Soft tissue density within the foramen magnum, a predictor for surgical intervention in pediatric patients with Chiari malformation type I

2020 ◽  
Vol 26 (6) ◽  
pp. 671-675
Author(s):  
William Fuell ◽  
Reem Elwy ◽  
Thomas Harkey ◽  
Matthew Carey ◽  
Gregory W. Albert
Keyword(s):  
Soft Tissue ◽  
Pediatric Patients ◽  
Surgical Intervention ◽  
Foramen Magnum ◽  
Type I ◽  
Soft Tissue Density ◽  
Tonsillar Herniation ◽  
Chiari Malformation Type I ◽  
Tissue Density ◽  
Cerebellar Tonsils

OBJECTIVEChiari malformation type I (CMI) is diagnosed as herniation of the cerebellar tonsils by at least 5 mm below the foramen magnum. However, the degree of tonsillar herniation is a poor predictor of the need for decompression surgery. Exploration for an alternative morphological predictor for surgical intervention could provide greater insight into the development of an appropriate treatment plan for these patients. To investigate this issue, the authors calculated the soft tissue density within the foramen magnum as a measure of impaction of the cerebellar tonsils. Soft tissue density within the foramen magnum and degree of tonsillar herniation were then assessed for their correlation with the need for surgical intervention.METHODSThe authors conducted a retrospective, longitudinal chart review of pediatric patients with CMI. Those who had undergone surgical intervention were considered symptomatic and those who had been treated conservatively, as asymptomatic. Soft tissue density was found by dividing the soft tissue occupancy of the foramen magnum (brainstem and cerebellar tonsils) by the total area of the bony foramen magnum. The predictive value of these two measurements for the need of surgery was determined.RESULTSOf the 465 patients seen for CMI at the authors’ institution between July 1, 2011, and May 31, 2017, 80 underwent surgical intervention and 385 were asymptomatic. The average tissue density was significantly greater in the surgical group than in the asymptomatic group (83.3% and 78.6%, respectively, p < 0.0001). The average tonsillar descent for surgical patients was 10.8 mm compared to 9.8 mm for asymptomatic patients (p = 0.140). The point-biserial correlation coefficient was assessed, and soft tissue density was found to positively correlate with the need for surgical intervention (rpb = 0.199, p = 0.0001), whereas tonsillar herniation did not correlate with the need for surgery (rpb = 0.083, p = 0.115). Additionally, the degree of tonsillar herniation did not correlate with soft tissue density (r = 0.09), indicating that soft tissue density is an independent morphological parameter.CONCLUSIONSThe study findings suggest that the need for surgical intervention in CMI patients is positively correlated with increasing soft tissue density within the foramen magnum, whereas the degree of tonsillar herniation did not show a correlation with the need for surgical intervention. Additionally, soft tissue density is a factor independent of the degree of tonsillar herniation. Further investigation of tissue density within the foramen magnum is needed in the hope of discovering a clinically applicable parameter that would indicate a need for surgical intervention in patients with CMI.

Complete posterior cranial vault distraction osteogenesis to correct Chiari malformation type I associated with craniosynostosis

2021 ◽  
pp. 1-7
Keyword(s):  
Foramen Magnum ◽  
Posterior Cranial Fossa ◽  
Type I ◽  
Intracranial Volume ◽  
Tonsillar Herniation ◽  
Chiari Malformation Type I ◽  
Cerebellar Tonsillar Herniation ◽  
Cranial Fossa ◽  
The Mean ◽  
Tonsillar Descent

