CM has proven to be difficult and may often take years to properly identify, as associated neurological symptoms may vary widely and overlap with symptoms of other disorders. Current methods of quantifying the severity of CM, such as radiographical measurement of the depth of hindbrain herniation into the spinal canal or measurement of posterior cranial fossa volume do not necessarily correlate to the symptom severity. Hence, there exists a need for a quantitative diagnostic method which may better characterize the severity of CM and, potentially, help neurosurgeons determine candidates for surgical treatment.

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Incidence of basioccipital hypoplasia in Chiari malformation Type I: comparative morphometric study of the posterior cranial fossa

Journal of Neurosurgery ◽

10.3171/2009.2.jns08284 ◽

2009 ◽

Vol 111 (5) ◽

pp. 1046-1052 ◽

Cited By ~ 66

Author(s):

Rémy Noudel ◽

Nicolas Jovenin ◽

Cristophe Eap ◽

Bernard Scherpereel ◽

Laurent Pierot ◽

...

Keyword(s):

Chiari Malformation ◽

Foramen Magnum ◽

Posterior Cranial Fossa ◽

Morphometric Study ◽

Control Group ◽

Type I ◽

Chiari Malformation Type I ◽

Cranial Fossa ◽

The Mean ◽

Sphenooccipital Synchondrosis

Object The chronic tonsillar herniation defining Chiari malformation Type I (CMI) is thought to result from overcrowding of a normally developing hindbrain within a congenitally small posterior cranial fossa (PCF) due to occipital hypoplasia. The goals in the present study were to authenticate the cranioencephalic disproportion in a group of patients with CMI and to discuss new developmental aspects according to which part of the occipital bone was underdeveloped. Methods The authors retrospectively examined a group of 17 patients with CMI. Measurements of osteotentorial and neural structures of the PCF were made on MR images of the brain. The results were compared with findings in 30 healthy controls by using the Mann-Whitney U-test. Results Dimensions of the neural structures did not differ between the 2 groups of patients. The mean length of the basiocciput was significantly shorter in the CMI group (19.4 mm) compared with the control group (25.7 mm; p = 0.0003). The mean diameter of the foramen magnum was larger in the CMI group, but this difference was not statistically significant. The dimensions of the supraocciput and the mean angle of the cerebellar tentorium were identical in the 2 groups. Conclusions Data in this study support the idea that occipital hypoplasia is the main cause of overcrowding within the PCF. Basioccipital shortness is a cardinal feature of the resultant shallow PCF and could proceed from a congenital disorder of the cephalic mesoderm of the parachordal plate or occur later in the infancy because of premature stenosis of the sphenooccipital synchondrosis.

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MRI-based Morphometric Analysis of Posterior Cranial Fossa in the Diagnosis of Chiari Malformation Type I

Journal of Neuroimaging ◽

10.1111/jon.12007 ◽

2013 ◽

Vol 24 (3) ◽

pp. 250-256 ◽

Cited By ~ 37

Author(s):

Aintzane Urbizu ◽

Maria-Antonia Poca ◽

Xavier Vidal ◽

Alex Rovira ◽

Juan Sahuquillo ◽

...

Keyword(s):

Morphometric Analysis ◽

Chiari Malformation ◽

Posterior Cranial Fossa ◽

Type I ◽

Chiari Malformation Type I ◽

Cranial Fossa

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Volumetric analysis of the posterior cranial fossa in a family with four generations of the Chiari malformation Type I

Journal of Neurosurgery Pediatrics ◽

10.3171/ped-08/01/021 ◽

2008 ◽

Vol 1 (1) ◽

pp. 21-24 ◽

Cited By ~ 39

Author(s):

R. Shane Tubbs ◽

Mark Hill ◽

Marios Loukas ◽

Mohammadali M. Shoja ◽

W. Jerry Oakes

Keyword(s):