OBJECTIVE Posterior vault distraction osteogenesis (PVDO) is an effective tool to increase intracranial volume and expand the posterior cranial fossa. During PVDO, the authors extended osteotomy posterior to the foramen magnum to fully expand the posterior cranial fossa. The aim of this study was to investigate the efficacy of complete PVDO in posterior fossa expansion and treatment of Chiari malformation type I (CM-I) in patients with craniosynostosis. METHODS Patients with craniosynostosis who had undergone complete PVDO between January 2012 and May 2020 were reviewed retrospectively. A coronal osteotomy extending to the foramen magnum was performed and the foramen magnum was decompressed by removing its posterior rim with a 1-mm Kerrison rongeur. Four distractor devices were placed and the vector of distraction was controlled from the posterior to the inferior-posterior direction, depending on the deformity. Changes in the intracranial volume, posterior cranial fossa area, and cerebellar tonsillar descent were measured after complete PVDO by using CT and MRI. RESULTS A total of 11 patients with craniosynostosis and concurrent CM-I were included in the study. The mean age was 34.6 ± 24.0 months (continuous variables are expressed as the mean ± SD throughout). One patient had sleep apnea, which was consistent with CM-I, and another patient had a headache, which was nonspecific. The intracranial volume increased from 1179.6 ± 180.2 cm3 to 1440.6 ± 251.5 cm3 (p = 0.003; 24.5% increase compared to the preoperative volume). The posterior skull base area increased from 44.9 ± 19.3 cm2 to 72.7 ± 18.1 cm2 (p = 0.004). Cerebellar tonsillar descent decreased in all 11 patients after complete PVDO (preoperative: 10.8 ± 3.7 mm, postoperative: 2.7 ± 3.0 mm; p = 0.003). Among the 11 patients, 5 showed complete resolution of cerebellar tonsillar herniation. CONCLUSIONS Complete PVDO can more efficiently expand the posterior cranial fossa, unlike conventional methods. Moreover, it helps to relieve cerebellar tonsillar herniation. Complete PVDO is a powerful tool to increase the intracranial and posterior fossa volumes in patients with craniosynostosis and concurrent CM-I.

Trzyipółletni chłopiec z malformacją Chiariego typu I – opis przypadku

2017 ◽  
Vol 21 (3) ◽  
Author(s):  
Anna Worch ◽  
Małgorzata Wielopolska
Keyword(s):  
Chiari Malformation ◽  
Foramen Magnum ◽  
Common Type ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Chiari Type I Malformation ◽  
Large Head ◽  
Exacerbation Of Symptoms ◽  
Chiari Type I ◽  
Cerebellar Tonsils

Chiari malformation is the most common structural defect of the posterior fossa and cerebellum, consisting of displacements of hindbrain inclination through the foramen magnum, often associated with syringomyelia. In the most common type I of this disease, only the cerebellar tonsils are descended. Chiari type I malformation may remain asymptomatic in early childhood, however a number of unspecific symptoms, such as: neck pains and headaches, vertigos, balance and sight disorders, may strengthen with age. Because of unspecificity and various exacerbation of symptoms the disease is often misdiagnosed or undiagnosed. We describe a case of a 3.5-year old boy with whom his mother visited a pediatrician because of a chronic cough. During the examination mother of the patient informed that all infections start with vomiting and the patient is not able to stand up from horizontal position without turning first to the side and then to the abdomen. During the examination, a large head circumference was noticed (56 cm, > 97 percentile). MRI showed elongated cerebellar tonsils descended below the foramen magnum (left 14 mm, right 11 mm). Chiari malformation type I with associated syringomyelia was diagnosed. The patient was reffered to neurosurgery consultation.

scholarly journals Surgical treatment of Arnold-Chiari malformation type I in an adult patient

2008 ◽  
Vol 65 (8) ◽  
pp. 648-652
Author(s):  
Marko Markovic ◽  
Iva Berisavac ◽  
Vladimir Bojovic ◽  
Bojan Kostic ◽  
Vuk Djulejic
Keyword(s):  
Cranial Nerves ◽  
Clinical Signs ◽  
Foramen Magnum ◽  
Clinical Image ◽  
Posterior Arch ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Truncal Ataxia ◽  
Dural Graft ◽  
Cerebellar Tonsils

Background. Herniation of the cerebellar tonsils through the foramen magnum into the cervical spinal canal with obliteration of the cerebellomedullary cistern is the primary feature of Arnold-Chiari type I malformation (ACM I). It is considered to be congenital malformation, although there have been reported cases of an acquired form. Case report. We presented a female patient, 45-year old, with ACM I without syringomyelia as a rare and unusual clinical image, as well as the effect of decompressive surgery in the treatment of this malformation. The patient was admitted to the Department of Neurosurgery with clinical signs of truncal ataxia worsening during the last six years. Moderate quadriparesis with predominant lower extremity involvement and the signs of the cranial nerves damages occured during the last seven months before admission, with progressive clinical course up to the date of admission. Neurosurgical treatment that included suboccipital medial craniectomy with resection of posterior arch C1 vertebrae and C2 laminectomy resulted in a significant clinical improvement and a much better quality of life. Conclusion. Posterior craniovertebral decompression with microsurgical reduction of the cerebellar tonsils and placement of an artificial dural graft is a treatment of choice in severe forms of ACM I without syringomyelia. .

Urgent surgical intervention in pediatric patients with Chiari malformation Type I

2007 ◽  
Vol 107 (1) ◽  
pp. 49-52 ◽  
Author(s):  
John C. Wellons ◽  
R. Shane Tubbs ◽  
Cuong J. Bui ◽  
Paul A. Grabb ◽  
W. Jerry Oakes
Keyword(s):  
Chiari Malformation ◽  
Pediatric Patients ◽  
Surgical Intervention ◽  
Type I ◽  
Chiari Malformation Type I

Fourth ventricle roof angle as a measure of fourth ventricle bowing and a radiographic predictor of brainstem dysfunction in Chiari malformation type I

2021 ◽  
pp. 1-8
Author(s):  
Scott C. Seaman ◽  
Luyuan Li ◽  
Arnold H. Menezes ◽  
Brian J. Dlouhy
Keyword(s):  
Fourth Ventricle ◽  
Foramen Magnum ◽  
Clinical Severity ◽  
Type I ◽  
Healthy Controls ◽  
Tonsillar Herniation ◽  
Chiari Malformation Type I ◽  
Brainstem Dysfunction ◽  
Roof Angle ◽  
Tonsillar Descent

OBJECTIVE Chiari malformation type I (CM-I) is a congenital and developmental abnormality that results in tonsillar descent 5 mm below the foramen magnum. However, this cutoff value has poor specificity as a predictor of clinical severity. Therefore, the authors sought to identify a novel radiographic marker predictive of clinical severity to assist in the management of patients with CM-I. METHODS The authors retrospectively reviewed 102 symptomatic CM-I (sCM-I) patients and compared them to 60 age-matched normal healthy controls and 30 asymptomatic CM-I (aCM-I) patients. The authors used the fourth ventricle roof angle (FVRA) to identify fourth ventricle “bowing,” a configuration change suggestive of fourth ventricle outlet obstruction, and compared these results across all three cohorts. A receiver operating characteristic (ROC) curve was used to identify a predictive cutoff for brainstem dysfunction. Binary logistic regression was used to determine whether bowing of the fourth ventricle was more predictive of brainstem dysfunction than tonsillar descent, clival canal angle, or obex position in aCM-I and sCM-I patients. RESULTS The FVRA had excellent interrater reliability (intraclass correlation 0.930, 95% CI 0.905–0.949, Spearman r2 = 0.766, p < 0.0001). The FVRA was significantly greater in the sCM-I group than the aCM-I and healthy control groups (59.3° vs 41.8° vs 45.2°, p < 0.0001). No difference was observed between aCM-I patients and healthy controls (p = 0.347). ROC analysis indicated that an FVRA of 65° had a specificity of 93% and a sensitivity of 50%, with a positive predictive value of 76% for brainstem dysfunction. FVRA > 65° was more predictive of brainstem dysfunction (OR 5.058, 95% CI 1.845–13.865, p = 0.002) than tonsillar herniation > 10 mm (OR 2.564, 95% CI 1.050–6.258, p = 0.039), although increasing age was also associated with brainstem dysfunction (OR 1.045, 95% CI 1.011–1.080, p = 0.009). A clival canal angle < 140° (p = 0.793) and obex below the foramen magnum (p = 0.563) had no association with brainstem dysfunction. CONCLUSIONS The authors identified a novel radiographic measure, the FVRA, that can be used to assess fourth ventricular bowing in CM-I and is more predictive of brainstem dysfunction than tonsillar herniation. The FVRA is easy to measure, has excellent interrater variability, and can be a reliable universal radiographic measure. The FVRA will be useful in further describing CM-I radiographically and clinically by identifying patients more likely to be symptomatic as a result of brainstem dysfunction.