Posterior Fossa ◽

Chiari Malformation ◽

Familial Aggregation ◽

Volumetric Analysis ◽

Posterior Cranial Fossa ◽

Preoperative Imaging ◽

Type I ◽

Chiari Malformation Type I ◽

Hindbrain Herniation ◽

Cranial Fossa

Object Many authors have concluded that the Chiari malformation Type I (CM-I) is due to a smaller than normal posterior cranial fossa. In order to establish this smaller geometry as the cause of hindbrain herniation in a family, the authors of this paper performed volumetric analysis in a family found to have this malformation documented in 4 generations. Methods Members from this family found to have a CM-I by imaging underwent volumetric analysis of their posterior cranial fossa using the Cavalieri method. Results No member of this family found to have CM-I on preoperative imaging had a posterior fossa that was significantly smaller than that of age-matched controls. Conclusions The results of this study demonstrate that not all patients with a CM-I will have a reduced posterior cranial fossa volume. Although the mechanism for the development of hindbrain herniation in this cohort is unknown, this manifestation can be seen in multiple generations of a familial aggregation with normal posterior fossa capacity.

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Pathogenesis of Chiari malformation: a morphometric study of the posterior cranial fossa

Journal of Neurosurgery ◽

10.3171/jns.1997.86.1.0040 ◽

1997 ◽

Vol 86 (1) ◽

pp. 40-47 ◽

Cited By ~ 367

Author(s):

Misao Nishikawa ◽

Hiroaki Sakamoto ◽

Akira Hakuba ◽

Naruhiko Nakanishi ◽

Yuichi Inoue

Keyword(s):

Posterior Fossa ◽

Medulla Oblongata ◽

Chiari Malformation ◽

Volume Ratio ◽

Basilar Invagination ◽

Posterior Cranial Fossa ◽

Control Group ◽

Adult Type ◽

Content Type ◽

Cranial Fossa

✓ To investigate overcrowding in the posterior cranial fossa as the pathogenesis of adult-type Chiari malformation, the authors studied the morphology of the brainstem and cerebellum within the posterior cranial fossa (neural structures consisting of the midbrain, pons, cerebellum, and medulla oblongata) as well as the base of the skull while taking into consideration their embryological development. Thirty patients with Chiari malformation and 50 normal control subjects were prospectively studied using neuroimaging. To estimate overcrowding, the authors used a “volume ratio” in which volume of the posterior fossa brain (consisting of the midbrain, pons, cerebellum, and medulla oblongata within the posterior cranial fossa) was placed in a ratio with the volume of the posterior fossa cranium encircled by bony and tentorial structures. Compared to the control group, in the Chiari group there was a significantly larger volume ratio, the two occipital enchondral parts (the exocciput and supraocciput) were significantly smaller, and the tentorium was pronouncedly steeper. There was no significant difference in the posterior fossa brain volume or in the axial lengths of the hindbrain (the brainstem and cerebellum). In six patients with basilar invagination the medulla oblongata was herniated, all three occipital enchondral parts (the basiocciput, exocciput, and supraocciput) were significantly smaller than in the control group, and the volume ratio was significantly larger than that in the Chiari group without basilar invagination. These results suggest that in adult-type Chiari malformation an underdeveloped occipital bone, possibly due to underdevelopment of the occipital somite originating from the paraxial mesoderm, induces overcrowding in the posterior cranial fossa, which contains the normally developed hindbrain. Basilar invagination is associated with a more severe downward herniation of the hindbrain due to the more severely underdeveloped occipital enchondrium, which further exacerbates overcrowding of the posterior cranial fossa.

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Imaging-Based Features of Headaches in Chiari Malformation Type I

Neurosurgery ◽

10.1227/neu.0000000000000740 ◽

2015 ◽

Vol 77 (1) ◽

pp. 96-103 ◽

Cited By ~ 15

Author(s):

Noam Alperin ◽

James R. Loftus ◽

Carlos J. Oliu ◽

Ahmet M. Bagci ◽

Sang H. Lee ◽

...