Chiari malformation Type I and syrinx in children undergoing magnetic resonance imaging

2011 ◽  
Vol 8 (2) ◽  
pp. 205-213 ◽  
Author(s):  
Jennifer Strahle ◽  
Karin M. Muraszko ◽  
Joseph Kapurch ◽  
J. Rajiv Bapuraj ◽  
Hugh J. L. Garton ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Mr Imaging ◽  
Chiari Malformation ◽  
Foramen Magnum ◽  
Type I ◽  
Csf Flow ◽  
Tonsillar Herniation ◽  
Chiari Malformation Type I ◽  
Age Related ◽  
Imaging Characteristics

Object Chiari malformation Type I (CM-I) with an associated spinal syrinx is a common pediatric diagnosis. A better understanding of the relative age-related prevalence and MR imaging characteristics of these associated conditions may lead to improved treatment decisions. Methods The authors performed a retrospective review of 14,116 consecutive individuals 18 years of age or younger who had undergone brain or cervical spine MR imaging at the University of Michigan between November 1997 and August 2008. In the patients with CM-I, demographic, clinical, and radiographic information was recorded. Results Five hundred nine children (3.6%) with CM-I were identified. Among these patients, 23% also had a spinal cord syrinx, and 86% of the syringes were found in the cervical spine. The MR imaging prevalence of CM-I with a syrinx was 1.2% in girls and 0.5% in boys (p < 0.0001). The severity of impaired CSF flow at the foramen magnum was associated with the amount of tonsillar herniation (p < 0.0001) and conformation of the tonsils (p < 0.0001). Patients with CM-I were treated surgically in 35% of cases; these patients exhibited more severe tonsillar herniation (p < 0.0001) and impaired CSF flow (p < 0.0001) as compared with those who did not undergo surgery. On imaging, 32% of all the patients with CM-I were considered symptomatic by the treating physician. Patients were more likely to be considered symptomatic if they were female, had a syrinx, displayed abnormal tonsillar pulsations, or had a greater amount of tonsillar herniation. Conclusions In this study the authors describe the age-related prevalence and MR imaging characteristics of CM-I and its association with a syrinx and other abnormalities in a large group of children who underwent MR imaging for any indication. Syringes are more common in older children, in girls, and in patients with a greater degree of tonsillar descent and CSF flow impairment.

scholarly journals Morphometric and volumetric comparison of 102 children with symptomatic and asymptomatic Chiari malformation Type I

2018 ◽  
Vol 21 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Siri Sahib S. Khalsa ◽  
Ndi Geh ◽  
Bryn A. Martin ◽  
Philip A. Allen ◽  
Jennifer Strahle ◽  
...  
Keyword(s):  
Posterior Fossa ◽  
Chiari Malformation ◽  
Pediatric Patients ◽  
Incidental Finding ◽  
Foramen Magnum ◽  
Cerebellar Tonsil ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Asymptomatic Patients ◽  
Volumetric Measurements

OBJECTIVEChiari malformation Type I (CM-I) is typically defined on imaging by a cerebellar tonsil position ≥ 5 mm below the foramen magnum. Low cerebellar tonsil position is a frequent incidental finding on brain or cervical spine imaging, even in asymptomatic individuals. Nonspecific symptoms (e.g., headache and neck pain) are common in those with low tonsil position as well as in those with normal tonsil position, leading to uncertainty regarding appropriate management for many patients with low tonsil position and nonspecific symptoms. Because cerebellar tonsil position is not strictly correlated with the presence of typical CM-I symptoms, the authors sought to determine if other 2D morphometric or 3D volumetric measurements on MRI could distinguish between patients with asymptomatic and symptomatic CM-I.METHODSThe authors retrospectively analyzed records of 102 pediatric patients whose records were in the University of Michigan clinical CM-I database. All patients in this database had cerebellar tonsil position ≥ 5 mm below the foramen magnum. Fifty-one symptomatic and 51 asymptomatic patients were matched for age at diagnosis, sex, tonsil position, and tonsil morphology. National Institutes of Health ImageJ software was used to obtain six 2D anatomical MRI measurements, and a semiautomated segmentation tool was used to obtain four 3D volumetric measurements of the posterior fossa and CSF subvolumes on MRI.RESULTSNo significant differences were observed between patients with symptomatic and asymptomatic CM-I related to tentorium length (50.3 vs 51.0 mm; p = 0.537), supraoccipital length (39.4 vs 42.6 mm; p = 0.055), clivus-tentorium distance (52.0 vs 52.1 mm; p = 0.964), clivus-torcula distance (81.5 vs 83.3 mm; p = 0.257), total posterior fossa volume (PFV; 183.4 vs 190.6 ml; p = 0.250), caudal PFV (152.5 vs 159.8 ml; p = 0.256), fourth ventricle volume to caudal PFV ratio (0.0140 vs 0.0136; p = 0.649), or CSF volume to caudal PFV ratio (0.071 vs 0.061; p = 0.138).CONCLUSIONSNo clinically useful 2D or 3D measurements were identified that could reliably distinguish pediatric patients with symptoms attributable to CM-I from those with asymptomatic CM-I.

scholarly journals Normalization of hindbrain morphology after decompression of Chiari malformation Type I

2012 ◽  
Vol 117 (5) ◽  
pp. 942-946 ◽  
Author(s):  
John D. Heiss ◽  
Giancarlo Suffredini ◽  
Kamran D. Bakhtian ◽  
Malisa Sarntinoranont ◽  
Edward H. Oldfield
Keyword(s):  
Chiari Malformation ◽  
Foramen Magnum ◽  
Control Group ◽  
Decompression Surgery ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Prospective Longitudinal Study ◽  
Tonsillar Ectopia ◽  
Prospective Longitudinal ◽  
Cerebellar Tonsils

Object Chiari malformation Type I (CM-I) is characterized by hindbrain deformity. We investigated the effects of craniocervical decompression surgery on the anatomical features of hindbrain deformity with a prospective MRI study of patients with CM-I. Methods A prospective longitudinal study was conducted in 48 patients with CM-I (39 with syringomyelia) treated with craniocervical decompression. Clinical examinations and cervical MRI were performed before surgery and 1 week, 3–6 months, and annually after surgery. Hindbrain deformity was defined by tonsillar ectopia, pointed cerebellar tonsils, and/or cervicomedullary protuberance. The length of the clivus, basiocciput (sphenooccipital synchondrosis to basion), supraocciput (internal occipital protuberance to opisthion), and anteroposterior (AP) width of CSF pathways at the foramen magnum were measured and compared with those from 18 healthy volunteers (control group). Results Before surgery, the patients' posterior fossa bones were short and their CSF pathways were narrow. All patients had tonsillar ectopia (mean [± SD] 12.3 ± 5.1 mm; normal 0.3 ± 1.0). The majority of patients had pointed tonsils and more than two-thirds exhibited a cervicomedullary protuberance. Clivus and basiocciput lengths were significantly shorter than the values obtained in the control group. However, the supraocciput length did not differ significantly from control measurements. The mean bulbopontine sulcus distance superior to the basion was 9.5 ± 2.6 mm (vs 13.6 ± 2.8 mm in controls; p < 0.0001). The AP widths of the CSF pathways at the level of the foramen magnum were significantly narrowed. After surgery, CSF pathways significantly expanded both ventrally and dorsally. By 3–6 months after surgery, pointed tonsils became round, cervicomedullary protuberance disappeared, and tonsillar ectopia diminished by 51% (to 6.0 ± 3.3 mm; p < 0.0001). Conclusions The cerebellar tonsils and brainstem assumed a normal appearance within 6 months after craniocervical decompression. These findings support the concept that the CM-I is not a congenital malformation of the neural elements but rather an acquired malformation that arises from pulsatile impaction of the cerebellar tonsils into the foramen magnum. Clinical trial registration no.: NCT00001327.