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Chiari Malformation ◽

Posterior Cranial Fossa ◽

Type I ◽

Intracranial Volume ◽

Resonance Imaging ◽

Chiari Malformation Type I ◽

Intracranial Compliance ◽

Cranial Fossa

Abstract BACKGROUND: Suboccipital cough-induced headaches are considered a hallmark symptom of Chiari malformation type I (CMI). However, non--Valsalva-related suboccipital headaches and headaches in other locations are also common in CMI. The diagnostic significance and the underlying factors associated with these different headaches types are not well understood. OBJECTIVE: To compare cranial morphology and hydrodynamics in 3 types of headaches in CMI to better understand the pathophysiological basis for the different headache characteristics. METHODS: Twenty-two cranial physiological and morphological measures were obtained with specialized magnetic resonance imaging scans from 63 symptomatic pretreated CMI patients, 40 with suboccipital headaches induced by Valsalva maneuvers (34 women; age, 36 ± 10 years), 15 with non--Valsalva-related suboccipital headaches (10 women; age, 33 ± 9 years), 8 with nonsuboccipital non--Valsalva-induced headaches (8 women; age, 39 ± 13 years), and 37 control subjects (24 women; age, 36 ± 12 years). Group differences were identified with the use of the 2-tailed Student t test. RESULTS: Posterior cranial fossa markers of CMI were similar among the 3 headache subtypes. However, the Valsalva-related suboccipital headaches cohort demonstrated a significantly lower intracranial compliance index than the non--Valsalva-related suboccipital headaches cohort (7.5 ± 3.4 vs 10.9 ± 4.9), lower intracranial volume change during the cardiac cycle (0.48 ± 0.19 vs 0.61 ± 0.16 mL), and higher magnetic resonance imaging--derived intracranial pressure (11.1 ± 4.3 vs 7.7 ± 2.8 mm Hg; P = .02). The Valsalva-related suboccipital headaches cohort had smaller intracranial and lateral ventricular volumes compared with the healthy cohort. The non--Valsalva-related suboccipital headaches cohort had reduced venous drainage through the jugular veins. CONCLUSION: Valsalva-induced worsening of occipital headaches appears to be related to a small intracranial volume rather than the smaller posterior cranial fossa. This explains the reduced intracranial compliance and corresponding higher pressure measured in CMI patients with headaches affected by Valsalva maneuvers.

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Posterior Cranial Fossa Meningioma Causing Tonsillar Herniation and Giant Cervicothoracic Syringomyelia, Case Report and Review of Literature

10.21203/rs.3.rs-1068693/v1 ◽

2021 ◽

Author(s):

Estelle Anne How Hong ◽

Shalid Ahmed ◽

Srihari Deepak ◽

Gueorgui Kounin

Keyword(s):

Spinal Cord ◽

Posterior Fossa ◽

Foramen Magnum ◽

Posterior Cranial Fossa ◽

Tonsillar Herniation ◽

Ataxic Gait ◽

Complete Excision ◽

Arnold Chiari Malformation ◽

Posterior Cranial Fossa Tumours ◽

Cranial Fossa

Abstract Background Syringomyelia is a fluid-filled cyst within the spinal cord and usually associated with Arnold-Chiari malformation. Posterior cranial fossa tumours are a rare cause of tonsillar herniation and secondary syringomyelia. Case Presentation: We report a rare case of a 56-year-old female with posterior cranial meningioma and secondary syringomyelia, admitted with headache, nausea, vomiting, and ataxic gait. MRI demonstrated a large posterior fossa lesion causing early ventriculomegaly and syrinx within the upper spinal cord extending from the hindbrain inferiorly to the level of T8. She underwent a posterior fossa craniectomy with left C1 hemilaminectomy and complete excision of the tumour. In 6 months following her procedure, MRI scan showed a significant reduction in the calibre of the syringomyelia throughout its length and there was a significant improvement in symptoms. Literature review: A PubMed literature search was carried out with keywords: “syringomyelia”, “posterior fossa” and “tumour”. 120 articles were reviewed. The inclusion criteria for this study was posterior fossa meningioma causing syrinx formation. A total of 9 isolated similar cases were identified. Discussion Tonsillar herniation and syringomyelia secondary to posterior cranial fossa meningioma are rare. The alteration in the dynamic flow of CSF is likely to be the cause for the formation and enlargement of the syrinx. Conclusion Although the pathophysiology of syrinx formation is still poorly understood, the alteration of CSF dynamic has been implicated, but a common unifying cause appears to be increased transcranial difference in intracranial pressure across the foramen magnum causing tonsillar herniation, irrespective of location in the posterior fossa. Posterior fossa craniotomy and excision of the lesion is the mainstay treatment.

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