313 Morphometric and Volumetric Comparison of Symptomatic and Asymptomatic Chiari Malformation Type I

Neurosurgery ◽  
2017 ◽  
Vol 64 (CN_suppl_1) ◽  
pp. 267-267
Author(s):  
Siri Sahib S Khalsa ◽  
Ndi Geh ◽  
Bryn A Martin ◽  
Philip A Allen ◽  
Jennifer Strahle ◽  
...  
Keyword(s):  
Posterior Fossa ◽  
Chiari Malformation ◽  
Pediatric Patients ◽  
Foramen Magnum ◽  
Cerebellar Tonsil ◽  
Type I ◽  
Chiari Malformation Type I ◽  
Asymptomatic Patients ◽  
Specific Symptoms ◽  
Volumetric Measurements

Abstract INTRODUCTION Chiari malformation type I (CMI) is typically defined by a cerebellar tonsil position 5 mm or more below foramen magnum. Low cerebellar tonsil position is a frequent incidental finding, even in asymptomatic individuals. Non-specific symptoms such as headache and neck pain are common in those with low tonsil position and in those with normal tonsil position, leading to uncertainty regarding appropriate management for many patients with low tonsil position and non-specific symptoms. Since cerebellar tonsil position is not strictly correlated with typical CMI symptoms, we sought to determine if other 2D morphometric or 3D volumetric measurements on MRI could distinguish asymptomatic from symptomatic CMI patients. METHODS We retrospectively analyzed 102 pediatric patients from the University of Michigan clinical CMI database. All patients in this database have cerebellar tonsil position at least 5 mm below foramen magnum. Fifty-one symptomatic and 51 asymptomatic patients were matched for age at diagnosis, sex, tonsil position, and tonsil morphology. Five 2D anatomic MRI measurements and four 3D volumetric measurements of posterior fossa and CSF sub-volumes on MRI were measured. RESULTS >There were no significant differences observed between symptomatic and asymptomatic CMI patients related to basilar impression (−5.9 mm vs. −7.0 mm; P = 0.026), tentorium length (50.3 mm vs. 51.0 mm; P = 0.537), supraoccipital length (39.4 mm vs. 42.6 mm; P = 0.055), clivus-tentorium distance (52.0 mm vs. 52.1 mm; P = 0.964), clivus-torcula distance (81.5 mm vs. 83.3 mm; P = 0.257), total posterior fossa volume (PFV; 183.4 mL vs. 190.6 mL; P = 0.250), caudal PFV (152.5 mL vs. 159.8 mL; P = 0.256), fourth ventricle volume to caudal PFV ratio (0.0140 vs. 0.0136; P = 0.649), or CSF volume to caudal PFV ratio (0.071 vs. 0.061; P = 0.138). CONCLUSION We did not identify any 2D or 3D measurements that could reliably distinguish pediatric patients with symptoms attributable to CMI from those with asymptomatic CMI.

Symptomatic posterior fossa and supratentorial subdural hygromas as a rare complication following foramen magnum decompression for Chiari malformation Type I

2011 ◽  
Vol 114 (2) ◽  
pp. 510-513 ◽  
Author(s):  
Biji Bahuleyan ◽  
Girish Menon ◽  
Easwer Hariharan ◽  
Mridul Sharma ◽  
Suresh Nair
Keyword(s):  
Posterior Fossa ◽  
Chiari Malformation ◽  
Surgical Intervention ◽  
Rare Complication ◽  
Foramen Magnum ◽  
Type I ◽  
Foramen Magnum Decompression ◽  
Subdural Hygroma ◽  
Chiari Malformation Type I ◽  
Good Outcome

Symptomatic subdural hygroma due to foramen magnum decompression for Chiari malformation Type I is extremely rare. The authors present their experience with 2 patients harboring such lesions and discuss treatment issues. They conclude that the possibility of subdural hygromas should be considered in all patients presenting with increased intracranial tension following foramen magnum decompression for Chiari malformation Type I. Immediate neuroimaging and appropriate surgical intervention provides a good outcome.

Sign in / Sign up

Export Citation Format

Share Document